The blue road: Provenance study of azurite samples from historical locations through the analysis of minor and trace elements

The pigments used by artists since ancient times play an important role in historical, artistic, and cultural investigations. They allow the acquisition of useful information for the study of human and technological development. This research aims at differentiating the various sources of azurite exploited in antiquity, based on the study of minor and trace elements. Azurite is one of the most important blue pigments in art history, widely used during the Middle Age and Renaissance. However, very few studies investigated the provenance of the pigment, so today it is still not possible to clearly identify the sources of azurite exploited in the past. This study is based on the analysis of several samples of azurite belonging to the MUST collection (Museum of Earth Sciences, Sapienza University of Rome, Italy) and coming from different historical localities: UK, Italy, Germany, France, Romania and Slovakia (both representative of the resources within the ancient Kingdom of Hungary), Greece and Russia. The samples were analysed by electron microscopy (EMPA and SEM-EDX) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), with the aim of detecting chemical features that are specific to the different azurite ore deposits. Among the trace elements analysed, Zn, As, Sn, Ca and Sr prove the most suitable for discriminating the origin of the samples, as well as rare earth elements. In particular, Ce and Eu anomalies are suggested as markers for the German and Hungarian localities.

Gender-specific effects of capsiate supplementation on body weight and bone mineral density: a randomized, double-blind, placebo-controlled study in slightly overweight women

INTRODUCTION

Overweight and obesity are highly prevalent conditions associated with premature morbidity and mortality worldwide. Capsiate, a nonpungent analogue of capsaicin, binds to TRP vanilloid 1 (TRPV1) receptor, which is involved in adipogenesis, and could be effective as a weight-lowering agent.

METHODS

Eighteen slightly overweight women were enrolled in this randomized, double-blind, placebo-controlled study. Nine patients were included in the capsiate intervention group and received 9 mg/day of capsinoids and 9 patients received placebo for 8 weeks. All patients underwent weight and waist circumference assessment before and after treatment. Body composition and bone mineral density (BMD) were also detected by dual-energy X-ray absorptiometry (DXA).

RESULTS

Fourteen patients completed the study. The treatment with capsiate or placebo for 8 weeks was not associated with significant changes in weight or waist circumference. After treatment, there was a significant improvement in BMD values measured at the spine in the capsiate group (1.158 vs 1.106 g/cm², + 4.7%; p = 0.04), but not in the group treated with placebo. Similarly, the capsiate group showed a 9.1% increase (p = 0.05) in the adipose tissue and an 8.5% decrease in lean mass measured at the supraclavicular level, whereas these changes were not statistically significant in the placebo group.

CONCLUSIONS

Treatment with capsiate for 8 weeks led to negligible changes in body weight in a small sample of slightly overweight women, but our findings suggest a potential effect of capsaicin on bone metabolism in humans.

A Machine Learning-Based Approach to Clinopyroxene Thermobarometry: Model Optimization and Distribution for Use in Earth Sciences

Thermobarometry is a fundamental tool to quantitatively interrogate magma plumbing systems and broaden our appreciation of volcanic processes. Developments in random forest-based machine learning lend themselves to a data-driven approach to clinopyroxene thermobarometry, allowing users to access large experimental data sets that can be tailored to individual applications in Earth Sciences. We present a methodological assessment of random forest thermobarometry using the R freeware package extraTrees. We investigate the model performance, the effect of hyperparameter tuning, and assess different methods for calculating uncertainties. Deviating from the default hyperparameters used in the extraTrees package results in little difference in overall model performance (<0.2 kbar and <3°C difference in standard error estimate, SEE). However, accuracy is greatly affected by how the final value from the distribution of trees in the random forest is selected (mean, median, or mode). Using the mean value leads to higher residuals between experimental and predicted P and T, whereas using median values produces smaller residuals. Additionally, this work provides two scripts for users to apply the methodology to natural data sets. The first script permits modification and filtering of the model calibration data set. The second script contains premade models, where users can rapidly input their data to recover PT estimates (SEE clinopyroxene-only model: 3.2 kbar, 72.5°C and liquid-clinopyroxene model: 2.7 kbar, 44.9°C). Additionally, the scripts allow the user to estimate the uncertainty for each analysis, which in some cases is significantly smaller than the reported SEE. These scripts are open source and can be accessed at https://github.com/corinjorgenson/RandomForest-cpx-thermobarometer.

Combined Astigmatic Arcuate Keratotomy with Descemet Automated Endothelial Keratoplasty

We report the results of simultaneous astigmatic arcuate keratotomy (AK) and Descemet automated endothelial keratoplasty (DSAEK). A 55-year-old patient with a history of high myopia was referred for the management of bullous keratopathy secondary to an anterior chamber phakic intraocular lens (pIOL). IOL explantation through a 5.5-mm corneal incision, cataract extraction, and posterior chamber IOL implantation, combined with DSAEK, were performed. Postoperatively, increased astigmatism up to 2.0 diopters (Dpt) was observed, attributed to the large corneal incision, and remained stable, despite suture removal at 3 months. One year postoperatively, the graft showed signs of progressive endothelial dysfunction. A combined procedure of astigmatic AK and DSAEK was thus performed. After 6 months, topographic astigmatism was significantly reduced to 0.5 Dpt and best-corrected visual acuity increased. In conclusion, simultaneous astigmatic AK and DSAEK could be an effective combination for treating patients with well-documented pre-existing astigmatism and endothelial decompensation.

Burr-Assisted Peripheral Superficial Keratectomy for the Treatment of Persistent Symptomatic Peripheral Corneal Edema

PURPOSE

To describe a simple technique of diamond burr-assisted superficial keratectomy for the treatment of peripheral corneal edema.

CASES PRESENTATION

Two patients with persistent symptomatic peripheral corneal edema underwent superficial keratectomy with the use of a diamond ophthalmic burr. The efficacy of the treatment was evaluated clinically as well as with anterior segment optical coherence tomography. During the postoperative follow-up period, no adverse events were observed and corneal edema reduced significantly. The patients were asymptomatic, no epithelial cysts could be identified clinically, and visual acuity remained unchanged.

CONCLUSION

Peripheral superficial keratectomy could be an effective alternative for the treatment of peripheral, symptomatic corneal edema.

Intraocular Lens Refractive Index and Its Impact on External Surface Reflections

PURPOSE

To determine and compare the origin of the external surface reflections produced by commonly used intraocular lenses (IOLs).

METHODS

The specular reflection taking place at the anterior surface of eight types of IOLs (IOL power = 22.00 diopters [D]) with different refractive indices (RIs), optical design, and ultraviolet and blue light-filtering function were measured. The experimental set-up included a laser beam light source (3.5 mW, 532 nm) and a saline-filled model eye containing the IOL to be examined. External surface reflections were measured using a power meter, and the IOL surface reflectance (%) was compared among the eight IOLs investigated.

RESULTS

External reflections from the anterior surface of the studied implants increased as the RI of the IOL material increased. The IOL models composed of high RI material (RI = 1.56 ± 0.02) were found to have a more than threefold higher external surface reflections compared to those with low RI (RI = 1.45 ± 0.02). Ultraviolet or blue light-filtering functions showed no significant correlation with the external reflectance.

CONCLUSIONS

IOLs with a high RI are associated with external surface reflections that are more than threefold higher than those with lower RI. The "cat's eye" phenomenon seen in pseudophakic eyes by an outside observer strongly depends on the RI, but is independent of the filter incorporated in the IOL. [J Refract Surg. 2021;37(6):398-402.].

Long-Term Follow-Up of Combined Photorefractive Keratectomy and Corneal Crosslinking in Keratoconus Suspects

Purpose

To present the long-term outcomes of photorefractive keratectomy (PRK) combined with accelerated corneal cross-linking (CXL) for refractive error correction in a series of keratoconus suspects.

Setting

University practice.

Design

Retrospective case series.

Methods

A series of patients with topographic findings suspicious for keratoconus underwent simultaneous PRK and prophylactic accelerated CXL (5 minutes with intensity of 18 mW/cm²) for the correction of their refractive error. The results were recorded for more than 4 years postoperatively.

Results

Ten eyes of 5 patients were included. Mean follow-up was 58.2 months (range from 54 to 62 months). Mean age at presentation was 25 years (range from 22 to 32 years). Mean spherical equivalent (SE) refraction was −2.76 (standard deviation [SD] 0.97D, range from −1.25 to −4.00 diopters [D]), while mean central corneal thickness was 511μm (SD 13μm, range from 485 to 536 μm). At last, follow-up 9 out of 10 eyes had SE refraction within ± 0.50D and all eyes had SE within ± 1.00D. None of the eyes lost any line of corrected distance visual acuity (CDVA), whereas 1 eye gained one line of CDVA. All eyes demonstrated stability of their results during the follow-up period.

Conclusion

Simultaneous PRK followed by prophylactic accelerated CXL (PRK plus) appeared to be a safe and effective option for the correction of the refractive error in this series of keratoconus suspect patients, without compromising corneal stability for up to 5 years postoperatively.

Corneal cross-linking (CXL) combined with refractive surgery for the comprehensive management of keratoconus: CXL plus

The past two decades have witnessed an unprecedented evolution in the management of keratoconus that demands a holistic approach comprising of inhibiting the ectatic progression as well as visual rehabilitation. The advent of corneal cross-linking (CXL) in the late 1990s resulted in long-term stabilization of the ectatic cornea along with limited reduction in corneal steepening and regularization of corneal curvature. However, CXL as a standalone procedure does not suffice in rehabilitating the functional vision especially in patients who are unwilling or intolerant towards contact lenses. The concept of “CXL plus” was proposed which incorporates adjunctive use of refractive procedures with CXL in order to overcome the optical inefficiency due to corneal irregularity, decrease the irregular astigmatism, correct the residual refractive error and improve functional visual outcome in keratoconus. Several refractive procedures such as conductive keratoplasty (CK), photorefractive keratectomy (PRK), transepithelial phototherapeutic keratectomy (t-PTK), intrastromal corneal ring segments (ICRS) implantation, phakic intraocular lens (PIOL) implantation and multiple other techniques have been combined with CXL to optimize and enhance the CXL outcome. This review aimed to summarize the different protocols of CXL plus, provide guidelines for selection of the optimum CXL plus technique and aid in decision-making for the comprehensive management of cases with primary keratoconus in addition to discussing the future and scope for innovations in the existing treatment protocols.

Vitrification treatment of municipal solid waste bottom ash

This study involves the chemical characterization of municipal solid waste (MSW) bottom ash (BA) produced at a combustor facility in Rimini (Italy), and vitrification experiments, performed at lab scale under atmospheric conditions, maximum temperature of 1100 °C, for different durations (2-16 h). LA-ICP-MS analyses of the glasses obtained revealed that the overall volatility of metal elements increases with the time but it cannot be simply predicted by element boiling point. Elements have been here categorized into three different groups depending on their volatility comparing the glass product with the BA starting sample- high, medium or low, respectively- (1) Cu, W, Cl; (2) Pb, Zn, Sr; (3) Mo, Cr, V, Ni. The behavior of Cs, Rb, Ag, Ba, Ga, Co, U, Zr, Hf and Ta in the glassy slag is not defined because we did not observe statistically significant changes in their volatility behavior. Vitrification allows us to produce chemically stable glassy materials and immobilize potentially harmful elements, thus producing from waste new vitreous materials that are relatively inert and suitable for potential re-utilization in new products and/or applications for building and construction industries. Moreover, the samples show REE chondrite-normalized patterns indicating relative enrichments in Light-Rare Earth Elements (LREE), in particular La and Nd which may be interesting from an economic point of view in terms of waste recovery. Thus, the results obtained show how to treat bottom ashes from incinerator in order to provide more chemically inert and economically useful resources for recycle and reuse of solid waste BA.

Timescales of water accumulation in magmas and implications for short warning times of explosive eruptions

Water plays a key role in magma genesis, differentiation, ascent and, finally, eruption. Despite the recognized crucial function of water, there are still several issues that continue to blur our view about its role in magmatic systems. What are the timescales of H₂O accumulation in crystallizing magmas? What are the ascent rates of water-rich residual melts leading to explosive eruptions? Here, we track the timescale of water accumulation in a residual melt resulting from crystallization of a hydrous CO₂-bearing magmatic mass stored at mid- to deep-crustal levels in a subduction-related geodynamic setting. Our results indicate that, after a repose period ranging from few to several thousand years, water-rich melts with water concentrations larger than 6–9 wt.% can migrate towards the Earth surface in very short timescales, on the order of days or even hours, possibly triggering explosive eruptions with short warning times and devoid of long-term geophysical precursors.

Volatiles such as water play a key role in magma ascent and ultimately triggering explosive eruptions. Here, the authors show that water-rich melts with water concentrations of 6–9 wt.% can ascend rapidly to the surface over the timescales of hours to days with very short warning times.

Corneal Neovascularization with Associated Lipid Keratopathy in a Patient with Obstructive Sleep Apnea-Hypopnea Syndrome Using a Continuous Positive Airway Pressure Machine

Objective

To report a case of corneal neovascularization with secondary lipid keratopathy in a patient treated with continuous positive airway pressure (CPAP) for obstructive sleep apnea-hypopnea syndrome (OSAHS).

Case Report

A 49-year-old male had been diagnosed with obstructive sleep apnea syndrome 10 years ago and has been treated with the application of a CPAP machine during night sleep ever since. For the past year, the patient had been complaining for ocular irritation and excessive tearing of the left eye on awakening. Slit-lamp biomicroscopy revealed the presence of neovascularization and lipid exudation in the inferior third of the cornea of the left eye. Ocular patching during night sleep resulted in recession of the reported symptoms and shrinkage of the neovascularization, while the area of lipid exudation ceased to enlarge.

Conclusion

To the best of our knowledge, this is the first report of corneal neovascularization in a patient using a CPAP machine for OSAHS.

Keratoconus Treatment Algorithm

Keratoconus management has significantly changed over the last two decades. The advent of new interventions such as cornea cross-linking, intrastromal corneal ring segments, and combined treatments provide corneal clinicians a variety of treatment options for the visual rehabilitation of keratoconus patients. This review summarizes current evidence for these treatments and highlights their place in keratoconus management while new promising emerging therapies are being investigated.

Surgical management of spontaneous, late-onset Descemet membrane detachment after penetrating keratoplasty for keratoconus: a case report

Background

To report a surgical method for treating corneal oedema in a case of late-onset Descemet membrane detachment after penetrating keratoplasty.

Case presentation

A 55-year old patient presented with sudden visual loss in his left eye 28 years after penetrating keratoplasty for keratoconus. Slit-lamp biomicroscopy revealed a distortion of the corneal graft anatomy with protrusion of the graft and peripheral thinning and steepening in the residual host tissue, accompanied by corneal graft oedema. Anterior segment optical coherence tomography revealed detachment of Descemet membrane localized to the area of the graft oedema. We proceeded with a full-thickness, partially circumferential incision in the graft-host junction, followed by repositioning and re-suturing of the graft in place, and intracameral air injection in order to achieve reattachment of Descemet membrane.

Conclusions

Corneal graft repositioning in combination with re-bubbling may represent an effective therapeutic option in keratoconic patients with peripheral thinning in the residual host corneal tissue and subsequent Descemet membrane detachment.

Treatment of anterior corneal scarring, following DSAEK graft failure, with combined graft exchange and phototherapeutic keratectomy

Background

To present a method, alternative to penetrating keratoplasty, for the restoration of impaired corneal clarity with anterior stromal scarring following long-standing corneal graft failure.

Case presentation

A 48-year old female who had previously underwent Descemet stripping automated endothelial keratoplasty (DSAEK) for the treatment of pseudophakic bullous keratopathy, presented with long-standing corneal oedema and anterior corneal scarring. A significant improvement in corrected distance visual acuity was demonstrated, as corneal clarity was restored following graft exchange and phototherapeutic keratectomy (PTK).

Conclusions

The combination of corneal graft exchange and phototherapeutic keratectomy may represent an effective therapeutic option for long-standing corneal oedema with concomitant anterior corneal scarring after failure of a DSAEK graft.

High-temperature apparatus for chaotic mixing of natural silicate melts

A unique high-temperature apparatus was developed to trigger chaotic mixing at high-temperature (up to 1800 °C). This new apparatus, which we term Chaotic Magma Mixing Apparatus (COMMA), is designed to carry out experiments with high-temperature and high-viscosity (up to 10(6) Pa s) natural silicate melts. This instrument allows us to follow in time and space the evolution of the mixing process and the associated modulation of chemical composition. This is essential to understand the dynamics of magma mixing and related chemical exchanges. The COMMA device is tested by mixing natural melts from Aeolian Islands (Italy). The experiment was performed at 1180 °C using shoshonite and rhyolite melts, resulting in a viscosity ratio of more than three orders of magnitude. This viscosity ratio is close to the maximum possible ratio of viscosity between high-temperature natural silicate melts. Results indicate that the generated mixing structures are topologically identical to those observed in natural volcanic rocks highlighting the enormous potential of the COMMA to replicate, as a first approximation, the same mixing patterns observed in the natural environment. COMMA can be used to investigate in detail the space and time development of magma mixing providing information about this fundamental petrological and volcanological process that would be impossible to investigate by direct observations. Among the potentials of this new experimental device is the construction of empirical relationships relating the mixing time, obtained through experimental time series, and chemical exchanges between the melts to constrain the mixing-to-eruption time of volcanic systems, a fundamental topic in volcanic hazard assessment.

Severe intrahepatic cholestasis caused by amiodarone toxicity after withdrawal of the drug: a case report and review of the literature

Cholestasis has been reported as a rare presentation among patients with severe liver injury secondary to amiodarone hepatic toxicity. We report an unusual case of amiodarone-induced cholestatic hepatotoxicity occurring after amiodarone had been discontinued and the initial abnormal liver function findings had improved. The patient, without jaundice at the initial presentation, developed severe jaundice about 4 months after withdrawal of amiodarone. Light and transmission electron microscopic examination of a specimen secured by computed tomographically guided liver biopsy was consistent with amiodarone hepatic toxicity as the cause of intrahepatic cholestasis. An abdominal ultrasound, endoscopic retrograde cholangiography, and dimethyl iminodiacetic acid and computed tomographic scans of the abdomen all failed to demonstrate any other causes for jaundice other than amiodarone toxicity. Thus, amiodarone hepatic toxicity may occur after drug withdrawal even if results of liver function tests improve. Histopathologic examination of a liver biopsy specimen is of value for diagnosis and prognosis. The liver biopsy findings, clinical course, and liver function test results are discussed, and the English-language literature on amiodarone cholestatic hepatotoxicity is reviewed.

ACTH receptor mRNA in human adrenocortical tumors: overexpression in aldosteronomas

We previously reported that ACTH receptor (ACTH-R) mRNA is expressed in cortisol-secreting adrenal tumors, with significant differences between adenomas and carcinomas. In order to complete the study we have now evaluated 11 aldosteronomas (APA), 14 non-hypersecreting adenomas, 2 androgen-secreting adenomas and 8 normal adrenal glands. The level of ACTH-R mRNA was evaluated by competitive RT-PCR using a non-homologous competitor. ACTH-R gene was expressed in all tissues. All APA showed highest ACTH-R mRNA levels. Despite signs of individual heterogeneity, the level of ACTH-R transcripts was reduced in carcinomas. Furthermore, no significant differences were observed among cortisol-secreting adenomas, non hypersecreting adenomas and controls. The results show that ACTH-R mRNA is expressed in all adrenocortical tumors. The overexpression of ACTH-R in APA supports the role of ACTH on aldosterone secretion in these tumors, as also suggested by the presence of a diurnal rhythm, the lack of response to Angiotensin II, upright posture and captopril administration. The low abundance of ACTH-R in carcinomas might be a useful molecular marker of malignancy even if some overlap between carcinomas and adenomas does exist.

Nonalcoholic fatty liver disease: assessment of variability in pathologic interpretations

The exact cause, prevalence, and rate of progression of nonalcoholic fatty liver disease (NAFLD) are unclear because of a lack of agreement on the pathologic features associated with the different types of NAFLD, their clinical syndromes, and because of a lack of accuracy in the interpretation of these pathologic features. Studies of NAFLD would be aided by a consistent and standardized approach to the interpretation of pathologic features. The aim of our study was to assess interobserver and intraobserver variation in the histologic abnormalities associated with NAFLD. We identified histologic features of NAFLD as reported in the literature, and we identified patients with the diagnosis of NAFLD through the databases of two large institutions. Histologic parameters were evaluated for each liver biopsy specimen by four hepatopathologists and twice by two of the four pathologists (blindly). Interobserver and intraobserver concordance among the pathologists was measured by kappa statistics. Nineteen histologic parameters compartmentalized into steatosis, inflammation, liver cell injury, and fibrosis were evaluated on 53 liver biopsy specimens. Significant, substantial, or moderate concordance was present in only six items: the extent of steatosis, sinusoidal location of fibrosis, perivenular fibrosis, grade of fibrosis, ballooning degeneration, and the presence of vacuolated nuclei. Substantial or moderate concordance also was seen for interobserver readings for location of steatosis and periportal injury. Parameters of inflammation were not scored as reliably as parameters of fibrosis and cell injury. We conclude that only some histologic features previously reported in NAFLD (especially those with substantial and moderate concordance for both interobserver and intraobserver interpretation) are interpreted uniformly by experienced pathologists. These histologic features might prove useful for the development of a standardized and reliable pathologic scoring system that includes the full histologic spectrum of NAFLD and its various clinical outcomes.

Intravesicular prostaglandin E2 for the prophylaxis of urinary retention after colpohysterectomy

The aim of this study was to assess the efficacy of PGE2 in enhancing bladder function after vaginal hysterectomy. A total of 110 women with or without urinary incontinence underwent vaginal hysterectomy and cystourethropexy surgery because of grade II or III genital prolapse. Preoperatively the patients were randomly assigned to two groups: group 1 (n = 50) received on the fourth post-operative day, before removal of the bladder catheter, an intravesicular solution of 1.50 mg PGE2 (2 x 0.75 mg); group 2 (n = 60) did not receive any prophylaxis for urinary retention. In the PGE2-treated group significantly fewer patients had urinary retention for 3 days or more (10%, P < 0.05) than in the control group (27%). The use of intravesicular PGE2 reduced the time taken to restore detrusor function.

First-trimester chromosome diagnosis by lavage of the uterine cavity

Fetal karyotyping of trophoblast cells obtained by lavage of the uterine cavity was evaluated on 86 first-trimester irrigation fluid samples. Villus fragments were observed in 72 fluid samples indicating an 83.7 per cent sampling success rate. The amount of villi in these samples ranged from 1 to 32 mg. In most cases, villus fragments showed degeneration of the external syncytiotrophoblast layer and absence of blood vessels. In the first phase of this study (15 samples), a high degree of maternal cell contamination was observed after long-term cultures. In the following phase (71 samples), this obstacle was overcome by the application of a semi-direct method. Chromosome preparations were set up after 24 h incubation of villus fragments and QFQ-banded metaphase spreads were scored for chromosome number and sex. Sixty samples showed the presence of villus fragments and the fetal karyotype was established in 40. Male and female chromosome complements were observed in 16 and 24 cases, respectively. In four cases, an abnormal fetal karyotype was diagnosed. These included trisomy of chromosomes 13, 15, and 16, and one mosaic with trisomy 12. Our results indicate that first-trimester fetal karyotyping might be feasible by a semi-direct method using chorionic villus fragments obtained at intrauterine lavage.

Fatal cutaneous necrosis mimicking calciphylaxis in a patient with type 1 primary hyperoxaluria

BACKGROUND

Cutaneous necrosis of the proximal lower extremities in a patient with end-stage renal disease is the classic presentation of calciphylaxis, an untreatable, rare, generally fatal necrotizing cutaneous syndrome. Type 1 primary hyperoxaluria (PH-1) usually presents in childhood with recurrent urolithiasis. Since enzymatic studies to confirm the metabolic defect are now available, some cases of idiopathic renal failure in adulthood have been shown to be caused by PH-1. These patients may develop vascular oxalate deposits resulting in livedo reticularis and distal acral vascular insufficiency.

OBSERVATIONS

We describe a patient who presented in end-stage renal failure with proximal lower extremity cutaneous necrosis suggestive of calciphylaxis. A cutaneous biopsy specimen revealed oxalate crystals within blood vessels, and a diagnosis of PH-1 was confirmed enzymatically.

CONCLUSIONS

This patient illustrates that PH-1 may present in adulthood, and, in the setting of cutaneous necrosis associated with end-stage renal disease, it may be confused with calciphylaxis. The importance of making a diagnosis of PH-1 is the potential ability to achieve long-term survival by reversing the underlying metabolic defect with hepatic transplantation.

Primary angiitis and angiopathy of the central nervous system and their relationship to systemic giant cell arteritis

Three cases of primary angiitis of the central nervous system were compared with previously published cases. Most cases occurred in older adults, were diagnosed histologically, and had a male-female ratio of 2:1. Angiographically identified cases, demonstrating angiopathy but not necessarily vasculitis as might be seen in histologically identified cases, were found in younger adults and showed a male-female ratio of 1:2. The autopsy cases had some similarities to systemic giant cell arteritis, including many cases with vasculitis in large branches of the circle of Willis and foci of systemic vasculitis. Vasculitides in arteries of different sizes may result from different responses to a variety of antigens or immune complexes rather than represent different disease processes. If causative immune mechanisms can be identified, primary angiitis of the central nervous system may become classified immunologically rather than histopathologically.