Expression of an inducible nitric oxide synthase gene in rainbow trout Oncorhynchus mykiss

Using oligonucleotide primers based on mammalian nitric oxide synthases (NOS), expression of an inducible NOS (iNOS) gene was detected in head kidney and gill tissue of bacterially-challenged rainbow trout. Three overlapping fragments were amplified by RT-PCR and used to construct a contiguous sequence of 1410bp, with high nucleotide homology to iNOS in birds (61%) and mammals (57-59%). The nucleotide sequence translated in one reading frame to produce a partial peptide containing 470 amino acids, with 69-71% amino acid homology with mammalian iNOS, 81% homology with chicken iNOS and 85% homology with a partial (492bp) goldfish iNOS sequence. In vitro stimulation of head kidney macrophages with LPS also induced expression of the trout iNOS RNA, with optimal expression seen using 20-50 microg/ml LPS at 2h to 6h post-stimulation. The evolutionary and functional significance of the trout iNOS sequence are discussed.     

Treatment of infrarenal aortic stenosis by stent placement: a 6-year experience

There is a significant re-stenosis rate with percutaneous treatment of stenoses of the infrarenal abdominal aorta with balloon angioplasty. Since 1990 the authors have primarily treated local infrarenal aortic stenoses with metallic endoluminal stents. The authors' experience with 12 consecutive patients (nine women and three men, aged from 30 to 72 years (mean age = 57 years)) is presented. Follow-up is available in 11 cases over 7-78 months (mean 32 months). The procedure was technically successful in all patients. Of the 11 patients with follow-up available, claudication was cured (n = 7) or significantly improved (n = 4). Those with persisting claudication had concurrent distal arterial disease. Periprocedural complications occurred in five cases, with two significant complications. One case required iliac angioplasty for embolized aortic atherosclerotic plaque, and one case required surgical thrombectomy and vein patch for iliac thrombosis complicating iliac dissection, without long-term sequelae in either case. One patient has had recurrent symptomatic aortic stenosis occurring 6 years after initial stenting, which responded to further stent insertion. Primary patency of 91% and secondary assisted patency of 100% has been achieved. Primary treatment of infrarenal aortic stenosis with endoluminal stenting results in high patency rates, with low morbidity and relatively low complication rates.     

Central core disease: clinical, pathological, and genetic features.

Central core disease (CCD) is a dominantly inherited congenital myopathy allelic to malignant hyperthermia (MH) caused by mutations in the RYR1 gene on chromosome 19q13.1. Eleven individuals with RYR1 mutations are described. Four index cases showed features consistent with a congenital myopathy (hypotonia, delayed motor milestones, and skeletal abnormalities including congenital hip dislocation and scoliosis). All four cases and subsequently seven other family members were found to possess novel mutations in the RYR1 gene. The degree of disability varied from one clinically normal individual, to another who had never achieved independent ambulation (the only patient with a de novo mutation). Four cases showed a mild reduction in vital capacity, repeated nocturnal polysomnography showed hypoxaemia in one case. A variety of muscle biopsy features were found; central cores were absent in the youngest case, and the biopsy specimens from two others were more suggestive of mini-core myopathy. In all cases missense mutations in exons 101, 102, and 103 of the RYR1 gene on were found. Future laboratory diagnosis of suspected cases and family members will be less invasive and more accurate with DNA analysis. Clinicians, especially paediatricians and orthopaedic surgeons, should be aware of this disorder because of the potential risk of MH.     

The purification and partial characterisation of two novel metalloproteinases from the venom of the West African carpet viper, Echis ocellatus.

Separation of previously uncharacterised Echis ocellatus venom by phenyl-Superose FPLC (Fast Liquid Protein Chromatography) yielded eight protein fractions. Three of these displayed high proteolytic activity when assayed by in vivo and in vitro assays (including enzyme linked immunosorbant assay), and were further separated using Superdex 75 and Mono-Q FPLC. This resulted in the purification of a non-haemorrhagic 24 kDa metalloproteinase (EoVMP1, pI 7.0), and a haemorrhagic 56 kDa metalloproteinase (EoVMP2, pI 5.5). Following tryptic digest, short amino acid sequences of EoVMP1 and EoVMP2 were obtained using Edman degradation. Both sequences displayed homology when aligned with existing snake venom metalloproteinases (SVMPs). The strong homology observed among previously well-characterised SVMPs suggests that principles governing the interaction of substrates and inhibitors are likely to be similar for EoVMP1, EoVMP2 and all members of the reprolysin family.     

Assessing outcome in lumbar disc surgery using patient completed measures

Measuring outcome after spinal surgery is difficult. The objective of this study was to assess the use of four measures in establishing outcome in patients undergoing lumbar discectomy. Forty-six consecutive patients who had undergone two operations for lumbar disc prolapse and 54 patients who had undergone one operation for the same condition over the same period were identified. The SF-36 questionnaire was used to assess general health. The Roland-Morris questionnaire and a simple modification of the Roland-Morris questionnaire were used to assess back and leg related disability, respectively. Analogue pain scales were used to measure back pain and sciatica. The SF-36 scores revealed significantly worse health status in the two operation compared with the one operation patients and in all patients compared with the normal population. Using the Roland-Morris and the leg disability questionnaires, patients who had undergone two operations reported significantly worse disability (Roland-Morris, 53%, poor outcome) than those who had undergone one operation (Roland-Morris, 19%, poor outcome). There was significantly greater back disability than leg disability in both groups of patients and this was confirmed by the analogue pain scales. In patients who had undergone two operations, 25% classified their back pain as very bad or unbearable, and 22.5% described very bad or unbearable leg pain. For the one operation patients these figures were 9.5 and 2.4%, respectively. The results demonstrate that both generic and condition specific patient completed measures have the potential to detect differences in outcome between patients who have undergone either one or two lumbar disc operations. The study provides support for the use of these patient completed measures in assessing outcome in lumbar disc surgery.     

Involvement of deprivation and environmental lead in neural tube defects: a matched case-control study

OBJECTIVE: To analyse the prevalence of neural tube defects in small geographical areas and seek to explain any spatial variations with reference to environmental lead and deprivation. SETTING: The Fylde of Lancashire in the north west of England. DESIGN: Cases were ascertained as part of a prospective survey of major congenital malformations in babies born in the Fylde to residents there between 1957 and 1981. A matched case-control analysis used infants with cardiovascular system, alimentary tract, and urinary system malformations as controls. Conditional logistic regression was used to assess the effects of more than 10 micrograms/l lead in drinking water and the Townsend deprivation score. RESULTS: The prevalence of neural tube defects in 1957-73 was higher in Blackpool, Fleetwood, and North Fylde, whereas the three control groups showed no significant spatial variation. In 1957-81 mothers living in electoral wards with either a higher proportion of houses with more than 10 micrograms/l lead in the water or a higher deprivation score had a greater risk of having a baby with a neural tube defect. For spina bifida and cranium bifidum alone, this was also true. For anencephaly, deprivation was less important although the effect of lead was still seen. In some neural tube defects, lead may act independently of other possible factors associated with deprivation. It seemed unlikely that lead levels changed significantly during the survey. The percentage of houses with 10 micrograms/l or more of lead in the water in 1984-5 was similar to that found in Great Britain 10 years previously. CONCLUSION: There is evidence to suggest that lead is one cause of neural tube defects, especially anencephaly. This could link the known preventive actions of hard water and folic acid. Calcium is a toxicological antagonist of lead. One cause of a deficiency of folic acid is impaired absorption secondary to zinc deficiency, which may be produced or exacerbated by lead.     

Tuberous sclerosis complex and Wolff-Parkinson-White syndrome

This report highlights the association between tuberous sclerosis and Wolff-Parkinson-White syndrome. Ten patients with concurrent diagnoses of Wolff-Parkinson-White syndrome and tuberous sclerosis were identified. Wolff-Parkinson-White syndrome presented early in life, nine cases being diagnosed in the first year. Eight of the 10 cases were male. In eight cases, the syndrome was associated with supraventricular tachycardias, and in nine with cardiac rhabdomyomata. One child died from cardiac failure secondary to obstruction of the left ventricular outflow tract by a rhabdomyoma. Five of nine survivors showed resolution of Wolff-Parkinson-White syndrome on follow up. The accessory pathway was localised in nine patients from surface electrocardiograms: six children had left sided pathways and three had right sided pathways.     

Blood-brain barrier and blood volume imaging of cerebral glioma using functional CT: A pictorial review

Five cases of cerebral glioma are presented here that illustrate the benefit of functional CT imaging of blood-brain barrier permeability and cerebral blood volume. Functional CT uses Patlak analysis of a single location dynamic sequence to extract physiological information that is useful clinically in the assessment of cerebral gliomas. Functional CT offers distinct advantages over other functional modalities including clearer delineation of tumour, tumour grading, measurement of tumour activity and monitoring response to therapy.     

Imaging of compressive vertebral haemangiomas

Compressive vertebral haemangiomas (VHs) are rare. Correct preoperative diagnosis is useful both for operative planning (since compressive VHs are extremely vascular lesions) and to allow preoperative embolisation. Numerous radiological signs for VHs have been described, but compressive VHs frequently have atypical features. In particular, magnetic resonance features are not well established. We present imaging features in three cases of compressive VH and review the imaging findings in an additional 106 previously published cases. Findings were typical in 52 of 80 plain film (65 %), 33 of 41 computed tomography (80 %) and 13 of 25 magnetic resonance examinations (52 %). The prevalence of previously described imaging features is reported. Awareness of the range of magnetic resonance features is important since this is frequently the initial investigation in patients presenting with symptoms of neural compression. Since computed tomography is typical in 80 % of cases, this is a useful confirmatory test if magnetic resonance features are suspicious but not diagnostic of compressive VH. Received: 6 August 1999; Revised: 4 November 1999; Accepted: 4 November 1999     

The role of professional expertise in the purchasing of health services.

Using data gathered from a mixture of quantitative and qualitative tools, this research into the purchasing of health services, namely occupational health services, is utilized to build an understanding of the role of service professionals in the purchasing of health services. In analysing the themes emerging from the interviews it was found that, typical of a complex, highly intangible professional service, the buyers found it difficult to objectively evaluate the service. The purchasing of occupational health services, similar to other professional services, was perceived to be an uncertain and risky process. The high uncertainties and risk of purchasing occupational health services lead to the utilization of the expertise of the service providers as a risk-reducing mechanism. This understanding of the role of health professionals in the purchasing of health services illustrates that the service characteristics enables the health professionals to utilize their expertise in influencing all stages of this process.