War-related stress scale

BACKGROUND

The current war in Ukraine has affected the well-being of people worldwide. In order to understand how difficult the situation is, specific stressors associated with war need to be measured. In response, an inventory of war-related stressors including its short form, has been developed.

METHODS

A list of potential war-related stressors was created, and the content validity of each item assessed. The list, along with other validated scales, was administered to a representative sample of the Slovak population (effective N = 1851). Exploratory factor analysis, confirmatory factor analysis, convergent validity analysis and network analysis were carried out to determine the optimal scale (long and short form) focused on war-related stressors.

RESULTS

The full version of the scale consists of 21 items, further divided into three factors: society-related stressors, person-related stressors, and security-related stressors. The short version of the scale comprises nine items loaded onto one factor. These items cover concerns for one's safety and future, access to necessities, potential worsening of the economic situation, and the risk of conflict escalation, including a nuclear threat. The results of the network analysis indicate that concern about escalation and fear of an economic crisis play a central role.

CONCLUSIONS

The scale attempts to encompass a wide spectrum of areas that are affected by war and its potential consequences on individuals who reside outside the conflict zone. Given the complexity of the issue, researchers are invited to modify the scale, tailoring it to specific cultural, geographical, and temporal contexts.

Risk and protective factors for (internet) gaming disorder: A meta-analysis of pre-COVID studies

This large-scale meta-analysis aimed to provide the most comprehensive synthesis to date of the available evidence from the pre-COVID period on risk and protective factors for (internet) gaming disorder (as defined in the DSM-5 or ICD-11) across all studied populations. The risk/protective factors included demographic characteristics, psychological, psychopathological, social, and gaming-related factors. In total, we have included 1,586 effects from 253 different studies, summarizing data from 210,557 participants. Apart from estimating these predictive associations and relevant moderating effects, we implemented state-of-the-art adjustments for publication bias, psychometric artifacts, and other forms of bias arising from the publication process. Additionally, we carried out an in-depth assessment of the quality of underlying evidence by examining indications of selective reporting, statistical inconsistencies, the typical power of utilized study designs to detect theoretically relevant effects, and performed various sensitivity analyses. The available evidence suggests the existence of numerous moderately strong and highly heterogeneous risk factors (e.g., male gender, depression, impulsivity, anxiety, stress, gaming time, escape motivation, or excessive use of social networks) but only a few empirically robust protective factors (self-esteem, intelligence, life satisfaction, and education; all having markedly smaller effect sizes). We discuss the theoretical implications of our results for prominent theoretical models of gaming disorder and for the existing and future prevention strategies. The impact of various examined biasing factors on the available evidence seemed to be modest, yet we identified shortcomings in the measurement and reporting practices.

A case of congenital multiple epiphyseal dysplasia from the Late Migration Period graveyard in Drnholec (Czech Republic)

OBJECTIVE

To contribute to differential diagnosis of multiple epiphyseal dysplasia (MED) in archeological and clinical contexts.

MATERIALS

A skeleton of a 30- to 45-year-old male (grave no. 806) from the Late Migration Period graveyard in Drnholec-Pod sýpkou (Czech Republic), radio-carbon dated to AD 492-530.

METHODS

Morphological and metric analyses.

RESULTS

Significant pathological changes were noted on ossa coxae and proximal ends of the femora, which appear similar to changes associated with Legg-Calvé-Perthes disease. X-ray examination made it possible to rule out pseudoachondroplasia, rickets and metabolic bone diseases.

CONCLUSIONS

The finding was evaluated as a probable case of congenital multiple epiphyseal dysplasia.

SIGNIFICANCE

This case will contribute to the construction of estimates of the occurrence of this disease in historical populations and can be instructive for diagnostics in current medical practice.

LIMITATIONS

The final diagnosis is limited by the lack of genetic analysis.

SUGGESTION FOR THE FUTURE RESEARCH

Further clarification leading to diagnosis will benefit from genetic analysis and evaluation of skeletal remains throughout Europe.

Measuring various aspects of coronavirus anxiety: a psychometric evaluation of Pandemic anxiety and Coronophobia scales from the latent and network perspective

Since the outbreak of COVID-19, understanding and describing the changes in experiences related to the pandemic and its correlates have become crucial. The current study aims to provide a psychometric evaluation and examination of the relationship of two COVID-related anxiety scales through the latent and network approach. The data was collected from the same participants at two time points (Nwave 1 = 1283; Nwave 2 = 1326). The study examined the psychometric properties of the Pandemic Anxiety Scale and Coronaphobia scale. It also examined the factor structure, invariance and relationship with selected variables through both the latent and network approach. The results revealed that both scales provided good fit and psychometric properties-PAS (wave1: CFI = 0.97, TLI = 0.95, RMSEA = 0.05 [0.04, 0.07], SRMR = 0.048; wave2: CFI = 0.97, TLI = 0.95, RMSEA = 0.05 [0.04, 0.07], SRMR = 0.049), and Coronaphobia scale (wave1: CFI = 0.99, TLI = 0.98, RMSEA = 0.05 [0.03, 0.07], SRMR = 0.027; wave2: CFI ~ 1, TLI = 0.99, RMSEA = 0.03 [0.002, 0.06], SRMR = 0.015). The results also indicated that distinguishing between them is crucial as they were related differently to various variables. The global network models provided a more complex insight in their connections with the set of selected variables. The PAS and Coronaphobia scales are brief and valid measures that can be used in research looking at mental health issues related to the pandemic. The present study shows a unique pattern of relationships of these scales with other variables, extending previous studies into the topic of COVID-related anxiety.

Manifestation of infantile scurvy in a skeleton from the high medieval village of Trutmanice (South Moravia, Czech Republic)

The study describes the pathological findings recorded on the human remains of a 3 to 4-year-old child found in the burial site of Trutmanice (Czech Republic), dated to the 13^th-15^th century. The human remains were examined using standard macroscopic osteological and paleopathological methods, supplemented by radiographic examination. Although the preservation of the bones limited the analysis, multiple pathological changes were observed mainly on the skull: cribra orbitalia, small pores and fine deposits of newly formed bone tissue, hypertrophic diploë, grooves indicating rich branching of meningeal arteries on the intracranial surface of the cranial vault. A very fine periostotic deposition of newly formed bone tissue was also observed at the distal end of the diaphysis of the right tibia and both distal ends of the femora. The radiographs of the femora showed white lines of Frankel, scurvy lines, and Wimberger's rings. The observed pathological changes were possibly consistent with scurvy based on differential diagnosis. Reports about cases of juvenile scurvy from rural areas within the context of landlocked countries of Central Europe are rare. While scurvy is now more frequently reported in the paleopathological literature, evidence for scurvy within one of the most natural agricultural areas in the Czech lands remains rare. We recommend using radiographic examination to complement the diagnosis of scurvy in future paleopathological and epidemiological studies of past populations.

Occurrence of calcaneal spurs on skeletal remains of historical populations in the context of footwear development

This communication is focused on monitoring the occurrence of plantar and dorsal exostoses (spurs) on the calcanei of skeletons from various dated historical periods. A total of 361 calcanei from 268 individuals were evaluated (prehistoric sites - Podivín, Modřice, Mikulovice; mediaeval sites - Olomouc-Nemilany, Trutmanice; modern age sites - the former Municipal Cemetery in Brno in Malá Nová Street, collections of the Department of Anatomy, Masaryk University, Brno). Differences in period footwear for individual population samples were taken into account when interpreting the findings. Health defects were sought for individual types of historical footwear, which could have a causal connection with the occurrence of exostoses on the calcanei. Plantar calcaneal spur occurred most frequently in the mediaeval population (23.5 %; N = 51), less frequently in prehistory (14.1 %; N = 85) and least in modern times (9.8%; N = 132). Similar results were observed for dorsal calcaneal spur in the attachment of the Achilles tendon, but with higher values. In the Middle Ages, its incidence was highest (47.0 %; N = 51), followed by prehistoric times (32.9 %; N = 85), with the least found from the modern age (19.9 %; N = 132). However, the results obtained correspond only to a certain extent to the defects in footwear in the relevant historical period.

Slovak parents' mental health and socioeconomic changes during the COVID-19 pandemic

The changes in people's mental health have become one of the hot topics during the COVID-19 pandemic. Parents have been said to be among the most vulnerable groups in terms of the imposed anti-pandemic measures. The present paper analyzes the trends in mental health indicators in a sample of Slovak parents (N = 363) who participated in four waves of data collection over a year and a half of the COVID-19 pandemic. The mental health indicators were represented by general levels of depression and anxiety as well as COVID-related stress and anxiety. While there were only minor changes in depression and anxiety, the dynamic in COVID-related stress and especially anxiety was more noteworthy. Besides some exceptions, the results hold even after controlling for the socioeconomic situation. The gender differences in the mental health trends were found to be negligible. Overall, we observed no substantial deterioration in the mental health indicators across the four waves of the study.

A very rare case of possible actinomycosis of the mandible from the Middle Ages

OBJECTIVE

Documented cases of actinomycosis in archaeological skeletons are very rare, especially from Central Europe. Our contribution will help facilitate the differential diagnosis of this disease for other paleopathologists.

MATERIAL

This paper describes a pathological finding of the skeleton of a 40-year-old male from a burial ground in Sady-Špitálky (Czech Republic) dated to the 10th-12th century.

METHODS

The affected skeleton was evaluated as a probable case of actinomycosis on the basis of a detailed macroscopic, X-ray and histological examination. The osteolytic foci examined were compared with similar changes caused by tuberculosis, syphilis and mycoses.

RESULTS

The character and location of the defect on the mandible is indicative of organ actinomycosis and is also reflected by the lytic lesion observed on a lumbar vertebra.

CONCLUSIONS

The described case can be considered one of the very rare paleopathological findings of possible actinomycosis in humans in Central Europe.

SIGNIFICANCE

Good evidence of bone actinomycosis findings may be beneficial for further paleopathological and epidemiological studies, especially for research focused on the diachronic development of actinomycosis in Europe. In doing so, all available factors, such as hygiene habits, nutrition, social structure and overall health of the population that could be causally related to its origin, course and treatment, can be taken into account.

LIMITATIONS

The mandible of the studied individual was damaged, especially in the area affected by the lesion, so the paleopathological analysis was difficult to perform.

SUGGESTION FOR THE FUTURE RESEARCH

In future, actinomycosis in this skeleton may be confirmed by bio-molecular analysis.

The possibilities of studying human embryos and foetuses using micro-CT: a technical note

The purpose of the study was to discover a way to study the internal structure and evolution of human embryos noninvasively. The human embryo was stained with phosphotungstic acid solution (PTA) in ethanol (EPTA) and scanned using a micro computed tomography (micro-CT) scanner. Using appropriate software, a three-dimensional image of the embryo was created, which could be further exploited. The methodology described could be used for the non-destructive examination of the internal structure of the human embryo, and the resulting data can be used as a resource for medical students, gynaecologists, and paediatricians.

Variability of the pronator teres muscle and its clinical significance

While investigating the cause of entrapment syndrome of the peripheral nerves in the elbow region, we observed variability of the pronator teres muscle and the relationship of this muscle to the median nerve and the surrounding vessels. Attention was also paid to the occurrence of the supracondylar process of the humerus and Struthers' ligament with regard to their ontogenetic and phylogenetic development. For this purpose, a classical anatomical dissection of the upper limbs of 68 adults, three fetuses and a phylogenetic assessment of five mammalian species was performed. In terms of variability in the anatomical structures of the elbow region, we found the most serious clinical condition to be where the median nerve ran through the pronator canal together with the ulnar vessels (1.5%), or when it passed through the ulnar head of the pronator teres (5.9%). The pronator teres examined by us in fetuses showed the same arrangement as in adult individuals, including the created ulnar head. The occurrence of a supracondylar process and Struthers' ligament was not observed in our collection. The presence of these structures was not confirmed during the fetal period, either. The phylogenetic part of the study re-opened the question of the meaning and function of the entepicondylar foramen, because we noted differences in the occurrence of this structure in two related genera with a very similar way of life (Djungarian hamster and golden hamster).

Tumors in the 18th and 19th centuries at Brno, Czech Republic

Symptoms signs of benign and malignant tumors were observed during paleopathological analysis of skeletal remains from the city of Brno in the Czech Republic. Approximately 1,200 skeletons were examined from two Modern era archaeology sites: the Malá Nová ulice (Little New Street) cemetery and the cemetery of the Nemocnice Milosrdných bratrí (Merciful Brothers' Hospital). Osteomas, usually located on the flat bones of the cranial vault, were the most frequent skeletal pathology. Symptoms signs of malignant tumors were observed in three cases. In one case lytic foci caused by the metastases of a malignant tumor in the soft tissue was observed. Traces of myeloma multiplex were found in two individuals. Living conditions in that period, and possible carcinogenic environmental influences were assessed for the general population of Brno. This report contributes to a better understanding of the historical development of cancers and the clarification of possible causes for their modern increase of incidence.

The effects of DPP-IV inhibition in NOD mice with overt diabetes

Sitagliptin is a dipeptidyl peptidase IV (DPP-IV) inhibitor that exerts an anti-hyperglycaemic effect by preventing degradation of glucagon-like peptide 1 with subsequent β-cell stimulation and potential regeneration. We tested whether sitagliptin therapy in symptomatic non-obese diabetic (NOD) mice would lead to changes in the immune cell profile, improve β-cell survival and induce diabetes remission. Flow cytometry analysis of immune cells in the spleen and peripheral lymph nodes, immunohistology of the pancreas and DPP-IV activity were investigated in diabetic NOD mice, either treated or non-treated with sitagliptin, at 0, 7, 14 and 28 days after hyperglycaemia onset, and in non-diabetic NOD controls. While compared to diabetic controls sitagliptin prevented increase of the CD8+/CD4+ ratio in pancreatic nodes after four weeks (0.443 ± 0.067 vs. 0.544 ± 0.131; P < 0.05), the population of Tregs in lymph nodes increased from day 0 to 28 in both treated and non-treated diabetic groups (8 ± 1.76 vs. 13.45 ± 5.07 % and 8 ± 1.76 vs. 13.19 ± 5.58 %, respectively). The severity of islet infiltration was similar in both diabetic groups and decreased in parallel with β-cell loss. Surprisingly, sitagliptin blocked the DPP-IV activity only temporarily (on day 7, 277.68 ± 89.2 vs. 547.40 ± 94.04 ng/ml in the diabetic control group) with no apparent effect later on. In conclusion, sitagliptin administered after the onset of overt hyperglycaemia in NOD mice had only a marginal immunological effect and did not lead to diabetes remission. Failure to block DPP-IV over time represents an important finding that requires further explanation.

Extracellular space diffusion and extrasynaptic transmission

The diffusion of neuroactive substances in the extracellular space (ECS) plays an important role in short- and long-distance communication between nerve cells and is the underlying mechanism of extrasynaptic (volume) transmission. The diffusion properties of the ECS are described by three parameters: 1. ECS volume fraction alpha (alpha=ECS volume/total tissue volume), 2. tortuosity lambda (lambda2=free/apparent diffusion coefficient), reflecting the presence of diffusion barriers represented by, e.g., fine neuronal and glial processes or extracellular matrix molecules and 3. nonspecific uptake k'. These diffusion parameters differ in various brain regions, and diffusion in the CNS is therefore inhomogeneous. Moreover, diffusion barriers may channel the migration of molecules in the ECS, so that diffusion is facilitated in a certain direction, i.e. diffusion in certain brain regions is anisotropic. Changes in the diffusion parameters have been found in many physiological and pathological states in which cell swelling, glial remodeling and extracellular matrix changes are key factors influencing diffusion. Changes in ECS volume, tortuosity and anisotropy significantly affect the accumulation and diffusion of neuroactive substances in the CNS and thus extrasynaptic transmission, neuron-glia communication, transmitter "spillover" and synaptic cross-talk as well as cell migration, drug delivery and treatment.

[The role of the extracellular space in biology of glial brain tumors]

The size, geometry and composition of the extracellular space (ECS) play an important role in influencing the biological behavior of primary brain tumors. Experiments employing the real-time TMA iontophoretic method to determine the size and geometry of the ECS, by monitoring the diffusion of TMA ions in the ECS, revealed a dramatic increase in ECS size in brain neoplasms when compared with that of unaffected brain cortex. Further, the increase of ECS volume in tumors was shown to correlate with increasing proliferative activity and increasing cellularity of astrocytomas. The increase in ECS size was surprisingly accompanied by a significant increase in diffusion barriers, slowing the diffusion of molecules in the ECS of tumors. In low-grade tumors, diffusion is hindered by the presence of a dense net of tumor cell processes. In high-grade gliomas, in which the cellular processes are shortened with reduced branching, the increase in diffusion barriers is caused by the overproduction of specific components of the extracellular matrix (ECM) by the tumor cells, mainly tenascin. The ECM glycoproteins produced represent a substrate for the subsequent adhesion and migration of tumor cells through the enlarged ECS. However, they might also critically reduce the diffusion of therapeutics into the tumor. The presence of tenascin in the ECS of a neoplasm correlates significantly with the increased malignancy of the tumor and a poor clinical outcome of the disease, thus making the immunohistochemical detection of tenascin diagnostically useful as a prognostic marker and a marker of aggressive biological behavior of tumors.

Extracellular matrix glycoproteins and diffusion barriers in human astrocytic tumours

The extracellular matrix (ECM) and changes in the size and geometry of the extracellular space (ECS) in tumour tissue are thought to be of critical importance in influencing the migratory abilities of tumour cells as well as the delivery of therapeutic agents into the tumour. In 21 astrocytic neoplasms, the ECM composition was investigated in situ by the immunohistochemical detection of ECM glycoproteins (tenascin, laminin, vitronectin, fibronectin, collagen types I-VI). To explain the changes in ECS size and to detect barriers to diffusion in the tumour tissue, the ECM composition, the cellularity, the density of glial fibrillary acidic protein (GFAP)-positive tumour cell processes and the proliferative activity of the tumours were compared with the size and geometry of the ECS. The ECS volume fraction and the complex of hindrances to diffusion in the ECS (i.e. the tortuosity) were revealed by the real-time iontophoretic tetramethylammonium method. Increased proliferative activity of the tumours correlated with increased ECS volume fraction and tortuosity. The tortuosity of the tumour tissue was not significantly influenced by tumour cell density. Higher tortuosity was found in low-grade astrocytomas associated with the presence of a dense net of GFAP-positive fibrillary processes of the tumour cells. The increase in tortuosity in high-grade tumours correlated with an increased accumulation of ECM molecules, particularly of tenascin. We conclude that the increased malignancy of astrocytic tumours correlates with increases in both ECS volume and ECM deposition.

Changes in extracellular space volume and geometry induced by cortical spreading depression in immature and adult rats

Changes in extracellular space (ECS) diffusion parameters, DC potentials and extracellular potassium concentration were studied during single and repeated cortical spreading depressions (SD) in 13-15 (P13-15), 21 (P21) and 90-day-old (adult) Wistar rats. The real-time iontophoretic method using tetramethylammonium (TMA+)-selective microelectrodes was employed to measure three ECS parameters in the somatosensory cortex: the ECS volume fraction alpha (alpha = ECS volume/total tissue volume), ECS tortuosity lambda (increase in diffusion path length) and the nonspecific TMA+ uptake k'. SD was elicited by needle prick. SD was significantly longer at P13-15 than at P21 and in adults. During SD, alpha in all age groups decreased from 0.21-0.23 to 0.05-0.09; lambda increased from 1.55-1.65 to 1.95-2.07. Ten minutes after SD, alpha (in adults) and lambda (all age groups) increased compared to controls. This increase persisted even 1 hour after SD. When SD was repeated at 1 hour intervals, both alpha and lambda showed a gradual cumulative increase with SD repetition. Our study also shows that cortical SD is, as early as P13, accompanied by severe ECS shrinkage and increased diffusion path length (tortuosity) with values similar to adults, followed by a long-lasting increase in ECS volume and tortuosity when compared to pre-SD values.

Glutamate, NMDA, and AMPA induced changes in extracellular space volume and tortuosity in the rat spinal cord

Glutamate release, particularly in pathologic conditions, may result in cellular swelling. The authors studied the effects of glutamate, N-methyl-D-aspartate (NMDA), and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) on extracellular pH (pH(e)), extracellular potassium concentration ([K(+)](e)), and changes in extracellular space (ECS) diffusion parameters (volume fraction alpha, tortuosity lambda) resulting from cellular swelling. In the isolated spinal cord of 4-to 12-day-old rats, the application of glutamate receptor agonists induced an increase in [K(+)](e), alkaline-acid shifts, a substantial decrease in alpha, and an increase in lambda. After washout of the glutamate receptor agonists, alpha either returned to or overshot normal values, whereas lambda remained elevated. Pretreatment with 20 mmol/L Mg(++), MK801, or CNQX blocked the changes in diffusion parameters, [K(+)](e) and pH(e) evoked by NMDA or AMPA. However, the changes in diffusion parameters also were blocked in Ca(2+)-free solution, which had no effect on the [K(+)](e) increase or acid shift. The authors conclude that increased glutamate release may produce a large, sustained and [Ca(2+)](e)-dependent decrease in alpha and increase in lambda. Repetitive stimulation and pathologic states resulting in glutamate release therefore may lead to changes in ECS volume and tortuosity, affecting volume transmission and enhancing glutamate neurotoxicity and neuronal damage.

Effect of osmotic stress on potassium accumulation around glial cells and extracellular space volume in rat spinal cord slices

In rat brain and spinal cord slices, the local extracellular accumulation of K(+), as indicated by K(+) tail currents (I(tail)) after a depolarization step, is greater in the vicinity of oligodendrocytes than that of astrocytes. It has been suggested that this may reflect a smaller extracellular space (ECS) around oligodendrocytes compared to astrocytes [Chvátal et al. [1997] J. Neurosci. Res. 49:98-106; [1999] J. Neurosci. Res. 56:493-505). We therefore compared the effect of osmotic stress in spinal cord slices from 5-11-day-old rats on the changes in reversal potentials (V(rev)) of I(tail) measured by the whole-cell patch-clamp technique and the changes in ECS volume measured by the real-time iontophoretic method. Cell swelling induced by a 20 min perfusion of hypoosmotic solution (200 mmol/kg) decreased the ECS volume fraction from 0.21 +/- 0.01 to 0.15 +/- 0.02, i.e., by 29%. As calculated from V(rev) of I(tail) using the Nernst equation, a depolarizing prepulse increased [K(+)](e) around astrocytes from 11.0 to 44.7 mM, i.e., by 306%, and around oligodendrocytes from 26.1 to 54.9 mM, i.e., by 110%. The ECS volume fraction decrease had the same time course as the changes in V(rev) of I(tail). Cell shrinkage in hyperosmotic solution (400 mmol/kg) increased ECS volume fraction from 0.24 +/- 0.02 to 0.32 +/- 0.02, i.e., by 33%. It had no effect on [K(+)](e) evoked by a depolarizing prepulse in astrocytes, whereas in oligodendrocytes [K(+)](e) rapidly decreased from 52 to 26 mM, i.e., by 50%. The increase in ECS volume was slower than the changes in [K(+)](e). These data demonstrate that hypoosmotic solution has a larger effect on the ECS volume around astrocytes than around oligodendrocytes and that hyperosmotic solution affects the ECS volume around oligodendrocytes only. This indicates that increased K(+) accumulation in the vicinity of oligodendrocytes could be due to a restricted ECS. Oligodendrocytes in the CNS are therefore most likely surrounded by clusters of "compacted" ECS, which may selectively affect the diffusion of neuroactive substances in specific areas and directions and facilitate spatial K(+) buffering.

Poly[N-(2-hydroxypropyl)methacrylamide] polymers diffuse in brain extracellular space with same tortuosity as small molecules

Integrative optical imaging was used to show that long-chain synthetic poly[N-(2-hydroxypropyl)methacrylamide] (PHPMA) polymers in a range of molecular weights from 7.8 to 1057 kDa were able to diffuse through the extracellular space in rat neocortical slices. Tortuosity (square root of ratio of diffusion coefficient in aqueous medium to that in brain) measured with such polymers averaged 1.57, a value similar to that obtained previously with tetramethylammonium, a small cation. When PHPMA was conjugated with bovine serum albumin (BSA) to make a bulky polymer with molecular weight 176 kDa, the tortuosity rose to 2.27, a value similar to that obtained previously with BSA alone and with 70-kDa dextran. The method of image analysis was justified with diffusion models involving spherical and nonspherical initial distributions of the molecules.

Glial swelling and astrogliosis produce diffusion barriers in the rat spinal cord

Cell swelling and astrogliosis (manifested as an increase in GFAP) were evoked in isolated rat spinal cords of 4-21-day-old rats by incubation in either 50 mM K+ or hypotonic solution (235 mosmol kg(-1)). Application of K+ and hypotonic solution resulted at first in a decrease of extracellular space (ECS) volume fraction alpha (ECS volume/total tissue volume) and an increase in tortuosity lambda (lambda2 = free/apparent diffusion coefficient) in spinal gray (GM) and white matter (WM). These changes resulted from cell swelling, since the total water content (TW) in spinal cord was unchanged and the changes were blocked in Cl- -free solution and slowed down by furosemide and bumetanide. Diffusion in WM was anisotropic, i.e., more facilitated along fibers (x-axis) than across them (y- or z-axis). The increase of lambda(y,z) was greater than that of lambda(x), reaching unusually high values above 2.4. In GM only, during continuous 45 min application, alpha and lambda started to return towards control values, apparently due to cell shrinkage of previously swollen cells since TW remained unchanged. This return was blocked by fluoroacetate, suggesting that most of the changes were due to the swelling of glia. A 45 min application of 50 mM K+ and, to a lesser degree, of hypotonic solution evoked astrogliosis, which persisted after washing out these solutions with physiological saline. During astrogliosis lambda increased again to values as high as 2.0, while alpha either returned to or increased above control values. This persistent increase in lambda after washout was also found in WM, and, in addition, the typical diffusion anisotropy was diminished. Our data show that glial swelling and astrogliosis are associated with a persistent increase in ECS diffusion barriers. This could lead to the impairment of the diffusion of neuroactive substances, extrasynaptic transmission, "crosstalk" between synapses and neuron-glia communication.

Heterogeneous PHPMA hydrogels for tissue repair and axonal regeneration in the injured spinal cord

A biocompatible heterogeneous hydrogel of poly[N-(2-hydroxypropyl) methacrylamide] (PHPMA) showing an open porous structure, viscoelastic properties similar to the neural tissue and a large surface area available for cell interaction, was evaluated for its ability to promote tissue repair and axonal regeneration in the transected rat spinal cord. After implantation, the polymer hydrogel could correctly bridge the tissue defect, from a permissive interface with the host tissue to favour cell ingrowth, angiogenesis and axonal growth occurred within the microstructure of the network. Within 3 months the polymer implant was invaded by host derived tissue, glial cells, blood vessels and axons penetrated the hydrogel implant. Such polymer hydrogel matrices which show neuroinductive and neuroconductive properties have the potential to repair tissue defects in the central nervous system by promoting the formation of a tissue matrix and axonal growth by replacing the lost of tissue.

Heterogeneous and anisotropic diffusion in the developing rat spinal cord

Extrasynaptic transmission is mediated by the diffusion of transmitters, through the extracellular space (ECS) to receptors on neurons and glia. The three-dimensional diffusion of tetramethylammonium (mol. wt 74.1 kDa) was investigated in the isolated rat spinal cord at postnatal days 4-20. The diffusion parameters of the ECS, volume fraction alpha, tortuosity lambda (lambda2 = free/apparent diffusion coefficient in tissue) and nonspecific uptake k', were different in gray and white matter. In both gray and white matter, alpha decreased with neuronal development and gliogenesis by about 15% while lambda significantly increased. Diffusion in gray matter remained isotropic (lambda = 1.65), while in white matter it became anisotropic, i.e. easier along the fibers (lambda = 1.38) than across the fibers (lambda = 1.80). Anisotropy increased in the second postnatal week, during pronounced myelination. In myelinated tissue, preferential diffusion of neuroactive substances occurs along the axons.

Dynamic changes in water ADC, energy metabolism, extracellular space volume, and tortuosity in neonatal rat brain during global ischemia

To obtain a better understanding of the mechanisms underlying early changes in the brain water apparent diffusion coefficient (ADC) observed in cerebral ischemia, dynamic changes in the ADC of water and in the energy status were measured at postnatal day 8 or 9 in neonatal rat brains after cardiac arrest using 1H MRS/MRI and 31P MRS, respectively. The time courses of the MR parameters were compared with changes in the extracellular space (ECS) volume fraction (alpha) and tortuosity (lambda), determined from concentration-time profiles of tetramethylammonium applied by iontophoresis. The data show a decrease of the ADC of tissue water after induction of global ischemia of which the time course strongly correlates with the time course of the decrease in the ECS volume fraction and the increase in ECS tortuosity. This indicates that cell swelling is an important cause for the ADC decrease of water.

Uncommon course of the ulnar artery through the pronator teres muscle

In this paper, we describe a very rare variant in the course of the ulnar artery that we encountered in dissecting the right upper limb of a 74-year-old man. The ulnar artery arose standardly from the brachial artery in the cubital fossa. However, its ensuing course differed from the norm. The artery entered together with the ulnar vein and median nerve into the pronator canal (between the humeral and ulnar heads of the pronator teres). Further, the ulnar artery descended classically to the ulnar side of the forearm between the flexor carpi ulnaris and flexor digitorum superficialis. Knowledge of this variation in the course of the ulnar artery may have significance in clinical practice because accumulation of anatomical structures in the pronator canal could be a predisposing factor for the compression of nerve or blood vessels. Keywords: anatomical variation; median nerve; pronator canal; pronator teres muscle; ulnar artery.