Transoral decompression and posterior stabilisation in Morquio's disease

A 3.5 year old boy with Morquio's disease was referred with a persisting left hemiparesis four months after a fall and was found to have craniocervical junction compression due to atlantoaxial subluxation and significant anterior soft tissue compression. Transient unconsciousness at the time of the fall was probably due to medullary concussion as a result of hyperextension, not a head injury. Spinal cord compression due to atlantoaxial subluxation at the craniovertebral junction is a major cause of disability and death in these patients. Once cervical myelopathy appears, early posterior occipitocervical fusion has been advocated in order to arrest the progression of neurological disability and this is successful in most cases. This conventional approach was considered unsafe because of the significant anterior compression. A combined anterior transoral decompression with posterior fusion to deal with this particularly difficult problem is described.

Damaged ligaments at the craniocervical junction presenting as an extradural tumour: a differential diagnosis in the elderly

An extradural mass at the craniocervical junction causing progressive neurological disability in five elderly patients is described. The lesion, which might be confused with a meningioma or other tumour, is composed of amorphous degenerate fibrocartilaginous material and could be due to degeneration of the ligaments responsible for atlanto-axial stability. Recognition of the condition early is important as the patient's clinical condition will deteriorate without decompression. Anterior transoral removal is relatively simple, unlike surgery for tumours in the area, and will not destabilise the craniovertebral junction. It is likely that a proportion of these lesions are undetected, misdiagnosed or untreated to the detriment of the patient.

The odontoid process in Morquio-Brailsford's disease. The effects of occipitocervical fusion

High definition computed cervical myelograms have been made in flexion and extension in 13 patients with Morquio-Brailsford's disease. We observed that: 1) odontoid dysplasia was present in every case, with a hypoplastic dens and a detached distal portion which was not always ossified; 2) atlanto-axial instability was mild, and anterior atlanto-axial subluxation was absent in most cases; 3) severe spinal cord compression, when present, was due to anterior extradural soft-tissue thickening; 4) this compression was not relieved by flexing or extending the neck and was manifested early in life; 5) posterior occipitocervical fusion resulted in disappearance of the soft-tissue thickening and normalisation of subsequent development of the dens. We conclude that the severity of neurological involvement at the craniovertebral junction was determined by soft-tissue changes, not by the type of odontoid dysplasia nor by subluxation. Posterior occipitocervical fusion proved to be an effective treatment.

Extended use of cranial CT in the evaluation of patients with stroke and transient ischaemic attacks

The hypothesis was explored that patterns of ischaemic brain damage shown by CT may be of greater value in estimating the relevance of angiographic stenosis in the carotico-vertebral arteries in some patients than presenting clinical features. Five angiographic and six CT abnormalities were defined and charted independently in a blinded manner in 312 patients whom clinical features and subsequent management were known. Charts were combined for statistical analysis. Statistically significant associations were found between two types of CT lesion and angiographic abnormalities, but these were present in only 18% of cases. The distribution of clinical features did not differ significantly within this subset compared to the whole population, from which it was concluded that the hypothesis was upheld. Furthermore significantly more patients in this subset were subjected to carotid endarterectomy, suggesting that management decisions may have been modulated by CT findings in some patients.

Stepwise correction of anaemia by subcutaneous administration of human recombinant erythropoietin in patients with chronic renal failure maintained by continuous ambulatory peritoneal dialysis

Sixteen anaemic CAPD patients (Hb less than 9 g/dl) were treated with thrice-weekly subcutaneous recombinant erythropoietin, epoetin-alfa. The dose was adjusted to induce a stepwise increase in haemoglobin. Fourteen patients reached a first target haemoglobin of 11.0-11.5 g/dl and eight of these a second of 13.0-13.5 g/dl, but one could not be maintained at this level. Failure to reach or maintain the second target in nine subjects was accounted for by incomplete responses associated with infection in one, extreme shortening of red-cell survival in another, and was unexplained in one subject. These three received the maximum dose studied of 450 IU/kg per week. Six other subjects were withdrawn from the study for reasons unrelated to treatment with erythropoietin. The median dose required to maintain the haemoglobin at 11.0-11.5 g/dl was 75 IU/kg per week and at 13.0-13.5 g/dl was 150 IU/kg per week. Quality of life, assessed in 12 patients at haemoglobin 11.0-11.5 g/dl, showed significant improvement in energy, and at 13.0-13.5 g/dl improvements in sleep and emotional wellbeing became significant. Twelve subjects required either institution of, or an increase in, treatment for hypertension. The thrice-weekly subcutaneous doses of erythropoietin were well tolerated and were a convenient and effective treatment for anaemia in patients on CAPD.

Identifiable causes for poor outcome in surgery for cervical spondylosis. Post-operative computed myelography and MR imaging

Outcome from surgery for cervical spondylosis is often disappointing. To identify possible causes of poor outcome 56 such patients referred for post-operative computed myelography or MRI were evaluated, 22 of which eventually had further surgery. Alternative diagnoses to cervical spondylosis were eventually established in 14.3%; 26.8% had spinal cord atrophy 15.6% of which also had myelomalacia; 28.6% had diffuse spinal canal stenosis; and in 57.1% surgery had failed to decompress the spinal canal. These findings can be partly explained by patient selection criteria; nevertheless they do serve to emphasises the point often ignored in discussions of the efficacy of surgery in cervical spondylosis, that operations significantly often fail to achieve adequate decompression. Furthermore there was no evidence in this material that osteophytes regress after spinal fusion.

The operative management of basilar impression in osteogenesis imperfecta

Four patients with osteogenesis imperfecta and neurologically significant basilar impression have been treated over the past 8 years. The experience has resulted in changes in our therapeutic strategy for this particularly difficult problem. These cases are discussed with respect to the disease process, neurological involvement, radiological findings, and modes of surgical therapy. The errors in management as well as the success resulting from our learning experience are described. Currently, we recommend the extensive removal of the anterior bony compression by a transoral approach. This should be followed by a posterior rigid fixation that transfers the weight of the head to the thoracic spine, in an effort to prevent further basilar invagination.

Clinical Utility of cranial CT in HIV positive and AIDS patients with neurological disease

An analysis was made of the clinical, pathological and radiological data relating to 117 requests for cranial CT on 83 patients who were HIV positive or had AIDS in one year at St Mary's Hospital. Central to the design was grouping of the patients according to clinical presentation. The aim was to establish whether there was evidence to support the view that, because of their immunocompromised state, these patients may commonly harbour serious, potentially treatable intracranial disease without the usual overt clinical signs. No patient who was only HIV antibody positive had treatable intracranial disease without focal neurological signs. In patients with AIDS, treatable or potentially treatable lesions were mainly confined to those with objective neurological signs or seizures. There is little evidence in this data to support the original hypothesis. While it would be inappropriate to advise that CT should never be carried out in the absence of focal signs or seizures, the results of this study should be useful in ascribing an appropriate degree of urgency to requests for cranial CT in these patients.

Three cases of craniopharyngioma showing optic tract hypersignal on MRI

Three patients presenting with visual failure had MRIs with hypersignal extending from the region of the optic chiasm along both optic tracts in 2 cases, and along 1 optic tract in the 3rd. In all patients intrinsic tumor of the chiasm was the most likely diagnosis based on MRI appearances, but all 3 had craniopharyngioma.

Subcutaneous administration of recombinant human erythropoietin to subjects on continuous ambulatory peritoneal dialysis: an erythrokinetic assessment

Erythrokinetic studies were performed in subjects on continuous ambulatory peritoneal dialysis, during a trial examining the effectiveness of subcutaneous administration of recombinant human erythropoietin (r-HuEPO) in correcting the anaemia associated with end stage renal disease. 15 subjects (mean haemoglobin concentration 6.9 g/dl, SD 1.1) entered the study, and during treatment 9 were restudied at a haemoglobin concentration of 11-11.5 g/dl and six underwent a third study at haemoglobin 13-13.5 g/dl. By adjusting the dose of r-HuEPO, a stepwise increase in haemoglobin concentration was achieved, and this was accompanied by increases in total red cell volume and erythron transferrin uptake. Plasma volume decreased as red cell volume increased, leaving total blood volume essentially unchanged. Red cell survival, modestly reduced before treatment (mean 64, range 44-96 d, n = 6) tended to increase during treatment and when subjects were retested at a haemoglobin concentration of 13-13.5 g/dl (after 38-62 weeks treatment), the mean increase in red cell survival was 20 d (95% confidence interval 1-39 d). Thus subcutaneous r-HuEPO is effective in correcting the anaemia of end stage renal disease when administered thrice weekly to subjects on continuous ambulatory peritoneal dialysis. It produces an increase in haemoglobin concentration primarily by expanding the erythron, and may have a secondary effect, seen after several months of treatment, of increasing red cell survival.

Fourier transform infrared assay of membrane lipids immobilized to silica: leaching and stability of immobilized artificial membrane-bonded phases

A nondestructive, sensitive assay to monitor the hydrocarbon content of silica-based chromatography particles has been developed. The assay requires a microscope accessory interfaced with a Fourier transform infrared (FTIR) spectrometer. For determining hydrocarbon content, undiluted alkyl-silica-bonded phases were pressed into a thin wafer. Hydrocarbon content was quantitated using the integrated hydrocarbon band intensity between 2995 and 2825 cm-1 [i.e., band area C-H] and the integrated silica oxide band intensity between 1945 and 1780 cm-1 [i.e., band area Si-O]. Plotting the [band area C-H]/[band area Si-O] ratio vs the carbon content determined by elemental analysis gave a correlation coefficient of r = 0.997. The FTIR assay was validated on 5-, 7-, and 12-microns silica particles using three different immobilized artificial membrane (IAM) silica-bonded phases. The utility of the FTIR assay in determining hydrocarbon content was demonstrated by evaluating hydrocarbon leaching from IAM phases exposed to mobile-phase solvents. The ability of organic solvents to leach hydrocarbon from IAM phases containing phosphatidylcholine (PC) as the immobilized ligand was chloroform greater than ethanol approximately methanol greater than ethyl acetate greater than methylene chloride greater than acetonitrile greater than acetone. Acetone and acetonitrile cause very little hydrocarbon leaching from HPLC-IAM.PC columns. When challenged with different mobile phases, IAM.PC columns perfused with mobile phase are more stable than IAM.PC-bonded phases stirred in mobile phases. IAM.PC contains lecithin linked to silica by amide bonds.(ABSTRACT TRUNCATED AT 250 WORDS)

Relative safety of intravenous digital subtraction angiography over other methods of carotid angiography and impact on clinical management of cerebrovascular disease

Data from a multicentre survey based on three London teaching hospitals on the relative safety and clinical utility of intravenous carotid digital subtraction angiography (DSA) over intra-arterial DSA and conventional carotid angiography are presented. The incidence of stroke during intra-arterial DSA was 0.7% (n = 538) and during conventional angiography was 0.8% (n = 780). The incidence of stroke during intravenous DSA was zero (n = 3710). When it constituted the initial investigation, intravenous DSA achieved a 93.8% replacement value over intra-arterial studies as a whole (n = 474) and 89% replacement value for patients having carotid endarterectomy (n = 99). It was also noted that the installation of DSA equipment at one unit coincided with a sixfold increase in the number of carotid angiographic examinations and an almost threefold increase in carotid endarterectomies.

Clinical diagnosis from digital displays: preliminary findings of the St Mary's Evaluation Project

Image quality is a fundamental issue in the introduction of picture archiving and communications systems (PACS), and one that has hitherto been eclipsed by other aspects of the considerable technological challenge facing scientists and manufacturers involved in its development. We conducted a formal evaluation of clinical radiological diagnosis from a commercially available PACS viewing station, using subperiosteal resorbtion in renal osteodystrophy as the test pathological diagnosis, with receiver operating characteristic (ROC) analysis of the results. We conclude that the displayed, digitised images were inferior to film using the apparatus tested and believe that careful, objective clinical evaluation of such systems is of paramount important.

Catechol estrogen formation in MCF-7 cell culture and effects of bromoestrogen inhibitors

Agonist and antagonist activities have been reported for several catechol estrogens given exogenously. Since the metabolic clearance rate for catechol estrogens in the body is very rapid, catechol estrogens produced at other tissues will have minimal effect on breast tissue. Information of the extent of catechol estrogen formation within cells is critical in assessing the overall importance of these estrogen metabolites. Investigations of the conversion of estrogens to catechol estrogens were performed in the MCF-7 human mammary carcinoma cell culture system. Reverse-phase high-performance liquid chromatography (HPLC) analysis demonstrated that very little metabolism of estradiol occurs after 48 h, with only small amounts of estrone, 2-hydroxyestradiol, 2-hydroxyestrone, and estriol being observed. The total amount of 2-hydroxyestrogen products formed from 1 microM estradiol was 406.2 pmol (SD = 60.9) per 3 x 10(7) cells in 48 h. Similar results were obtained using the simpler radiometric assay for estrogen 2-hydroxylase, which measures the release of 3H2O from [2(-3)H]estradiol. The effects of inhibitors of estrogen 2-hydroxylase were also examined in MCF-7 cells. 2-Bromoestradiol, 4-bromoestradiol, and 2,4-dibromoestradiol effectively block estrogen 2-hydroxylase in a dose-dependent manner in MCF-7 cultures, with ED50 of approximately 1 microM for each inhibitor. Furthermore, these bromoestrogens bind poorly to estrogen receptors in MCF-7 cells and do not alter cell growth. Thus, in MCF-7 mammary cell cultures, metabolism of estradiol occurs to only a minor degree, and it is unlikely that the levels of catechol estrogens would reach physiologically relevant concentrations in the intact breast cancer cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Outpatient myelography: an acceptable and cost-effective technique

Sixty-five patients with stable low back pain had their lumbar myelography performed as outpatients, staying in the department for 1 h after the examination. The incidence of post-myelogram headache was similar to that reported for inpatients. No serious after-effects occurred in the study group. The vast majority of patients preferred to be at home following the study. It is concluded that outpatient myelography is safe, less expensive and preferred by the patients.

A model for capacity planning of a comprehensive integrated information system for hospitals and clinics

Appropriate system sizing is essential to ensuring a reasonable computer response time for end users. A model is discussed that describes the type and number of interactions between user terminals and printers and the central processor for a comprehensive, integrated medical information system. The system modeled includes support to inpatient and outpatient order entry and results reporting for clinical services; registration; admission, disposition, and transfer; patient appointing; pharmacy, clinical laboratory, and radiology; medical record management; and electronic messages. Originally developed for use in benchmark testing of comprehensive systems designed for military hospitals and clinics, the model has been generalized to be applicable to other systems and settings. Results are presented for a routine busy day in a 200-bed teaching hospital providing extensive outpatient services, and a large free-standing clinic. The model results can be applied to several facets of system planning, including sizing of the central processor and communications network, determining the optimal number of storage devices and user devices, and fine tuning the user interface.

Acute effects of the aldehyde dehydrogenase inhibitors, disulfiram, pargyline and cyanamide, on circulating ketone body levels in the rat

Acetonemia is generally associated with the ketogenic states of fasting and diabetes. Disulfiram (DS), an inhibitor of aldehyde dehydrogenase (AlDH) that is used as an alcohol deterrent drug, is also known to elevate blood acetone in humans, but in the absence of a commensurate increase in its metabolic precursor, acetoacetate. We reexamined the effects of DS and other AlDH inhibitors on circulating ketone body levels in male rats of Sprague-Dawley descent and again demonstrated a 6- and 16-fold increase in blood acetone along with normal levels of acetoacetate at 6 and 24 hr after DS. Pargyline, another inhibitor of AlDH, maintained normal blood acetone levels in the presence of reduced acetoacetate levels. A third inhibitor of AlDH, cyanamide, administered to fasted and nonfasted rats, elevated blood acetone levels 10-fold over controls, with, however, a commensurate 5- and 7-fold increase in blood acetoacetate levels. The threshold values for the cyanamide-induced elevation of blood acetone and acetoacetate were equivalent, i.e. approximately 0.25 mmol/kg body weight (i.p.). The elevation of acetoacetate and the inhibition of hepatic catalase activity by cyanamide are not mechanistically linked, since 3-amino-1,2,4-triazole, another inhibitor of catalase, elevated blood acetone but not acetoacetate levels. These findings suggest that DS-induced acetonemia is due to inhibition of acetone metabolism, whereas enhanced acetone formation through acetoacetate contributes significantly to cyanamide-induced acetonemia.

Inhibition by bromoestrogens of the effects of estradiol on apomorphine-induced climbing behavior

The chronic administration of estrogens to mice or rats will result in antidopaminergic effects. Apomorphine-induced climbing behavior in mice, the result of direct stimulation of dopamine receptors in the striatal and mesolimbic regions, is a simple animal model for examining these antidopaminergic effects of estrogens. Bromoestrogens, inhibitors of catechol estrogen formation, have been utilized in order to examine the role of estrogen metabolism in dopaminergic antagonism. Mice were pretreated for 3 days with 2-bromoestradiol, 4-bromoestradiol, or 2,4-dibromoestradiol dibenzoates alone or in combination with estradiol benzoate prior to apomorphine administration. The haloestrogens did not alter the climbing-induced responses elicited by apomorphine, whereas estradiol benzoate clearly attentuated the actions of apomorphine. Furthermore, the bromoestradiol dibenzoates were effective in reversing the effects of estradiol benzoate when the two steroids (estradiol benzoate and a bromoestrogen dibenzoate) were administered simultaneously during pretreatment. Thus, the bromoestrogens are able to inhibit the antidopaminergic effects of estradiol exhibited in the apomorphine-induced mouse climbing model.