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Sixty-four patients with suspected cystic myelopathy following spinal cord trauma were examined radiologically. In twenty-seven of these, spinal cord cysts were confirmed at surgery; in five, cysts were excluded by surgery and/or autopsy; the rest were unconfirmed. In water soluble myelography the most frequent sign in those with confirmed cysts was distention of the involved segments of the spinal cord. A less frequent but reliable sign was variation in cord size with position in a paradoxical fashion to the well established changes which occur with air myelography. Focal concentrations of contrast medium were visible within cord substance at CT in two of the patients in whom no cyst was found at surgery or autopsy. Some correlations between clinical features, including rate of progression and results of surgery, and radiological findings are unexpected on the basis of existing theories on pathogenesis.

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.

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.

Thirty-six control subjects had computer assisted myelography (CAM) using the EMI CT 5005 scanner. The normal cervical cord is elliptical, more circular at the upper and lower ends and flatter in the mid-segments. Asymptomatic cord deformities, usually mild, were present in nine subjects (25%). Four measurements, namely, sagittal diameter (APD), transverse diameter (TD), area (a) and circumference (c) were made and two more parameters calculated i.e. APD/TD ratio and circularity (= 4 pi a/c2). These control values form the basis of qualitative and quantitative assessment of cord deformity. When cord measurements are to be used, control values should be obtained for each scanner and procedures should be standardized.

Meningiomas occurring in 160 patients were studied in relation to oedema production using computerised tomography. Statistically significant positive correlations with oedema production were found with tumours of large surface area, anterior parasagittal position, prominent vascularity, involving dural sinuses, and with short clinical history. Significant negative correlations were found with small tumour size and the presence of calcification. It is considered that hydromechanical factors predominate in oedema production with meningioma.

The theoretical risk of injuring the vertebral artery or anomalous vessels at lateral cervical puncture is assessed. In just less than 30% of vertebral arteries the vessel overlies the lateral aspect of the spinal canal between the first and second cervical vertebrae, usually the antero-inferior quadrant. Directing the spinal needle to the posterior third of the canal virtually eliminates the possibility of injuring this and most anomalous arteries traversing the region. The likelihood of inducing subarachnoid haemorrhage by injuring these vessels would appear to be considerably less in lateral cervical than in cisternal puncture.

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)

The distribution of oedema detected by computed tomography in 46% of 160 patients with cerebral meningiomas was studied. Oedema occurred most frequently in the centrum semiovale and deep white matter around the ventricular trigones and frontal horns, the distribution reflecting mainly the size of the interstitial spaces adjacent to the tumour. Other theoretically relevant factors such as hydrocephalus and cerebral atrophy did not influence oedema distribution. Cyst like spaces of various types were observed in 20% and their aetiology is discussed. Oedema usually resolved after surgery, but in at least 13% it persisted after 3 months. Atrophy related to tumour size and not to presence or extent of oedema. Increased oedema after surgery was never of vasogenic type and could nearly always be ascribed to a definable complication.

Using a role and exchange theory framework, this study examines the commitment to their organization and to the federal service of 634 managers in 71 federal government organizations. Results indicate that certain role factors such as tenure and work overload and personal factors such as attitude toward change and job involvement are strong influences on commitment. Implications of the findings and the need for further theoretical and methodological refinements are discussed.

Sepsis continues to be a major cause of patient death following hemorrhagic shock. To explain this increased susceptibility to infection on a cellular level, neutrophil function was studied in nine adult baboons subjected to severe hemorrhage. Neutrophil migratory activity was found to be significantly decreased immediately after hemorrhage (P less than 0.05 vs control) and continued to decline throughout the experiment. After an initial small decline, neutrophil adherence increased to significant levels after 4 h of hypotension (P less than 0.05 vs control). The present data support the hypothesis that increased susceptibility to infection after sustained hemorrhage is a result of impaired neutrophil function.

N,N-Disubstituted dopamine and 2-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene (6,7-ADTN) analogues were synthesized and tested intraperitoneally in mice for dopamine agonism. Compounds inducing asymmetric postures in unilaterally caudectomized mice were further tested in mice treated with reserpine and alpha-methyl-p-tyrosine methyl ester. ED50 values determined for reversal of reserpine-induced catalepsy were used to rank drug potency and correlated with molecular structure. N-n-Propyl N-substituted compounds were more effective than other N,N-dialkyl homologues. Of these, analogues with one alkyl group larger than propyl became inactive or their dopaminomimetic effect was reduced when the propyl was replaced with a larger group. N-Monosubstituted analogues were inactive as dopamine agonists. N-n-P-r-N-n-Bu-6,7-ADTN was six times more potent than N-n-propyl-N-n-pentyl- and N-n-propyl-N-phenethyldopamine but ten times less potent than apomorphine. The availability of an array of structurally related dopamine analogues with dopaminomimetic properties may make it possible to test the hypothesis that there are more than one type of dopamine receptor and that stereotypy and locomotor activity may have different central nervous system loci. Moreover, they may be of potential use in the treatment of parkinsonism and other extrapyramidal disorders.

The salient features of the normal CT anatomy of the various lobules of the cerebellar hemispheres and vermis are described. The subdivisions of the vermis were found to be most constant. The surface appearance of the hemisphere lobules was also relatively constant; however, at CT these fissures are imaged at depth and this constancy is not reflected in CT images because folia cross the depths of the major sulci from one lobule to the other in a highly variable manner. The flocculus has been confused with the anterior angle of the cerebellum, and the cerebellar tonsils with the biventral lobule.

The features of 17 symptomatic subependymomas on X-ray computed tomography are described. Thirteen were reviewed from isolated case reports and 4 were original material. Over half were entirely intraventricular, 6 extended into brain substance and 2 into subarachnoidal cisterns. Twelve were isodense, 15 showed diffuse but irregular enhancement, and 5 contained nodular calcification. Large low density cysts, intratumoural haemorrhage and brain oedema were found almost exclusively in lesions extending into brain substance. It is concluded that subependymomas resemble ependymomas too closely on CT to be distinguished radiographically from them as a separate group. However subependymomas contain calcification slightly less frequently, and usually appear as mainly intraventricular lesions even when they occur above the tentorium.

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.

Sixty-nine patients with cervical spondylotic myelopathy (CSM), radiculopathy (CSR), or both (CSMR) were studied with computed tomography (CT). Computer-assisted myelography (CAM) accurately determines the site and nature of spondylotic protrusions and provides good visualisation of the subarachnoid space and cord deformities even in areas with dilute metrizamide. However, excessive vertebral movement and bulging ligamenta flava with their effects on cord deformity, so easily visualised in myelograms, are completely or partially missed. In the assessment of CSM, metrizamide myelography (MM) followed by CAM should be performed, particularly when the myelographic images are unsatisfactory due to contrast dilution or blockage, when cord compression cannot be ascertained with MM and when cord atrophy is suspected. In CSR, the diagnostic information from MM and CAM is comparable. The diagnostic criteria in CAM are, however, less direct and since MM is adequate in uncomplicated cases, CAM is generally not necessary. The APD, APD/TD ratio, area and circularity are sensitive indices of cord deformity and the first two should be used more often to assist visual assessment of cord deformity. The relation between cord parameters and treatment response is better reflected in CSM cases managed conservatively and the results suggest that the degree of cord deformity is helpful in determining the outcome and hence the choice between surgical and conservative treatment. In plain CT, the osteophytes and calcified discs are adequately visualised and canal dimensions measured with accuracy, but the cervical cord and roots cannot be properly assessed and the diagnosis of CSM or CSR cannot be ascertained. At present, its role in cervical spondylosis is therefore limited.

An investigation into the relative elastic and non-elastic components of compressive deformity of the cervical spinal cord has been made. Sixteen patients were examined by computed myelography with the neck flexed and extended, and one fresh specimen of a human spinal cord was studied under reversible transverse compression with the specimen in a stretched and shortened state. In conditions of transverse compression cord tissue undergoes an alteration in viscoelastic properties, manifesting itself as reduced expansion of the compressed segment as the cord shortens, which in some cases is independent of whether the agent is seen to actually contact the cord. The presence of degenerative changes in cord substance probably accentuates this alteration in mechanical properties.

Decreased chemotaxis of burn patient neutrophils has been observed in many studies. This study attempts to analyze the basis of this defect by determining the effect of filter pore size on chemotaxis, utilizing the Boyden chamber technique. Directed migration of burn patient neutrophils, as compared to normal controls, was greatly decreased when 3.0-micron filters were used. When 8.0-micron filters were used, however, the directed migration of burn patient neutrophils was identical to that of the normal controls. These findings indicate that the failure of burn patient neutrophils to undergo directed migration using Boyden chambers is not due to an inability to migrate toward a chemoattractant. Our data suggests that when utilizing the Boyden chamber technique to measure chemotaxis, the failure to give a normal response should not necessarily be interpreted as a chemotactic defect. In fact, mechanical impediments may play a major role in the decreased migration.

Thirty one patients with suspected myelopathy due to rheumatoid arthritis were examined by plain radiography and 27 had computed myelography. Clinical features and radiological findings were compared. Deformity of the spinal cord could occur in the absence of combined anterior and posterior compression and correlated closely with clinical features only when considered in combination with skeletal and adjacent soft tissue abnormalities. The best surgical results were achieved by transoral odontoidectomy.

Cervical myelopathy is a rare but potentially dangerous complication of rheumatoid arthritis and presents considerable therapeutic problems. A conservative approach carries high mortality and surgical intervention is not without serious risks. Reduction of subluxation and posterior fusion is widely practised but may require prolonged bed rest and continuous skull traction, sometimes for many weeks. When anterior decompression has been attempted prolonged immobilisation and external fixation have created problems. In this series 23 rheumatoid patients with cervical myelopathy were investigated over a four-year period. Seventeen underwent anterior decompression of the cervical cord, of whom 14 had a transoral removal of the odontoid peg and pannus and posterior occipitocervical fusion during the same anaesthetic without mortality or serious postoperative complications; all but one have improved. The authors believe that early mobilisation after a combined cord decompression and internal fixation has reduced the mortality and morbidity. Management of cervical myelopathy in rheumatoid arthritis and indications for operation are discussed.

Four, and later five, of the medical schools in the one multiple choice question (MCQ) paper in Obstertrics and Gynaecology to their students at the end of the Obstetrics and Gynaecology courses. The paper was amended twice after intervals of approximately 12 months. The results showed differences in performance between the five schools on questions and alternatives within questions, which were common to all editions of the paper (the "short" paper). These differences were also shown in the first two editions of the full paper (the "long" paper), but were not apparent in the third. There was a significant improvement in performance from the first to the second paper edition of the long by approximately 11%, but this was reversed from the second to the third edition, where there was a significant decrease in performance by approximately 4%. We cannot here exclude the possibility that this decrease in the third edition has resulted from sample bias. The rank order of the schools may result from differences in methods of teaching. It seems that such relative performance between London medical schools in contributed to by the differences in course legnth and by the occurence of mid-course test. It appears also that student performance in any of the schools has not been uniform over the period of the study, there being a peak during the period when the second edition of the paper was used. Variations in student selection occuring between schools may effect some of these differences. There was also a marked difference in students' performance between Obstetrics and Gynaecology. The short papers appeared easier than the full papers. Whilst this may due to the greater clarity of phrasing for the questions of the short paper, we also believe the subject matter of the short paper may be more relevant. A distinct effect could also be shown, over the period, due to improvements in the wording of the questions. It is possible that students perform better at Obstetrics than at Gynaecology.

A case of myelopathy with both intradural and extradural spinal arachnoid cysts is reported treated by cysto-peritoneal shunt, the spinal end of which was inserted percutaneously under fluoroscopic control. The site of drainage was determined by findings at computed myelography. The case illustrates the value of the latter in demonstrating the pathological bio-mechanics producing myelopathy in this condition.

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.

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.

Four patients with clinical and investigative features suggestive of cavernous sinus thrombosis are reported. Radiological investigations included computed tomography of head and orbits. The problem of clinical and radiological distinction from orbital infection is discussed. Serious intracranial complications developed in two patients and the value of computed tomography in detecting these is stressed.

A total of 53 patients with cervical spondylotic myelopathy and/or radiculopathy were studied with computer-assisted myelography following metrizamide myelography. Cervical cord deformities resulting from spondylotic protrusions were classified into four groups. The A shape (anterior central concavity) is the commonest and is often associated clinically with bilateral anterolateral and posterior column deficits. In the B shape (lateral deformity on one side), unilateral anterolateral column and root signs, usually mild, predominate. The symptomatology of the C shape (lateral deformity on both sides) and the D shape (flattened anterior surface) is bilateral, although not often symmetrical, and includes anterolateral and posterior column disturbances and root signs. Radiculopathy may, however, occur in the absence of cord deformity if the spondylotic lesion is close to or inside the intervertebral foramen. As there is some relationship between cord shapes and symptomatology, the decision as to whether a particular deformity is responsible for the clinical presentation may be made with more confidence. Moreover, the degree of cord deformity correlates well with the severity of symptomatology. Those with mild deformity had relatively few or mild cord signs, whereas in those with severe deformity cord signs were numerous and severe. Certain observations on cord deformity in vivo support the view that compression is an important pathogenetic mechanism in cervical spondylotic myelopathy. Most patients had anterior cord compression and the anterolateral signs were more frequent and marked. Severity of cord signs is associated with the degree of compression. Removal of the compression is followed by re-expansion of the cord and clinical improvement. In a small number of cases where cord compression by osteophytic protrusion was mild, and where clinical improvement followed the removal of the protrusion, the theory of cord traction and friction appears to apply. The contribution of other mechanical factors and of ischaemia to cord damage is also discussed.

Cervical myelopathy is an uncommon but potentially fatal complication of rheumatoid atlanto-axial subluxation. Computerised myelotomography with three-dimensional reconstruction shows that rheumatoid pannus, together with the odontoid peg, contributes significantly to anterior cervico-medullary compression. These findings were the basis for treatment by transoral anterior decompression and posterior occipitocervical fusion, which removes both bony and soft-tissue causes of compression and allows early mobilisation without major external fixation. We report encouraging results from this combined approach in 14 patients who had progressive neurological deterioration.

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)

This article presents a new translation of the papyrus Kahun. Interest in the papyrus lies in its being indisputably the most ancient document on gynaecology known. The text consists of a continuum of individual "cases" which lend themselves to subdivsion into four major sections. Selected commentaries accompany the translation which consist in the main of illuminating quotations from other Egyptian papyri. The aim is to propagate some insight into the gynaecological concepts behind medical practice around 2000 B.C.

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 combined clinical myelographic and computed myelographic study was performed in 30 patients with cervical spondylotic myelopathy; computed myelography was also performed in 16 control patients. Good correlation was found between degree of deformity of cross-sectional shapes of the cord and the outcome of surgery, and measurements of anteroposterior diameter and area of the cord seemed helpful in this preliminary study. There was also reasonably good correlation between the clinical features when grouped according to specific tract involvement, and the pattern of deformity shown by the abnormal cross-sectional cord shapes.