Monolacunary Wells-Dawson Polyoxometalate as a Novel Contrast Agent for Computed Tomography: A Comprehensive Study on In Vivo Toxicity and Biodistribution.

Polyoxotungstate nanoclusters have recently emerged as promising contrast agents for computed tomography (CT). In order to evaluate their clinical potential, in this study, we evaluated the in vitro CT imaging properties, potential toxic effects in vivo, and tissue distribution of monolacunary Wells-Dawson polyoxometalate, α2-K10P2W17O61.20H2O (mono-WD POM). Mono-WD POM showed superior X-ray attenuation compared to other tungsten-containing nanoclusters (its parent WD-POM and Keggin POM) and the standard iodine-based contrast agent (iohexol). The calculated X-ray attenuation linear slope for mono-WD POM was significantly higher compared to parent WD-POM, Keggin POM, and iohexol (5.97 ± 0.14 vs. 4.84 ± 0.05, 4.55 ± 0.16, and 4.30 ± 0.09, respectively). Acute oral (maximum-administered dose (MAD) = 960 mg/kg) and intravenous administration (1/10, 1/5, and 1/3 MAD) of mono-WD POM did not induce unexpected changes in rats' general habits or mortality. Results of blood gas analysis, CO-oximetry status, and the levels of electrolytes, glucose, lactate, creatinine, and BUN demonstrated a dose-dependent tendency 14 days after intravenous administration of mono-WD POM. The most significant differences compared to the control were observed for 1/3 MAD, being approximately seventy times higher than the typically used dose (0.015 mmol W/kg) of tungsten-based contrast agents. The highest tungsten deposition was found in the kidney (1/3 MAD-0.67 ± 0.12; 1/5 MAD-0.59 ± 0.07; 1/10 MAD-0.54 ± 0.05), which corresponded to detected morphological irregularities, electrolyte imbalance, and increased BUN levels.

Arterial supply and morphological characteristics of sympathetic neurons in the human superior cervical ganglion.

The aim of this study was the micromorphological analysis of the distribution of microvessels, mast cells and ganglionic neurons in two parts, proximal and distal of the human superior cervical sympathetic ganglions (SCSGs). Statistical analyses were applied to detect the possible metric regional differences in their densities. Five injected human SCSGs with colored India ink and gelatin were microdissected and examined. Second group of five human SCSGs was prepared and serially sliced for CD34 and mast cell tryptase immunostaining. The microscopic fields of two parts of the SCSGs were analyzed for the following quantifications: microvessel density (MVD), mast cell density (MCD), and ganglionic cell count and measurements. The mean number of CD34-positive microvessels in microscopic fields, the MVD, had a value of 83 for the upper parts, and 82.7 for the lower parts of SCSGs. The mean number of tryptase-positive mast cells in microscopic fields, the MCD, was 4.5 in the proximal parts, and 4.7 in the distal parts of SCSGs. The mean number of ganglionic neurons in microscopic fields was 19.5 in the proximal parts, and 19.8 in the distal parts of SCSGs. The density of CD34-positive microvessels, the density of tryptase-positive mast cells, and the density, mean diameters and mean areas of ganglionic neurons were not significantly different in two observed parts, upper and lower of the SCSGs. In conclusion, the distributions of microvessels, mast cells, and neurons in two parts of the SCSGs were uniform with no specific micromorphological variations, there is a homogenous vascular and cellular pattern within the SCSGs.

Persistent median artery and communicating branch related to the superficial palmar arch.

Microvascular surgery, plastic and reconstructive hand surgery, and coronary artery bypass surgery call for a microanatomical study of the branching pattern of the superficial palmar arch (SPA). For the anatomical analysis, we used a group of 20 dissected human hands injected with 4% formaldehyde solution and a 10% mixture of melted gelatin and India ink. The morphometric study was performed on 40 human hands of adult persons injected with methyl-methacrylate fluid into the ulnar and radial arteries simultaneously and afterwards corroded in 40% KOH solution for the preparation of corrosion cast specimens. The mean diameter of the SPA, between the second and third common palmar digital arteries, was 1.86 ± 0.08 mm. We identified the persistent median artery (PMA) in 5% of hands. We distinguished the three main groups of the SPAs according to variations in morphology and branching of the arch: Type 1, the long SPA; Type 2, the middle length SPA; and Type 3, the short SPA found in 27.5% of specimens. The communicating branch (CB), a vessel interconnecting the SPA to the closest branch of the radial artery, is classified into two different morphological groups. The third type of incomplete short arterial arch is the most important of the three groups of SPAs. That short SPA is potentially inadequate for restoring circulation after occlusion or radial artery harvesting for coronary artery bypass.

In vivo toxicity evaluation of a polyoxotungstate nanocluster as a promising contrast agent for computed tomography.

In this study, we demonstrate for the first time, that a discrete metal-oxo cluster α-/ß-K6P2W18O62 (WD-POM) exhibits superior performance as a computed tomography (CT) contrast agent, in comparison to the standard contrast agent iohexol. A toxicity evaluation of WD-POM was performed according to standard toxicological protocols using Wistar albino rats. The maximum tolerable dose (MTD) of 2000 mg/kg was initially determined after oral WD-POM application. The acute intravenous toxicity of single WD-POM doses (1/3, 1/5, and 1/10 MTD), which are at least fifty times higher than the typically used dose (0.015 mmol W kg-1) of tungsten-based contrast agents, was evaluated for 14 days. The results of arterial blood gas analysis, CO-oximetry status, electrolyte and lactate levels for 1/10 MTD group (80% survival rate) indicated the mixed respiratory and metabolic acidosis. The highest deposition of WD-POM (0.6 ppm tungsten) was found in the kidney, followed by liver (0.15 ppm tungsten), for which the histological analysis revealed morphological irregularities, although the renal function parameters (creatinine and BUN levels) were within the physiological range. This study is the first and important step in evaluating side effects of polyoxometalate nanoclusters, which in recent years have shown a large potential as therapeutics and contrast agents.

Acute Peripheral Facial Nerve Palsy in Children and Adolescents: Clinical Aspects and Treatment Modalities.

BACKGROUND: Peripheral facial nerve palsy is a relatively frequent, rather idiopathic, and isolated nonprogressive disorder with a tendency toward spontaneous recovery in children. It is primarily characterized by unilateral paresis or paralysis of the mimic musculature affecting verbal communication, social interactions, and quality of life. OBJECTIVE: This study aimed to evaluate the clinical aspects and efficacy of different therapeutic modalities in the population of children and adolescents with acute peripheral facial nerve palsy, the quality and recovery rate in comparison to different therapy modalities and etiological factors as well as to determine parameters of recovery according to the age of patients. METHODS: The retrospective study included children and adolescents (n=129) with an acute onset of peripheral facial nerve palsy, diagnosed and treated in the Clinic of Neurology and Psychiatry for Children and Youth in Belgrade (2000-2018). The mean age of the patients was 11.53 years (SD±4.41). Gender distribution: 56.6% female and 43.4% male patients. RESULTS: There were 118 (91.5%) patients with partial and 11 (8.5%) patients with complete paralysis. Left-sided palsy occurred in 67 (51.9%) patients, right-sided in 58 (45.0%), while there were 4 (3.1%) bilateral paralyses. The most common etiological factor was idiopathic (Bell's palsy) - 74 (57.4%) patients followed by middle ear infections - 16 (12.4%). Regardless of etiology, age, and therapy protocols, there was a significant recovery in most of the patients (p<0.001), without significant differences in recovery rate. Comparison of inpatient and outpatient populations showed significant differences regarding the number of relapses, severity of clinical presentation, and recovery rate in relation to etiology. CONCLUSION: Bell's palsy is shown to be the most common cause of peripheral facial nerve palsy in children and adolescents, regardless of gender. It is followed by mid-ear infections, respiratory infections, and exposure to cold. Most children and adolescents recovered in three weeks after initial presentation, regardless of etiology, age, and therapy.

In vivo toxicity evaluation of two polyoxotungstates with potential antidiabetic activity using Wistar rats as a model system.

In this study, the in vivo hypoglycemic effect of a donut-shaped polyanion salt (NH4)14[Na@P5W30O110]·31H2O {NaP5W30} and its Ag-containing derivative K14[Ag@P5W30O110]·22H2O·6KCl {AgP5W30}, as well as their hepatotoxicity and nephrotoxicity, was evaluated. In the screening hypoglycemic study, Wistar albino rats with streptozotocin induced diabetes were treated intraperitoneally with three single doses (5, 10, and 20 mg per kg per b.w.) of both investigated polyoxotungstates. The blood glucose levels, measured before and after 2, 4 and 6 h polyoxotungstate application, showed that both studied compounds induced the most pronounced and time dependent glucose lowering effects at the doses of 20 mg kg-1. Thus, daily doses of 20 mg kg-1 were administered to Wistar albino rats orally for 14 days in further toxicity examinations. The serum glucose concentration and biochemical parameters of kidney and liver function, as well as a histopathological analysis of kidney and liver tissues were evaluated 14 days after the polyoxotungstate administration. Both investigated compounds did not induce statistically significant alterations of the serum glucose and uric acid concentrations, as well as some of the liver function markers (serum alanine and aspartate aminotransferases, and alkaline phosphatase activities). However, the significant decrease in serum total protein and albumin concentrations and the increase in biochemical parameters of renal function - serum urea (up to 63.1%) and creatinine concentrations (up to 23.3%) were observed for both polyoxotungstates. In addition, the detected biochemical changes were in accordance with kidney and liver histhopathological analysis. Accordingly, the hepatotoxic and nephrotoxic effects of these potential antidiabetic polyoxotungstates could be considered as mild.

Silver Nanomaterials in Contemporary Molecular Physiology Research.

Silver nanoparticles have numerous potential applications in engineering, industry, biology and medicine. Because of their unique chemical properties, they have become the focus of many research teams all over the world. Silver nanoparticles may exhibit significant antimicrobial and anticancer effects, and they may be a valuable part of various bioassays and biosensors. However, the research on biological and medical uses of AgNPs is related with numerous potential problems and challenges that need to be overcome in the years ahead. Possible toxic effects of silver nanoparticles on living organisms represent a great concern, both in clinical medicine and public health. Nevertheless, in the future, it may be expected that all metallic nanomaterials, including the ones made from silver will greatly benefit almost all natural scientific fields. In this short review, we focus on the recent research on silver nanoparticles in experimental physiology, as well as other areas of fundamental and clinical medicine.

Toxicity evaluation of two polyoxotungstates with anti-acetylcholinesterase activity.

A toxicity evaluation of two Keggin-type heteropolytungstates, K7[Ti2PW10O40]·6H2O and K6H[SiV3W9O40]·3H2O, with different inhibitory potencies toward acetylcholinesterase activity (IC50 values of 1.04×10-6 and 4.80×10-4mol/L, respectively) was performed. Wistar albino rats were orally treated with single doses (5 and 50mg/kg) of both investigated compounds. The biochemical parameters of renal (serum urea and creatinine) and liver function (direct and total bilirubin, alanine transaminase, and aspartate aminotransferase) were determined after 24h and 14days. A histopathological analysis of liver tissue was carried out 14days after the polyoxotungstate administration. Both applied doses of the investigated compounds did not induce statistically significant alterations of the renal function markers. However, the polyoxotungstate treatment caused an increase in the activities of serum alanine transaminase and aspartate aminotransferase in a time- and concentration-dependent manner, although statistically significant changes in bilirubin concentrations were not observed. Furthermore, the detected hepatotoxic effect was confirmed by histhopathological analysis that suggested some reversible liver tissue damage two weeks after the treatment, especially in the case of K6H[SiV3W9O40]·3H2O. Accordingly, the toxicity of these two polyoxotungstates with anti-acetylcholinesterase effect cannot be considered as a severe one, but their potential clinical application would require a more complex toxicological study.

Chromatin Fractal Organization, Textural Patterns, and Circularity of Nuclear Envelope in Adrenal Zona Fasciculata Cells.

Despite previous research efforts in the fields of histology and cell physiology, the relationship between chromatin structural organization and nuclear shape remains unclear. The aim of this research was to test the existence and strength of correlations between mathematical parameters of chromatin microarchitecture and roundness of the nuclear envelope. On a sample of 240 nuclei of adrenal zona fasciculata cells stained using the DNA-specific Feulgen method, we quantified fractal parameters such as fractal dimension and lacunarity, as well as textural parameters such as angular second moment (ASM), entropy, inverse difference moment, contrast, and variance. Circularity of the nuclear envelope was determined from the nuclear area and perimeter. The results indicate that there is a statistically significant negative correlation between chromatin ASM and circularity. Moreover, there was a statistically significant positive correlation between chromatin fractal dimension and envelope circularity. This is the first study to demonstrate these relationships in adrenal tissue, and also one of the first studies to test the connection between circularity and fractal and gray-level co-occurrence matrix parameters in DNA-specific Feulgen stain. The results could be useful both as an addition to the current knowledge on chromatin/nuclear envelope interactions, and for design of future computer-assisted research software for evaluation of nuclear morphology.

Fractal analysis and Gray level co-occurrence matrix method for evaluation of reperfusion injury in kidney medulla.

Fractal analysis and Gray level co-occurrence matrix method represent two novel mathematical algorithms commonly used in medical sciences as potential parts of computer-aided diagnostic systems. In this study, we tested the ability of these methods to discriminate the kidney medullar tissue suffering from reperfusion injury, from normal tissue. A total of 320 digital micrographs of Periodic acid-Schiff (PAS) - stained kidney medulla from 16 Wistar albino mice (20 per animal), were analyzed using National Institutes of Health ImageJ software (NIH, Bethesda, MD) and its plugins. 160 micrographs were obtained from the experimental group with induced reperfusion injury, and another 160 were obtained from the controls. For each micrograph we calculated the values of fractal dimension, lacunarity, as well as five GLCM features: angular second moment, entropy, inverse difference moment, GLCM contrast, and GLCM correlation. Discriminatory value of the parameters was tested using receiver operating characteristic (ROC) analysis, by measuring the area below ROC curve. The results indicate that certain features of GLCM algorithm have excellent discriminatory ability in evaluation of damaged kidney tissue. Fractal dimension and lacunarity as parameters of fractal analysis also had a relatively good discriminatory value in differentiation of injured from the normal tissue. Both methods have potentially promising application in future design of novel techniques applicable in cell physiology, histology and pathology.

White Matter Changes in Two Leber's Hereditary Optic Neuropathy Pedigrees: 12-Year Follow-Up.

We are presenting two Leber's hereditary optic neuropathy (LHON) pedigrees with abnormal magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (H-MRS) findings but without neurological manifestation associated with LHON. The study included 14 LHON patients and 41 asymptomatic family members from 12 genealogically unrelated families. MRI showed white matter involvement and H-MRS exhibited metabolic anomalies within 12 LHON families. Main outcome measures were abnormal MRI and H-MRS findings in two pedigrees. MRI of the proband of the first pedigree showed a single demyelinating lesion in the right cerebellar hemisphere, while the proband of the second family displayed multiple supratentorial and infratentorial lesions, compatible with the demyelinating process, and both the absolute choline (Cho) concentration and Cho/creatinine ratio were increased. MRI and H-MRS profiles of both affected and unaffected mitochondrial DNA mutation carriers suggest more widespread central nervous involvement in LHON. Although even after 12 years our patients did not develop neurological symptoms, MRI could still be used to detect possible changes during the disease progression.

Morphometric analysis of the fascicular organisation of the optic nerve.

BACKGROUND/AIM: The optic nerve is anatomically observed in four segments: intrabulbar, orbital, canalicular, and cranial. According to the literature, the surface of the transversal cut of the nerve is different through it. The aim of this study was to evaluate the fascicular organisation of the optic nerve, throughout its three segments fromthe eye. METHODS: Five pairs of optic nerves, obtained from the autopsies were examined. Using Heidenhain's (azan) staining, the cuts were prepared for microscopy. Morphometric analysis was performed using the stereological methods for morphometric cytology--the Weible's testing system M42. The following measures were established: the surface of the transverse cut of the nerve, the entire surface of fasciculi, the entire surface of connective tissue and blood vessels, the number of fasciculi, the surface of a single fasciculus. RESULTS: The surface of the transverse cut of the nerve was found to grow from the orbital to the cranial segment, as well as the entire surface of fasciculi. While their number is significantly lower in the cranial segment, the number of fasciculi varied slightly between the orbital and the canalicular segment. The surface of a single fasciculus grows from the bulb to the chiasma. There is probable a cause to believe that this may be due to fusion of the "small" fasciculi in the orbitocranial direction. CONCLUSION: There are significant differences among the examined parameters of the different parts of the optic nerve.

Leber hereditary optic neuropathy in the population of Serbia.

BACKGROUND: Leber hereditary optic neuropathy (LHON) is the most common mitochondrial disorder. However, few countries have published their population-based findings related to this multisystemic disease. THE AIM: In order to get a better insight into the epidemiological and clinical picture of this maternally inherited disorder, we performed the first population-based clinical and molecular-genetic study of LHON in the Serbian population. METHODS: Prospective study included patients who were diagnosed with LHON after detailed medical examination and molecular-genetic confirmation. RESULTS: We identified 41 individuals from 12 genealogically unrelated families, carrying one of the three "primary" mitochondrial (mt) DNA point mutations associated with LHON. Fourteen of them were clinically affected, giving a minimum point prevalence of 1.9 per 1,000,000. The minimum point prevalence for mtDNA LHON mutations was 5.2 per 1,000,000. Male to female ratio was 6:1. Only one affected patient harboured mutant mtDNA in heteroplasmic condition. All patients were presented with common clinical findings. CONCLUSION: We observed significantly lower prevalence and higher gender ratio than expected. However, frequencies of primary mutations, incidence of heteroplasmy and clinical findings are in accordance with other studies in Caucasoid populations. Our results might be a consequence of poor recognition and misdiagnosis due to lack of diagnostic possibilities of the entity in different region of our country or less likely be in part due to specific haplotype background of Serbian population which should be further investigated.

Intramesencephalic course of the oculomotor nerve fibers: microanatomy and possible clinical significance.

Comprehension of the mesencephalic syndromes that affect oculomotor nerve fascicles requires a detailed knowledge of their relationship with the adjacent structures and the blood supply of the central midbrain region. This was the reasoning behind our study, which was performed in ten serially sectioned midbrains stained with cresyl violet and luxol fast blue, in three microdissected midbrains, and in two injected and cleared specimens. Three continuous groups of the intramesencephalic oculomotor nerve fascicles were distinguished: the caudal, intermediate and rostral. The caudal fascicles, which most likely innervate the superior rectus and the levator palpebrae superioris muscles, extend through the superior cerebellar peduncle just caudal to the red nucleus and close to the lateral lemniscus. The intermediate fascicles, devoted to the medial rectus and the inferior oblique muscles, always pass through the superior cerebellar peduncle, just medial to the caudal part of the red nucleus (60 %), and less frequently (40 %) through the nucleus itself. The rostral oculomotor fascicles, which terminate in the inferior rectus and sphincter pupillae muscles, course medial to the rostral part of the red nucleus. While the rostral and intermediate oculomotor fascicles are supplied only by the medial twigs of the paramedian mesencephalic perforating arteries, the caudal fascicles are also nourished by the lateral branches of the same perforating arteries. The data obtained form an important basis for the explanation of certain mesencephalic syndromes, and even anticipate some new syndromes not yet described in the literature.

Morphometric analysis, region of supply and microanatomy of the lenticulostriate arteries and their clinical significance.

The lenticulostriate arteries (LSA) and their microanatomy, region of supply and atherosclerosis were examined in 24 microdissected brains, arterial casts, and histological specimens. The LSA ranged from 2 to 12 in number and from 0.10 mm to 1.28 mm in diameter. They always arose from the initial segment of the middle cerebral artery (MCA), often from the MCA leptomeningeal branches (38.24%), and rarely from the insular segment (2.94%). They always originated as individual branches, often (61.76%) with their own common stems. In two hemispheres we found that the LSA supplied either a larger or a smaller portion of the basal ganglia and internal capsule than usual. The number of twigs to the innominate substance (substantia innominata) (3-11), and their diameters (0.07-0.30 mm), has been described for the first time, to our knowledge. Microatheromas were found in two LSA. Data about the LSA microanatomy and territory could form the basis of safer neurosurgery, more accurate neuroimaging evaluation, and precise neurological diagnosis in patients with focal ischemic lesions in the basal ganglia and internal capsule.

Cochlea and other spiral forms in nature and art.

BACKGROUND: The original appearance of the cochlea and the specific shape of a spiral are interesting for both the scientists and artists. Yet, a correlation between the cochlea and the spiral forms in nature and art has been very rarely mentioned. AIM: The aim of this study was to investigate the possible correlation between the cochlea and the other spiral objects in nature, as well as the artistic presentation of the spiral forms. METHODS: We explored data related to many natural objects and examined 13,625 artworks created by 2049 artists. We also dissected 2 human cochleas and prepared histologic slices of a rat cochlea. RESULTS: The cochlea is a spiral, cone-shaped osseous structure that resembles certain other spiral forms in nature. It was noticed that parts of some plants are arranged in a spiral manner, often according to Fibonacci numbers. Certain animals, their parts, or their products also represent various types of spirals. Many of them, including the cochlea, belong to the logarithmic type. Nature created spiral forms in the living world to pack a larger number of structures in a limited space and also to improve their function. Because the cochlea and other spiral forms have a certain aesthetic value, many artists presented them in their works of art. CONCLUSIONS: There is a mathematical and geometric correlation between the cochlea and natural spiral objects, and the same functional reason for their formation. The artists' imagery added a new aspect to those domains. Obviously, the creativity of nature and Homo sapiens has no limits--like the infinite distal part of the spiral.

Vasculature and neurovascular relationships of the trigeminal nerve root.

BACKGROUND: Specific microanatomical characteristics of the trigeminal nerve root (TNR) blood supply and close neurovascular relationships with surrounding vessels as well as their possible clinical significance were the main reasons for this study. METHOD: The vasculature of 25 adult and four fetal TNRs were microdissected and examined under the stereoscopic microscope, after injecting their arteries with India ink. RESULTS: The trigeminal vessels, which varied between two and five in number, arose from two or three of the following arteries: the superolateral pontine (92%), anterior inferior cerebellar (AICA) (88%), inferolateral pontine (72%), and superior cerebellar (SCA) (12%). The trigeminal vascular twigs had a mean diameter of 0.215 mm. A single vessel may supply either the motor portion of the nerve root or the sensory portion or both. The trigeminal vasculature formed the proximal and distal rings. The proximal ring was located at the trigeminal root entry zone. Its central branches extended along the TNR to the principal sensory and motor trigeminal nuclei while its peripheral longitudinal twigs followed the TNR fascicles. The incomplete distal arterial ring embraced the middle portion of the TNR before the level of its entrance into the arachnoid sleeve. The most frequent contact of the TNR was noticed with the SCA (20%), the petrosal or Dandy's vein (24%), and the AICA (12%). CONCLUSIONS: The observed characteristics of the TNR vasculature could be the anatomical basis for decompressive neurovascular surgery.

[Vasculature of the distal part of optic nerve].

BACKGROUND/AIM: Vascularisation of the distal, namely intracranial and intracanalicular parts of the optic nerve have not been explained in conventional textbooks of anatomy, while there have been explanations of proximal, that is intraorbital segment. The aim of this research was to study the pattern of arterial supply of the intracranial and intracanalicular part (the distal part) of human optic nerve. METHODS: The optic nerve and the ophthalmic artery (OA), predominately in their intracranial and intracanalicular parts, were investigated in 25 human specimens by three different methods: macroscopic, stereomicroscopic, and histological observations. Mixture with 10% of India ink and gelatin was injected through the intracranial part of the internal carotid artery, and the most proximal part of the OA. Each optic canal specimen was fixed in formaldehyde and finally paraffin embedded, sectioned, and stained with Masson trichrome, Azan, Toluidin blue, and Van Gieson methods. RESULTS: OA passed through the optic canal within the dural sheath of the optic nerve. In 44% of our specimens the OA was on the inferomedial side of the optic nerve at the entrance point to the optic canal. OA left the optic canal at its lateral border in the apex of the orbit in 72% of our specimens. The intracanalicular portion of the optic nerve receives arterial blood principally from the intracanalicular part of OA. OA gives one (72% of the specimens) to two branches that supply the intracanalicular part of the optic nerve. Each branch pierces the dura mater from below and then supplies the nerve through the pia mater. These arteries then terminate in a pial vascular network of continuous transverse centripetal arterioles and capillaries that surround each optic nerve. The rich anastomoses with branches of superior hypophyseal artery, from the cranial cavity, which take part in the optic nerve vascularization in its hole length, was observed. There were no intraaxial vessels in the intracranial and intracanalicular parts of the nerve in our specimens. CONCLUSION: These anatomical data offer important informations for understanding the variety of the pathology in the region of optic canal and orbito-cranial junction, and is also useful for designing operative strategies. This report indicates the delicacy and vulnerability of the intracranial and intracanalicular capillary network to traumatic disruption.

Immunohistochemistry of displaced sensory neurons in the trigeminal nerve root.

The aim of this study was to examine the morphology and the immunohistochemical features of displaced ganglion cells in the trigeminal nerve root (TNR). Forty human TNRs of 20 persons, obtained during routine autopsy in accordance with the Declaration of Helsinki, were examined following Klüver-Barrera and azan trichrome histological staining, and immunohistochemical reactions against certain neuronal markers, neuropeptides and neurotransmitters. A total number of 61 displaced neurons were investigated, which were present in 80% of individuals studied. Displaced neurons were found in 55.0% of the TNRs, either in the sensory portion (22.5%), motor portion (22.5%) or both (10.0%). Neuronal diameter varied from 12.5 x 25.0 to 45.0 x 63.7 (mean 27.6 x 41.6) microm, and in area between 245 and 2,065 (mean 927) microm(2). Each neuron was surrounded by 2-17 elongated satellite cells per slice. The immune reaction was positive in all the neurons studied for neuron-specific enolase, protein gene product 9.5, neurofilament protein and synaptophysin, and in some neurons for calcitonin gene-related peptide (CGRP; 24.4%), cholecystokinin (CCK; 13.3%), somatostatin (SST; 17.8%), substance P (SP; 15.6%), vasoactive intestinal polypeptide (4.4%), neuropeptide Y (8.9%), and serotonin (11.1%). The immune reactions were most frequent against the CGRP, SP, CCK and SST. We concluded that displaced neurons in the TNR morphologically and immunohistochemically resembled the sensory neurons in the trigeminal ganglion.

Ultrastructure and immunohistochemistry of the trigeminal peripheral myelinated axons in patients with neuralgia.

OBJECTIVE: Detailed ultrastructural and immunohistochemical examination of the trigeminal axons surrounded by the peripheral type of the myelin could add new information about the extent of the trigeminal nerve lesion in neuralgia. PATIENTS, MATERIALS AND METHODS: The examination comprised, firstly, the 10 trigeminal nerve roots (TNRs) in which the neurovascular contact was found in 20% of the cases, and the 2 additional control TNRs. Secondly, the biopsy specimens were taken from 6 patients with trigeminal neuralgia and 2 patients with trigeminal neuropathy following a partial TNR rhizotomy. The specimens were examined under the electron microscope (EM) and/or using the immunohistochemical (IHC) methods. RESULTS: In addition to the central zone of demyelination, the EM examination of the TNR also revealed alterations of the peripheral myelin, i.e. deformation, thickening, demyelination and remyelination, as well as changes of the peripheral axons, that is, atrophy or hypertrophy, neurofilaments increase, loss of the myelin and sprouting occasionally. Some Schwann cells were also damaged. The IHC examination usually showed a moderate immune reaction against neuron-specific enolase (NSE) and protein gene product 9.5 (PGP9.5), but sporadically weaker reaction against the S-100 protein, synaptophysin (SY), neurofilament protein (NFP) and glial fibrillary acidic protein (GFAP). The substance P (SP) and calcitonin gene-related peptide (CGRP) immunoreactivity was weak at some sites, but strong at some other places. CONCLUSIONS: The pathological changes affect not only the central nerve fibers of the TNR, but also some of the peripheral axons, their myelin sheath and Schwann cells. These are signs of the retrograde ultrastructural and biochemical alterations, which could participate in the pathophysiological mechanism underlying the trigeminal neuralgia.