Subacute cerebellar infarct mimicking meningioma.
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Cerebellum↗
Biomedical subjects
M C Patel
Publications and source records attributed to M C Patel.
Erythrodermic syringotropic cutaneous T-cell lymphoma.
Syringotropic cutaneous T-cell lymphoma (CTCL) is a rare localized variant of CTCL, characterized histologically by eccrine gland and ductal hyperplasia surrounded by a dense syringotropic lymphocytic infiltrate. Previously reported only in men, we describe the first woman with syringotropic CTCL. Unusually, she presented with erythroderma, cutaneous nodules, poikilodermatous patches, widespread alopecia and lymphadenopathy.
Alopecia↗
Rhodium-catalyzed regioselective olefin hydrophosphorylation.
Parameters influencing the selectivity of the (PPh(3))(3)RhCl-catalyzed hydrophosphorylation of olefins and enynes are described. The reaction between differentiated dienes was shown to be highly responsive to olefin substitution. The trimethylsilyl group effectively reversed the normal preference for hydrophosphorylation of an alkyne over an alkene. [reaction: see text]
Journal Article↗
Muscle paralysis produced by botulinum toxin type A injection in treated torticollis patients compared with toxin naive individuals.
We sought to determine whether the response to varying doses of botulinum toxin type A (BTX-A) injected in BTX-A-treated torticollis patients differed from the same injections given in toxin-naive individuals. We have developed a technique to objectively measure muscle weakness resulting from BTX injections in humans and have validated the technique in those not previously treated with BTX. We now examine BTX-A-treated torticollis patients to see if their response to BTX-A injection is similar to that of toxin-naive individuals. We injected 11 torticollis patients who had been receiving BTX-A injections with a standard 5-mouse unit (mu) dose into one extensor digitorum brevis (EDB) muscle and a varying dose into the other EDB, measuring muscle paralysis 2 weeks after the injection. Nine of the 11 patients were clinical and electrophysiologic responders. Two patients were non-responders. In the 9 responding patients the dose response curve to increasing doses of BTX-A was very similar to that seen in toxin-naive individuals. The mean muscle paralysis from the standard 5 mu dose was also similar to that previously reported in toxin-naive individuals. Torticollis patients who continue to respond clinically to BTX-A injections demonstrate essentially the same degree of muscle paralysis from the EDB injections as do subjects who have never been exposed to BTX-A.
Adult↗
Phase I trial of lobradimil (RMP-7) and carboplatin in children with brain tumors.
PURPOSE: To determine the maximum tolerated dose (MTD), the incidence and severity of toxicities, and the pharmacokinetics of lobradimil administered intravenously over 10 min in combination with carboplatin in children with refractory brain tumors. METHODS: A group of 25 children with primary brain tumors received carboplatin and lobradimil on two consecutive days every 28 days. The 10-min lobradimil infusion began 5 min before the end of the carboplatin infusion. Four lobradimil dose levels (100, 300, 450 and 600 ng/kg ideal body weight, IBW) were studied in cohorts of 4 to 13 patients. Carboplatin was adaptively dosed based on the glomerular filtration rate to achieve a target plasma area under the concentration-time curve (AUC) of 7.0 mg min/ml per course (5.0 mg min/ml for patients who had previously received craniospinal radiation or myeloablative chemotherapy). RESULTS: Lobradimil toxicity was immediate, tolerable and rapidly reversible. The most frequent toxicities were hypotension, flushing, headache and gastrointestinal complaints. One patient on the 600 ng/kg dose level had a seizure during the lobradimil infusion. The incidence and severity of lobradimil toxicities were not dose-related and the lobradimil dose was not escalated beyond the 600 ng/kg IBW dose level. Two patients had partial responses and ten patients had stable disease. Myelosuppression (thrombocytopenia more prominent than neutropenia) was the primary toxicity attributed to carboplatin. Lobradimil pharmacokinetics were characterized by rapid clearance from the plasma compartment and substantial interpatient variability. CONCLUSIONS: The combination of carboplatin and lobradimil is safe and tolerable. An MTD for lobradimil was not defined because toxicity was not dose-related. The recommended pediatric phase II dose of lobradimil is 600 ng/kg IBW.
Adolescent↗
Imaging infection with LeuTech.
LeuTech is a 99Tcm labelled, anti-CD15, IgM, murine monoclonal antibody shown to have high affinity (Kd = 10(-11) M) for CD15 receptors (5.1 x 10(5)/cell) expressed on human neutrophils. LeuTech was injected directly, intravenously, and its efficacy in imaging infection in 46 consecutive patients was determined. Human anti-mouse antibody (HAMA) response was examined in 30 normal volunteers using a standard LeuTech dose reconstituted with decayed 99Tcm solution. There were 38 true positive, six true negative, and two false negative scans. Of the 38 positive images, 33 (92%) were positive within 10 min after injection of LeuTech. LeuTech accuracy in this group of patients was 96%, sensitivity 95%, specificity 100%, positive predictive value (PPV) 100%, and negative predictive value (NPV) 75%. No elevation of the HAMA titre was observed in any of the 30 normal volunteers and no adverse reaction was noted in any patient. LeuTech is a highly promising agent for rapid imaging of infectious foci.
Adult↗
Spontaneous obliteration of pial arteriovenous malformations: a review of 27 cases.
BACKGROUND AND PURPOSE: Brain arteriovenous malformations (AVMs) occur in approximately 0.14% of the population. The most common presentations are hemorrhage (50%) and seizures (25%). Although they are congenital abnormalities, their angioarchitecture may vary over time. A rare but well-recognized phenomenon of AVMs is that of spontaneous obliteration. It is not known what factors predispose to spontaneous obliteration. The purpose of our study was to determine whether spontaneous thrombosis of AVMs can be predicted by their angioarchitecture and whether there is any risk of recurrence once obliteration has occurred. METHODS: We retrospectively reviewed the angiographic and cross-sectional imaging data amassed over an 18-year period, including follow-up imaging studies and mail surveys of referring and family physicians. A control group was obtained from contemporaneous AVMs of a similar size. RESULTS: We identified 28 cases of spontaneous obliteration in a series of 2162 patients. The mean time between initial diagnostic angiography and angiographic obliteration was 10 months, during which time there was no intervention and no history of repeat hemorrhage; nor had hemorrhage recurred during the follow-up period (mean, 53 months). Most of the AVMs were deep (22/27) with only one draining vein (21/27) and few feeding arteries. In more than half the cases (15/27) drainage was exclusively into the superficial venous system. CONCLUSION: Spontaneous obliteration is rare (1.3%). Common features include hemorrhagic presentation and few arterial feeding vessels. Although we found no instance of repeat hemorrhage during the follow-up period, AVMs can recanalize, and follow-up is therefore recommended.
Adolescent↗
Multimodality MR imaging depiction of hemodynamic changes and cerebral ischemia in subarachnoid hemorrhage.
BACKGROUND AND PURPOSE: Subarachnoid hemorrhage (SAH) is a common and serious neurologic emergent condition. We tested the hypothesis that multimodality MR imaging depicts changes in cerebral blood flow SAH, before any surgical or endovascular intervention, and that the frequency of these changes increases with time after ictus. METHODS: We prospectively examined 37 patients with suspected SAH and three with symptoms of acute stroke but who subsequently had SAH. Routine CT and multimodality MR imaging were performed within 18 h of presentation. Standard MR imaging, diffusion-weighted MR imaging, time-of-flight MR angiography, and dynamic first-pass gadolinium-enhanced MR perfusion imaging were performed. Images were reviewed for abnormalities in cerebral blood flow, ischemia, and infarction. Nine patients did not have SAH at CT and CSF investigations. Of 31 patients with proved SAH, 13 were examined during the acute stage (within 4 d of ictus) and 18, during the subacute stage (4-14 d after ictus). RESULTS: MR imaging showed alteration in cerebral blood flow parameters in 16 of 31 patients before surgery or endovascular treatment. The frequency of blood flow changes and associated complications increased with worsening clinical grade and increasing time after ictus. CONCLUSION: Multimodality MR imaging provides information not available from CT in patients with SAH. MR imaging shows oligemic and ischemic areas in SAH before surgery or endovascular treatment. MR imaging is a simple noninvasive method of assessing cerebral blood flow and its complications in SAH. It can be performed in a clinical environment.
Adult↗
Effect of P-glycoprotein modulation with cyclosporin A on cerebrospinal fluid penetration of doxorubicin in non-human primates.
PURPOSE: P-glycoprotein (Pgp) is a transmembrane drug efflux pump that is expressed in multidrug-resistant cancer cells and in a variety of normal tissues, including brain capillary endothelial cells which comprise the blood-brain barrier. We studied the effects of the Pgp inhibitor, cyclosporin A (CsA), on the cerebrospinal fluid (CSF) penetration of the Pgp substrate, doxorubicin, in non-human primates. METHODS: The animals received doxorubicin alone (2.0 mg/kg i.v. over 60 min) or doxorubicin (1 mg/kg i.v. over 60 min) and CsA (loading dose 4.0 mg/kg i.v. over 2 h, followed by continuous infusion of 12 mg/kg per day over 48 h). Plasma and CSF were collected over 48 h and the doxorubicin concentration was measured by reverse-phase high-pressure liquid chromatography (HPLC) with fluorescence detection (detection limit 5 nM). A two-compartment model was fitted to the plasma concentration-time data. RESULTS: Pgp was demonstrated to be present in the epithelium of the choroid plexus by immunohistochemical methods, indicating that CSF drug penetration could be used as a surrogate for blood-brain barrier penetration. Steady state whole blood CsA concentrations, which were measured with a fluorescence-polarization immunoassay (TDX) that detects both CsA and its metabolites, ranged from 551-1315 microg/l at 24 h. The clearance of doxorubicin in four animals was reduced by 34%, 38%, 45% and 49% when given with CsA. The doxorubicin concentration in the CSF was <5 nM in all animals, both after doxorubicin alone and doxorubicin with CsA. CONCLUSIONS: The Pgp inhibitor, CsA, at a concentration that alters systemic clearance of doxorubicin, does not appear to significantly increase the CSF penetration of doxorubicin.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
Acute neuromedical and neurosurgical admissions. Standard and ultrafast MR imaging of the brain compared with cranial CT.
PURPOSE: To evaluate the role of standard and ultrafast MR brain imaging and compare the information with CT. MATERIAL AND METHODS: This was a prospective study of 114 patients with acute neurological symptoms and signs. CT brain examinations consisted of axial non-enhanced images. MR imaging consisted of standard spin-echo/fast spin-echo sequences and a series of rapid techniques including echoplanar and single shot fast spin-echo sequences. RESULTS: Using standard MR methods, 41% of the patients had all five sequences of good technical quality, while using ultrafast methods 81% of the patients had good technical quality examinations in all five sequences. In 3% of the cases, ischaemic stroke was incorrectly reported on CT. In 24% of the cases, MR gave extra diagnostic information not reported on CT and in a further 8%, one neuroradiologist reported the abnormality in agreement with the MR, whilst the other neuroradiologist reported the CT as normal. In 2 cases, subarachnoid haemorrhage was missed on MR. Subarachnoid haemorrhage was not shown on the ultrafast sequences. CONCLUSION: MR can be used to image acute neurological admissions with a high success rate, particularly using ultrafast methods. In many cases, MR provided extra information of direct clinical relevance not shown on CT.
Acute Disease↗
Blind loop syndrome. Diagnosis by In-111-labeled leukocyte scintigraphy.
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Blind Loop Syndrome↗
Subclavian and internal jugular veins at Doppler US: abnormal cardiac pulsatility and respiratory phasicity as a predictor of complete central occlusion.
In 21 consecutive patients, the authors analyzed changes in venous Doppler waveforms of damped or diminished cardiac pulsatility and respiratory phasicity. Each patient was suspected of having upper limb venous thrombosis, but thrombus was not visible at gray-scale ultrasonography (US) in the subclavian and brachiocephalic veins. US findings were compared with phlebographic findings. The results show that US can be used to establish the presence or absence of thrombosis in the distal portion of the brachiocephalic or subclavian veins, which are inaccessible to direct insonation.
Adult↗
Riedel's lobe of the liver: fact or fiction?
Riedel's lobe should be considered in all patients undergoing cross-sectional imaging. It may harbor a lesion that might not be demonstrated unless the most inferior aspect of the liver is imaged. We have tried to identify the prevalence of Riedel's lobe in a series of patients with normal abdominopelvic computed tomographic (CT) findings. We reviewed the digital CT data of 105 patients, ages 20-89 years, to define the position of the liver in relation to the costal margin and the iliac crest. There were no significant differences in the prevalence of Riedel's lobe between sexes. The proportion of individuals in whom the most caudal margin of the liver was inferior to the most caudal costal margin was age-dependent and increased to 65% in the 50-59 age group. The craniocaudal dimension of the liver decreased with age (P < 0.02). Riedel's lobe appears to be a common variant of normal anatomy, its prevalence being dependent on age-related changes in liver size and skeletal shape.
Adult↗
Radiology in the management of pleural disease.
This is a review of the role of radiological intervention in the pleural space. It discusses the radiological management of effusions, empyemas (including the use of fibrinolytic agents), pneumothoraces and pleural thickening.
Biopsy, Needle↗
Peripartum hypopituitarism and lymphocytic hypophysitis.
The classical cause of postpartum hypopituitarism is Sheehan's syndrome, in which an obstetric catastrophe is associated with hypotension. However, with improvements in obstetric care, the most common cause now may be lymphocytic hypophysitis. Five women with postpartum hypopituitarism, whose symptoms occurred during or immediately after pregnancy, had detailed endocrine and pituitary imaging for the duration of follow-up. Two presented with visual symptoms, and three with non-specific illnesses related to varying deficiencies of anterior pituitary hormones. Four were unable to lactate, and four were initially amenorrhoeic. Initially, four of the five women had enlarged pituitary glands on magnetic resonance imaging. Four have to some extent recovered pituitary function. One patient had associated thyroiditis: in two cases antinuclear antibodies became positive during follow-up, and in one of these dsDNA antibody was also detected. In no case were pituitary antibodies detected. None had complicated pregnancies or deliveries, and the two who had caesarean sections had no episodes of hypotension. The presentation of secondary hypothyroidism combined with ACTH deficiency in four of the five women strongly suggests lymphocytic hypophysitis. This diagnosis should be considered in postpartum women with general malaise and persistent amenorrhoea, as well as in women who develop visual impairment in the last trimester of pregnancy without antecedent pituitary disease. A conservative policy of management of the pituitary enlargement should be pursued as this resolves.
Adrenocorticotropic Hormone↗
Secondary hypoadrenalism with hypercalcaemia.
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Adrenal Insufficiency↗
Regional distribution study of brain perfusion and metabolic agents in normal and tumour bearing rat brains using autoradiographic technique.
Regional distribution of brain perfusion imaging agents, [131I]N,N,N'-trimethyl-N'-[2-hydroxy-3-methyl-5-iodobenzyl]1,3 propanediamine (HIPDM) and [131I]-N-isopropyl-p-iodoamphetamine (IMP), was compared with the distribution of patterns of [14C]L-methionine and [14C]D-glucose in normal and tumour bearing rat brains using autoradiographic technique. There was higher concentration of the radiopharmaceutical in grey than white matter in normal rat brain. Autoradiographs of brain tumour sections showed very low uptake of [131I]HIPDM and [131I]IMP as compared to normal brain tissue. There was moderate concentration of [14C]D-glucose and avid uptake of [14C]L-methionine in tumours. Autoradiographic study is useful for evaluating distribution patterns of radiopharmaceuticals.
Amphetamines↗
An online technique for estimating cerebral carbon dioxide reactivity.
A technique for measuring cerebral reactivity using transcranial pulsed Doppler ultrasound is described; the system includes a spectrum analyser and capnometer. Data acquisition and manipulation is under software control. Main stem middle cerebral artery blood velocity is monitored continuously using the transcranial Doppler technique, whilst the operator initiates data collection and controls the inspired gas composition. The calculation of cerebral CO2 reactivity is based upon linear regression analysis of normalized, time-averaged middle cerebral velocity on end-tidal pCO2 and is displayed graphically. Measurement of middle cerebral CO2 reactivities can be completed within 15 min. Results from two subjects, a healthy volunteer and a patient with occlusive disease, are shown to illustrate the technique.
Blood Flow Velocity↗