Organisation and molecular analysis of repeated DNA sequences in the rice blast fungus Magnaporthe grisea

The distribution of a previously described repeated DNA sequence present as a 1.3-kb PstI fragment in the genome of the rice blast fungus Magnaporthe grisea was analysed by carrying out DNA fingerprint analysis of 36 isolates including rice, non-rice and laboratory strains. The analysis of various higher-molecular-weight PstI fragments with homology to the 1.3-kb repeat revealed that these may arise predominantly from transposon insertions or point mutations. Analysis of a 5.1-kb derivative revealed both a point mutation at a PstI site and an insertion of a putative transposable element which caused an increase in molecular weight from 1.3 to 5.1 kb. Another repeat element of 1.4 kb was identified and found to exist in association with the 1.3-kb repeat. Both 1.3- and 1.4-kb elements were found to be parts of MGR583 (Hamer et al. 1989), a LINE-like element. These elements were present in a high copy number in all the rice and a majority of non-rice pathogens indicating that MGR583 is not a host-specific sequence as reported earlier. Our results suggest that repeated DNA elements in M. grisea have amplified independently of one another and further indicate that different isolates of M. grisea may have evolved from several distinct lines of origin. Received: 12 April / 12 November 1996     

A simplified ELISA for anti-receptor antibodies in myasthenia gravis

Nicotinic acetylcholine receptor (nAchR) from triton extracts of muscle adsorbed specifically and optimally to microtitration plates at pH 7.4 rather than at pH 9.6. An ELISA for anti-receptor antibodies in myasthenia gravis based on direct adsorption of the receptor at pH 7.4 is described (direct assay). The direct assay compares very well in sensitivity and specificity with an indirect assay, in which the receptor was attached through alpha-bungarotoxin adsorbed on the solid phase (correlation coefficient 0.94).     

Cancer of the colon in an egg donor: policy repercussions for donor recruitment

This paper describes the tragic case of a young woman who died of cancer of the colon after successfully donating eggs to her younger sister. Although there is no direct link between her operation and the subsequent development of bowel carcinoma, this case imparts a feeling of unease when seen in conjunction with other cases reported during the last few years. It is a reminder that little is known of the long-term consequences of some aspects of assisted conception. Women undergoing ovarian stimulation for themselves or a matched recipient have the right to be advised, in an agreed format, that there is some concern about unproven potential risks from the stimulatory drugs. The safety of egg donors must assume priority over all other considerations, including lack of donors or any moral position. The recent decision by the Human Fertilisation and Embryology Authority (HFEA) to withdraw any form of payment or recompense to egg donors does not seem to us to be based on a balance of scientific advances, patient needs and the ethics of gamete supply. They state that the intention to withdraw payments was implicit in the 1990 Human Fertilisation and Embryology (HFE) Act. However the Act was based on the Warnock report made 6 years earlier. Even in 1990 ovum donation was uncommon and fertility drugs had not yet caused any unease. The Act provided the HFEA with discretionary powers to issue directions so that the future policies would be consistent with any emerging new medical evidence. It is imperative that the HFEA provide convincing evidence on how the current policy of payment to donors harms society, donors or recipients, and how in the UK the new policy will improve medical practice in assisted conception. Successful pilot studies must precede the implementation of any new policy. Failure to do this could cause irreversible harm to the practice of assisted conception using donor gametes, which will ultimately be against the basic aims of the 1990 HFE Act.      

A locus for autosomal dominant anterior polar cataract on chromosome 17p

Inherited cataract is a clinically and genetically heterogeneous disease. Here we report the identification of a new locus for an autosomal dominant anterior polar cataract on the short arm of chromosome 17. To map this new locus we performed genetic linkage analysis with microsatellite markers in a four-generation pedigree. After exclusion of seven candidate loci for cataract, we obtained significant positive LOD scores for markers D17S849 (Z = 4.01 / theta = 0.05) and D17S796 (Z = 4.17 / theta = 0.05). Multipoint analysis gave a maximum LOD score of 5.2 (theta max = 0.06) between these two markers. From haplotype analysis, the cataract locus lies in the 13 cM interval between markers D17S849 and D17S796. This study provides the first genetic mapping of an autosomal dominant anterior polar cataract.      

Egg-sharing in assisted conception: ethical and practical considerations

The present acute shortage of eggs for donation cannot be overcomeunless adequate guidelines are set to alleviate the anxietiesregarding payments, in cash or kind, to donors. The currentHuman Fertilisation and Embryology Authority (HFEA) guidelinesdo not allow direct payment to donors but accept the provisionof lower cost or free in-vitro fertilization (IVF) treatmentto women in recognition of oocyte donation to anonymous recipients.Egg-sharing achieved in this way enables two infertile couplesto benefit from a single surgical procedure. However, the practicalguidelines related to this approach are ill-defined at the presenttime leading to some justifiable uncertainty. A pilot studywas therefore undertaken in order to establish the place ofegg-sharing in an assisted conception programme. The currentHFEA guidelines on medical screening of patients, counselling,age and rigid anonymity between the donor and recipient werefollowed. The study involved 55 women (25 donors and 30 recipients)in 73 treatment cycles involving fresh and frozen-thawed embryos.Donors were previous IVF patients who, regardless of their abilityto pay, shared their eggs equally with matched anonymous recipients.They paid only for their consultations and tests right up tothe point of being matched with a recipient The sole recipientpaid the cost applicable in egg donation of a single egg collection,although both received embryo transfers. The results indicatethat although the recipients were older than the donors (41.4± 0.9 versus 31.6 ± 0.5 years), and there wasno difference in the mean number of eggs allocated, the percentagefertilization rates, or the mean number of embryos transferred,there were more births per patient amongst recipients than amongstdonors (30 versus 20%). We conclude that providing the donorsare selected carefully, this scheme whereby a sub-fertile donorhelps a sub-fertile recipient is a very constructive way ofsolving the problem of the shortage of eggs for donation. Thereare also the advantages of including a group of women who wouldotherwise be denied treatment Problems related to ‘patientcoercion’ can, in our view, be fully overcome by the applicationof strict common-sense safeguards. The ideal of pure altruismis not without its medical and moral risk. The success of egg-sharingdepends on shared interests and a degree of altruism betweenthe donor, the recipient and the centre. The current HFEA guidelinesshould be applauded for enabling a highly effective conceptof mutual help to develop.     

Intra-articular morphine versus bupivacaine for postoperative analgesia following knee arthroscopy

In a prospective, double blind, randomized study, 30 ASA I patients were allocated to three groups depending on the drug injected intra-articularly, in an attempt to establish the best postoperative analgesic protocol following knee arthroscopy. Group 1 received 3 mg of preservative-free morphine in 25 ml saline; group 2, 5 mg of preservative-free morphine in 25 ml saline; and group 3, 25 ml 0.25% bupivacaine. The degree of postoperative pain was evaluated by visual analogue scale and the need for additional analgesics at 1, 2, 3, 8 and 24 h. We conclude that bupivacaine 0.25% provides analgesia of early onset and of short duration. While 3 mg-preservative free morphine provides moderate postoperative analgesia with peak effect during the eighth postoperative hour, 5 mg preservative-free morphine provides effective and long lasting (more than 24 h) pain relief. No side effects were noted.     

C-spine clearance in poly-trauma patients: A narrative review

The incidence of cervical spine injury in patients with polytrauma is 3.7%. Early identification and management of cervical spine injuries in these patients play a crucial role in preventing secondary cervical spine and cord injuries. C-spine clearance assumes a pivotal role in reducing the morbidity and mortality associated with cervical spine injury. Despite the availability of various validated management algorithms and protocols for C-spine clearance, there are several controversies regarding C-spine clearance, such as the ideal protocol and imaging modality, clearance of obtunded patients and management of patients that lie out of the described protocols and rules. The current article aims to provide a comprehensive review of the relevant literature and address the prevalent controversies.