Managing Temporomandibular Joint Osteoarthritis by Dental Stem Cell Secretome

The potential therapeutic role of the Dental Pulp Stem Cells Secretome (SECR) in a rat model of experimentally induced Temporomandibular Joint (TMJ) Osteoarthritis (OA) was evaluated. Proteomic profiling of the human SECR under specific oxygen tension (5% O2) and stimulation with Tumor Necrosis Factor-alpha (TNF-α) was performed. SECR and respective cell lysates (CL) samples were collected and subjected to SDS-PAGE, followed by LC-MS/MS analysis. The identified proteins were analyzed with Bioinformatic tools. The anti-inflammatory properties of SECR were assessed via an in vitro murine macrophages model, and were further validated in vivo, in a rat model of chemically-induced TMJ-OA by weekly recording of the head withdrawal threshold, the food intake, and the weight change, and radiographically and histologically at 4- and 8-weeks post-treatment. SECR analysis revealed the presence of 50 proteins that were enriched and/or statistically significantly upregulated compared to CL, while many of those proteins were involved in pathways related to "extracellular matrix organization" and "immune system". SECR application in vitro led to a significant downregulation on the expression of pro-inflammatory genes (MMP-13, MMP-9, MMP-3 and MCP-1), while maintaining an increased expression of IL-10 and IL-6. SECR application in vivo had a significant positive effect on all the clinical parameters, resulting in improved food intake, weight, and pain suppression. Radiographically, SECR application had a significant positive effect on trabecular bone thickness and bone density compared to the saline-treated group. Histological analysis indicated that SECR administration reduced inflammation, enhanced ECM and subchondral bone repair and regeneration, thus alleviating TMJ degeneration.

The Effects of Tissue Healing Factors in Wound Repair Involving Absorbable Meshes: A Narrative Review

Wound healing is a complex and meticulously orchestrated process involving multiple phases and cellular interactions. This narrative review explores the intricate mechanisms behind wound healing, emphasizing the significance of cellular processes and molecular factors. The phases of wound healing are discussed, focusing on the roles of immune cells, growth factors, and extracellular matrix components. Cellular shape alterations driven by cytoskeletal modulation and the influence of the 'Formin' protein family are highlighted for their impact on wound healing processes. This review delves into the use of absorbable meshes in wound repair, discussing their categories and applications in different surgical scenarios. Interleukins (IL-2 and IL-6), CD31, CD34, platelet rich plasma (PRP), and adipose tissue-derived mesenchymal stem cells (ADSCs) are discussed in their respective roles in wound healing. The interactions between these factors and their potential synergies with absorbable meshes are explored, shedding light on how these combinations might enhance the healing process. Recent advances and challenges in the field are also presented, including insights into mesh integration, biocompatibility, infection prevention, and postoperative complications. This review underscores the importance of patient-specific factors and surgical techniques in optimizing mesh placement and healing outcomes. As wound healing remains a dynamic field, this narrative review provides a comprehensive overview of the current understanding and potential avenues for future research and clinical applications.

Bartha-K61 vaccine protects nursery pigs against challenge with novel european and asian strains of suid herpesvirus 1

The present study investigates the pathogenicity of two recently isolated strains of Suid herpesvirus 1 (SuHV1), the Greek strain Hercules and the Chinese strain HeN1, in unvaccinated pigs and in pigs vaccinated with a Bartha-K61 strain. In an experiment performed in negative pressure kiosks (isolators), 45-day old seronegative pigs previously oronasally /intramuscularly vaccinated with the Bartha-K61 vaccine strain, along with unvaccinated controls, were challenged either with the Hercules strain or the HeN1 strain of SuHV1. All animals were observed daily for clinical signs and body temperature and nasal swabs, faeces, blood and bodyweight were collected up to a maximum period of 20 days post-challenge (dpc). The results showed that, in the unvaccinated pigs, HeN1 strain was more virulent than the Hercules strain, with increased mortality, shorter time to death and higher group clinical score (p < 0.05). However, after vaccination with the Bartha-K61 vaccine, there was a drastic reduction in morbidity, mortality, bodyweight loss and virus excretion to almost a similar extent in both strains (p < 0.05). No significant differences were seen among the pigs of the two vaccinated groups compared to unvaccinated unchallenged controls, except a slight elevation in body temperature and in clinical score in the HeN1 vaccinees at 2 and 3 dpc, while bodyweight gain was similar to that of the negative control pigs. Our study showed that despite differences in virulence, the standard vaccination scheme with the Bartha-K61 strain could equally protect nursery pigs against both the European and Chinese strains.

Age-Dependent Invasion of Pseudorabies Virus into Porcine Central Nervous System via Maxillary Nerve

Pseudorabies virus (PRV) is the causative agent for Aujeszky’s disease, a disease that mainly affects pigs and incidentally other domestic and wild animals. While PRV is almost always fatal, causing neurological disease independently of the age in non-porcine species, the development of neurological manifestation in its host species, the pig, highly depends on the age. In this study, an attempt was made to investigate the effect of nerve development on the outcome of virus infection and the effect of virus infection on the structure of nerves in piglets of various ages. For that reason, 42 pigs at the age of one (n = 14), three (n = 14) and five (n = 14) weeks were inoculated with 10⁷ TCID₅₀ of PRV Kaplan strain and euthanized at one- or four-days post inoculation (DPI). The tissues of the trigeminal nervous pathway were collected and examined for virus replication (titration) in cell cultures for nerve morphology by light and transmission electron microscopy, and for viral antigen visualization by immunohistochemistry. The results showed that as the age of the pig increases, virus titers and clinical manifestations reduced, while, at the same time, myelin and axon development ceased. Following infection, the nerve structure was disrupted at all ages examined, being more prominent in one-week-old pigs compared to five-week-old pigs. In conclusion, the age-dependent PRV neuroinvasion in pigs seems to correlate with the morphological changes of neurons.

The Combined Use of Platelet-Rich Plasma and Adipose-Derived Mesenchymal Stem Cells Promotes Healing. A Review of Experimental Models and Future Perspectives

Wound healing and tissue regeneration are a field of clinical medicine presenting high research interest, since various local and systematic factors can inhibit these processes and lead to an inferior result. New methods of healing enhancement constantly arise, which, however, require experimental validation before their establishment in everyday practice. Platelet-rich plasma (PRP) is a well-known autologous factor that promotes tissue healing in various surgical defects. PRP derives from the centrifugation of peripheral blood and has a high concentration of growth factors that promote healing. Recently, the use of adipose-derived mesenchymal stem cells (ADMSCs) has been thoroughly investigated as a form of wound healing enhancement. ADMSCs are autologous stem cells deriving from fat tissue, with a capability of differentiation in specific cells, depending on the micro-environment that they are exposed to. The aim of the present comprehensive review is to record the experimental studies that have been published and investigate the synergistic use of PRP and ADMSC in animal models. The technical aspects of experimentations, as well as the major results of each study, are discussed. In addition, the limited clinical studies including humans are also reported. Future perspectives are discussed, along with the limitations of current studies on the long-term follow up needed on efficacy and safety.

Adrenal glands of mice and rats: A comparative morphometric study

Mice and rats are among the most used laboratory animals. They share numerous similarities along with differences, some yet unexplored. One of them is the morphometry of their adrenal glands, whose characteristics may be related to differences in energy management, immune response, drug metabolism, behaviour and temperament. The present study tries to fill this knowledge gap with the evaluation and comparison of adrenal gland anatomical/morphometric parameters of mice and rats. In groups of 10 (n = 10) adult, male and female BALB/c mice and Wistar rats, one in every 20 sections transverse to the longitudinal axis of the gland was used for measuring entire gland area, capsule, entire cortex, cortex zones and medulla with the aid of an image analysis system and subjected to statistical analysis. Quotients of the individual areas were calculated and comparison between the resulting ratios was performed. Gland length and volume were also calculated. Statistically significant differences were revealed between the rat female and male cortex area, rat and mouse medulla/cortex, medulla/gland, zona glomerulosa/cortex and cortex/gland ratios, male and female rats' medulla/cortex, medulla/gland, capsule/gland, zona glomerulosa/cortex, zona reticularis/cortex and zona glomerulosa/zona fasciculata ratios, length and volume. The correlation evaluation revealed that in male rats and in female mice the larger medulla area was accompanied by a larger cortex area and vice versa. In general, a larger cortex area was accompanied by larger areas of cortex zones. The collected data and the revealed differences can possibly contribute to the understanding of the physiology of the two species.

Birth and death of neurons in the developing and mature mammalian brain

Neuron birth and death are two contradictory processes, yet serving the same purpose of the formation of the brain. They coexist during brain development, when cytoarchitecture and synaptic contacts are progressively established. It is the highly programmed interplay between these two processes that results in the making of a mature, complex-wired, functional brain. Neurogenesis is the process that begins with the birth of naïve new neurons, which are gradually specified to their prospective cell fate, translocate through migratory streams to the brain area they are destined for and terminally differentiate into mature neurons that integrate into neuronal networks with sophisticated functions. This is an ongoing process until adulthood, when it mediates brain neuroplasticity. Neuron death is the process through which the fine sculpting and modeling of the brain is achieved. It serves to adjust final neuron numbers, exerting quality control on neurons that birth has generated or overproduced. It additionally corrects early wiring and performs systems matching by negatively selecting neurons that fail to gain neurotransmitter-mediated neuronal activity or receive neurotrophic support for maintenance and function. It is also a means by which organizing centers and transient structures are removed early in morphogenesis. Both processes are evolutionary conserved, genetically programmed and orchestrated by the same signaling factors regulating the cell cycle, neuronal activity/neurotransmitter action and neurotrophic support. This review summarizes and highlights recent knowledge on birth and death of neurons, the two mutually dependent contributors to the formation of the highly evolved mammalian brain.

Adult neurogenesis and gliogenesis in the dorsal and ventral canine hippocampus

Dentate gyrus (DG) of the mammalian hippocampus gives rise to new neurons and astrocytes all through adulthood. Canine hippocampus presents many similarities in fetal development, anatomy, and physiology with human hippocampus, establishing canines as excellent animal models for the study of adult neurogenesis. In the present study, BrdU-dated cells of the structurally and functionally dissociated dorsal (dDG) and ventral (vDG) adult canine DG were comparatively examined over a period of 30 days. Each part's neurogenic potential, radial glia-like neural stem cells (NSCs) proliferation and differentiation, migration, and maturation of their progenies were evaluated at 2, 5, 14, and 30 days post BrdU administration, with the use of selected markers (glial fibrillary acidic protein, doublecortin, calretinin and calbindin). Co-staining of BrdU+ cells with NeuN or S100B permitted the parallel study of the ongoing neurogenesis and gliogenesis. Our findings reveal the comparatively higher populations of residing granule cells, proliferating NSCs and BrdU+ neurons in the dDG, whereas newborn neurons of the vDG showed a prolonged differentiation, migration, and maturation. Newborn astrocytes were found all along the dorso-ventral axis, counting however for only 11% of newborn cell population. Comparative evaluation of adult canine and rat neurogenesis revealed significant differences in the distribution of resident and newborn granule cells along the dorso-ventral axis, division pattern of adult NSCs, maturation time plan of newborn neurons, and ongoing gliogenesis. Concluding, spatial and temporal features of adult canine neurogenesis are similar to that of other gyrencephalic species, including humans, and justify the comparative examination of adult neurogenesis across mammalian species.

Dental pulp stem cells in chitosan/gelatin scaffolds for enhanced orofacial bone regeneration

OBJECTIVE

Biomimetic chitosan/gelatin (CS/Gel) scaffolds have attracted great interest in tissue engineering of several tissues. However, limited information exists regarding the potential of combining CS/Gel scaffolds with oral cells, such as dental pulp stem cells (DPSCs), to produce customized constructs targeting alveolar/orofacial bone reconstruction, which has been the aim of the present study.

METHODS

Two scaffold types, designated as CS/Gel-0.1 and CS/Gel-1, were fabricated using 0.1 and 1% (v/v) respectively of the crosslinker glutaraldehyde (GTA). Scaffolds (n=240) were seeded with DPSCs with/without pre-exposure to recombinant human BMP-2. In vitro assessment included DPSCs characterization (flow cytometry), evaluation of viability/proliferation (live/dead staining, metabolic-based tests), osteo/odontogenic gene expression analysis (qRT-PCR) and structural/chemical characterization (scanning electron microscopy, SEM; energy dispersive X-ray spectroscopy, EDX; X-ray powder diffraction, XRD; thermogravimetry, TG). In vivo assessment included implantation of DPSC-seeded scaffolds in immunocompromised mice, followed by histology and SEM-EDX. Statistical analysis employed one/two-way ANOVA and Tukey's post-hoc tests (significance for p<0.05).

RESULTS

Both scaffolds supported cell viability/proliferation over 14 days in culture, showing extensive formation of a hydroxyapatite-rich nanocrystalline calcium phosphate phase. Differential expression patterns indicated GTA concentration to significantly affect the expression of osteo/odontogenic genes, with CS/Gel-0.1 scaffolds being more effective in upregulating DSPP, IBSP and Osterix. In vivo analysis demonstrated time-dependent production of a nanocrystalline, mineralized matrix at 6, 8 and 10 weeks, being more prominent in constructs bearing rhBMP-2 pre-treated cells. The latter showed higher amounts of osteoid and fully mineralized bone, as well as empty space reduction.

SIGNIFICANCE

These results reveal a promising strategy for orofacial bone tissue engineering.

The Effect of Iloprost in the Healing of Colonic Anastomosis in Rats under Chemotherapy with Irinotecan

PURPOSE

We have investigated the possible positive effect of iloprost in the healing of colonic anastomosis, in rats under intraperitoneal chemotherapy with irinotecan.

METHOD

Forty male Wistar rats have been divided into four groups. They underwent a partial colectomy and a termino-terminal anastomosis. They were administered, intraperitoneally, saline (group 1), irinotecan (group 2), iloprost (group 3), or irinotecan and iloprost (Group 4). After the sacrifice of the animals what followed was an autopsy, a macroscopic examination and the measurement of the anastomotic rupture pressure. A portion of the anastomosis was sent over for histological examination and determination of hydroxyproline levels. Results: The frequency of the leakage from the anastomosis was considered as significantly increased in group 2 compared with the other groups. In group 2, a significantly greater degree of adhesions, compared to all the remaining groups, was observed. The bursting pressure of the anastomosis was significantly lower in group 2, as compared with all the remaining groups, and significantly increased in the group 4 compared with group 2. Leukocytosis, fibroblasts, the neocollagen and the levels of hydroxyproline in group 4 showed significantly increased values, compared with group 2. The angiogenesis was significantly increased in groups 3 and 4 compared with group 2. Conclusions: Intraperitoneal administration of iloprost after colectomy, termino-terminal anastomosis and intraperitoneal administration of irinotecan promotes the healing process of the colon anastomoses as it competes the inhibitory effect of irinotecan.

Seven days post-injury fate and effects of genetically labelled adipose-derived mesenchymal cells on a rat traumatic brain injury experimental model

Mesenchymal stromal cells (MSC) have been suggested to have beneficial effects on animal models of traumatic brain injury (TBI), owing to their neurotrophic and immunomodulatory properties. Adipose tissue-derived stromal cells (ASCs) are multipotent MSC that can be harvested with minimally invasive methods, show a high proliferative capacity, low immunogenicity if allogeneic, and can be used in autologous or heterologous settings. In the present study ASCs were genetically labelled using the Sleeping Beauty transposon to express the fluorescent protein Venus. Venus+ASCs were transplanted intra-cerebroventricularly (ICV), on a rat TBI model and their survival, fate and effects on host brain responses were examined at seven days post-injury (7dPI). We provide evidence that Venus+ASCs survived, migrated into the periventricular striatum and were negative for neuronal or glial lineage differentiation markers. Venus+ASCs stimulated the proliferation of endogenous neural stem cells (NSCs) in the brain neurogenic niches, the subventricular zone (SVZ) and the hippocampal dentate gyrus (DG). It was also evident that Venus+ASCs modify the host brain's cellular microenvironment both at the injury site and at their localization area by promoting a significant reduction of the lesion area, as well as altering the post-injury, pro-inflammatory profile of microglial and astrocytic cell populations. Our data support the view that ICV transplantation of ASCs induces alterations in the host brain's cellular response to injury that may be correlated to a reversal from a detrimental to a beneficial state which is permissive for regeneration and repair.

Myelin Sheath Development in the Maxillary Nerve of the Newborn Pig

Myelination, the ensheathing of neuronal axons by myelin, is important for the proper function of both central and peripheral nervous systems. Various studies have investigated the quantitative parameters of myelination in certain species. Pigs are among the species of which their use as laboratory animals in neuroscience research increased the past few decades. However, there is limited data regarding the myelination process in the pig. Moreover, the maxillary nerve is crucial for Pseudorabies Virus (PrV) neuropathogenesis. In this context, a quantitative analysis of various myelination parameters of the maxillary nerve was performed, during the first 5 weeks of porcine post-natal development, the time period, which exhibits the highest interest for PrV neuropathogenesis. The evaluation was conducted in four groups of uninfected pigs, at the time of birth (group 0w), at the age of 1 week (group 1w), 3 weeks (group 3w) and 5 weeks (group 5w), using toluidine blue staining, immunofluorescence and electron microscopy. Axon and fibre diameter, perimeter and surface, myelin sheath thickness and g-ratio were measured on histological sections transverse to the longitudinal axis of the maxillary nerve. The thickness of myelin sheath was 0.76 μm for group 0w, 0.94 μm for group 1w, 0.98 μm for group 3w and 1.03 μm for group 5w. The g-ratio was 0.529, 0.540, 0.542 and 0.531 for the respective animal groups. The results of this study contribute to the understanding of the myelination process in the pig will be used for the study of PrV effects on the myelination development of newborn piglets' maxillary nerve and may shed new light to their vulnerability to the virus.

Neurogenesis in the septal and temporal part of the adult rat dentate gyrus

Structural and functional dissociation between the septal and the temporal part of the dentate gyrus predispose for possible differentiations in the ongoing neurogenesis process of the adult hippocampus. In this study, BrdU-dated subpopulations of the rat septal and temporal dentate gyrus (coexpressing GFAP, DCX, NeuN, calretinin, calbindin, S100, caspase-3 or fractin) were quantified comparatively at 2, 5, 7, 14, 21, and 30 days after BrdU administration in order to examine the successive time-frames of the neurogenesis process, the glial or neuronal commitment of newborn cells and the occurring apoptotic cell death. Newborn neurons' migration from the neurogenic subgranular zone to the inner granular cell layer and expression of glutamate NMDA and AMPA receptors were also studied. BrdU immunocytochemistry revealed comparatively higher numbers of BrdU(+) cells in the septal part, but stereological analysis of newborn and total granule cells showed an identical ratio in the two parts, indicating an equivalent neurogenic ability, and a common topographical pattern along each part's longitudinal and transverse axis. Similarly, both parts exhibited extremely low levels of newborn glial and apoptotic cells. However, despite the initially equal division rate and pattern of the septal and temporal proliferating cells, their later proliferative profile diverged in the two parts. Dynamic differences in the differentiation, migration and maturation process of the two BrdU-incorporating subpopulations of newborn neurons were also detected, along with differences in their survival pattern. Therefore, we propose that various factors, including developmental date birth, local DG microenvironment and distinct functionality of the two parts may be the critical regulators of the ongoing neurogenesis process, leading the septal part to a continuous, rapid, and less-disciplined genesis rate, whereas the quiescent temporal microenvironment preserves a quite steady, less-demanding neurogenesis process.

Mast cells populations fluctuate along the spinal dura mater of the developing rat

The present study reveals developmental changes in the number, the phenotype and the distribution pattern of mast cells (MCs) along the cervical, the thoracic and the lumbar parts of the spinal dura mater. Postnatal infiltration of spinal dura by MCs does not appear to follow a sequential developmental pattern and meningeal MCs are unevenly distributed along the various parts of the examined dura. At each spinal level, areas most densely populated by MCs are the dorsal dura and the dural sleeves of the dorsal (sensory) spinal roots The developmental time course of the total MCs number is characterized by significant fluctuations in all three parts examined, with notable increases at P1, P4, P21 and P60 (peak value) for the cervical part, at P1 (peak value), P7 and P21 for the thoracic part and at P1, P7 (peak value) and P30 for the lumbar part. At P180, MCs number declines to 56%, 33% and 13% of the peak values for the cervical, the thoracic and the lumbar part, respectively. However, a different developmental pattern is followed by each subpopulation of MCs identified on the basis of their staining characteristics, namely connective tissue type mast cells (CTMCs), mucosal type or cells with characteristics of immature mast cells (MTMCs) and mixed type MCs, in each part examined. The findings may be of importance in elucidating physiological and pathological processes in the dura mater and the vertebral column.

Developmental changes in the vascular network of the rat visual areas 17, 18 and 18a

The present study examines quantitatively the areal and the laminar fluctuations of the vascular network in the visual areas 17, 18 and 18a of the rat cerebral cortex, from postnatal day (P) 1 to P60. For this purpose, the detailed vascular networks of the visual areas, marked after transcardial perfusion of India ink, are analyzed with the use of an image analysis system in order to measure the total vascular density (VD) and the relative density of capillaries (CD), of medium (MD)- and large (LD)-sized vessels in combination with changes in the mean diameter of all three types of vessels. Comparative quantitative microscopy showed that both VD and CD do not exhibit significant interareal differences in the adult rat brain. However, while VD reaches adult values much earlier in area 18a (P21) than in areas 17 and 18 (P60), CD obtains adult values at P31 in areas 17 and 18a, but later (P60) in area 18. Maturation process of laminar VD, CD, MD and LD was not found to follow a simple (i.e. inside-out or mediolateral) sequence, and, in each cortical area, laminar fluctuations of vessels density revealed a complicated developmental pattern, which might be attributed to their changing structural and functional status. Developmental changes in the diameter of capillaries, examined in conjunction with concomitant changes of vascular and capillary density in each area, suggest the existence of angiogenesis in all three visual areas during the third postnatal week of age.

Areal and laminar variations in the vascularity of the visual, auditory, and entorhinal cortices of the developing rat brain

Understanding of place-specific cortical cerebrovascular changes after insult and injury depends on the detailed knowledge of the areal and laminar variations in cortical vascularity. The present study examines comparatively the developmental changes of the total vascular density and the density of capillaries and medium- and large-sized vessels in the primary visual cortex (Oc1), the primary auditory cortex (Te1), and the lateral entorhinal cortex (EntL) of the developing rat brain. Vascular networks in the three cortical areas were marked after transcardial perfusion of India ink and quantified with an image analysis system. Parameters examined exhibited (i) peculiar developmental time course within individual cortical layers and (ii) area- and age-dependent variations. Angioarchitecture in Te1 layers was stabilized earlier than that in Oc1 layers and the period of postnatal development of the vascularity of neocortical sensory areas Oc1 and Te1 appeared to be more protracted compared to that of the phylogenetically older entorhinal cortex. By the end of the first postnatal month, vascular densities in the three cortical areas established a dorsoventral gradient (Oc1 > Te1 > EntL). Finally, in all areas, layer IV was the first layer to obtain adult values of capillary density.

Colonoscopy effects on serum prostate specific antigen levels

INTRODUCTION

To evaluate the colonoscopy effects on serum levels of prostate specific antigen (PSA) and PSA ratio.

SUBJECTS AND METHODS

Thirty men were studied (median age 68 years, range 32-89). All of them had their serum PSA (total and free) measured 24 hours prior to colonoscopy and also 24 hours, 7 and 30 days after procedure.

RESULTS

14 of 30 (47%) patients, had significantly (p = 0.045) increased Total PSA levels 24 hours after the procedure, 14 (47%) patients had insignificantly (p = 0.139) increased levels 7 days after, while 13 (43%) of them had insignificantly (p = 0.061) increased levels 30 days after colonoscopy. In 7 patients (23%), with total PSA levels in the "gray zone" (4-10 ng/ml) before colonoscopy, a near significant (p = 0.063) raise in PSA ratio was also observed 24 hours after.

CONCLUSION

Flexible colonoscopy affect serum PSA (free and total) levels in certain patients. Special attention must be given to those patients with PSA levels in the "gray zone" before colonoscopy.

Vascular network of the rat hippocampus is not homogeneous along the septotemporal axis

Qualitative and quantitative image analysis of hippocampal vascular bed, after transcardial perfusion of India ink, reveals significant differences among hippocampal subfields and along the septotemporal axis of the rat hippocampus. Ventral hippocampus exhibits significantly higher levels of vascularization compared to dorsal hippocampus, which, however, is characterized by significantly higher capillary density. These results may explain the selective ischemia vulnerability of hippocampus along its septotemporal axis.

Parallel development of blood vessels and mast cells in the lateral geniculate nuclei

The present study examined quantitatively developmental changes of the vasculature in the dorsal (dLGN) and the ventral (vLGN) lateral geniculate nuclei together with concomitant changes in the number of mast cells (MCs), known for their role in angiogenesis. Vascular network, marked after transcardial perfusion of India ink, and MCs detected with conventional histochemical techniques were examined at postnatal days (P) 1, 8, 14, 21, 31, 90 and 300 of Wistar rats. Quantitative analysis by means of an image analysis system showed age-dependent changes in both vascular parameters [vascular area and relative frequency (%) of capillaries and medium- and large-diameter vessels] and mast cells number in the developing dLGN and vLGN. Despite quantitative differences in the vascularization and MC infiltration between the two nuclei at some age points, MC number, vascular area and the percentage frequency of capillaries exhibited similar developmental time courses, especially up to the end of the first postnatal month. Both MC number and the capillary frequency reached maximal levels at P31 and declined thereafter, following a massive or a partial, respectively, decrease up to P300.

Segmental myoclonus in Whipple's disease

A patient suffering from Whipple's disease, presenting with segmental myoclonus in the muscular distribution of the muscles of the right facial nerve, which is one of the first neurological findings of the disease is described. Patients suffering from segmental myoclonus and Whipple's disease are reported and the possible anatomical sites of the injury, responsible for the presence of this symptom is discussed.

Stargardt's disease with neurological involvement: case report

The diagnosis of Stargardt's disease, in cases of macular degeneration associated with neurological symptomatology, has been questioned. A 23 year old man, suffering from well characterized Stargardt's disease since childhood, presented with progressive spastic tetraparesis and cerebellar involvement since the age of 18. The case is presented and the association between the two clinical pictures is discussed.

Whipple's disease with tubular aggregates in asymptomatic muscle

A patient with Whipple's disease aged 34 years is presented. At muscle biopsy, the patient presented with tubular aggregates of the quadriceps muscle. The patient did not exhibit any clinical and electromyographical indications of muscular involvement nor direct or indirect histological indications of muscular infiltration with Whipple's bacillus. The possible etiopathogenetic factors creating these aggregates are discussed.