A rare case of pancreatic head hydatid cyst.

Hydatidosis or Echinococcosis is a parasitic disease caused by infection with the larval stage of Echinococcus granulosus. Primary isolated pancreatic hydatidosis is very rare even in countries where echinococcosis disease is highly endemic. The objective of this case report is to highlight this unusual and rare hydatid cyst presentation to avoid incorrect diagnosis and management. In our case, preoperative evaluation guided the diagnosis toward cystic pancreatic neoplasms, leading us to contemplate a radical surgical approach (Pancreaticoduodenectomy). Pancreatic hydatid cysts can be confused with cystic pancreatic neoplasms, it should always be considered as a differential diagnosis in endemic areas, to prevent misdiagnosis and inappropriate management.

Fatigue-independent alterations in muscle activation and effort perception during forearm exercise: role of local oxygen delivery.

The oxygen-conforming response (OCR) of skeletal muscle refers to a downregulation of muscle force for a given muscle activation when oxygen delivery (O2D) is reduced, which is rapidly reversed when O2D is restored. We tested the hypothesis that the OCR exists in voluntary human exercise and results in compensatory changes in muscle activation to maintain force output, thereby altering perception of effort. In eight men and eight women, electromyography (EMG), oxyhemoglobin (O2Hb) and deoxyhemoglobin (HHb), forearm blood flow (FBF), and task effort awareness (TEA) were measured. Participants completed two nonfatiguing rhythmic handgrip tests consisting of 5-min steady state (SS) followed by two bouts of 2-min brachial artery compression to reduce FBF by ~50% of SS (C1 and C2), separated by 2 min of no compression (NC1) and ending with 2 min of no compression (NC2). When FBF was compromised during C1, EMG/Force (1.58 ± 0.39) increased compared with SS (1.31 ± 0.33, P = 0.001). However, EMG/Force was not restored upon FBF restoration at NC1 (1.48 ± 0.38, P = 0.479), consistent with C1 evoking skeletal muscle fatigue. When FBF was compromised during C2, EMG/Force increased (1.73 ± 0.50) compared with NC1 (1.48 ± 0.38, P = 0.013). EMG/Force returned to NC1 levels during NC2 (1.50 ± 0.39, P = 0.016), consistent with an OCR in C2. TEA (SS 2.2 ± 2.3, C1 3.9 ± 2.5, NC1 3.4 ± 2.7, C2 4.6 ± 2.7, NC2 3.9 ± 2.8) mirrored changes in EMG. It is noteworthy that during the second compromise and then restoration of muscle oxygenation EMG and TEA were rapidly restored to precompromise levels. We interpreted these findings to support the existence of an OCR and its ability to rapidly modify perception of effort during voluntary exercise. NEW & NOTEWORTHY In healthy individuals, when force output is maintained during rhythmic handgrip exercise, muscle activation and perception of effort rapidly increase with compromised muscle oxygen delivery (O2D) and then return to precompromised levels when muscle O2D is restored. These findings suggest that an oxygen-conforming response (OCR) exists and is able to modify perception of effort during voluntary exercise. Therefore, similar to fatigue, an OCR may have implications for exercise tolerance.

Risk factors associated with major cerebrovascular complications after intracranial stenting.

BACKGROUND: There are limited data on the relationship between patient and site characteristics and clinical outcomes after intracranial stenting. METHODS: We performed a multivariable analysis that correlated patient and site characteristics with the occurrence of the primary endpoint (any stroke or death within 30 days of stenting or stroke in the territory of the stented artery beyond 30 days) in 160 patients enrolled in this stenting registry. All patients presented with an ischemic stroke, TIA, or other cerebral ischemic event (e.g., vertebrobasilar insufficiency) in the territory of a suspected 50-99% stenosis of a major intracranial artery while on antithrombotic therapy. RESULTS: Cerebral angiography confirmed that 99% (158/160) of patients had a 50-99% stenosis. In multivariable analysis, the primary endpoint was associated with posterior circulation stenosis (vs anterior circulation) (hazard ratio [HR] 3.4, 95% confidence interval [CI] 1.2-9.3, p = 0.018), stenting at low enrollment sites (< 10 patients each) (vs high enrollment site) (HR 2.8, 95% CI 1.1-7.6, p = 0.038), < or = 10 days from qualifying event to stenting (vs > or = 10 days) (HR 2.7, 95% CI 1.0-7.8, p = 0.058), and stroke as a qualifying event (vs TIA/other) (HR 3.2, 95% CI 0.9-11.2, p = 0.064). There was no significant difference in the primary endpoint based on age, gender, race, or percent stenosis (50-69% vs 70-99%). CONCLUSIONS: Major cerebrovascular complications after intracranial stenting may be associated with posterior circulation stenosis, low volume sites, stenting soon after a qualifying event, and stroke as the qualifying event. These factors will need to be monitored in future trials of intracranial stenting.

Racial differences in idiopathic intracranial hypertension.

OBJECTIVE: To evaluate racial differences in idiopathic intracranial hypertension (IIH). METHODS: Medical records of all consecutive patients with definite IIH seen between 1989 and 2006 were reviewed. Demographics, associated factors, and visual function at presentation and follow-up were collected. Black patients were compared to non-black patients. RESULTS: We included 450 patients (197 black, 253 non-black). Obesity, systemic hypertension, anemia, and sleep apnea were more common in black patients than in non-black patients (p

The NIH registry on use of the Wingspan stent for symptomatic 70-99% intracranial arterial stenosis.

BACKGROUND: The Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial showed that patients with symptomatic 70% to 99% intracranial arterial stenosis are at particularly high risk of ipsilateral stroke on medical therapy: 18% at 1 year (95% CI = 3% to 24%). The Wingspan intracranial stent is another therapeutic option but there are limited data on the technical success of stenting and outcome of patients with 70% to 99% stenosis treated with a Wingspan stent. METHODS: Sixteen medical centers enrolled consecutive patients treated with a Wingspan stent in this registry between November 2005 and October 2006. Data on stenting indication, severity of stenosis, technical success (stent placement across the target lesion with <50% residual stenosis), follow-up angiography, and outcome were collected. RESULTS: A total of 129 patients with symptomatic 70% to 99% intracranial stenosis were enrolled. The technical success rate was 96.7%. The mean pre and post-stent stenoses were 82% and 20%. The frequency of any stroke, intracerebral hemorrhage, or death within 30 days or ipsilateral stroke beyond 30 days was 14.0% at 6 months (95% CI = 8.7% to 22.1%). The frequency of >or=50% restenosis on follow-up angiography was 13/52 (25%). CONCLUSION: The use of a Wingspan stent in patients with severe intracranial stenosis is relatively safe with high rate of technical success with moderately high rate of restenosis. Comparison of the event rates in high-risk patients in Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) vs this registry do not rule out either that stenting could be associated with a substantial relative risk reduction (e.g., 50%) or has no advantage compared with medical therapy. A randomized trial comparing stenting with medical therapy is needed.

Long-term results of primary transpupillary thermal therapy for the treatment of choroidal malignant melanoma.

BACKGROUND/AIMS: This is a long-term follow-up report investigating primary transpupillary thermal therapy (TTT) for choroidal melanoma. METHODS: Retrospective case series of 135 patients harbouring choroidal melanoma treated with primary TTT. Patient demographics, tumour characteristics, treatment responses and complications, visual acuity outcomes and mortality data were captured and reported. A statistical analysis was performed for predictors of treatment failure. RESULTS: Successful tumour regression was achieved in 76% of patients. Of the 32 patients who failed, 12 had enucleation, and 20 had irradiation. Metastatic disease has occurred in three patients, and two patients have died (3/135, or 2%). Multivariate analysis determined that tumour diameter, tumour thickness greater than 3 mm and tumours exhibiting high-risk characteristics were significant predictors of failure. Patient age, gender, number of treatments and proximity of the tumour to the disc or fovea were not predictive of failure. Kaplan-Meier cumulative probability predicted a 19% 5-year treatment failure and 33% 10-year treatment failure. Treatment failure occurred as late as 99 months. Final visual acuity was 20/40 or better in 50% of patients; 32% had a final visual acuity of 20/200 or worse. Thirty-two per cent of patients developed one or more complications as a result of the TTT, the most concerning of which was intra- or extrascleral extension of tumour (occurring in 11 patients). CONCLUSIONS: Though not as successful as radiation therapy, TTT successfully induced regression in 76% of patients. TTT may still have a role in our treatment paradigm but should probably be reserved for specific cases, such as monocular patients with tumours near critical visual structures, surgically unstable patients or patients with advanced diabetic retinopathy. All patients considering TTT as monotherapy for choroidal melanoma must be selected, counselled and followed appropriately.

The "sunglasses sign" predicts nonorganic visual loss in neuro-ophthalmologic practice.

OBJECTIVE: The aim of our study was to evaluate whether wearing sunglasses (the "sunglasses sign") can be used by neuro-ophthalmologists to predict nonorganic visual loss (NOVL) in their patients. METHODS: We prospectively collected information on all new patients seen by us over 13 months. We included all patients who ultimately received a diagnosis of NOVL, and all patients wearing sunglasses in our clinic. We recorded demographics, iris color, number of positive review of systems, ocular examination, precipitating event or trauma, workers' compensation claims, disability and lawsuit related to the visual loss, and the reason for wearing sunglasses. RESULTS: Among the 1,377 consecutive new patients seen in our clinic during the study, 34 patients wore sunglasses, among whom 7 (20.6%) had organic visual loss. During the study period, 59 patients were diagnosed with NOVL, among whom 27 (45.8%) wore sunglasses. The sensitivity of wearing sunglasses for NOVL was 0.46 (95% CI 0.33 to 0.59). The probability that a patient walking into our clinic had NOVL was 0.043 (95% CI 0.033 to 0.055); it increased to 0.79 (95% CI 0.62 to 0.91) in sunglasses patients. The specificity of sunglasses for the diagnosis of NOVL was 0.995 (95% CI 0.989 to 0.998). At least one of the following characteristics (highly positive review of systems, workers' compensation claim, disability, and lawsuit) was found in 26 of 27 (96.3%) of NOVL patients wearing sunglasses and in none of the sunglasses patients with organic neuro-ophthalmic disorders. All 7 sunglasses patients with organic neuro-ophthalmic disorders had reasonable ophthalmic explanations for wearing sunglasses. CONCLUSION: The "sunglasses sign" in a patient without an obvious ophthalmic reason to wear sunglasses is highly suggestive of nonorganic visual loss.

Risk factor status and vascular events in patients with symptomatic intracranial stenosis.

BACKGROUND: There are limited data on the relationship between control of vascular risk factors and vascular events in patients with symptomatic intracranial arterial stenosis. METHODS: We utilized the Warfarin Aspirin Symptomatic Intracranial Disease study database to analyze vascular and lifestyle risk factors at baseline and averaged over the course of the trial. Cutoff levels defining good control for each factor were prespecified based on national guidelines. Endpoints evaluated included 1) ischemic stroke, myocardial infarction, or vascular death or 2) ischemic stroke alone. Univariate associations were assessed using the log-rank test and multivariable analysis was done using Cox proportional hazards regression. RESULTS: From baseline until year 2 follow-up, there was not a significant improvement in blood pressure control. During the same period, there were improvements in patients with total cholesterol <200 mg/dL (54.6% to 79.2%, p < 0.001) or low-density lipoprotein <100 mg/dL (28.7% to 55.9%, p < 0.001). Multivariable analysis showed that systolic blood pressure >or=140 mm Hg (HR = 1.79, p = 0.0009, 95% confidence limits 1.27 to 2.52), no alcohol consumption (HR 1.69, 1.21 to 2.39, p = 0.002), and cholesterol >or=200 mg/dL (HR 1.44, 1.004 to 2.07, p = 0.048) were associated with an increased risk of stroke, myocardial infarction, or vascular death. The same risk factors were predictors of ischemic stroke alone in multivariable analysis. CONCLUSIONS: Elevated blood pressure and cholesterol levels in symptomatic patients with intracranial stenosis are associated with an increased risk of stroke and other major vascular events.

Warfarin vs aspirin for symptomatic intracranial stenosis: subgroup analyses from WASID.

The WASID trial showed no advantage of warfarin over aspirin for preventing the primary endpoint of ischemic stroke, brain hemorrhage, or vascular death. In analyses of selected subgroups, there was no definite benefit from warfarin. Warfarin reduced the risk of the primary endpoint among patients with basilar artery stenosis, but there was no reduction in stroke in the basilar artery territory or benefit for vertebral artery stenosis or posterior circulation disease in general.

Natural history of homonymous hemianopia.

OBJECTIVE: To describe the characteristics of spontaneous recovery of homonymous hemianopia (HH). METHODS: The authors reviewed medical records of all patients with HH confirmed by formal visual field testing and seen in follow-up in their service between 1989 and 2004. Clinical characteristics, causes, neuroradiologic definition of lesion location, final outcome, and evolution of the visual field defects were recorded. The associations among final visual field defect outcome, time from injury, and clinical features were analyzed. RESULTS: A total of 254 patients with 263 HH were included in this study. Spontaneous visual field defect recovery was observed in 101 HH (38.4%). The likelihood of spontaneous recovery decreased with increasing time from injury to initial visual field testing (p = 0.0003). The probability of improvement was related to the time since injury (p = 0.0003) with a 50 to 60% chance of improvement for cases tested within 1 month after injury that decreased to about 20% for cases tested at 6 months after surgery. No other factor was found to correlate with the final outcome of the visual field defects. Improvement after 6 months from injury was mild and usually related to improvement of the underlying disease. CONCLUSION: Spontaneous improvement of homonymous hemianopia is seen in at least 50% of patients first seen within 1 month of injury. In most cases, the improvement occurs within the first 3 months from injury. Spontaneous improvement after 6 months postinjury should be interpreted with caution as it is most likely related to improvement of the underlying disease or to improvement in the patient's ability to perform visual field testing reliably.

Homonymous hemianopias: clinical-anatomic correlations in 904 cases.

OBJECTIVE: To describe the clinical characteristics and clinical-anatomic correlations of homonymous hemianopia (HH). BACKGROUND: Homonymous hemianopia impairs visual function and frequently precludes driving. Most knowledge of HH is based on relatively few cases with clinical-anatomic correlations. METHODS: The authors reviewed medical records of all patients with HH seen in their service between 1989 and 2004. Demographic characteristics, characteristics of visual field defects, causes of visual field defects, neuroradiologic definition of lesion location, and associated neurologic deficits were recorded. RESULTS: A total of 904 HH were found in 852 patients. A total of 340 HH (37.6%) were complete and 564 HH (62.4%) were incomplete. Homonymous quadrantanopia (264 HH, 29%) was the most common type of incomplete HH, followed by homonymous scotomatous defects (116 HH, 13.5%), partial HH (114 HH, 13%), and HH with macular sparing (66 HH, 7%). A total of 407 HH (45.0%) were isolated. Causes of HH included stroke (629 HH, 69.6%), trauma (123, 13.6%), tumor (102, 11.3%), brain surgery (22, 2.4%), demyelination (13, 1.4%), other rare causes (13, 1.4%), and unknown etiology (2, 0.2%). The lesions were most commonly located in the occipital lobes (45%) and the optic radiations (32.2%). Every type of HH, except for unilateral loss of temporal crescent and homonymous sectoranopia, was found in all lesion locations along the retrochiasmal visual pathways. CONCLUSION: Homonymous hemianopia is usually secondary to stroke, head trauma, and tumors. Although the characteristics of visual field defects can be helpful in lesion location, specific visual field defects do not always indicate specific brain locations.

Longitudinal changes in the spherical equivalent refractive error of children with accommodative esotropia.

AIM: To assess the longitudinal changes in the spherical equivalent (SE) refractive errors of children with accommodative esotropia as a function of the age when glasses were prescribed. METHODS: Refractive errors were followed longitudinally for 126 children with accommodative esotropia for a mean of 4.4 (SD 2.5) years. Cycloplegic refractions were performed using an autorefractor for older children and retinoscopy for younger children. The refractive data were analysed for three groups of children based on their age at the time spectacles were prescribed. RESULTS: The initial SE refractive error was age dependent (<2 years, 5.1 (1.9) D; 2-<4 years, 4.2 (1.9) D; 4-8 years, 3.8 (1.7) D). Children in all age groups had an initial increase in their SE refractive error, followed by a later decrease; however, the greatest decrease occurred in the patients in the oldest age group. The SE refractive error peaked 1 year after spectacles were prescribed for the children 4-8 years of age versus 6 years after spectacles were prescribed for the children less than 2 years of age. CONCLUSION: Longitudinal changes in SE refractive error for children with accommodative esotropia vary as a function of their age when spectacle wear is initiated.

Autonomic dysfunction in Parkinson's disease: a comprehensive symptom survey.

BACKGROUND: Autonomic dysfunction occurs in Parkinson's disease (PD), but few studies have addressed it in a comprehensive manner. METHODS: Autonomic symptoms were evaluated by a questionnaire in sixty-eight subjects (44 patients and 24 controls). RESULTS: PD patients experienced higher frequency and severity of autonomic dysfunction. When all autonomic symptoms were pooled into an aggregate score, differences between patients and controls were highly statistically significant (p<0.0001). 'Increased salivation', 'frequency of dysphagia', decreased 'BM (bowel movement) frequency', i.e. constipation, and 'orthostatic dizziness' were more frequent in PD patients (p<0.05). A prediction model to determine the predictors of autonomic dysfunction was unsuccessful. CONCLUSION: Differences in the prevalence of autonomic symptoms in PD and non-parkinsonian controls are apparent from this study.

Neuro-ophthalmic manifestations of head trauma.

OBJECTIVE: To describe the neuro-ophthalmic findings in a group of patients with head trauma. MATERIALS AND METHODS: A retrospective chart review of all patients given a diagnosis code of head trauma in the neuroophthalmology unit at Emory University between 1991 and 1999. RESULTS: A total of 326 consecutive patients were reviewed (203 [63%] men and 123 [37.0%] women). Age ranged from 2 to 86 years, with a mean of 30 years. Motor vehicle accident was the most common cause of head trauma, occurring in 195 (59.8%) patients. An abnormal neuro-ophthalmic examination was noted in 185 of 326 patients (56.7%). Loss of consciousness was not associated with any outcome, but the presence of a neuroimaging abnormality, particularly intracranial hemorrhage, was significantly associated with specific neuroophthalmic deficits. CONCLUSIONS: Head trauma causes a number of neuroophthalmic manifestations. The afferent and efferent pathways are vulnerable to traumatic injury, although the efferent system is more commonly affected. Loss of consciousness may not be a reliable predictor of specific neuro-ophthalmic outcomes, but neuroimaging abnormalities may.

Stages of improvement in visual fields after pituitary tumor resection.

PURPOSE: To use static threshold perimetry to examine the stages of improvement and the potential for late improvement of visual fields after surgical resection of pituitary adenomas causing visual loss from compression of the anterior visual pathways. METHODS: Retrospective review of charts of patients with pituitary tumors and abnormal static threshold perimetry before or soon after treatment who had subsequent visual fields. Quantification of the visual field mean deviation overall, superotemporally, and inferotemporally was performed and compared between visits. Postoperative visits were considered in five time periods: visit 1 (surgery to 1 week), visit 2 (1 month to 4 months), visit 3 (6 months to 1 year), visit 4 (2 years), and visit 5 (3 or more years). RESULTS: Sixty-two patients were included (33 men and 29 women; mean age 54 years [SD +/- 15 years; range, 22 to 83 years]). At visit 1, the relative improvement of the overall mean deviation for the right eye was 30.8% (P =.01) and for the left eye was 13.7% (P =.3067). At visit 2, the relative improvement of the overall mean deviation for the right eye was 30. 4% (P =.0142) and for the left eye was 32.6% (P =.0092). At visits 1 and 2, the inferotemporal quadrants were the quadrants with greatest improvement (visit 1, right eye, 37.8% [P =.0082]; visit 2, left eye, 30.8% [P =.0074]). At visits 3, 4, and 5, an overall trend toward mild improvement was observed with statistical significance only for the inferotemporal quadrant of the left eye from visit 2 to visit 3, which improved 19.7% (P =.0270). CONCLUSION: The pattern of recovery of visual function after decompression of the anterior visual pathways suggests at least three phases of improvement. The early fast phase (surgery to 1 week) of improvement may lead to normalization of visual fields in some individuals. The early slow phase (1 month to 4 months) is the period of most notable improvement. A late phase (6 months to 3 years) of mild improvement does not appear significant overall but may be marked in some individuals. Each of these phases may have one or more mechanisms underlying the observed improvement.

Long-term surgical and visual outcomes in primary congenital glaucoma: 360 degrees trabeculotomy versus goniotomy.

PURPOSE: To compare the visual outcome and refractive status of children with primary congenital glaucoma who underwent 360 degrees trabeculotomy or goniotomy as an initial surgical procedure. METHODS: This retrospective study describes 24 eyes (15 patients) with primary congenital glaucoma that underwent 360 degrees trabeculotomy as the initial procedure and 40 eyes (23 patients) that underwent goniotomy as the initial procedure. Inclusion criteria were: (1) diagnosis of primary congenital glaucoma and initial angle surgery before 1 year of age, (2) no other ocular or systemic diseases, (3) 360 degrees trabeculotomy or goniotomy as the first surgical procedure, and (4) ability to obtain an Allen or Snellen visual acuity. A postoperative vision of 20/50 or better was considered good. Surgical success was defined as an intraocular pressure (IOP) less than 22 mm Hg with or without medication and without evidence of a progressive optic neuropathy. RESULTS: The IOP was successfully controlled in 92% of eyes in the trabeculotomy group and in 58% of eyes in the goniotomy group (P =.004). Of eyes in the trabeculotomy group, 79% had vision of 20/50 or better compared with 53% in the goniotomy group (P =.03). High myopia was more prevalent in the goniotomy group, but this difference was not statistically significant (P =.16). A poor visual outcome was associated with failure of the angle surgery or poor compliance with follow-up and amblyopia therapy. CONCLUSION: For primary congenital glaucoma, 360 degrees trabeculotomy is a highly effective procedure that results in excellent pressure control and is at least as successful as multiple standard procedures. In this study, 360 degrees trabeculotomy resulted in better vision than what is reported in the literature for standard angle procedures.

Neoadjuvant interferon alfa-2b treatment in a murine model for metastatic ocular melanoma: a preliminary study.

OBJECTIVES: To investigate the treatment of metastasis from uveal melanoma and to test the effect of interferon (IFN) alfa-2b in a murine model. METHODS: The B16-LS9 tissue culture melanoma cells were inoculated into the posterior intraocular compartment of 3 groups of C57BL/6 mice. The inoculated eyes were enucleated at 9 days and the mice were euthanized at 26 days after inoculation; the site and number of metastases were determined using standard histologic techniques. Group 1 was the control group; group 2 was given 20,000 international units (IU) of IFN alfa-2b intramuscularly 12 hours before enucleation, and group 3 received daily injections of 20,000 IU of IFN alfa-2b intramuscularly starting 4 days before enucleation. RESULTS: Pulmonary metastases were detected in 57%, 33%, and 0% of groups 1, 2, and 3, respectively; hepatic micrometastases were detected only in group 1. These results showed a significant decrease in hepatic metastases in mice receiving IFN alfa-2b vs controls (P =.005). CONCLUSION: Treatment with IFN alfa-2b results in decreased hepatic metastases from intraocular melanoma in a murine model. Arch Ophthalmol. 2000;118:1085-1089

A standardized method for measuring intracranial arterial stenosis.

BACKGROUND AND PURPOSE: Atherosclerosis of the major intracranial arteries is an important cause of ischemic stroke. We established measurement criteria to assess percent stenosis of a major intracranial artery (carotid, middle cerebral, vertebral, basilar) and determined the interobserver/intraobserver agreements and interclass/intraclass correlations of these measurements. METHODS: We defined percent stenosis of an intracranial artery as follows: percent stenosis = [(1 - (D(stenosis)/D(normal)))] x 100, where D(stenosis) = the diameter of the artery at the site of the most severe stenosis and D(normal) = the diameter of the proximal normal artery. If the proximal segment was diseased, contingency sites were chosen to measure D(normal): distal artery (second choice), feeding artery (third choice). Using a hand-held digital caliper, three neuroradiologists independently measured D(stenosis) and D(normal) of 24 stenotic intracranial arteries. Each observer repeated the readings 4 weeks later. We determined how frequently two observers' measurements of percent stenosis of each of the 24 diseased arteries differed by 10% or less. RESULTS: Among the three pairs of observers, interobserver agreements were 88% (observer 1 versus observer 2), 79% (observer 1 versus observer 3), 75% (observer 2 versus observer 3) for the first reading and were 75% (observer 1 versus observer 2), 100% (observer 1 versus observer 3), and 71% (observer 2 versus observer 3) for the second reading. Intraobserver agreement for each of the observers was 88%, 83%, and 100%. Interclass correlation was 85% (first reading) and 87% (second reading). Intraclass correlation was 92% (first and second readings combined). CONCLUSION: This method shows good interobserver and intraobserver agreements for the measurement of intracranial stenosis of a major artery. If validated in subsequent studies, this method may serve as a standard for the measurement of percent stenosis of an intracranial artery.

Redox state of glutathione in human plasma.

Thiol and disulfide forms of glutathione (GSH) and cysteine (Cys) were measured in plasma from 24 healthy individuals aged 25-35 and redox potential values (E(h)) for thiol/disulfide couples were calculated using the Nernst equation. Although the concentration of GSH (2.8 +/- 0.9 microM) was much greater than that of GSSG (0.14 +/- 0.04 microM), the redox potential of the GSSG/2GSH pool (-137 +/- 9 mV) was considerably more oxidized than values for tissues and cultured cells (-185 to -258 mV). This indicates that a rapid oxidation of GSH occurs upon release into plasma. The difference in values between individuals was remarkably small, suggesting that the rates of reduction and oxidation in the plasma are closely balanced to maintain this redox potential. The redox potential for the Cys and cystine (CySS) pool (-80 +/- 9 mV) was 57 mV more oxidized, showing that the GSSG/2GSH and the CySS/2Cys pools are not in redox equilibrium in the plasma. Potentials for thiol/disulfide couples involving CysGly were intermediate between the values for these couples. Regression analyses showed that the redox potentials for the different thiol/disulfide couples within individuals were correlated, with the E(h) for CySS-mono-Gly/(Cys. CysGly) providing the best correlation with other low molecular weight pools as well as protein disulfides of GSH, CysGly and Cys. These results suggest that E(h) values for GSSG/2GSH and CySS-mono-Gly/(Cys. CysGly) may provide useful means to quantitatively express the oxidant/antioxidant balance in clinical and epidemiologic studies.

Depletion of NK cell activity results in growth of hepatic micrometastases in a murine ocular melanoma model.

PURPOSE: To study the role of natural killer (NK) cells in growth of spontaneous hepatic metastasis in a murine intraocular melanoma model. METHODS: Tissue culture B16-LS9 melanoma cells were analyzed by flow cytometry for MHC class I expression of all haplotypes and inoculated into the posterior compartment (PC) of one eye of C57BL6 mice. The eyes were enucleated at 12 days post-inoculation and histologically examined for tumor growth. One group of mice (n = 10) were given intraperitoneal injections of anti-asialo GM1 for NK cell depletion post-enucleation and a second group of mice (n = 9) served as controls. The mice were sacrificed at 24 days post-inoculation and necropsies were performed to determine the number and size of metastasis. RESULTS: The B16-LS9 cells failed to express MHC class I antigen. Tumor grew in the PC of all eyes and metastasized to the lungs and livers of all mice, with the average number of hepatic micrometastases greater in the NK depleted group versus the control group (p =.009). There was no significant difference in the average number of pulmonary metastases in the treated versus the control group (p =.072). Hepatic metastases grew to an average diameter of 600 microm in diameter in two NK depleted mice. CONCLUSIONS: NK depletion in this model of metastatic ocular melanoma results in increased number and growth of hepatic micrometastases.