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Dlugi AM, Miller JD, Knittle J. Lupron depot (leuprolide acetate for depot suspension) in the treatment of endometriosis: a randomized, placebo-controlled, double-blind study. Lupron Study Group. Fertil Steril 1990; 54:419-27. [PMID: 2118858 DOI: 10.1016/s0015-0282(16)53755-8] [Citation(s) in RCA: 184] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The safety and efficacy of leuprolide acetate (LA) for depot suspension (Lupron depot; TAP Pharmaceuticals, North Chicago, IL), 3.75 mg versus placebo, in the treatment of pain associated with endometriosis was assessed in a randomized, double-blind, multicenter study involving 52 patients. Dysmenorrhea, pelvic pain, and pelvic tenderness all responded significantly to LA treatment in comparison with placebo. Menses were suppressed in all of the LA patients. Estradiol decreased significantly to menopausal levels in the LA group. There were small to moderate changes in a variety of laboratory parameters, but these were not clinically significant. The most common adverse event was vasodilatation, occurring significantly more frequently in the LA group. Lupron depot was shown to be safe and effective in inducing a hormonal and menstrual suppression in patients with endometriosis, resulting in alleviation of pain symptoms.
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Kilduff TS, Miller JD, Radeke CM, Sharp FR, Heller HC. 14C-2-deoxyglucose uptake in the ground squirrel brain during entrance to and arousal from hibernation. J Neurosci 1990; 10:2463-75. [PMID: 2376782 PMCID: PMC6570375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Neuronal activity underlying various phases of the mammalian hibernation cycle was investigated using the 14C-2-deoxyglucose (2DG) method. Relative 2DG uptake (R2DGU) values were computed for 96 brain regions across 7 phases of the hibernation cycle: euthermia, 3 body temperature (Tb) intervals during entrance into hibernation, stable deep hibernation, and 2 Tb intervals during arousal from hibernation. Multivariate statistical techniques were employed to identify objectively groups of brain regions whose R2DGU values showed a similar pattern across all phases of hibernation. Factor analysis revealed that most of the variability in R2DGU values for the 96 brain regions across the entire cycle could be accounted for by 3 principal factors. These factors could accurately discriminate the various phases of hibernation on the basis of the R2DGU values alone. Three hypothalamic and 3 cortical regions were identified as possibly mediating the entrance into hibernation because they underwent a change in R2DGU early in entrance into hibernation and loaded strongly on one of the principal factors. Another 4 hypothalamic regions were similarly identified as possibly causally involved in the arousal from hibernation. These results, coupled with characteristic changes in ordinal rank of the 96 brain regions in each phase of hibernation, support the concept that mammalian hibernation is an active, integrated orchestration of neurophysiological events rather than a state entered through a passive process.
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328
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Savard ME, Miller JD, Salleh B, Strange RN. Chlamydosporol, a new metabolite from Fusarium chlamydosporum. Mycopathologia 1990; 110:177-81. [PMID: 2388683 DOI: 10.1007/bf00437543] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Extracts of rice on which an isolate of Fusarium chlamydosporum had been cultured were toxic to brine shrimps. The toxic fraction was purified by flash chromatography to give two compounds which were identified by UV, IR, NMR and mass spectroscopy at the 6 alpha and 6 beta isomers of 5-hydroxy-4-methoxy-6,8a-dimethyl-6,7-dihydro-2H, 8aH-pyrano[2,3-b]pyran-2-one. These lactones for which the name chlamydosporol is proposed have not been reported previously. When tested in brine shrimp and HeLa cell assays, the LC50 concentration for a mixture of the isomers was approximately 400 micrograms/ml in both systems.
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Abstract
Between 1926-36 Norman Dott managed 39 patients with suspected intracranial haemorrhage. During this period he established important principles of diagnosis and developed new methods for the medical and surgical treatment of aneurysmal subarachnoid haemorrhage. Dott performed the first intracranial operation to treat an aneurysm and the first angiogram to demonstrate an intracranial aneurysm. This article reviews Dott's early experiences of aneurysmal subarachnoid haemorrhage.
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330
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Miller JD, Fuller CA. The response of suprachiasmatic neurons of the rat hypothalamus to photic and serotonergic stimulation. Brain Res 1990; 515:155-62. [PMID: 2357553 DOI: 10.1016/0006-8993(90)90590-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Single-unit activity of the rat suprachiasmatic nucleus and surrounding regions was recorded in vivo. Photically responsive neurons were typically inhibited by low intravenous doses of the serotonin (5-HT) agonist quipazine. The 5-HT antagonist, metergoline, administered in a low intravenous dose, reversed the effects of quipazine. The subsequent response to photic stimulation was essentially identical to the initial photic response. Thus the photic response of neurons in the suprachiasmatic nucleus (SCN) and adjacent regions is relatively uninfluenced by 5-HT blockade.
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331
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Whittle IR, MacPherson JS, Miller JD, Smyth JF. The disposition of TCNU (tauromustine) in human malignant glioma: pharmacokinetic studies and clinical implications. J Neurosurg 1990; 72:721-5. [PMID: 2157825 DOI: 10.3171/jns.1990.72.5.0721] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Tauromustine (TCNU), 130 mg/sq m, was administered intraoperatively by nasogastric tube to 10 patients with malignant glioma (seven glioblastomas and three anaplastic astrocytomas). High-performance liquid chromatography analysis of 32 tumor specimens for TCNU revealed that tissue concentrations ranged from 0 to 554 ng/gm: TCNU was not detected in necrotic regions of the tumor. Levels of TCNU in brain adjacent to tumor were similar to those recorded within the gliomas (range 0 to 635 ng/gm). The variability in the tissue level of TCNU was partly attributable to variable absorption of the drug, since peak plasma TCNU levels ranged from 164 to 3333 ng/ml. There were close quantitative and temporal relationships between the times of peak plasma levels (median 456 ng/ml at 45 minutes after administration), peak tumor levels (median 250 ng/gm tissue at 55 minutes), and brain adjacent to tumor levels (median 256 ng/gm tissue at 50 minutes). Linear regression analysis of the ratio between tissue and plasma TCNU levels at particular times after drug administration suggest that plasma concentrations can be used to estimate tissue concentrations. This study demonstrates that TCNU enters malignant glioma. In view of the activity of TCNU against a range of tumors, a full clinical evaluation of this new nitrosourea in malignant glioma seems justified.
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Johnston FG, Bell BA, Robertson IJ, Miller JD, Haliburn C, O'Shaughnessy D, Riddell AJ, O'Laoire SA. Effect of calcitonin-gene-related peptide on postoperative neurological deficits after subarachnoid haemorrhage. Lancet 1990; 335:869-72. [PMID: 1969982 DOI: 10.1016/0140-6736(90)90473-i] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
An infusion of calcitonin-gene-related peptide (CGRP) at progressively increased concentrations was given to 15 patients with neurological deficits after intracranial aneurysm surgery for subarachnoid haemorrhage. In 9 of the patients the deficits, quantified by a modified Glasgow coma scale, improved with no adverse effects; after a placebo infusion only 2 of the 15 patients showed improvement. If CGRP can reverse cerebral ischaemia after early intracranial aneurysm surgery, its use may improve the safety of such early surgery, remove the need for late surgery with its increased risk of death from rebleeding, and reduce overall morbidity and mortality of aneurysmal subarachnoid haemorrhage.
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334
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Rivlin ME, Miller JD, Krueger RP, Patel RB, Bower JD. Leuprolide acetate in the management of ureteral obstruction caused by endometriosis. Obstet Gynecol 1990; 75:532-6. [PMID: 2106110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Endometriotic ureteral obstruction is a serious event commonly diagnosed late and therefore associated with a major risk of hydronephrotic renal atrophy. The standard therapy is surgical. However, medical treatment has been reported using danazol, progestins, and estrogen-progestin combinations, although solid documentation of the effect of hormonal therapy against ureteral endometriosis is lacking. Gonadotropin-releasing hormone (GnRH) agonist treatment of endometriosis has yielded good results but has not been adequately reported in patients with ureteric involvement. We report three patients treated with a GnRH agonist, leuprolide acetate, for 6-9 months as a preoperative course. One patient had bilateral and two had unilateral obstruction. The preoperative course relieved the obstruction in the patient with bilateral disease and in one with unilateral changes. The failure occurred in a patient with intrinsic ureteric endometriosis. This early experience suggests a place for GnRH agonist therapy for patients with ureteric obstruction due to endometriosis, probably, but not necessarily, in conjunction with a planned surgical procedure. If medical therapy is attempted, close surveillance of renal function is mandatory.
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Miller JD, Faull KF, Bowersox SS, Dement WC. CNS monoamines and their metabolites in canine narcolepsy: a replication study. Brain Res 1990; 509:169-71. [PMID: 1689603 DOI: 10.1016/0006-8993(90)90328-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In two separate studies a significantly greater concentration of DA (dopamine) and its metabolite, DOPAC (3,4-dihydroxyphenylacetic acid), was observed in the amygdala of narcoleptic canines. DOPAC was also significantly elevated in the reticularis parvicellularis, whereas NE (norepinephrine) was significantly elevated in the reticularis oralis, but depressed in the preoptic hypothalamus. No changes were observed in concentrations of serotonin or its metabolite, 5-HIAA (5-hydroxyindoleauric acid) in any region in the narcoleptic canine brain. Results of the two studies were similar, except that previously observed differences between narcoleptic and control canines in DOPAC levels in the caudate and reticularis oralis failed to replicate. Thus, steady state measures of neurotransmitter/metabolite tissue concentrations suggest region-specific alterations in DA and NE metabolism, rather than a global deficit in catecholamine neurotransmission in canine narcolepsy.
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Abstract
Secondary pathophysiological insults occurring after injury have been prospectively assessed in 50 head-injured patients who required intrahospital transfer. 35 patients were transported from the intensive care unit (ICU) and 15 from the accident and emergency department. Physiological variables were recorded every minute in the four hours before transfer (ICU group only), during the move, and for four hours afterwards. Pretransfer insults were predictive of further insults during and after transport. There was significant correlation between increased frequency of insults post-transfer (compared with pre-transfer) and high injury severity score. A greater proportion of the patients transported from the emergency department had secondary injuries post-transfer. Adequate resuscitation before moving the patient, especially in patients with multiple injury, is important.
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Abstract
In the 14-year period from 1974-1987 during which CT scanning was available in Edinburgh, 36 patients with benign, non-tumour related aqueduct stenosis were identified from a group of 342 patients with hydrocephalus. In terms of age at presentation, the patients separate into two groups, 9 cases diagnosed during the first year of life and 27 patients aged from 7 to 72 years. The presentation in the early cases was fairly acute, the diagnosis was secure and the operative treatment by ventricular peritoneal shunt was relatively free of complications. In the older patients, the first presentation was more chronic, and further investigation required a change of diagnosis in 5 of the 27 patients. More than half of the patients had recurrent symptoms which were much more acute and operative treatment was attended by a significant number of complications including death from intraventricular haemorrhage in one case.
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340
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Weddell RA, Miller JD, Trevarthen C. Voluntary emotional facial expressions in patients with focal cerebral lesions. Neuropsychologia 1990; 28:49-60. [PMID: 1690362 DOI: 10.1016/0028-3932(90)90085-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This study investigates the voluntary production of emotional facial expressions in 43 brain-damaged and 9 control subjects. The expressions of right- and left-hemisphere lesion groups did not differ significantly, but those of the anterior lesion group were impoverished relative to the posterior lesion and control groups. Deficits of voluntary expression were dissociable from impairments in "non-emotional" facial-motor functions, dysphasia, and unilateral neglect.
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341
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Piper IR, Miller JD, Whittle IR, Lawson A. Automated time-averaged analysis of craniospinal compliance (short pulse response). ACTA NEUROCHIRURGICA. SUPPLEMENTUM 1990; 51:387-90. [PMID: 2128580 DOI: 10.1007/978-3-7091-9115-6_130] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We have developed an automated method [Short Pulse Response (SPR)] of measuring craniospinal compliance using an electronic square wave pressure generator to produce a small (0.05 ml) and reproducible transient volume increase in the CSF space (pulse duration 100 msec). In experimental models of intracranial hypertension, arterial hypertension, arterial hypotension and arterial hypercarbia in cats, the new method accurately followed physiological changes in compliance when compared to the manual volume-pressure injection method. The VPR overestimated compliance compared to the new SPR method (by 20% to 162%, mean = 77%). The SPR method was less variable between sequential measurements with a coefficient of variation (CV) ranging from 0.6% to 9.6% (mean CV = 2.6%), compared with a CV ranging from 5.6% to 48% (mean CV = 17%) for the VPR method. Repeated compliance measurements by the new method over a 12 hour period, produced no neuropathological evidence of either blood brain barrier breakdown or tissue damage resulting from the repeated volume injections.
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342
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Limpus CJ, Miller JD. The Use of Measured Scutes of Hawksbill Turtles, Eretmochelys-Imbricata, in the Management of the Tortoiseshell (Bekko) Trade. WILDLIFE RESEARCH 1990. [DOI: 10.1071/wr9900633] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A strong positive correlation is demonstrated between the size of selected carapacial scutes (costal 1, vertebral 1 and vertebral 5) and the curved carapace length of hawksbill turtles (Eretmochelys imbricata). A count of any one of these distinctive scute types, and the measurement of these scutes, can be used to determine the number and size class distribution of E. imbricata represented in consignments of raw tortoiseshell.
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343
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Whittle IR, Piper IR, Miller JD. The contribution of secondary mediators to the etiology and pathophysiology of brain oedema: studies using a feline infusion oedema model. ACTA NEUROCHIRURGICA. SUPPLEMENTUM 1990; 51:71-3. [PMID: 2128586 DOI: 10.1007/978-3-7091-9115-6_24] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Secondary mediator compounds are postulated to have a role in vasogenic oedematogenesis. They may also cause focal brain dysfunction due to their neuronal, axonal and glial modulating properties. Using the feline model of infusion brain oedema the effects of right frontal intracerebral infusion (200 microliters/hr for 3 hrs) of saline, bradykinin (10(-4) to 10(-6) M), arachidonic acid (10(-2) to 10(-3) M), 20% protein and four human glioma cyst fluids were evaluated. Somatosensory evoked potentials (SSEP), motor evoked potentials (MEPs), rCBF and rCBF CO2 reactivity (Hydrogen clearance). ICP, craniospinal compliance, local brain tissue water content (microgravimety), brain histology and BBB function (Evans Blue 2%) were measured. Brain water content increased locally from 69% to 79%, ICP increased (by mean 14 mmHg) and compliance decreased (mean 70%) and there were the histological features of brain oedema with all infusates. BBB opening occurred with Bradykinin (+), arachidonic acid (++), 20% protein ( ) and glioma cyst fluid (4+). Polymorphic and macrophage infiltrates were seen with all infusions but rCBF and MEPs remained normal. SSEPs changed with high dose bradykinin and some glioma cyst infusates whilst CBF CO2 reactivity was locally impaired by all infusates except saline and arachidonic acid. This study suggests that certain compounds in brain oedema fluid could mediate local brain dysfunction.
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Miller JD, Pattisapu JV. Disseminated intravascular coagulation associated with spinal cord laceration: a case report. THE JOURNAL OF TRAUMA 1989; 29:1178-9. [PMID: 2760960 DOI: 10.1097/00005373-198908000-00019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A 31-year-old man was thrown from his motorcycle, sustaining a thoracolumbar fracture and cervical spine fracture with no evidence of neurologic function below L1. At the time of spinal fusion, there was diffuse bleeding from the soft tissues. Visualization of the thoracolumbar fraction revealed separation of the laminae with a dural tear and extruding spinal cord tissue. Laboratory evaluation identified abnormal clotting studies intraoperatively and postoperatively. We postulate that release of potent spinal cord thromboplastins into the systemic circulation may elicit a coagulopathy, as has been recognized following craniocerebral trauma.
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de Leon MJ, George AE, Reisberg B, Ferris SH, Kluger A, Stylopoulos LA, Miller JD, La Regina ME, Chen C, Cohen J. Alzheimer's disease: longitudinal CT studies of ventricular change. AJR Am J Roentgenol 1989; 152:1257-62. [PMID: 2785749 DOI: 10.2214/ajr.152.6.1257] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A 3-year longitudinal study was conducted with 50 Alzheimer's disease patients and 45 elderly control subjects. All study participants received an extensive evaluation that included brain CT at baseline and follow-up. Quantitation of ventricular size, using both linear and volume methods, revealed highly significant cross-sectional and longitudinal differences between the Alzheimer patients and control subjects. Specifically, the annual rate of change in ventricular volume was approximately 9% in the Alzheimer patients and approximately 2% in the controls. The presence of age-related white matter lesions had no effect on the clinical course of the patients or on the changes in ventricular size. Among the Alzheimer patients, the rate of clinical decline was strongly related to the rate of change in ventricular size. Baseline ventricular measurements were of no value in predicting the subsequent rate of clinical deterioration or ventricular enlargement. The results suggest that changes in ventricular size closely reflect the clinical changes in Alzheimer patients.
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Swierkosz EM, Flanders R, Melvin L, Miller JD, Kline MW. Evaluation of the Abbott TESTPACK RSV enzyme immunoassay for detection of respiratory syncytial virus in nasopharyngeal swab specimens. J Clin Microbiol 1989; 27:1151-4. [PMID: 2666434 PMCID: PMC267517 DOI: 10.1128/jcm.27.6.1151-1154.1989] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The Abbott TESTPACK RSV assay (Abbott Laboratories, North Chicago, Ill.), a rapid (20-min) enzyme immunoassay, was compared with culture and direct immunofluorescence (DFA) of nasopharyngeal cells for the detection of respiratory syncytial virus (RSV) in nasopharyngeal swab specimens. Nasopharyngeal swab specimens, collected from 234 infants, were placed in viral transport medium. Portions of specimen in transport medium were used for each test. Of 234 specimens, 70 (30%) were culture positive, 103 (44%) were DFA positive, 107 (46%) were culture or DFA positive, and 112 (48%) were TESTPACK RSV positive. Of 19 specimens positive by TESTPACK RSV but negative by culture or DFA, 15 were positive by the blocking assay. A total of 122 specimens were culture, DFA, or blocking assay positive; TESTPACK RSV detected 108 specimens (sensitivity, 89%). The specificity, positive predictive value, and negative predictive value of TESTPACK RSV as compared with those of culture, DFA, and the blocking assay were 96, 96, and 89%, respectively. By comparison, the sensitivity, specificity, positive predictive value, and negative predictive value of combined culture and DFA were 88, 100, 100, and 88%, respectively. TESTPACK RSV is a rapid and reliable enzyme immunoassay for the direct detection of RSV antigen in nasopharyngeal swab specimens.
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348
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Todd NV, Tocher JL, Jones PA, Miller JD. Outcome following aneurysm wrapping: a 10-year follow-up review of clipped and wrapped aneurysms. J Neurosurg 1989; 70:841-6. [PMID: 2715810 DOI: 10.3171/jns.1989.70.6.0841] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
One hundred and eighty-one patients with single aneurysms involving the anterior circulation were treated either by wrapping (60 cases) or clipping (121 cases), and 96.1% of them were followed for 10 years. The rate of early rebleeding (less than 6 months) from wrapped aneurysms was 8.6% (confidence interval 1.4% to 15.8%) and the late rebleeding (6 months to 10 years) rate was 1.5% per annum (confidence interval 0.3% to 2.5%/yr). Wrapping an aneurysm offers some protection from rebleeding, particularly during the first 6 months when the risk of rebleeding is high.
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349
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Miller JD. GnRH analog delivery systems: present and future options. Obstet Gynecol Surv 1989; 44:326-9. [PMID: 2726104 DOI: 10.1097/00006254-198905000-00009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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350
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Miller JD. Auditory-perceptual interpretation of the vowel. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 1989; 85:2114-2134. [PMID: 2659639 DOI: 10.1121/1.397862] [Citation(s) in RCA: 92] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The major issues in relating acoustic waveforms of spoken vowels to perceived vowel categories are presented and discussed in terms of the author's auditory-perceptual theory of phonetic recognition. A brief historical review of formant-ratio theory is presented, as well as an analysis of frequency scales that have been proposed for description of the vowel. It is illustrated that the monophthongal vowel sounds of American English can be represented as clustered in perceptual target zones within a three-dimensional auditory-perceptual space (APS), and it is shown that preliminary versions of these target zones segregate a corpus of vowels of American English with 93% accuracy. Furthermore, it is shown that the nonretroflex vowels of American English fall within a narrow slab within the APS, with spread vowels near the front of this slab and rounded vowels near the back. Retroflex vowels fall in a distinct region behind the vowel slab. Descriptions of the vowels within the APS are shown to be correlated with their descriptions in terms of dimensions of articulation and timbre. Additionally, issues related to talker normalization, coarticulation effects, segmentation, pitch, transposition, and diphthongization are discussed.
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