New stand magnifiers do not meet rated levels of performance

A new range of stand magnifiers has been released by the COIL company in the United Kingdom. Examination of these magnifiers reveals that they fail to deliver the rated magnifications labelled prominently on the appliances, as a result of the manufacturer's conformance with the requirements of the German DIN standard and the use of back vertex power (F'_v) rather than equivalent dioptric power (F_m) of the magnifier. In this study we provide information on the optometric parameters of these new stand magnifiers that will assist the more accurate specification of improvements in vision expected from their use.     

The management of symptoms in advanced cancer: experience in a hospital-based continuing care unit.

The treatment received by 158 patients with advanced cancer admitted over one year to the Continuing Care Unit at the Royal Marsden Hospital has been reviewed. The unit is an integral part of the hospital and this is reflected in the fact that 46 patients (29%) received radiotherapy, hormone therapy, chemotherapy or surgery in addition to symptomatic treatment for palliation of troublesome symptoms. One hundred and thirty-one patients received oral morphine in doses ranging from 2.5 mg 4-hourly to 700 mg 4-hourly. Patients with renal or hepatic impairment required lower doses of morphine and there was a highly significant inverse relationship between morphine dose and age. Eighty-five patients (54%) received parenteral diamorphine at some time due to their inability to take oral morphine. One hundred and twenty-three patients (78%) received a co-analgesic drug and anti-emetics were required by 78 patients (49% overall; 56% of those receiving morphine). Transcutaneous electrical nerve stimulation, acupuncture and relaxation were employed in selected patients, and graduated compression sleeves were used to treat lymphoedema. These data highlight the wide range of therapeutic options available to control the symptoms of advanced cancer and also indicate that tumoricidal treatments used in conjunction with symptomatic treatments may have a significant part to play.     

EFNS Guidelines on diagnosis and treatment of brain metastases: report of an EFNS Task Force

The objectives have been to establish evidence-based guidelines and identify controversies regarding the management of patients with brain metastases. The collection of scientific data was obtained by consulting the Cochrane Library, bibliographic databases, overview papers and previous guidelines from scientific societies and organizations. A tissue diagnosis is necessary when the primary tumor is unknown or the aspect on computed tomography/magnetic resonance imaging is atypical. Dexamethasone is the corticosteroid of choice for cerebral edema. Anticonvulsants should not be prescribed prophylactically. Surgery should be considered in patients with up to three brain metastases, being effective in prolonging survival when the systemic disease is absent/controlled and the performance status is high. Stereotactic radiosurgery should be considered in patients with metastases of 3–3.5 cm of maximum diameter. Whole-brain radiotherapy (WBRT) after surgery or radiosurgery is debated: in case of absent/controlled systemic cancer and Karnofsky Performance score of 70 or more, one can either withhold initial WBRT or deliver early WBRT with conventional fractionation to avoid late neurotoxicity. WBRT alone is the treatment of choice for patients with single or multiple brain metastases not amenable to surgery or radiosurgery. Chemotherapy may be the initial treatment for patients with brain metastases from chemosensitive tumors.     

Pheochromocytoma and paraganglioma: comparison of MR imaging with CT and I-131 MIBG scintigraphy

To ascertain the magnetic resonance (MR) imaging characteristics of pheochromocytomas and paragangliomas and to compare MR with computed tomography (CT) and iodine-131 metaiodobenzylguanidine (I-131 MIBG), 19 patients (18 with pheochromocytomas, one with a paraganglioma) were studied. The 18 patients with pheochromocytomas had had positive findings with I-131 MIBG scintigraphy. Abdominal pheochromocytomas were generally hypointense compared with normal liver on T1-weighted MR images and extremely hyperintense on T2-weighted MR images. MR imaging was preferable to CT in the evaluation of primary pheochromocytomas due to superior tissue characterization, particularly in the patient with hypertension and borderline catecholamine levels. For patients with recurrent or metastatic disease, the data suggest that I-131 MIBG scintigraphy is the examination of choice.     

Inhibition by sumatriptan of central trigeminal neurones only after blood-brain barrier disruption.

1. The 5-hydroxytryptamine (5-HT1)-like agonist, sumatriptan, is highly efficient in the relief of migraine headache and its accompanying symptoms. 2. Experimental evidence has indicated that its site of action may be on the cranial vessels or on the trigeminal innervation of the cranium, or both, since sumatriptan does not pass the blood-brain barrier easily under normal circumstances. It is, however, not clear whether the blood-brain barrier is normal or abnormal during a migraine attack. 3. In this study, single unit activity and trigeminal somatosensory evoked potentials in central trigeminal neurones were monitored during electrical stimulation of the superior sagittal sinus. 4. Intravenous administration of sumatriptan (100 micrograms kg-1) did not alter trigeminal evoked activity unless the permeability of the blood-brain barrier had been increased by infusion of an hyperosmolar mannitol solution. After blood-brain barrier disruption, sumatriptan decreased the peak-to-peak amplitude of evoked potentials by 40 +/- 6% and the probability of firing of single units by 30 +/- 9%. Mannitol infusions alone in control animals caused no changes in evoked potentials or single unit activity. 5. The data suggest that in normal circumstances sumatriptan does not have sufficient access to trigeminal neurons to alter their function.     

Chaperonin-mediated assembly of wild-type and mutant subunits of human propionyl-CoA carboxylase expressed in Escherichia coli

We developed a bacterial expression system for the human alpha and beta cDNAs of propionyl-CoA carboxylase (PCC). These cDNAs (less the putative mitochondrial matrix targeting presequences) were co-expressed in Escherichia coli on one plasmid vector with each cDNA having its own IPTG-inducible promoter. Only negligible amounts of active PCC were measured despite the presence of both alpha and beta subunits as indicated by Western blot analysis and the almost complete biotinylation of the alpha subunit. Co-expression of this plasmid with a second plasmid vector over-expressing the E. coli chaperonin proteins, groES and groEL, resulted in a several hundred-fold increase in PCC specific activity, to a level comparable with that found in crude human liver extracts. PCC was partially purified on monomeric avidin affinity resin and the presence of both alpha and beta subunits was demonstrated, thereby confirming the assembly of both subunits into an active enzyme. Deficiency of either alpha PCC or beta PCC results in propionic acidemia, an autosomal recessive disorder. We used this expression system to characterize one missense mutation previously described in five Japanese alleles, namely C1283T (Thr428lle) in beta PCC. This mutation, when expressed in E.coli under the same conditions as that of wild-type PCC, had null activity, despite the presence of assembled alpha PCC and beta PCC subunits. This bacterial expression system can be useful for analysis of either alpha PCC or beta PCC mutations. Our findings indicated that the groES and groEL chaperonin proteins were essential for folding and assembly of the human PCC heteromeric subunits.      

Malignancy may adversely influence the quality and behaviour of oocytes

A case series of eight cycles of in-vitro fertilization (IVF) in five women diagnosed with malignant disorders is presented. These patients chose to defer definitive treatment for a chance for preservation of potential fertility. The response of these patients to ovarian stimulation, and the outcome, was compared with 17 IVF cycles in 12 age- matched patients with isolated tubal infertility. An apparent adverse influence of malignant disease on the quality and behaviour of oocytes was observed. Despite a comparable total number of oocytes per cycle in the two groups, a significantly reduced percentage of mature oocytes was retrieved per cycle from patients with malignant diseases. The oocytes from patients with malignant disorders were of a poorer quality and exhibited a significantly impaired fertilization rate compared to the controls. We propose that neoplastic processes, irrespective of the site or cell of origin, may have a detrimental impact on the biology of oocytes, an effect akin to that seen on spermatozoa in men with certain malignancies.