Oropharyngeal hairy polyp with meningothelial elements

The so-called hairy or teratoid polyp is a rare lesion of bigerminal origin that comprises elements derived from both ectodermal and mesodermal cell lines. In this article we report the presence of meningothelial elements in a hairy polyp, a previously undescribed component of this entity. The lesion was characterized by a pedunculated outgrowth from the hard palate. The surface of the outgrowth was covered by squamous epithelium and a central core of fibroadipose tissue, pilosebaceous glands, cleftlike pseudovascular spaces, and groups of epithelioid cells. These reticulated and cellular foci had the immunohistochemical and ultrastructural features of meningothelial tissue.     

The effects of midazolam or propofol followed by suxamethonium on the QT interval in humans

Atretic encephaloceles or myelomeningoceles are frequently solid due to hamartomatous proliferation of fibrous tissue and blood vessels. Because of the fibrous nature of the tumor with no cystic cavity and unusual location with no connection to CNS, they are frequently regarded as insignificant hamartomas. Apart from this terminology, they are also described as cutaneous meningiomas or hamartomas with ectopic meningothelial elements by the presence of meningothelial cells. We report a case of atretic encephalocele in the parietal scalp of an 8 year-old boy and a case of myelomeningocele in the posterior mediastinum of a 31 year-old woman. The terms atretic encephalocele and myelomeningocele are more appropriate for these cases because they include their pathogenesis and the non-neoplastic nature of the lesion.     

Inflammatory pseudotumor of the ileum. A report of a multifocal, transmural lesion with regional lymph node involvement

Inflammatory pseudotumor (inflammatory fibroid polyp) of the ileum is a rare, usually solitary and polypoid lesion that frequently presents clinically as small-intestinal intussusception and obstruction. Regional lymph nodes are usually not involved. We describe an inflammatory pseudotumor of the ileum that was multifocal, not polypoid, and involved one regional lymph node. Grossly, two circumferential transmural nodules were separated by 8.5 cm of normal ileum. Microscopically, the lesion extended through the muscularis propria into peri-intestinal adipose tissue and involved one noncontiguous regional lymph node. The pseudotumor was composed of highly vascularized stroma with a mixture of spindle cells and chronic inflammatory cells including numerous eosinophils, lymphocytes, plasma cells, histiocytes, neutrophils, and multinucleated giant cells forming small granulomas. Immunohistochemically, the majority of spindle cells reacted with vimentin but not smooth-muscle, endothelial, or lymphoid markers. Ultrastructurally, the spindle cells had abundant rough endoplasmic reticulum, cytoplasmic filaments, and dense bodies consistent with myofibroblasts, plump endothelial cells (some with Weibel-Palade bodies), and chronic inflammatory cells. We prefer the term inflammatory pseudotumor to inflammatory fibroid polyp for the lesion in this case, since it was not polypoid and shared many histologic features with inflammatory pseudotumors arising at sites other than the gastrointestinal tract.     

Proliferating cell nuclear antigen (PCNA) expressed in human leptomeninges

Here we report on the presence of proliferating cell nuclear antigen (PCNA) in human leptomeninges from 35 normal subjects with ages ranging from 57 to 94 years. Strong immunoreactivity with PC10 (a monoclonal antibody to PCNA) was detected in the nuclei of meningothelial cells, smooth muscle cells of leptomeningeal vessels, and ependymal cells. An immunoblot of leptomeningeal homogenate with PC10 showed the presence of a single band at 35 KD, the expected molecular mass of PCNA. Ki-67, another marker for cell proliferation, was undetectable in human leptomeninges. These observations point to isolated PCNA expression in tissue in which cells are not actively proliferating.     

Neurophysiology of central retinal degeneration in cat

Receptive fields of ganglion cells have been studied in cats possessing a chronic, arrested lesion of central retinal degeneration. Lesions were characterized by an ophthalmoscopically sharp border separating apparently normal retina from the region of the lesion. Under direct ophthalmoscopic guidance, a succession of recordings was obtained from ganglion cells having cell bodies at various positions relative to the lesion. Cells located more than 1 deg outside the ophthalmoscopic border had normal visual sensitivity as assessed by area-threshold experiments. Inside the lesion cells within 1 deg of the border had reduced sensitivity which often precluded functional classification by the usual visual tests. Ganglion cells located more than 1 deg inside the border of large lesions were blind and some had abnormal patterns of maintained discharge of action potentials. Nevertheless, the antidromic latencies of these blind cells fell into the familiar conduction groups (T1/T2/T3). Receptive-field maps of cells near the border of the lesion often appeared truncated, with the missing portion of the field covered by the lesion. These observations were consistent with the abnormal form of area-threshold curves. Although the responsiveness of cells near the lesion was abnormally low for grating stimuli, cutoff spatial frequency and orientation bias of these cells were within normal limits.     

Inclusion body fibromatosis of the breast. Two cases with immunohistochemical and ultrastructural findings

Two cases of fibromatosis of the breast, characterized by a proliferation of spindle cells containing intracytoplasmic, spherical, eosinophilic inclusion bodies, are reported. The light and electron microscopic features, as well as the immunohistochemical features, are indistinguishable from those found in infantile digital fibromatosis. The proliferating spindle cells are characterized as myofibroblasts, whereas the inclusion bodies show an immunohistochemically nonreactive, hollow-like pattern with peripheral reactivity for actin filaments. This lesion, observed for the first time in the breast, expands the number of extradigital inclusion body fibromatoses.     

Utilization of molecular genetics in the differentiation between adrenal cortical adenomas and carcinomas

Cutaneous pseudolymphomas have been defined as benign lymphocytic infiltrates of the skin that simulate cutaneous lymphoma clinically or histologically. The authors report on a 2-year-old boy with a lesion of molluscum contagiosum in which the inflammatory infiltrate that surrounded a cystlike structure containing molluscum bodies consisted of atypical hyperchromatic mononuclear cells with abundant mitotic figures, some of them atypical. Immunohistochemical investigation demonstrated that the infiltrate was predominantly composed of T lymphocytes. A previous report documented pseudoleukemia cutis associated with molluscum contagiosum, and this report expands the spectrum of histopathologic pseudomalignancies that may be seen in lesions of molluscum contagiosum.     

The urethral sling and stress urinary incontinence

We report the case of a 40-year-old Filippino woman, with a 5-year history of a slowly spreading, painful skin lesion on her left foot. Histological examination showed a dermal, granulomatous infiltrate consisting of neutrophils, histiocytes and lymphocytes, with "sclerotic bodies" in the cytoplasm of phagocytic cells. Mycological culture revealed the presence of Phialophora verrucosa and confirmed the histopathological diagnosis of chromo-blastomycosis. Association of surgical curettage of the exuberant, infected tissue with systemic fluconazole administration gave good therapeutic results with no relevant side effects.     

Neuritic outgrowth associated with astroglial phenotypic changes induced by antisense glial fibrillary acidic protein (GFAP) mRNA in injured neuron-astrocyte cocultures

In the adult CNS, axons fail to regenerate after injury. Among the cell interactions that lead to this failure are those developed with astrocytes. In an effort to elucidate the mechanisms underlying these negative interactions, we have used astrocytes treated with antisense glial fibrillary acidic protein (GFAP) mRNA to inhibit the formation of gliofilaments, indispensable for the astroglial morphological response to injury, and have studied their permissivity for neuritic outgrowth. In a neuron-astrocyte coculture, a mechanical lesion led to hypertrophy of astrocytes neighboring the lesion. Neuronal cell bodies and neurites were absent both from the area of lesion and from its surroundings. Reactive astrocytes appeared, therefore, to be a nonpermissive substrate. Transfection that used antisense GFAP mRNA blocked astroglial morphological changes and was characterized by both a persistence of neuronal cell bodies in the vicinity of the lesion site and a growth of neurites into the same region. These morphological differences were associated with a 46% decrease in the GFAP translation capacity and a 50% increase in the concentration of GAP-43 in the treated cultures. Neurons were associated mainly with an extracellular laminin network, which was predominant at the lesion site in treated cocultures. In contrast, those astrocytes highly laminin-immunoreactive appeared to be a nonpermissive substrate for neurons. These results show that inhibition in GFAP synthesis, leading to a reduction of astroglial hypertrophy, relieves the blockade of neuritic outgrowth that normally is observed after a lesion. The mechanisms may involve changes in the secretion of extracellular matrix molecules by astrocytes.     

Microscopic polyangiitis: a case report]

Vertebral osteomyelitis arising from an enteric fistula in patients with inflammatory bowel disease is rare. We report on a patient with Crohn's disease who developed an enteric fistula, resulting in a presacral abscess and vertebral osteomyelitis involving the L4 and L5 vertebral bodies and related disc spaces. This was managed by a defunctioning colostomy with drainage of the pre-sacral abscess. The vertebral lesion was successfully managed non-operatively.     

Clonal analysis of meningiomas

Meningiomas are primary brain tumors arising from meningothelial cells. They usually grow slowly and are surgically easy to separate from the brain. A recent clonal analysis of meningiomas, using methylation-sensitive restriction fragment length polymorphisms, suggested a monoclonal origin. Using the same technique but with a highly informative X chromosome probe (M27 beta), we found that 17 (85%) of the 20 meningiomas analyzed were informative. Of the 17 informative tumors, 8 (47%) were monoclonal, 3 (18%) had loss of heterozygosity on the X chromosome, and, unexpectedly, 6 (35%) had a polyclonal pattern. Samples from two areas of one tumor showed a monoclonal pattern and loss of heterozygosity, respectively, on the X chromosome. A review of the histopathological and radiological features of the 17 informative tumors did not help to distinguish the clonal from the polyclonal tumors. We conclude that meningiomas are heterogeneous in clonal composition.     

Traumatic dislocations of the lesser toes

Meningiomas are common lesions in adults but unusual in infancy and meningiomas located in the posterior cranial fossa are even more rare. Metaplastic changes of meningothelial meningiomas can lead to the rarely observed xanthomatous form. We describe the case of a posterior pyramid xanthomatous meningioma in a 2-year-old girl. After detailed neuroradiological evaluation, the histological diagnosis was confirmed with the aid of immunohistochemical evaluation. A critical case evaluation in the light of the more recent literature, the surgical strategy and technique, and an immunohistological hypothesis are reported.     

Classification of several types of maturational arrest of spermatogonia according to Sertoli cell morphology: an approach to aetiology

Bilateral testicular biopsies and clinical histories from 34 adult men with maturational arrest of spermatogonia were examined. According to the morphology of Sertoli cell nuclei, five testicular types of spermatogonial maturational arrest were established. In type I lesion, Sertoli cells resembled the immature Sertoli cells of infant testes. These cells had a round, regularly outlined, dark nucleus with a small nucleolus. The seminiferous tubules showed no apparent lumen and a poorly developed lamina propria lacking in elastic fibres. This lesion was found in patients exhibiting a eunuchoid phenotype, with small tests and low serum levels of gonadotrophins and testosterone (hypogonadotrophic hypogonadism). Type II lesion showed morphologically normal, mature, adult Sertoli cells which had a pale, irregularly outlined nucleus, many often triangle-shaped, with a large, centrally located nucleolus. The seminiferous tubules were reduced in diameter and showed a few spermatocytes and spermatids. This lesion was found in patients with varicocoele, epididymitis, testicular trauma or idiopathic infertility. Serum FSH levels were normal or increased while LH and testosterone levels were normal. In type III lesion, Sertoli cells resembled the involuting Sertoli cells found in the testes of aging men, and displayed very infolded nuclei, with abundant dense chromatin patches and a large nucleolus. The seminiferous tubules showed a slightly dilated lumen and a normal tubular wall. The most relevant clinical findings in patients with this lesion were alcoholism, varicocoele, falciform cell anaemia, epididymitis and germ cell tumour. Serum follicle stimulating hormone (FSH) levels were normal or increased while luteinizing hormone (LH) and testosterone levels were normal. Type IV lesion Sertoli cells presented with a de-differentiated appearance. These cells had a small, round euchromatic nucleus with a small nucleolus and vacuolated cytoplasm. The seminiferous tubules were devoid of lumen or ectatic, and the tubular wall was thick and contained abundant elastic fibres. This lesion was characteristic of patients who underwent hormonal treatment because of prostatic carcinoma or sex change. Type V lesion showed abnormally differentiated, probably dysgenetic, Sertoli cells which had a round to ovoid regularly outlined nucleus, with small heterochromatin granules, and the number of these cells was increased. The seminiferous tubules had a central lumen, or were ectatic with vacuolated Sertoli cells, and the amount of elastic fibres was decreased. The most relevant clinical finding in patients with this lesion was orchidopexy. Serum FSH and LH levels were normal or slightly increased. These findings indicate that spermatogonial maturational arrest is associated with a characteristic Sertoli cell morphology that can be easily identified. This morphology may shed light on the aetiology of the disorder, and be useful for establishing the prognosis and bases for treatment in subfertile patients.     

Changes in morphology and spatial position of coiled bodies during NGF-induced neuronal differentiation of PC12 cells

Interphase nuclei are organized into structural and functional domains. The coiled body, a nuclear organelle of unknown function, exhibits cell type-specific changes in number and morphology. Its association with nucleoli and with small nuclear ribonucleo-proteins (snRNPs) indicates that it functions in RNA processing. In cycling cells, coiled bodies are round structures not associated with nucleoli. In contrast, in neurons, they frequently present as nucleolar "caps." To test the hypothesis that neuronal differentiation is accompanied by changes in the spatial association of coiled bodies with nucleoli and in their morphology, PC12 cells were differentiated into a neuronal phenotype with nerve growth factor (NGF) and coiled bodies detected by immunocytochemical localization of p80-coilin and snRNPs. The fraction of cells that showed coiled bodies as nucleolar caps increased from 1.6 +/- 0.9% (mean +/- SEM) in controls to 16.5 +/- 1.6% in NGF-differentiated cultures. The fraction of cells with ring-like coiled bodies increased from 17.2 +/- 5.0% in controls to 57.8 +/- 4.4% in differentiated cells. This was accompanied by a decrease, from 81.2 +/- 5.7% to 25.7 +/- 3.1%, in the fraction of cells with small, round coiled bodies. SnRNPs remained associated with typical coiled bodies and with ring-like coiled bodies during NGF-induced recruitment of snRNPs to the nuclear periphery. Together with the observation that coiled bodies are also present as nucleolar caps in sensory neurons, the results indicate that coiled bodies alter their morphology and increase their association with nucleoli during NGF-induced neuronal differentiation.     

Differential effects of double and triple lesions of the cat's limbic system on subsequent learning behavior.

Investigated the effects of multiple lesions of the chain-linked subicular cortex, mamillary bodies, and anterior thalamus on the acquisition of a visual reversal and an active 2-way avoidance task by 45 cats. Compared with controls, Ss with lesions of the anterior thalamus and the mamillary bodies (Group AT/MM), of the anterior thalamus and the subiculum (Group AT/SUB), or of the mamillary bodies and the subiculum (Group MM/SUB) were strongly impaired in acquiring the reversal task; Ss with lesions of all 3 structures (Group AT/MM/SUB) were unimpaired. Similarly, in the active avoidance task, 2 of the 3 groups with double lesions (MM/SUB and AT/SUB) were impaired, but Groups AT/MM and AT/MM/SUB were not, compared with the control group. It is suggested that lesion-induced shifts possibly act on intact cortical and/or thalamic structures that, prior to massive limbic lesion, remained inhibited or otherwise suppressed. It is assumed that the influence of 1 of the 3 core regions of the modified Papez-circuit is sufficient for inhibiting the action of such structures, which, following a complete lesion of the system, may control essential parts of the behaviors tested. (60 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Periodontal inflammatory and cystlike lesions in BDF1 and B6C3F1 mice

Periodontal inflammatory and cystlike lesions were detected in aged BDF1 and B6C3F1 mice. Lesions were unilateral, single, and located in the labial region of the incisor teeth. The largest cystlike lesion deformed the skull. Histologically, the cystlike lesions were classified into three types: predominantly an inflammatory reaction, predominantly a cyst formation, and a mixed lesion. These periodontal inflammatory and cystlike lesions were pathogenetically similar and were considered sequential changes; the lesions showing both cyst formation and inflammatory reaction seemed to be intermediate along a path toward formation of large cysts. The cysts probably were derived from periodontal tissue and developed as a result of inflammatory reaction to foreign bodies, including hair. The term "murine periodontal cyst" is proposed for this lesion. Detailed pathogenetic studies on murine odontogenic cystic lesions may be warranted.     

Disruption of the blood-brain interface in neonatal rat neocortex induces a transient expression of metallothionein in reactive astrocytes

Exposure of the adult rat brain parenchyma to zinc induces an increase in the intracerebral expression of the metal-binding protein, metallothionein, which is normally confined to astrocytes, ependymal cells, choroid plexus epithelial cells, and brain endothelial cells. Metallothionein is expressed only in diminutive amounts in astrocytes of the neonatal rat brain, which could imply that neonatal rats are devoid of the capacity to detoxify free metals released from a brain wound. In order to examine the influence of a brain injury on the expression of metallothionein in the neonatal brain, PO rats were subjected to a localized freeze lesion of the neocortex of the right temporal cortex. This lesion results in a disrupted blood-brain interface, leading to extravasation of plasma proteins. From 16 h, reactive astrocytosis, defined as an increase in the number and size of cells expressing GFAP and vimentin, was observed surrounding the neocortical lesion site. Astrocytes and pial cells situated adjacent to the area of injury also became positively stained for metallothionein. At 3-6 days post-lesion, the highest level of reactive astrocytes expressing metallothionein was observed. Neo-Timm staining revealed that histochemically reactive zinc had disappeared from the lesion site. Extracellular albumin and metallothionein-positive astrocytes were absent approximately 2 weeks after the lesion, whereas reactive astrocytosis was still observed. These results show that a lesion of the neonatal rat brain induces a transient expression of metallothionein in reactive astrocytes, probably as a response to metals released from the site of the brain injury.     

Nucleolar organizer regions in meningiomas

Paraffin sections of 305 meningeal tumours were analysed for the presence of nucleolar organizer region (Ag-NOR) in the neoplastic cells, using a one step silver-colloidal staining method. The mean (+/- SEM) Ag-NOR counts were 2.73 +/- 0.21 for atypical and 2.91 +/- 0.18 for papillary variants of meningioma. In meningotheliomatous and transitional variants of meningioma, the mean Ag-NOR counts were 1.41 +/- 0.34 and 1.38 +/- 0.31, respectively. The recurrence rates were significantly higher in atypical meningiomas than in other histopathological variants (p < 0.05). Differences in the mean Ag-NOR numbers between meningothelial and transitional variants in their primary and recurrent tumours were not significantly different (p > 0.05). The results of this study indicates that estimation of Ag-NORs can be applied in predicting the aggressive clinical behaviour of primary meningeal tumours.     

Adult insect mushroom body neurons in primary culture: cell morphology and characterization of potassium channels

The dissociation and maintenance in culture of cells derived from the mushroom bodies of adult crickets (Acheta domesticus) are described. This primary culture was developed in order to investigate maturation and differentiation of mushroom-body cells including Kenyon cells, the major intrinsic interneurons of mushroom bodies, which have been shown to be involved in learning and memory in insects. Three distinct cell types were observed, all identified as neural cells on the basis of their size, morphology and immunocytochemical staining with horseradish peroxidase. These cells appear to correspond to the three cell types observed in vivo: Kenyon cells, ganglion mother cells and neuroblasts. Some cells showed neurite growth, usually with long unipolar processes, occasionally with either bipolar or, more rarely, multipolar processes. Neuronal cell bodies readily formed seals with patch pipettes, allowing stable, whole-cell, patch-clamp electrophysiological recordings. Depolarization of the cell under voltage-clamp resulted in at least two types of outwardly directed potassium currents: a delayed rectifier-type of current that was sensitive to tetraethylammonium, and a cadmium-sensitive current with rapid inactivation. Neither type of current was affected by quinidine, a blocker of potassium currents recorded from pupal honeybee Kenyon cells. Other ionic currents, which have yet to be characterized, were also observed.     

CD63 is a component of Weibel-Palade bodies of human endothelial cells

Weibel-Palade bodies are secretory granules of vascular endothelial cells specialized in the storage of von Willebrand factor (vWF) and P-selectin, two adhesion proteins that can be rapidly mobilized to the cell surface by exocytosis in response to thrombin or other agonists. In this study, we attempted to identify additional components of Weibel-Palade bodies by raising monoclonal antibodies to these granules, purified by cell fractionation. One antibody, 2C6, was found to be specific for CD63, a membrane glycoprotein previously described in the lysosomes of platelets and other cell types. The immunopurified 2C6 antigen was recognized by an anti-CD63 reference antibody, 2.28, by Western blotting. Also, the biosynthetic profile of the 2C6 antigen in endothelial cells showed a nascent molecular mass and a glycosylation pattern identical to that of CD63. Immunofluorescence staining with 2C6 showed the lysosomes, and also elongated structures identified as Weibel-Palade bodies by their shape, distribution, and positive staining with anti-vWF antibodies, CD63 was also found by Western blotting of subcellular fractions highly enriched in Weibel-Palade bodies. Our results indicate that CD63 colocalizes with vWF and P-selectin in the Weibel-Palade bodies of endothelial cells, and together with these adhesion proteins it could be rapidly expressed on the cell surface in areas of vascular injury and inflammation.