Vascular mineralization in the monkey brain

Red fox as a potential bioindicator of metal contamination in a European environment

In times of widespread environmental pollution with heavy metals of anthropogenic origin and the increasing dynamics of this process, it is justified to collect as much data as possible on the concentration of metals in terrestial mammals from unpolluted areas. The purpose of this research was to present the concentration of essential (chromium, copper, iron, manganese, molybdenum, and zinc), probably essential (nickel, vanadium) and non-esential element (cadmium, lead, silver, strontium, and tin) in the liver, kidneys, muscles and brain of red fox (Vulpes vulpes) inhabiting north-western Poland. We revealed that the concentration of all metals, apart from Ni, was different between studied tissues. Sn and Mo have the highest affinity to the liver, whereas Ag, Sr, Cr had higher concentrations in the brain than in other organs. Various positive relationship between the concentrations of metals were observed in the tissues. Moreover, we noted negative correlations between Ag and Sn in the kidneys and brain, and between Cu and Ag in the liver. In our study the red fox was used as biomonitor for the assessment of exposure of carnivores to metals, in the generally unpolluted areas of Central Europe. Data presented in the report may be used as comparative values in similar ecotoxicological studies.

The Interplay Between Brain Vascular Calcification and Microglia

Vascular calcifications are characterized by the ectopic deposition of calcium and phosphate in the vascular lumen or wall. They are a common finding in computed tomography scans or during autopsy and are often directly related to a pathological condition. While the pathogenesis and functional consequences of vascular calcifications have been intensively studied in some peripheral organs, vascular calcification, and its pathogenesis in the central nervous system is poorly characterized and understood. Here, we review the occurrence of vessel calcifications in the brain in the context of aging and various brain diseases. We discuss the pathomechanism of brain vascular calcification in primary familial brain calcification as an example of brain vessel calcification. A particular focus is the response of microglia to the vessel calcification in the brain and their role in the clearance of calcifications.

Nonhuman primates exposed to Zika virus in utero are not protected against reinfection at 1 year postpartum

There is limited information about the impact of Zika virus (ZIKV) exposure in utero on the anti-ZIKV immune responses of offspring. We infected six rhesus macaque dams with ZIKV early or late in pregnancy and studied four of their offspring over the course of a year postpartum. Despite evidence of ZIKV exposure in utero, we observed no structural brain abnormalities in the offspring. We detected infant-derived ZIKV-specific immunoglobulin A antibody responses and T cell memory responses during the first year postpartum in the two offspring born to dams infected with ZIKV early in pregnancy. Critically, although the infants had acquired some immunological memory of ZIKV, it was not sufficient to protect them against reinfection with ZIKV at 1 year postpartum. The four offspring reexposed to ZIKV at 1 year postpartum all survived but exhibited acute viremia and viral tropism to lymphoid tissues; three of four reexposed offspring exhibited spinal cord pathology. These data suggest that macaque infants born to dams infected with ZIKV during pregnancy remain susceptible to postnatal infection and consequent neuropathology.

Pathology of the Aging Brain in Domestic and Laboratory Animals, and Animal Models of Human Neurodegenerative Diseases

According to the WHO, the proportion of people over 60 years is increasing and expected to reach 22% of total world’s population in 2050. In parallel, recent animal demographic studies have shown that the life expectancy of pet dogs and cats is increasing. Brain aging is associated not only with molecular and morphological changes but also leads to different degrees of behavioral and cognitive dysfunction. Common age-related brain lesions in humans include brain atrophy, neuronal loss, amyloid plaques, cerebrovascular amyloid angiopathy, vascular mineralization, neurofibrillary tangles, meningeal osseous metaplasia, and accumulation of lipofuscin. In aging humans, the most common neurodegenerative disorder is Alzheimer’s disease (AD), which progressively impairs cognition, behavior, and quality of life. Pathologic changes comparable to the lesions of AD are described in several other animal species, although their clinical significance and effect on cognitive function are poorly documented. This review describes the commonly reported age-associated neurologic lesions in domestic and laboratory animals and the relationship of these lesions to cognitive dysfunction. Also described are the comparative interspecies similarities and differences to AD and other human neurodegenerative diseases including Parkinson’s disease and progressive supranuclear palsy, and the spontaneous and transgenic animal models of these diseases.

Intracranial atherosclerosis

Atherosclerotic disease often involves the intracranial arteries including those encased by cranial bones and dura, and those located in the subarachnoid space. Age, hypertension, and diabetes mellitus are independent risk factors for intracranial atherosclerosis. Intracranial atherosclerosis can result in thromboembolism with or without hypoperfusion leading to transient or permanent cerebral ischaemic events. High rates of recurrent ischaemic stroke and other cardiovascular events mandate early diagnosis and treatment. Present treatment is based on a combination of antiplatelet drugs, optimisation of blood pressure and LDL cholesterol values, and intracranial angioplasty or stent placement, or both, in selected patients.

Mineralizing angiopathy with infantile basal ganglia stroke after minor trauma

AIMS

The objective of this study was to describe a cohort of infants with basal ganglia stroke associated with mineralization in the lenticulostriate arteries and their clinical outcomes.

METHOD

Subcortical strokes occurring in infants during the study period were categorized as arterial ischaemic, venous, or haemorrhagic. A cohort of infants with basal ganglia infarcts and associated mineralization of lenticulostriate arteries were identified. This group was analysed for possible aetiological factors, clinical course, and recurrence rate of the stroke.

RESULTS

Of 23 infants with basal ganglia arterial ischaemic stroke, 22 (16 males, six females; mean age 11mo [±SD 4.8mo]) were found to have lenticulostriate artery mineralization. Twenty infants presented with hemiparesis and two presented with recurrent episodes of hemidystonia. Eighteen infants had a history of minor trauma before onset of stroke. No other predisposing factors were identified in this cohort. There were no demonstrable causes for vascular and soft tissue calcification. The mean follow-up was 11 months, during which five infants experienced stroke recurrence. Of the 17 infants who did not experience a recurrent stroke, eight exhibited complete neurological recovery, and nine had mild residual hemiparesis.

INTERPRETATION

Acute basal ganglia stroke after minor trauma associated with mineralization of lenticulostriate arteries in infants is a distinct clinicoradiological entity. Investigations for prothrombotic states and vasculopathies are normal. Although neurological outcomes in most children are good, trauma is a risk factor for recurrence of stroke.

Vacuolation and mineralisation as dominant age-related findings in hamster brains

Syrian golden hamsters (Mesocricetus auratus) are laboratory animals increasingly used for research and toxicological studies. Despite the need for an adequate knowledge of spontaneously occurring lesions, studies investigating the background pathology of different organ systems in hamsters are lacking. The aim of this study was to investigate the occurrence of spontaneous, age-dependent lesions in the central nervous system of this species. Multiple brain and spinal cord transverse sections of 520 hamsters of 1, 3, 6, 12, and 24 months of age were investigated using histology and immunohistochemistry. Vacuolation of grey matter neuropil and mineralisation especially in the brain stem were the most prominent findings. They gradually increased in severity and frequency with age. Vacuolation and mineralisation affected approximately 100% and 50% of 24-month-old hamsters, respectively. In addition, pigment deposition and mast cell infiltration were commonly detected. Whether vacuolation and mineralisation represent an incidental finding or are related to a cognitive dysfunction syndrome remains to be determined.

Regional differences in MRI detection of amyloid plaques in AD transgenic mouse brain

Our laboratory and others have reported the ability to detect individual Alzheimer's disease (AD) amyloid plaques in transgenic mouse brain in vivo by magnetic resonance imaging (MRI). Since amyloid plaques contain iron, most MRI studies attempting to detect plaques in AD transgenic mouse brain have employed techniques that exploit the paramagnetic effect of iron and have had mixed results. In the present study, using five-way anatomic spatial coregistration of MR images with three different histological techniques, properties of amyloid plaques in AD transgenic mouse brain were revealed that may explain their variable visibility in gradient- and spin-echo MR images. The results demonstrate differences in the visibility of plaques in the cortex and hippocampus, compared to plaques in the thalamus, by the different MRI sequences. All plaques were equally detectable by T(2)SE, while only thalamic plaques were reliably detectable by T(2)*GE pulse sequences. Histology revealed that cortical/hippocampal plaques have low levels of iron while thalamic plaques have very high levels. However, the paramagnetic effect of iron does not appear to be the sole factor leading to the rapid decay of transverse magnetization (short T(2)) in cortical/hippocampal plaques. Accordingly, MRI methods that rely less on iron magnetic susceptibility effect may be more successful for eventual human AD plaque MR imaging, particularly since human AD plaques more closely resemble the cortical and hippocampal plaques of AD transgenic mice than thalamic plaques.

Incidences and range of spontaneous findings in control cynomolgus monkeys (Macaca fascicularis) used in toxicity studies

The authors performed a retrospective study to determine the incidences and range of spontaneous pathology findings in control cynomolgus monkeys. Data were collected from 570 monkeys (285 animals per sex), aged twelve to thirty-six months, from sixty regulatory studies evaluated at our laboratory between 2003 and 2009. The most common finding overall was lymphoplasmacytic infiltrates observed in the following incidence: liver (60.7%), kidneys (28.8%), heart (25.8%), salivary glands (21.2%), and stomach (12.1%). Inflammation also commonly occurred in the heart, kidneys, lungs, and stomach. The most common degenerative changes were localized fatty change in the liver, myocardial degeneration, and mineralization and pigment deposits in various tissues. Parathyroid, thyroid, and pituitary cysts; ectopic thymus in the parathyroid or thyroid gland; accessory spleen within the pancreas; and adrenohepatic fusion were among the most common congenital findings. Some incidental findings bearing similarities to drug-induced lesions were also encountered in various organs. It is hoped that the results presented here and elsewhere could form the groundwork for the creation of a reliable database of incidental pathology findings in laboratory nonhuman primates.

Parenchymal and vascular lesions in ageing equine brains: histological and immunohistochemical studies

Many age-related changes are described in the nervous system of different species, but detailed studies of brain lesions in ageing horses are lacking. The aim of the present study was to systematically characterize lesions in the brains of 60 horses aged from 7 to 23 years. No gross changes were present in any brain. Microscopically, spongiform changes, lipofuscin storage, corpora amylacea, gliosis and satellitosis were common, together with axonal and neuronal swellings. The most important findings were the presence of pseudocalcium-calcium (pCa-Ca) deposits and arterial wall degeneration. Scanning electron microscopical examination of two cases with vascular mineralization revealed marked deposition of an amorphous substance in the vessel walls that was probably formed by a polyanionic protein matrix and a mineral component. Immunohistochemically, numerous axonal spheroids were positively labelled for ubiquitin. No PrPsc was detected in sections with neuronal vacuolation. Neuronal swelling, corpora amylacea, hippocampal Tau-positive neurons and methenamine-positive diffuse (preamyloid) plaques were also detected. Congo red staining failed to detect amyloid deposition. The characterization of age-related lesions in the brains of these horses will allow these changes to be discriminated from pathological processes in future studies. Some lesions described here, including some vascular changes, the presence of diffuse plaques and tau accumulation in hippocampal neurons, have not been described previously in the horse.

Leucoencephalopathy with cerebral calcinosis in a young chimpanzee (Pan troglodytes) - a case report

CASE HISTORY

A 4-year-old chimpanzee (Pan troglodytes) had a clinical history of a 2-year progressive central nervous dysfunction including convulsions and severe paralysis.

RESULTS

Gross pathology revealed cerebral atrophy, ventricular enlargement and a severe encephalomalacia with extensive calcifications. Histologically, the white matter showed diffuse demyelination as well as vascular and perivascular calcifications which also involved the basal ganglia. Blood vessels with less distinctive calcium deposits exhibited periodic acid Schiff positive hyalinosis. Large areas of necrosis, hemorrhage and intense gliosis were also present. Activation of astrocytes and macrophages was confirmed by immunohistochemical methods.

CONCLUSIONS

The etiology of the leucoencepalopathy could not be ascertained by macroscopic, histological and immunohistochemical examinations. Potential differential diagnoses include the rarely occurring Fahr's disease in humans, arteriosclerosis, storage disease and the Aicardi-Goutières syndrome. Based on the results of the postmortal examinations Fahr's disease is regarded as the most likely diagnosis in the present case of the chimpanzee.

Acute neuropathogenicity with experimental infection of equine herpesvirus 9 in common marmosets (Callithrix jacchus)

BACKGROUND

Equine herpesvirus 9 (EHV-9) is a new neurotropic equine herpesvirus which induced encephalitis in a variety of animals. However, there was no information on the susceptibility of EHV-9 in primates.

METHODS

To assess the infectivity of EHV-9, four common marmosets (Callithrix jacchus) were inoculated by the nasal route with 10(6) plaque-forming units of EHV-9.

RESULTS AND CONCLUSIONS

All of the inoculated animals exhibited various neurological signs progressing to collapse. Histologically, the affected animals had severe encephalitis characterized by neuronal degeneration and necrosis with intranuclear inclusion bodies, which extended from the olfactory bulb to the rhinencephalon and piriform lobe. Immunohistochemistry revealed EHV-9 antigens in degenerating neuronal cells. The nasal cavity had severe necrotizing rhinitis with prominent intra-nuclear inclusion bodies in the olfactory mucosa. These findings indicate that the marmosets are susceptible to EHV-9.

Mineralization of the basal ganglia: implications for neuropsychiatry, pathology and neuroimaging

This article examines the evidence for and against the existence of basal ganglia mineralization as a defined clinico-pathological entity. In reviewing the literature on basal ganglia mineralization, this article emphasizes evidence derived from different neuroimaging modalities, genetics, metabolic studies, postmortem series and their possible neuropsychiatric correlates. Relevant articles were collected through Medline and Index Medicus searches. Researchers have encountered multiple difficulties in accepting basal ganglia mineralization as a distinct entity. This syndrome lacks set clinical criteria or a unique etiology; not surprisingly, numerous articles have applied varied definitions. Because many of the reported cases have not been examined postmortem, both the extent and nature of their mineralization remains uncertain. Furthermore, researchers have considered small foci of basal ganglia mineralization a normal phenomenon of aging. However, when brain deposits are extensive, they are associated with a set of age-dependent, progressive clinical symptoms. They include cognitive impairment, extrapyramidal symptoms and psychosis. Most cases are related to abnormalities of calcium metabolism, but rare familial cases of idiopathic origin have been reported. Overabundant mineralization of the brain is judged pathological based on its amount, distribution and accompanying clinical symptoms. Although its relation with calcium dysregulation is well known, modern studies have emphasized abnormalities of iron and dopamine metabolism. The authors suggest that these metabolic abnormalities may link basal ganglia mineralization to psychotic symptomatology.

Prevalence of psammoma bodies in meninges and choroid plexuses of raccoons (Procyon lotor) from Parramore Island, Virginia

Microscopic evidence of multifocal mineralizations (psammoma bodies) were seen in brains of 33/53 (62%) raccoons (Procyon lotor) necropsied on Parramore Island, Virginia. Most mineralized foci had concentric laminations and were present in small capillaries of meninges of the brain (15/33), in choroid plexus (3/33), or at both these sites (13/33). In 2 raccoons, the lesions were confined to the meninges of the proximal cervical spinal cord. In most cases, the affected vessels appeared to have been completely occluded. However, no evidence of ischemic changes in the brain parenchyma was seen, and none of the raccoons had abnormal neurologic signs prior to euthanasia. The condition appears to be a common incidental histopathologic finding in raccoons from the eastern United States. Although the exact cause of this condition is not known, a primary vascular insult with resultant dystrophic mineralization of the affected vessels is suspected.

Spontaneous vascular mineralization in the brains of cows

The frequency of occurrence and the characteristics of vascular mineralization in the brains of cows were studied. Mineralized lesions were found in the pallidal arteries in eight of 13 cows. They appeared as basophilic deposits in the arterial walls, were sheath-like or tubular in shape, and were accompanied by intimal oedema or fibrous thickening. The deposits were positive for periodic acid-Schiff, von Kossa's, alizarin red and Berlin blue stains. Elemental analysis revealed the presence of large amounts of phosphorus, calcium and zinc, as well as small amounts of iron, copper and sodium.