Hosing of a Long Relativistic Particle Bunch in Plasma

Experimental results show that hosing of a long particle bunch in plasma can be induced by wakefields driven by a short, misaligned preceding bunch. Hosing develops in the plane of misalignment, self-modulation in the perpendicular plane, at frequencies close to the plasma electron frequency, and are reproducible. Development of hosing depends on misalignment direction, its growth on misalignment extent and on proton bunch charge. Results have the main characteristics of a theoretical model, are relevant to other plasma-based accelerators and represent the first characterization of hosing.

Challenges in prospective observational studies evaluating pressure ulcer costs: how to price the items correctly

OBJECTIVE

Pressure ulcers (PUs) are a significant healthcare problem with a negative impact on patients' quality of life and incurring substantial healthcare expenses. Our study aimed to analyse the costs of treating PUs in hospitalised patients in the Czech Republic, in the context of current treatment procedures and price levels, and to pilot-test the detailed methodology developed.

METHOD

A prospective, observational, non-interventional study was conducted at the Clinic of Anesthesiology, Resuscitation and Intensive Medicine, the Internal Medicine Department and the Surgical Department of the University Hospital Ostrava. The study included all hospitalised patients with a PU from March-May 2021. Data were collected using the hospital information system. A bottom-up, person-based approach to cost analysis was used, based on a comprehensive cost structure using accurate patient-specific consumption records.

RESULTS

The length of hospitalisations ranged from 1-31 (mean: 12.7) days. The average cost of PU treatment per hospitalisation was calculated at €1579. The average daily cost of PU treatment was €179, including antibiotic therapy (ATB) and €112 without ATB. Most of the costs were associated with ATB (38.6%) and caregivers' time (35.9%). Based on the results, a predictive model was developed to estimate the cost of treating a hospitalised patient with a PU, which could be used in future research to assess the costs of treating these patients.

CONCLUSION

We have faced many challenges in the methodology of preparation of cost analysis (e.g., how to count amorphous topical agents and sprays, how to properly identify PUs, how to price the positioning aids and mattresses, and how to relate the ATB treatment to the PU). This analysis provides important input for developing a comprehensive and more accurate methodology for monitoring PU costs in hospitalised patients, applicable in clinical practice for inpatient healthcare providers.

Controlled Growth of the Self-Modulation of a Relativistic Proton Bunch in Plasma

A long, narrow, relativistic charged particle bunch propagating in plasma is subject to the self-modulation (SM) instability. We show that SM of a proton bunch can be seeded by the wakefields driven by a preceding electron bunch. SM timing reproducibility and control are at the level of a small fraction of the modulation period. With this seeding method, we independently control the amplitude of the seed wakefields with the charge of the electron bunch and the growth rate of SM with the charge of the proton bunch. Seeding leads to larger growth of the wakefields than in the instability case.

Film or mirror? The exploration of narratives during the road from recognition to recovery of addictive disorders

Introduction

The examination of the cinematic metanarrative provides many possibilities for recovery-oriented addiction consultation. The key to efficiency can be the approach of the recipient’s point of view and attitude, with which the client can interpret his own traumas and life story retrospectively.

Objectives

Our aim is to show that the recognition, the turning points, the acknowledgement and the recovery from addiction can be described as a model in the deep structure of recovery stories. Can narrative research explore more deeply the main stages of recovery andidentity shaping, with the possible use of the film’s narrative technique?

Methods

12 recovering addicts were interviewed who have been clean for at least 4 years. Interviews covered the years spent as addicts and the path to recovery using the method of deductive metanarrative analysis.

Results

Based on the results of the analysis, elements of the film narrative could be found together major psychoanalysis concepts and literary theory models in the semi-structured interviews. Emotion control dysregulation all appear in the stories. Together these can be traced to a summary narrative and a historical line. Furthermore, the addicted person as a hero, the compulsion to repeat and its spookiness, and the role of the helpers also appear in the retrospective narratives without exception.

Conclusions

The well-structured, coherent recovery stories help the recoverer to reconstruct their self, to make the behavioral change permanent, thus reducing the chances of relapse. The film narrative and toolkit provide an opportunity based on similarities with the narrator’s framework, which can strengthen the recovering identity.

Disclosure

No significant relationships.

Transition between Instability and Seeded Self-Modulation of a Relativistic Particle Bunch in Plasma

We use a relativistic ionization front to provide various initial transverse wakefield amplitudes for the self-modulation of a long proton bunch in plasma. We show experimentally that, with sufficient initial amplitude [≥(4.1±0.4)  MV/m], the phase of the modulation along the bunch is reproducible from event to event, with 3%-7% (of 2π) rms variations all along the bunch. The phase is not reproducible for lower initial amplitudes. We observe the transition between these two regimes. Phase reproducibility is essential for deterministic external injection of particles to be accelerated.

Possible relationships of addictive disorders and attention deficit hyperactivity disorder (ADHD)

Introduction

One of the most recent topics in addictive disorders is videogame-use disorder which is continuously under research, especially in adolescents. The specific structure of digital games (immortality, infinity, etc.) can sensitize adolescents to the development of problematic use. The number of researches about problematic video game use has increased significantly during the last decade. In 2013, this problem was included among “Disorders requiring further research” in DSM-5, and it was also included in ICD-11 as a separate diagnostic category in 2019.

Objectives

We review studies investigating the association between the co-occurrence of ADHD and video game use in adolescents. We attempt to summarize new theoretical approaches to video game use disorder and the areas of present research.

Methods

We conducted a literature search in 4 databases (PubMed, Medline, Google Scholar, Web of Science) using keywords (ADHD, adolescents, video game use disorder, internet addiction, game addiction) over the past 5 years. Exclusion criteria were the following: publication date before 2014, adult population, or comorbidity beside ADHD.

Results

The comorbidity of video game use disorder and ADHD was frequent. Primarily cross-sectional studies examined the presence of hyperactivity, attention deficit, and impulsivity symptoms separately. The presence of attention deficit clearly showed an association with the development of video game use disorder.

Conclusions

Adolescents diagnosed with ADHD have a greater possibility of developing video game use disorder and/or problematic psychoactive substance users. More attention should be paid to this comorbidity in not only the diagnostic process, but also in the development of prevention programs.

Disclosure

No significant relationships.

Proton Bunch Self-Modulation in Plasma with Density Gradient

We study experimentally the effect of linear plasma density gradients on the self-modulation of a 400 GeV proton bunch. Results show that a positive or negative gradient increases or decreases the number of microbunches and the relative charge per microbunch observed after 10 m of plasma. The measured modulation frequency also increases or decreases. With the largest positive gradient we observe two frequencies in the modulation power spectrum. Results are consistent with changes in wakefields' phase velocity due to plasma density gradients adding to the slow wakefields' phase velocity during self-modulation growth predicted by linear theory.

Proton-driven plasma wakefield acceleration in AWAKE

In this article, we briefly summarize the experiments performed during the first run of the Advanced Wakefield Experiment, AWAKE, at CERN (European Organization for Nuclear Research). The final goal of AWAKE Run 1 (2013-2018) was to demonstrate that 10-20 MeV electrons can be accelerated to GeV energies in a plasma wakefield driven by a highly relativistic self-modulated proton bunch. We describe the experiment, outline the measurement concept and present first results. Last, we outline our plans for the future. This article is part of the Theo Murphy meeting issue 'Directions in particle beam-driven plasma wakefield acceleration'.

It Is Not Necessary to Discontinue Seizure Threshold-Lowering Medications Prior to Myelography

BACKGROUND AND PURPOSE

There is no consensus on whether patients undergoing myelography should discontinue medications that could lower their seizure threshold. The purpose of this study was to document the most commonly prescribed seizure threshold-lowering medications in patients undergoing myelography and determine whether withholding such medications decreases the incidence of seizures.

MATERIALS AND METHODS

We performed a retrospective observational study of all the myelograms obtained in 2016 at 2 affiliated hospitals. At hospital A, seizure threshold-lowering medications are discontinued before myelography, and prophylactic diazepam is given for all cervical myelograms. At hospital B, seizure threshold-lowering medications are not withheld before the procedure, and medical seizure prophylaxis is not implemented. The seizure threshold-lowering medications the patients were taking at the time of the procedure and postmyelographic seizure incidence were documented.

RESULTS

A total of 311 patients underwent myelography during 2016. One hundred eleven patients (36%) were on at least 1 seizure threshold-lowering medication, and 30 (10%) were on at least 2. The most common medications were duloxetine, sertraline, venlafaxine, bupropion, and trazodone. The most common tricyclic antidepressant was amitriptyline. Three patients across both sites had a controlled seizure disorder and were on antiepileptics. None of the patients at either hospital had seizures during or within 3 hours following any of the myelograms during the study period.

CONCLUSIONS

Continuing seizure threshold-lowering medications during myelography does not increase the risk of seizures. Screening for and withholding seizure threshold-lowering medications are not indicated for routine myelography.

High-frequency forced oscillations in neuronlike elements

We analyzed a generic relaxation oscillator under moderately strong forcing at a frequency much greater that the natural intrinsic frequency of the oscillator. Additionally, the forcing is of the same sign and, thus, has a nonzero average, matching neuroscience applications. We found that, first, the transition to high-frequency synchronous oscillations occurs mostly through periodic solutions with virtually no chaotic regimes present. Second, the amplitude of the high-frequency oscillations is large, suggesting an important role for these oscillations in applications. Third, the 1:1 synchronized solution may lose stability, and, contrary to other cases, this occurs at smaller, but not at higher frequency differences between intrinsic and forcing oscillations. We analytically built a map that gives an explanation of these properties. Thus, we found a way to substantially "overclock" the oscillator with only a moderately strong external force. Interestingly, in application to neuroscience, both excitatory and inhibitory inputs can force the high-frequency oscillations.

Ducks in space: from nonlinear absolute instability to noise-sustained structures in a pattern-forming system

A subcritical pattern-forming system with nonlinear advection in a bounded domain is recast as a slow-fast system in space and studied using a combination of geometric singular perturbation theory and numerical continuation. Two types of solutions describing the possible location of stationary fronts are identified, whose origin is traced to the onset of convective and absolute instability when the system is unbounded. The former are present only for non-zero upstream boundary conditions and provide a quantitative understanding of noise-sustained structures in systems of this type. The latter correspond to the onset of a global mode and are present even with zero upstream boundary conditions. The role of canard trajectories in the nonlinear transition between these states is clarified and the stability properties of the resulting spatial structures are determined. Front location in the convective regime is highly sensitive to the upstream boundary condition, and its dependence on this boundary condition is studied using a combination of numerical continuation and Monte Carlo simulations of the partial differential equation. Statistical properties of the system subjected to random or stochastic boundary conditions at the inlet are interpreted using the deterministic slow-fast spatial dynamical system.

Canards in a minimal piecewise-linear square-wave burster

We construct a piecewise-linear (PWL) approximation of the Hindmarsh-Rose (HR) neuron model that is minimal, in the sense that the vector field has the least number of linearity zones, in order to reproduce all the dynamics present in the original HR model with classical parameter values. This includes square-wave bursting and also special trajectories called canards, which possess long repelling segments and organise the transitions between stable bursting patterns with n and n + 1 spikes, also referred to as spike-adding canard explosions. We propose a first approximation of the smooth HR model, using a continuous PWL system, and show that its fast subsystem cannot possess a homoclinic bifurcation, which is necessary to obtain proper square-wave bursting. We then relax the assumption of continuity of the vector field across all zones, and we show that we can obtain a homoclinic bifurcation in the fast subsystem. We use the recently developed canard theory for PWL systems in order to reproduce the spike-adding canard explosion feature of the HR model as studied, e.g., in Desroches et al., Chaos 23(4), 046106 (2013).

Response to interferon-beta treatment in multiple sclerosis patients: a genome-wide association study

Up to 50% of multiple sclerosis (MS) patients do not respond to interferon-beta (IFN-β) treatment and determination of response requires lengthy clinical follow-up of up to 2 years. Response predictive genetic markers would significantly improve disease management. We aimed to identify IFN-β treatment response genetic marker(s) by performing a two-stage genome-wide association study (GWAS). The GWAS was carried out using data from 151 Australian MS patients from the ANZgene/WTCCC2 MS susceptibility GWAS (responder (R)=51, intermediate responders=24 and non-responders (NR)=76). Of the single-nucleotide polymorphisms (SNP) that were validated in an independent group of 479 IFN-β-treated MS patients from Australia, Spain and Italy (R=273 and NR=206), eight showed evidence of association with treatment response. Among the replicated associations, the strongest was observed for FHIT (Fragile Histidine Triad; combined P-value 6.74 × 10^-6) and followed by variants in GAPVD1 (GTPase activating protein and VPS9 domains 1; combined P-value 5.83 × 10^-5) and near ZNF697 (combined P-value 8.15 × 10^-5).

Inflection, canards and excitability threshold in neuronal models

A technique is presented, based on the differential geometry of planar curves, to evaluate the excitability threshold of neuronal models. The aim is to determine regions of the phase plane where solutions to the model equations have zero local curvature, thereby defining a zero-curvature (inflection) set that discerns between sub-threshold and spiking electrical activity. This transition can arise through a Hopf bifurcation, via the so-called canard explosion that happens in an exponentially small parameter variation, and this is typical for a large class of planar neuronal models (FitzHugh-Nagumo, reduced Hodgkin-Huxley), namely, type II neurons (resonators). This transition can also correspond to the crossing of the stable manifold of a saddle equilibrium, in the case of type I neurons (integrators). We compute inflection sets and study how well they approximate the excitability threshold of these neuron models, that is, both in the canard and in the non-canard regime, using tools from invariant manifold theory and singularity theory. With the latter, we investigate the topological changes that inflection sets undergo upon parameter variation. Finally, we show that the concept of inflection set gives a good approximation of the threshold in both the so-called resonator and integrator neuronal cases.

Interleukin 6-174G>C polymorphism and risk of aneurysmal subarachnoid hemorrhage: case-control study and meta-analysis

OBJECTIVES

Vascular inflammation contributes to the pathogenesis of aneurysmal subarachnoid hemorrhage (aSAH). Interleukin 6 (IL6) is a proinflammatory cytokine involved in many vascular pathologies. Two studies analyzing an association of the functional IL6 gene -174G>C promoter polymorphism with aSAH provided inconsistent results. The aim of this study was to investigate whether this IL6 polymorphism is associated with aSAH in a Polish population.

MATERIAL AND METHODS

We genotyped 276 aSAH patients and 581 unrelated control subjects. All were of Caucasian origin. In addition, a meta-analysis combining results of the current and previously published studies was conducted.

RESULTS

The distribution of IL6 genotypes and alleles did not differ significantly between aSAH (GG - 29.7%, GC - 50.0%, CC - 20.2%, G - 54.7%) and control subjects (GG - 32.0%, GC - 47.3%, CC - 20.7%, G - 44.3%). In the meta-analysis, the IL6-174G>C polymorphism was not associated with aSAH risk either.

CONCLUSIONS

We failed to find an association between the IL6 -174G>C polymorphism and aSAH in analyzed European populations.

[Neurotrauma in treatment of nervous system injuries--principles in cooperating with anesthesiologists]

After brain trauma neuronal degeneration results due to the combination of primary mechanical disruption of CNS parenchyma and the secondary pathophysiological events. The fact that the treatment can modified the clinical course and the final outcome, implies that is indeed a modifiable secondary neurodegenerative process which is caused by the mechanical injury. Contemporary in patients with craniocerebral trauma and with polytrauma our management is focused on prevention of secondary brain injury. On the accident scene that is crucial to appropriate ventilate the patient, stabilize blood pressure and prevent shock. The diagnostic tool of choice is CT, but made in the very early stage could revealed false negative scan. That could be the cause of missed beginning of intracranial pressure increase in artificially ventilated patients. Multimodality monitoring in highly specialized centers could enable early detection of such increase (ICP) and help in estimation of indication for surgical treatment. The mechanism, direct sequelae of head trauma and neurological symptoms dynamics are also important.

Expression of mRNA for growth hormone-releasing hormone and splice variants of GHRH receptors in human malignant bone tumors

Splice variants (SV) of receptors for growth hormone-releasing hormone (GHRH) have been found in several human cancer cell lines. GHRH antagonists inhibit growth of various human cancers, including osteosarcomas and Ewing's sarcoma, xenografted into nude mice or cultured in vitro and their antiproliferative action could be mediated, in part, through these SV of GHRH receptors. In this study, we found mRNA for the SV(1) isoform of GHRH receptors in human osteosarcoma line MNNG/HOS and SK-ES-1 Ewing's sarcoma line. We also detected mRNA for GHRH, which is apparently translated into the GHRH peptide and secreted by the cells, as shown by the presence of GHRH-like immunoreactivity in the conditioned media of cell cultures. In proliferation studies in vitro, the growth of SK-ES-1 and MNNG/HOS cells was dose-dependently inhibited by GHRH antagonist JV-1-38 and an antiserum against human GHRH. Our study indicates the presence of an autocrine stimulatory loop based on GHRH and SV(1) of GHRH receptors in human sarcomas. The direct antiproliferative effects of GHRH antagonists on malignant bone tumors appear to be exerted through the SV(1) of GHRH receptors on tumoral cells.

Transient Sensitivity of Rat Cerebellar Purkinje Cells to N-methyl-D-aspartate during Development. A Voltage Clamp Study in in vitro Slices

In vitro sagittal slices of immature rat cerebellum were used to study the development of the sensitivity of Purkinje cells (PC) to L-glutamate (Glu) and N-methyl-D-aspartate (NMDA). In 8-day-old animals, all PCs recorded in magnesium-free medium responded to iontophoretic applications of both agonists by transient and dose dependent inward currents which, in both cases, were heavily contaminated by a Glu and NMDA-induced synaptic noise. When 5 x 10-6 M tetrodotoxin (TTX) was added to the perfusing medium, this evoked synaptic noise was completely abolished in most cells whereas clear-cut inward currents induced in PCs by Glu and NMDA applications on their dendrites were still visible. These responses were selectively antagonized by the non-NMDA glutamate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and by the NMDA receptor antagonist D-2-aminophosphono-5-valeric acid (2APV) respectively. Excitatory responses induced by aspartate in 8 - 10-day-old PCs were also markedly antagonized by CNQX. At this stage, the sensitivity of PCs to NMDA was about one order of magnitude less than that to Glu. In 15 - 20-day-old animals, all PCs were still responsive to Glu whereas only 70% of them were still excited by NMDA in the presence of TTX in the bath. Furthermore, the sensitivity of PCs to Glu was higher than at 8 days of age, whereas that to NMDA was significantly lower, even when considering only those cells which still responded to this agonist. This trend was still accentuated later on since at 2 months of age, only 25% of PCs were excited by NMDA whereas their sensitivity to Glu was similar to that observed in 15 - 20-day-old animals. Therefore, the present results are fully consistent with the view that PCs have a transient expression of NMDA receptors during development.

[Brain stereotactic procedures in the Department of Neurotraumatology CM UJ in Cracow]

Stereotactic procedures using Leksell frame have been performed in that Department since 1995, and as jet 199 such operations were carried out. The most frequent complication after stereotaxic biopsies was intracerebral haemorrhage occurring in 0.6 to 7.2% of cases, according to various authors. In the presented material it occurred in 1.3% of biopsies. Besides biopsy, the stereotactic procedures (105 cases) were applied for reducing the size or removal of tumours, including multiple tumours in one or both hemispheres, in one-step operations. The histological diagnoses were based on the examination of HE-stained smears, immunocytochemical reactions and electron microscopic studies. The effectiveness of the operations was assessed in control examinations (CT). The greatest group of cases undergoing stereotaxic surgery were metastatic tumours (47 cases, 61.3%), primary brain tumours were treated in 22 cases (28.57%), meningiomas in 4 (5.19%), abscesses in 3 cases (3.89%). In patients with metastatic tumours improvement was obtained in 97% of cases. One patient died from disseminated malignancies with cardiorespiratory failure. In the remaining patients no worsening of the objective status was noted after stereotaxic surgery.

Targeting of doxorubicin to ES-2 human ovarian cancers in nude mice by linking to an analog of luteinizing hormone-releasing hormone improves its effectiveness

Receptors for luteinizing hormone-releasing hormone (LHRH), expressed by ovarian cancers, can be used for targeting chemotherapeutic compounds more selectively to these tumors. We investigated the effects of cytotoxic LHRH analog AN-152, consisting of doxorubicin (DOX)-14-O-hemiglutarate linked to the epsilon-amino group of [D-Lys6]LHRH, on the growth of LHRH receptor-positive ES-2 human ovarian cancer line xenografted into nude mice. A single injection of AN-152, at a dose of 345 nmol/20 g body weight, caused a 34.5% reduction (P<0.05) in tumor growth after 28 days, while its cytotoxic moiety DOX was inactive at the same dose. Since the overexpression of certain growth factors and/or their receptors, such as vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR) and HER-2/neu, as well as various oncogenes like c-fos and c-jun, is associated with unfavorable prognosis and contributes to progressive growth of ovarian carcinomas, their mRNA levels were analyzed by RT-PCR. Treatment with AN-152 significantly (P<0.05) reduced the expression of EGFR, VEGF, c-fos and c-jun, to 49%, 48%, 55% and 58% respectively, compared to controls. HER-2/neu mRNA expression was also decreased to non-detectable levels. Conversely, DOX decreased non-significantly the expression levels for EGFR by 32%, VEGF 35%, both c-fos and c-jun approximately 20% and HER-2/neu by only 15%. In conclusion, cytotoxic LHRH analog AN-152 could be considered for chemotherapy of ovarian cancers expressing LHRH receptors.

[Post-traumatic bacterial meningitis]

10 patients with posttraumatic bacterial meningitis were treated in the Department of Infectious Diseases of the Jagielloniam University--Collegium Medicum during the period of 63 months. Traffic accidents were responsible for 80% of all cases of trauma. The most common place of injury was the base of anterior cranial fossa. Infecting agent was established in 8 cases. Gram-positive aerobic cocci (Streptococcus pneumoniae, Enterococcus faecalis, and Enterococcus spp.) were found in 4 patients, Gram-negative aerobic cocci (Neisseria meningitidis) in 2 patients, and Gram-negative aerobic rods (Acinetobacter baumanii, Pseudomonas aeruginosa, Klebsiella spp, Escherichia coli) in 3 patients. Streptococcus pneumoniae was still highly sensitive to penicillin, ampicillin and cefotaxime. Enterococcus faecalis and Enterococcus spp. were sensitive to vancomycin and teicoplanin. Neisseria meningitidis was sensitive to penicillin, cefotaxime, amoxicillin/clavulonate. Gram negative aerobic rods were sensitive to third-generation cephalosporins, carbapenems and aminoglycosides. Among 10 patients treated for posttraumatic bacterial meningitis 1 patient died and in 1 preserved vegetative state was diagnosed. In 4 patients severe or moderate disabilities developed, however 4 recovered completely. 6 patients after regression of the CNS infection were qualified to neurosurgical intervention. In 3 patients reconstructive operation of the basis of anterior cranial fossa with tissue glue Beriplast P. was done, the recovery was complete. 3 patients didn't agree to surgical operation, and we don't know what has happened with them. They have not come to the control visit.

Dynamics of the membrana granulosa during expansion of the ovarian follicular antrum

As an endocrine organ, the ovary has some unique characteristics. The formation, the maturation and the regression of the hormone producing cells really determine the timing, the amount and the type of hormone secreted. Here, we focus on the granulosa cells of ovarian follicles which express 17beta-hydroxysteroid dehydrogenase type 1 and cytochrome P450 aromatase. Follicles only produce estradiol late in follicular development before either ovulation or atresia ensues. We discuss the evidence that the membrana granulosa has many characteristics in common with other epithelia, including that it arises from stem cells. The corollary of this is that individual cells within the membrana granulosa are of different ages or stages of specialization. This is evident as regional differences across the membrana granulosa in terms of cell ages, shapes, gene expression, and even behaviour on cell death. We discuss theoretical considerations of the effects of antrum formation on the behavior of the membrana granulosa, and show evidence for differences between follicles in cell shapes, basal lamina phenotypes and location of younger cells, which we speculate is due to different rates of antrum expansion. Clearly, the membrana granulosa is dynamic, and this could explain much about the differences in the behaviors of cells from within the membrana granulosa, and between ovarian follicles.

[Determination of melatonin concentrations in patients with consciousness disturbances after craniocerebral trauma. Preliminary communication]

The study was performed in cooperation of the Department of Neurotraumatology and the Department of Clinical Biochemistry Jagiellonian University in Cracow. In patients with central nervous system injury, diagnosed upon computerized tomography scan, melatonin levels were measured. The most frequent reason of damage was severe craniocerebral trauma. Consciousness, assessed according to Glasgow Coma Scale, was between 3 to 13 points. Melatonin levels were measured at 8 a.m. The investigation could not demonstrate any correlations between consciousness disturbances after head injury and serum melatonin levels in the morning. To draw a final conclusion further experiments are necessary. They will help to explain the role of endogenous melatonin in patients after craniocerebral injury.

Development of the membrana granulosa of bovine antral follicles: structure, location of mitosis and pyknosis, and immunolocalization of involucrin and vimentin

The membrana granulosa of the ovarian follicle is termed the 'follicular epithelium', yet there have been no studies considering its epithelial nature and how it changes during follicular development. Therefore, these issues were investigated using histology (n = 45 ovaries), considering its structure and the location of proliferating and dying cells, and drawing analogies with other epithelia. Additionally, differences between the layers of granulosa cells were demonstrated by immunohistochemistry (n = 7 ovaries). The structure of the membrana granulosa differed between follicles. Six arbitrary classifications were designed based on these structures, 80 follicles were allocated (n = 13 ovaries) to these classes and the follicular diameters were then measured. For the first time, differences in membrana granulosa structure were shown to correspond to follicle size. Follicles in classes 1-3, where basal granulosa cells were columnar with nuclei positioned basally in the cell, were all < or = 3 mm in diameter. All follicles larger than 3 mm had either columnar basal cells with nuclei positioned centrally (class 4), or had rounded basal cells (class 5), and all follicles > 5 mm had only rounded basal cells. In all these classes, cells in the middle zone were rounded; cells aligning the antrum were often flattened. Irrespective of follicle class, cell proliferation and cell death were shown to be predominantly in the middle portions, rather than the most antral or most basal portions, of the membrana granulosa of healthy and atretic follicles. Involucrin, a marker of keratinocyte differentiation, was localized to the suprabasal region of the membrana granulosa of healthy follicles, particularly in the second and third cellular layers in from the follicular basal lamina. Conversely, the staining intensity for the intermediate filament protein vimentin was lowest in this region, and greatest in the more antral and basal regions. In atretic follicles, there was widespread staining for involucrin and vimentin throughout the membrana granulosa. In conclusion, the membrana granulosa is highly structured, and alters with follicular development. Layers in the membrana granulosa can differ in terms of cell shape, and differ in proliferation and gene expression. In the light of the current work, and an associated study, it is proposed that proliferation occurs in the middle layers, and that granulosa cells, then progress basally or antrally, the latter undergoing terminal differentiation.

Roles of extracellular matrix in follicular development

The cellular biology and changes in the extracellular matrix of ovarian follicles during their development are reviewed. During growth of the bovine ovarian follicle the follicular basal lamina doubles 19 times in surface area. It changes in composition, having collagen IV alpha 1-26 and laminin alpha 1, beta 2 and gamma 1 at the primordial stage, and collagen IV alpha 1 and alpha 2, reduced amounts of alpha 3-alpha 5, and a higher content of laminin alpha 1, beta 2 and gamma 1 at the antral stage. In atretic antral follicles laminin alpha 2 was also detected. The follicular epithelium also changes from one layer to many layers during follicular growth. It is clear that not all granulosal cells have equal potential to divide, and we have evidence that the granulosal cells arise from a population of stem cells. This finding has important ramifications and supports the concept that different follicular growth factors can act on different subsets of granulosal cells. In antral follicles, the replication of cells occurs in the middle layers of the membrana granulosa, with older granulosal cells towards the antrum and towards the basal lamina. The basal cells in the membrana granulosa have also been observed to vary in shape between follicies. In smaller antral follicles, they were either columnar or rounded, and in follicles > 5 mm the cells were all rounded. The reasons for these changes in matrix and cell shapes are discussed in relation to follicular development.

Prenatal exposure to the dopamine agonist SKF-38393 disrupts the timing of the initial response of the suprachiasmatic nucleus to light

The abuse of social drugs such as cocaine during pregnancy represents enormous risks to the offspring. Recent studies showed that drugs administered to the pregnant rat can activate cell populations in the fetal brain, possibly altering the timing of key neuronal developmental events. The current study examined the ontogeny of light-responsiveness of the neonatal rat suprachiasmatic nucleus using c-FOS protein in SCN nuclei as a marker. The effect of acute administration of the dopamine D1 agonist, SKF-38393, on the development of light responsiveness was also examined. Pregnant dams received either SKF-38393 (10 mg/kg) or vehicle 7 h after dawn on gestational day 20. Litters were then assigned to one of seven experimental time points from 4 h after subjective dark onset on the day of birth (P0-CT16) at 4-h intervals until CT16 on the day after birth (P1-CT16). Half of the pups in each litter were exposed to a 200 lux/2 h light pulse and the other half remained in darkness. Three time points (P1-CT0, P1-CT8 and P1-CT16) were used to examine the prenatal drug effects on light-responsiveness. Light exposure at the time of subjective lights on, the day after birth (P1-CT0), resulted in a significant increase in c-FOS-positive cells. The number of positive cells recorded in the SCN after a light pulse at P1-CT0 and P1-CT8 was significantly less in SKF-38393 pretreated pups compared to vehicle treated animals. The exposure to dopaminergic stimulation during gestation may have altered the timing of development of afferent connections to the fetal SCN, resulting in alteration of the initial response of the circadian timing system to light.

[Clinical observations concerning piracetam treatment of patients after craniocerebral injury]

Piracetam (Nootropil) is a cytoprotective to brain tissue and improving cerebral blood flow medicine. In the Department of Neurotraumatology we investigated results of piracetam treatment in a group of 100 succeeding patients admitted between 1995-96 due to craniocerebral injury. High doses (24-30 g per day) of this medicine have a positive effect on final result of treatment, when treatment is initiated immediately after the injury and described conditions are abided. We also showed usefulness of piracetam treatment in posthospital management.

[Diagnostic difficulties in a polytrauma case]

Even with the advent of the present diagnostic possibilities, polytraumas are still a serious problem with a large mortality. Owing to the complexity of the clinical picture, severe craniocerebral injury masks other extracerebral signs and creates a risk of unnoticeable injury of another organ. We describe a case of a 63 year-old patient, who suffered a polytrauma in road accident. A typical treatment of traumatic subarachnoid haemorrhage was administered and patient's state of consciousness improved. On 5-th day after the trauma the patient's state deteriorated. The neurological examination didn't reveal intracranial hypertension signs. Increasing anaemia was detected and an extracerebral reason of deterioration was sought. The following x-ray picture of chest was taken revealing elevation of the diaphragm without any other posttraumatic lesions. The patient was selected for thoracosurgical operation because pericordial sac disruption and diaphragm contusion were found. The pericardial sac was sutured. During further treatment the patient's state improved. He was discharged walking and independent.