Myofibroblastic differentiation of stromal cells in giant cell tumor of bone: an immunohistochemical and ultrastructural study

The nature of the mononuclear stromal cells (MSCs) in giant cell tumor of bone (GCTB) has not been thoroughly investigated. The purpose of this study was to evaluate the degree and significance of myofibroblastic differentiation in 18 cases of GCTB by immunohistochemistry (IH) and/or electron microscopy (EM). All immunostained cases were found positive for smooth muscle actin (SMA) and/or muscle specific actin (MSA), most in 1-33% of the MSCs. Ultrastructurally, most MSCs were fibroblasts, and a significant number of cells displayed myofibroblastic differentiation. Myofibroblasts are an important component of MSCs in GCTB. The myofibroblastic population may be responsible in part for the production of matrix metalloproteinases (MMPs), which probably play a role in bone destruction, tumor aggression, and recurrence.

Mesenchymal-epithelial differentiation of adamantinoma of long bones: an immunohistochemical and ultrastructural study

Three cases of adamantinoma were studied by electron microscopy and immunohistochemistry. In the tubular pattern, well-differentiated epithelial cells and glandular structures were present, in addition to ill-defined glands. In the basaloid pattern, less differentiated epithelial cells with discohesion were seen in the central epithelial masses. This study established the epithelial nature of some tubular structures with slit-like lumina, easily misinterpreted as capillaries by light microscopy. Results also showed that the irregular spaces observed within the basaloid pattern probably result from cell discohesion. Moreover, this investigation demonstrates the epithelial nature of a subset of spindle cells within the stroma of adamantinoma and offers ultrastructural evidence for a probable mesenchymal-epithelial transformation as its histogenesis.

LEF1 identifies androgen-independent epithelium in the developing prostate

Lymphoid enhancer-binding factor (LEF)1 is a major mediator and a target in canonical Wnt/β-catenin pathway. Interactions between the androgen receptor (AR) and canonical Wnt pathways have been implicated in the development of the genitourinary organs. Here, we investigated the localization and role of LEF1-positive cells during development of the prostate gland in human and in the murine model. We show that during human prostate development, LEF1 is restricted to the basal epithelial layer of the urogenital sinus. During mouse development, Lef1 is also present in the urogenital mesenchyme in addition to the basal epithelial layer of the urogenital sinus. In the course of elongation and branching of the prostatic ducts, Lef1 is localized to the proliferating epithelium at the distal tips of the buds. Notably, during branching morphogenesis, domains of Lef1 and AR are mutually exclusive. We further employed the TOPGAL reporter strain to examine the dynamics of Wnt signaling in the context of prostate regression upon a 7-d treatment with a competitive AR inhibitor, bicalutamide. We found that Wnt/Lef1-positive basal cells are not dependent upon androgen for survival. Furthermore, upon bicalutamide treatment, Wnt/Lef1-positive basal progenitors repopulated the luminal compartment. We conclude that Wnt/Lef1 activity identifies an androgen-independent population of prostate progenitors, which is important for embryonic development and organ maintenance and regeneration in the adult.

Congenital minor salivary gland sialoblastoma: a case report and review of the literature

Sialoblastoma is the most common epithelial tumor of the salivary gland. We report a case of congenital sialoblastoma arising in a minor salivary gland of the buccal mucosa of a male infant. After radiologic evaluation, an incisional biopsy was performed and then the mass was excised en bloc. Histologic features were both favorable and unfavorable. However, there was no recurrence for 5 months. In spite of a reported histologic grading system, the clinical course of isolated sialoblastoma is considered unpredictable. More published case reports of this rare tumor may enable histologic and clinical correlation in order to accurately predict prognosis.

Integrin alphavbeta6 and mediators of extracellular matrix deposition are up-regulated in experimental biliary atresia

INTRODUCTION

Biliary atresia (BA) is a progressive obliteration of the extrahepatic bile ducts resulting in hepatic fibrosis. The underlying mechanisms have not been defined. We used an animal model of BA to evaluate mediators of extracellular matrix (ECM) processing to determine which factors may be involved.

METHODS

Newborn BALB/c mice received an intraperitoneal injection with rhesus rotavirus or saline within 24 h of birth. Livers were harvested on days 7 and 14 for histology and immunohistochemistry (IHC). RNA expression was determined using quantitative real-time PCR. Human liver from patients with BA and those having a resection for nonfibrosing diseases was also evaluated.

RESULTS

In experimental mice, mRNA expression for tissue inhibitor of metalloproteinase (TIMP)-1 and matrix metalloproteinase (MMP)-7 was increased 18-fold and 69-fold, respectively on day 7, with further increases on day 14. On day 14, mRNA expression for plasminogen activator inhibitor (PAI)-1 (38-fold), TIMP-4 (9.5-fold), and MMP-9 (5.5-fold) mRNA was also observed. Furthermore, integrin alpha(v) beta(6) mRNA expression was increased on days 7 (11-fold) and 14 (6-fold). Presence of integrin alpha(v) beta(6) protein was confirmed by IHC in both mouse and human specimens in the proliferating biliary epithelium.

CONCLUSIONS

Our data suggest experimental BA is associated with increased mRNA expression of ECM degradation inhibitors, TIMP-1, PAI-1, and TIMP-4. MMP-7 and MMP-9 expression is also elevated in this model. Furthermore, increased gene expression of integrin alpha(v)beta(6) was demonstrated and IHC confirmed protein expression. Integrin alpha(v)beta(6) or the inhibitors of ECM breakdown may be attractive targets for future treatment strategies.

Expression of epidermal growth factor receptor, but not K-RAS mutations, is present in congenital cystic airway malformation/congenital pulmonary airway malformation

Congenital cystic airway malformation/congenital pulmonary airway malformation (CCAM/CPAM) of the lung is a rare but well-described malformative lesion of pulmonary parenchyma characterized by the abnormal maturation of airways along with an increase in terminal respiratory structures, resulting in cysts of variable sizes. Five types have been classified based on morphological analysis. Although the etiology of the lesion is still unclear, recent data suggest that bronchial atresia is a predisposing/associated anomaly. A described association between type 1 CCAM/CPAM and bronchioloalveolar carcinoma suggests that type 1 CCAM/CPAM may predispose to malignant transformation by as yet unidentified tumorigenic mechanisms. Here we studied epidermal growth factor receptor (EGFR) and K-RAS oncogene, 2 biological markers closely associated with tumorigenesis and altered in many types of tumors, including lung carcinomas. For this purpose, we used immunohistochemistry and gene sequencing in paraffin-embedded tissue. Our results demonstrate expression of EGFR in types 1 and 3 CCAM/CPAM, with a distinctive distribution and intensity, compared with that of type 2. Of special interest, mucinous areas in 2 cases of type 1 CCAM/CPAM lacked EGFR expression, whereas adjacent epithelial cystic linings were strongly positive. This supports the hypothesis that mucinous differentiation in CCAM/CPAM, always present in cases with malignant transformation, could be related to other molecular pathways. The K-RAS gene was screened for mutations usually found in lung carcinomas; however, no mutations were present in any of the studied samples. These findings support the notion that EGFR may play an important role in the pathogenesis and phenotype of CCAM/CPAM.

Splenic infarction due to concomitant hereditary spherocytosis and sickle cell trait

Concomitant hereditary spherocytosis and sickle cell trait, although extremely rare, could potentially lead to splenic sequestration or infarction. We report here the first case of splenic infarction in a child with hereditary spherocytosis and sickle cell trait while flying on a commercial aircraft. The presence of hypoxia, hemoconcentrated erythrocytes, and sickle hemoglobin created the perfect environment for clinical sequelae.

Prepubertal Unilateral Fibrous Hyperplasia of the Labium Majus

OBJECTIVE

To report and propose a consensus term for eight cases of a newly recognized, asymptomatic, rapidly growing unilateral labium majus mass without palpable borders in prepubertal girls, appearing to be temporally associated with the physiologic increase of adrenal hormones.

METHODS

Histologic examination, special stains, and immunohistochemistry were performed on all cases. In our personal cases, electron microscopy and chromosomal analysis were also performed, together with pelvic magnetic resonance imaging (MRI), inguinal exploration, vaginoscopy with biopsies, and adrenal hormone levels.

RESULTS

Of the eight cases, seven were Ashkenazi Jewish girls from the same area in New York City. The unilateral masses were asymptomatic, soft, without palpable borders. The overlying skin had a slightly tan peau d'orange surface. The masses could not be completely excised because they extended into the contiguous pelvic floor. Histologically, the masses were composed of bland hypocellular fibrous tissue extending into the deep subcutaneous tissue. The masses blended into the surrounding tissue and adjacent pelvic floor as shown by MRI preoperatively and postoperatively. Residual tissue did not progress after incomplete resection.

CONCLUSION

These fibrous lesions develop in months at the time of physiologic increase in adrenal hormone secretion just before puberty and subsequently appear to stop growing. The surgeon should not attempt a complete removal but simply excise sufficient tissue for a reasonable cosmetic result and to confirm the diagnosis. The lesions reflect fibroblastic hyperplasia, which is possibly hormone-driven. The ethnic and geographic clustering of cases raises consideration of environmental exposures or genetic predisposition.

Epidermal growth factor receptor in osteosarcoma: expression and mutational analysis

Activation of intracellular mitogenic signal transduction pathways driven by the ErbB family of receptor tyrosine kinases has been implicated in the development and/or progression of a variety of cancers. Studies on ErbB receptors in osteosarcoma have focused on HER-2 and have produced conflicting results with few studies evaluating the expression of the epidermal growth factor receptor (EGFR). In this study, we determined the level of expression of EGFR and the mutational status of the EGFR receptor in a subset of osteosarcoma tumor samples as well as in a series of established bone tumor-derived cell lines. EGFR protein expression was detected in the form of strong membranous staining by immunohistochemistry in 21 (57%) of 37 cases analyzed. Six of 12 (50%) osteosarcoma cell lines revealed moderate to high expression levels of EGFR. Two somatic alterations (E829E and R831C) were identified in the cytoplasmic domain of the EGFR gene in 1 of 10 tumor samples. The significance of these findings for the pathobiology of osteosarcomas will be investigated further.

The expression and function of androgen receptor coactivator p44 and protein arginine methyltransferase 5 in the developing testis and testicular tumors

PURPOSE

The role of androgen receptor coactivators in testicular development and cancer formation is unclear. p44/Mep50 was identified as an androgen receptor coactivator that functions in a complex with protein arginine methyltransferase 5. We studied the expression of p44 and protein arginine methyltransferase 5 in developing fetal testis and adult testicular tumors, including seminomas and Leydig cell tumors.

MATERIALS AND METHODS

A total of 30 human fetal testes from abortuses at a gestational age of 10 to 40 weeks, 33 human seminomas and 11 human Leydig cell tumors were retrieved from the archives of the departments of pathology. Immunohistochemistry was performed with affinity purified p44 and IgG purified protein arginine methyltransferase 5 polyclonal antibodies.

RESULTS

Protein arginine methyltransferase 5 and p44 were expressed predominantly as nuclear proteins in fetal Leydig cells and human adult nonneoplastic testes, including germ cells and Leydig cells, while they were expressed in the cytoplasm of germ cells of the fetal testis. Expression was strongest in the fetal testis during the second trimester. Compared to adult nonneoplastic testes, human seminoma and Leydig tumor cells showed a marked decrease in nuclear expression of p44 and protein arginine methyltransferase 5 with a concomitant marked increase in cytoplasmic expression of these proteins. Furthermore, average testicular size was increased by 29% in p44(+/-) heterzygotic mice.

CONCLUSIONS

These results suggest distinct functions of the nuclear and the p44/protein arginine methyltransferase 5 complexes in the developing fetal testis and in the oncogenesis of testicular tumors. Further studies are needed to confirm the functional relevance of these findings.

An appendiceal leiomyoma in a child with acquired immunodeficiency syndrome

Children with acquired immunodeficiency syndrome (AIDS) are at an increased risk for lymphoproliferative and neoplastic disorders. Included among these are smooth muscle neoplasms such as leiomyomas and leiomyosarcomas. There have been at least 15 reported cases of smooth muscle tumors in the approximately 8,000 children with AIDS, however the incidence in immunocompetent children is only two per ten million. The lesions in children with human immunodeficiency virus infection are usually found in the lung, liver, and gastrointestinal tract. Here, we present an unusual case of a 12-year-old African American girl with vertically acquired AIDS who presented to the pediatric emergency department with severe diffuse abdominal pain. She was ultimately found to have an appendiceal leiomyoma on abdominal exploration, the first reported case. Our report suggests that smooth muscle tumors of the appendix be included in the differential diagnosis of abdominal masses in children with AIDS.

Aneurysm syndromes caused by mutations in the TGF-beta receptor

BACKGROUND

The Loeys-Dietz syndrome is a recently described autosomal dominant aortic-aneurysm syndrome with widespread systemic involvement. The disease is characterized by the triad of arterial tortuosity and aneurysms, hypertelorism, and bifid uvula or cleft palate and is caused by heterozygous mutations in the genes encoding transforming growth factor beta receptors 1 and 2 (TGFBR1 and TGFBR2, respectively).

METHODS

We undertook the clinical and molecular characterization of 52 affected families. Forty probands presented with typical manifestations of the Loeys-Dietz syndrome. In view of the phenotypic overlap between this syndrome and vascular Ehlers-Danlos syndrome, we screened an additional cohort of 40 patients who had vascular Ehlers-Danlos syndrome without the characteristic type III collagen abnormalities or the craniofacial features of the Loeys-Dietz syndrome.

RESULTS

We found a mutation in TGFBR1 or TGFBR2 in all probands with typical Loeys-Dietz syndrome (type I) and in 12 probands presenting with vascular Ehlers-Danlos syndrome (Loeys-Dietz syndrome type II). The natural history of both types was characterized by aggressive arterial aneurysms (mean age at death, 26.0 years) and a high incidence of pregnancy-related complications (in 6 of 12 women). Patients with Loeys-Dietz syndrome type I, as compared with those with type II, underwent cardiovascular surgery earlier (mean age, 16.9 years vs. 26.9 years) and died earlier (22.6 years vs. 31.8 years). There were 59 vascular surgeries in the cohort, with one death during the procedure. This low rate of intraoperative mortality distinguishes the Loeys-Dietz syndrome from vascular Ehlers-Danlos syndrome.

CONCLUSIONS

Mutations in either TGFBR1 or TGFBR2 predispose patients to aggressive and widespread vascular disease. The severity of the clinical presentation is predictive of the outcome. Genotyping of patients presenting with symptoms like those of vascular Ehlers-Danlos syndrome may be used to guide therapy, including the use and timing of prophylactic vascular surgery.

Localized persistent interstitial pulmonary emphysema presenting as a spontaneous tension pneumothorax in a full term infant

Persistent interstitial pulmonary emphysema (PIPE) is a syndrome characterized by air-leakage in the perivascular tissues of the lung, primarily affecting mechanically ventilated neonates. Reports in the literature of infants developing PIPE with no history of respiratory distress syndrome (RDS) or mechanical ventilation are scarce. Here, we present a case of a 3-month-old former full term male infant with no history of RDS or mechanical ventilation who presented with focal cystic lung disease associated with spontaneous tension pneumothorax. He was ultimately found to have PIPE based on pathologic evaluation of the resected cystic region. We believe that focal PIPE should be included in the differential diagnosis of cystic lung disease in a full term, unventilated infant, even when spontaneous pneumothorax is the presenting entity.

Investigation of the sudden death of infants: a multicenter analysis

The investigation of sudden death of infants varies, and death rates may depend on local practices of death certification. We studied the extent of the investigation and the final cause of death (COD) in 3 regions: New York, New York, USA (NY); King County, Washington, USA (KC); and Montevideo, Uruguay (MU). We conducted a retrospective review of 543 cases (NY 258, KC 56, MU 229) of previously healthy babies who died suddenly without obvious trauma, at ages 0 to 12 months, over a 3-year period (1998 to 2001). All cases included a complete autopsy and histologic examination. Cases were assessed for completion of special studies (including radiographs, photos, toxicology and metabolic sampling, cultures, and vitreous humor chemistry), measurements, and scene investigation. Specialized pediatric measurements and testing were done less often than routine procedures, and were done less often in cases overall compared with cases certified as sudden infant death syndrome (SIDS). Fifty-five percent of SIDS cases in NYC and 12% of SIDS cases in KC had no scene investigation. Manhattan had a complete workup in 42% of SIDS cases, whereas the remaining sites had fewer that 15% of cases completely worked up. The most common non-natural COD was suffocation at all 3 sites. The overall most common COD were respiratory infection in MU (22%) and SIDS in NY (45%) and KC (86%). We conclude that the sudden death of infants requires special consideration and still lacks consistency. SIDS investigations are not done completely in all cases and rates may depend on regional differences in certifying infant deaths.

Giant cell tumor of soft tissue with pulmonary metastases: pathologic and cytogenetic study

Giant cell tumor of soft tissue (GCTST) has gained general acceptance as an uncommon but distinct primary soft tissue tumor since it was first described in 1972. GCTST is predominantly seen in adults and typically shows uniformly dispersed osteoclast-like giant cells admixed with oval to polygonal mononuclear cells. It usually follows a benign clinical course, although the malignant variant has been described in cases in which the mononuclear cells demonstrate obvious dysplastic features. It is still not clear whether the two variants belong to the spectrum of the same tumor. No cytogenetic chromosomal abnormalities have been reported in the literature of GCTST. Interestingly, the osseous counterpart of giant cell tumor, which shares similar histologic features, quite often displays a telomeric association at the cytogenetic level, a finding that has never been reported in GCTST. We report the case of a 12-year-old girl with GCTST of the right leg that metastasized to the lung. Cytogenetic studies from the primary tumor showed the phenomenon of telomeric association involving multiple chromosomes.

Lipoblastoma of Infancy Mimicking Hemangioma of Infancy

Lipoblastomas are rare benign tumors of infancy that usually affect children younger than 3 years. Most lipoblastomas (70%) occur on the extremities. Lipoblastomas may mimic other infantile tumors, including hemangiomas, hibernomas, lipomas, and liposarcomas, and correct diagnosis is necessary to ensure appropriate treatment. Lipoblastomas fall under 2 discrete subtypes: well-circumscribed lipoblastomas and diffuse lipoblastomatosis. Both types present with firm, nontender masses of lobulated, well-circumscribed soft tissue. Histologically they can be highly vascularized with plexiform capillaries, often with an individual feeder artery to each lobule. Complete surgical removal is the recommended treatment. Only 2 cases of lipoblastomas of the cheek have been reported in the English-language literature. We present the case of a young child with a cheek lipoblastoma, emphasizing the importance of correct diagnosis and highlighting techniques used to provide suitable treatment.

EXPRESSION OF ANDROGEN RECEPTOR ASSOCIATED PROTEIN 55 (ARA55) IN THE DEVELOPING HUMAN FETAL PROSTATE

PURPOSE

Development and differentiation of the human fetal prostate are androgen dependent and follow a specific pattern of solid bud-ductal morphogenesis, which involves stromal-epithelial interactions. Androgen receptor associated protein 55 (ARA55) an androgen receptor coactivator localized in stromal cells, binds to androgen receptor (AR) and regulates androgen receptor translocation and transcriptional activity. We investigated whether ARA55 has a role in human prostate development.

MATERIALS AND METHODS

ARA55 expression was examined in 25 human prostates from fetuses at gestational ages 10 to 40 weeks and compared to the expression of 34betaE12 (a basal cell marker), smooth muscle actin, desmin (a smooth muscle marker), vimentin (a mesenchymal marker) and Ki-67 (a proliferation marker) by immunohistochemistry.

RESULTS

Prostatic epithelium appeared as solid epithelial buds from the urogenital sinus. It underwent arborization and ductal differentiation from the center to the periphery. ARA55 was expressed in stromal cells with a zonal pattern, primarily in the peripheral zone surrounding the noncanalized acini. Most cells in solid buds were positive for 34betaE12, while only basal layer cells in the centrally located epithelial ducts stained with 34betaE12. Solid buds also had a higher proliferation index than ducts. In addition, ARA55 expressing stromal cells but not ARA55 negative stromal cells showed smooth muscle differentiation.

CONCLUSIONS

The intimate relationship between ARA55 expressing stromal cells and mitotically active, noncanalized acini suggests that ARA55 has a role in the stromal-epithelial interaction involved in fetal prostate development.

Thymoma in children: report of two cases and review of literature

Thymoma is an uncommon tumor of childhood. Stage of the tumor is an independent prognostic factor for survival. Surgery is the treatment of choice for stage I and stage II tumors. Chemotherapy is reserved for patients with refractory or metastatic disease. Thymomas are moderately radiosensitive. However, radiation therapy is not an attractive option for children due to its side-effects on developing organs. The authors describe 2 children with completely encapsulated thymoma who were successfully treated with surgery alone. Both patients remain free of disease 3 years after surgery. One of the patients also has nevus sebaceous. The authors also discuss the possible association between the two disease entities.

Small cells in hepatoblastoma lack "oval" cell phenotype

Hepatoblastoma, a childhood tumor of the liver, is composed of epithelial and mesenchymal elements in varying proportions and at various stages of differentiation. The epithelial element recapitulates the stages of hepatocyte development from the primitive blastema through embryonal hepatocytes to fetal hepatocytes. The blastemal or undifferentiated cells have been postulated to represent neoplastic hepatocyte progenitor cells. In this study, we examine the immunophenotype of the various epithelial cells of hepatoblastoma with special emphasis on the small undifferentiated cell component and compare it with that of adult hepatocytes and hepatic stem (oval) cells. Putative stem cells in the liver can express all of the following markers: alpha-feto protein, CK19 (OV-6), chromogranin A, Bcl-2, HepPar-1, and alpha1 microglobulin. The latter, like alpha-feto protein, is a plasma protein synthesized by hepatocytes. Both alpha1 microglobulin and HepPar-1 are expressed in fetal liver cells as early as 7 weeks of intrauterine life. They are also expressed in hepatocellular carcinoma and in hepatocytic cell lines derived from normal fetal or adult liver. Formalin-fixed, paraffin-embedded archival tissues from 10 predominantly epithelial hepatoblastomas were immunostained with antibodies directed against CD 34, alpha1 microglobulin, Bcl-2, HepPar 1, and CK19 using the avidin-biotin-peroxidase method. The undifferentiated small cell component did not express any of the markers studied, namely, Bcl-2, HepPar-1, alpha(1) microglobulin, CD34, or CK19. Hepatocyte-like cells were alpha1 microglobulin- and HepPar-1-positive, with the intensity of staining correlating with the degree of hepatocytic differentiation. Bcl-2 expression was restricted to areas of ductular differentiation. CK19 was detected in foci that showed duct formation. The small cells of hepatoblastoma did not express HepPar-1, Bcl-2, CK19, alpha1 microglobulin, or CD34, markers that characterize the immunophenotype of hepatic stem cells ("oval" cells). Thus, this observation raises the following questions: (1) is "hepatoblastoma" a misnomer? (2) is the expression of tumor antigens dysregulated in hepatoblastoma? (3) does the liver have two different types of progenitor cells, oval cells and blastemal cells, with differing immunophenotypes? and (4) do the blastemal cells, rather than oval cells, represent the more primitive progenitor cells of the liver?

Congenital laryngeal atresia associated with partial diaphragmatic obliteration

OBJECTIVE

Laryngeal atresia is a rare, life-threatening congenital malformation. Prenatal sonographic diagnosis has been described; however, in many cases, the precise diagnosis is established only at autopsy. Our aim was to describe an atypical prenatal presentation of congenital laryngeal atresia in which the final diagnosis was made only at autopsy.

METHODS

Sonographic and postmortem examinations were performed on a fetus with bilateral enlarged echogenic lung fields, an everted diaphragm, and polyhydramnios, which were initially noted on prenatal sonography at 26 weeks' gestation.

RESULTS

Unfortunately, the mother was lost to follow up at our inner-city clinic, thus precluding a definitive diagnosis. At birth, tracheostomy was not performed because of the anomalous appearance of the neonate and the suspicion of multiple congenital anomalies. Neonatal death occurred after 18 minutes of life. Autopsy revealed laryngeal atresia with a right hemidiaphragmatic defect and multiple other congenital anomalies.

CONCLUSIONS

This was a rare case with prenatal sonographic findings in a fetus with congenital laryngeal atresia associated with partial diaphragmatic obliteration.

Region-specific changes in immediate early gene expression in response to sleep deprivation and recovery sleep in the mouse brain

Previous studies have documented changes in expression of the immediate early gene (IEG) c-fos and Fos protein in the brain between sleep and wakefulness. Such expression differences implicate changes in transcriptional regulation across behavioral states and suggest that other transcription factors may also be affected. In the current study, we examined the expression of seven fos/jun family member mRNAs (c-fos, fosB, fos related antigen (fra)1, fra-2, junB, c-jun, and junD) and three other IEG mRNAs (egr-1, egr-3, and nur77) in mouse brain following short-term (6 h) sleep deprivation (SD) and 4 h recovery sleep (RS) after SD. Gene expression was quantified in seven brain regions by real-time reverse transcription-polymerase chain reaction (RT-PCR). Multivariate analysis of variance revealed statistically significant variation in cerebral cortex, basal forebrain, thalamus and cerebellum. Levels of c-fos and fosB mRNA were elevated during SD in all four of these brain regions. In the cerebral cortex, junB mRNA was also elevated during SD whereas, in the basal forebrain, fra-1 and fra-2 mRNA levels increased in this condition. During RS, the only IEG mRNA to undergo significant increase was fra-2 in the cortex. C-jun and junD mRNAs were invariant across experimental conditions. These results indicate that the expression of fos/jun family members is diverse during SD. Among other IEGs, nur77 mRNA expression across conditions was similar to c-fos and fosB, egr-1 mRNA was elevated during SD in the cortex and basal forebrain, and egr-3 mRNA was elevated in the cortex during both SD and RS. The similarity of fosB and nur77 expression to c-fos expression indicates that these genes might also be useful markers of functional activity. Along with our previous results, the increased levels of fra-2 and egr-3 mRNAs during RS reported here suggest that increased mRNA expression during sleep is rare and may be anatomically restricted.

Effects of lateral hypothalamic lesion with the neurotoxin hypocretin-2-saporin on sleep in Long-Evans rats

Narcolepsy, a disabling neurological disorder characterized by excessive daytime sleepiness, sleep attacks, sleep fragmentation, cataplexy, sleep-onset rapid eye movement sleep periods and hypnagogic hallucinations was recently linked to a loss of neurons containing the neuropeptide hypocretin. There is considerable variability in the severity of symptoms between narcoleptic patients, which could be related to the extent of neuronal loss in the lateral hypothalamus. To investigate this possibility, we administered two concentrations (90 ng or 490 ng in a volume of 0.5 microl) of the neurotoxin hypocretin-2-saporin, unconjugated saporin or saline directly to the lateral hypothalamus and monitored sleep, the entrained and free-running rhythm of core body temperature and activity. Neurons stained for hypocretin or for the neuronal specific marker were counted in the perifornical area, dorsomedial and ventromedial nucleus of the hypothalamus. More neuronal nuclei (NeuN) cells were destroyed by the higher concentration of hypocretin-2-saporin (-55%) compared with the lower concentration (-34%) in the perifornical area, although both concentrations lesioned the hypocretin neurons almost equally well (high concentration=91%; low concentration=88%). The high concentration of hypocretin-2-saporin also lesioned neurons in the dorsomedial nucleus of the hypothalamus and ventromedial nucleus of the hypothalamus. Narcoleptic-like sleep behavior was produced by both concentrations of the hypocretin-2-saporin. The high concentration produced a larger increase in non-rapid eye movement sleep amounts during the normally active night cycle than low concentration. Neither concentration of hypocretin-2-saporin disrupted the phase or period of the core temperature or activity rhythms. The low concentration of unconjugated saporin did not significantly lesion hypocretin or neurons and did not alter sleep. The high concentration of unconjugated saporin produced some loss of neuronal nuclei-immunoreactive (NeuN-ir) neurons and hypocretin immunoreactive neurons, but only a transient increase in non-rapid eye movement sleep. These results led us to conclude that the extent of hypocretin neuronal loss together with an accompanying loss of cells in the lateral hypothalamus may explain the differences in severity of symptoms seen in human narcolepsy.

Appropriate and inappropriate use of day-hospital care in Italy

This study describes the extent of inappropriate day-hospital assistance and the effect of different variables on such inappropriateness. A random sample of patients admitted to pediatric and adult day-hospital care during the period Janurary--December 2000 in three hospitals located in the area of Catanzaro, Italy were reviewed. Assessment of appropriateness was made for the first access and for each of the following accesses in day-hospital. A total of 826 patients were reviewed. Overall, 23.8% of the first access in day-hospital care was judged to be inappropriate and 49.7% of the sample showed at least one inappropriate access for day-hospital care with a mean of 1.4 inappropriate accesses. Multiple logistic regression analysis indicated that the inappropriateness of the first access significantly increased with relation to lower distance from hospital to patient's home; admission to general medicine wards; first access from Monday to Thursday; lower number of patient's diagnostic procedures and medical examinations in the first access. Stepwise multiple linear regression analysis showed that the number of inappropriate accesses was significantly higher for general medicine and surgery and trauma/orthopedics wards; in patients who the first access was inappropriate; in those who received a lower number of diagnostic procedures and medical examinations; in patients who showed a higher length of care in day-hospital. The findings suggest the need for standardized diagnostic and therapeutic guidelines for day-hospital care.

Tuberous sclerosis in a 19-week fetus: immunohistochemical and molecular study of hamartin and tuberin

Tuberous sclerosis complex (TSC) is a genetically heterogeneous disease caused by mutations of TSC1 or TSC2 genes. It involves multiple organ systems resulting in mild to lethal hamartoma formation due to gene mutation in the germ line and loss of heterozygosity (LOH) in somatic cells. Hamartin (TSC1) and tuberin (TSC2) are expressed broadly. However, little is known about tissue susceptibility to hamartomas when equal or similar amounts of TSC gene expression are present. In this study, we present a 19-week gestational age fetus with pathological features of TSC, which was confirmed by finding LOH of TSC2 in a cardiac rhabdomyoma. Developmental expression of hamartin and tuberin in the TSC fetus, an age-matched non-TSC fetus, and a 26-week gestational age non-TSC fetus were analyzed by immunohistochemistry. We found that in addition to the differential expression of the TSC genes in some normal tissues compared with that in the TSC-affected fetus, the cellular localization and distribution of hamartin and tuberin were dramatically different in different tissues. In general, hamartin and tuberin are mainly expressed in epithelial cells, myocytes, and neural tissues. By comparing the incidence of the hamartomas in early childhood and gene expression in tissues, it appears that tissues with co-expression of hamartin and tuberin are prone to a higher incidence of hamartomas than those expressing only one protein, or two proteins but in different patterns of cellular localization.

Epithelioid gastrointestinal stromal tumor of the stomach with liver metastases in a 12-year-old girl: aspiration cytology and molecular study

Gastrointestinal stromal tumor (GIST), a stromal tumor of the gastrointestinal tract defined as CD117 (c-kit)-positive neoplasm, occurs primarily in adults. GIST with CD117 (c-kit) mutation and certain cytogenetic abnormalities is associated with malignancy, though a definite relationship between prognosis and molecular alterations remains to be elucidated. We report the cytologic features of an epithelioid GIST arising in the stomach of a child and metastatic to the liver, and the molecular mutational analysis of both the primary gastric tumor and the liver metastasis. Literature of pediatric GISTs was also reviewed. Fine needle aspiration of the liver metastasis, processed by Ultrafast Papanicolaou stain, showed fragments of cohesive small epithelioid cells with bland oval nuclei and unipolar cytoplasm transected by capillaries. Immunohistochemically, all nodules in the stomach and liver expressed CD117 (c-kit). Interestingly, some of the gastric tumor clusters were uniformly CD34 positive, whereas others were uniformly CD34 negative, suggesting heterogeneity of tumor clones. The presence of neurosecretory granules further subtyped the tumor into gastric autonomic nerve tumor (GANT). Molecular mutational analysis, performed in both the gastric tumor and the liver metastasis, showed no sequence abnormality in exons 9, 11, and 13 of CD117 (c-kit). Cytogenetic study revealed normal karyotype. These features might suggest a different molecular mechanism leading to malignancy in certain GISTs arising in children.

Detection of substrates of keratinocyte transglutaminase in vitro and in vivo using a monoclonal antibody to dansylcadaverine

A method providing more sensitive detection of transglutaminase substrates was developed to localize transglutaminase activity in tissue and to identify in vivo substrates in epidermal extracts. The enhanced sensitivity of this method was achieved via the generation of a monoclonal antibody (designated E7) made to dansylcadaverine. Transglutaminase substrates were visualized by western blot after a 1-min incubation with dansylcadaverine in contrast to the 2 h required when [14C]putrescine incorporation was measured by autoradiography of SDS-polyacrylamide gels. In addition, putative substrates not apparent using conventional methods were readily detected by western analysis. An ELISA assay to measure transglutaminase activity showed similar sensitivity to the traditional radiometric assay (Lorand et al., 1972). The correlation between the ELISA procedure and the radiometric assay was high (r2 = 0.924). Strips of neonatal human and mouse skin incubated in dansylcadaverine-supplemented culture medium were used to localize enzyme activity and to detect substrates in vivo. Transglutaminase activity was demonstrated at the cellular periphery in the upper spinous and granular cell layers of the epidermis. Substrates detected in epidermal extracts were similar to those detected using the in vitro assay. This technique allows for highly sensitive and nonradiometric analysis of both enzymatic activity and the substrates involved. The extension of this methodology to an in vivo system is the first demonstration of a system in which the dynamics of cornified envelope assembly may be further studied.

Tenascin-C promotes microvascular cell migration and phosphorylation of focal adhesion kinase

Enhanced expression of tenascin-C (TN-C) at the invasive edges of glioblastoma multiforme in close association with vascular sprouts, suggests a role for TN-C in microvascular cell migration. To test this hypothesis, we studied the migration of endothelial cells in vitro. In an aggregate migration assay, bovine retinal endothelial cells (BRECs) and human umbilical vein endothelial cells spread and migrated similarly on TN-C or fibronectin (FN). In contrast, U251 MG glioma cells migrated less on TN-C than on FN. Morphological features of U251 MG glioma cells on TN-C included poor cell spreading and short processes. In contrast, on FN, U251 MG glioma cells spread and exhibited long radial processes. Using a transmembrane migration assay, we observed that BREC adhesion was similar on TN-C or FN, whereas U251 MG glioma cells adhered better to FN than to TN-C. In addition, BRECs migrated more across the membrane toward regions coated with TN-C than FN, and conversely, U251 MG glioma cells migrated more toward FN than TN-C. Migration of endothelial and glioma cells toward TN-C or FN occurred in a dose-dependent manner and was strongly dependent on cell adhesion. In this assay, ultrastructural study revealed the migrating phenotype of the endothelial cells through the micropores of the membrane and their spread morphology on TN-C. Moreover, in situ hybridization revealed specific expression of TN-C in migrating microvascular cells in a cerebral microvascular ring assay. Finally in a phosphorylation assay, TN-C enhanced focal adhesion kinase phosphorylation of BRECs, but not of U251 MG glioma cells, and FN enhanced focal adhesion kinase phosphorylation of both BRECs and U251 MG cells. The expression of TN-C by migrating endothelial cells and the promotion of endothelial cell adhesion and migration by TN-C suggest a potential role for TN-C in pathological angiogenesis.

Distribution of hypocretin-containing neurons in the lateral hypothalamus and C-fos-immunoreactive neurons in the VLPO

The present study investigated the distribution of neurons implicated in the regulation of sleep in three species generally used in sleep research, i.e., mice, rats and cats. We focused on sleep active neurons in the ventral lateral preoptic (VLPO) area and the hypocretin/orexin-containing neurons in the lateral hypothalamus. The latter groups of neurons were found recently to play an important role in the regulation of REM sleep. The expression of the transcription factor, c-Fos, was used to identify the VLPO. In mice and rats, in response to sleep, a discrete cluster of c-Fos positive cells was found in the VLPO. In mice, this cluster was located more medially compared to the rat, and as in the rat, galanin immunostained neurons were found in the VLPO. In the cat, c-Fos positive cells did not segregate to a specific location but were more diffusely represented in the preoptic area. In all three species, orexin/hypocretin-containing neurons were located only in the lateral hypothalamus with the distribution being more diffuse in the cat. The grouping of sleep-active cells in rodents makes it feasible to extract these cells for tissue culture and molecular analysis. Moreover, given that rodents have a distinct circadian distribution of sleep-wakefulness, the connectivity with the suprachiasmatic nucleus can also be determined.

Complement-independent, peroxide-induced antibody lysis of platelets in HIV-1-related immune thrombocytopenia

Immunologic thrombocytopenia is seen commonly in HIV-1 infection. The pathogenesis of this problem has been unclear, but it is associated with circulating immune complexes that contain platelet membrane components and anti-platelet membrane GPIIIa49-66 IgG antibodies. These antibodies cause acute thrombocytopenia when injected into mice. We now show that purified anti-GPIIIa49-66 causes platelet fragmentation, in vitro in the absence of complement, and in vivo in wild-type and C3-deficient mice. The mechanism of complement-independent platelet lysis is shown to be caused by the antibody-induced generation of H202, as indicated by in vitro experiments with inhibitors of reactive oxygen species, and in vivo studies carried out with p47phox-deficient mice. Thus, a novel mechanism of immunologic platelet clearance is described in which an anti-platelet IgG causes platelet fragmentation via the induction of reactive oxygen species.

Origin of cardiac mucosa: ontogenic consideration

The origin and histology of the cardiac mucosa remains controversial. The classical concept that the cardiac mucosa is of gastric origin has been challenged by those who advocate that the cardiac mucosa results from a metaplastic esophageal process. Some regard cardiac mucosa as consisting solely of pure mucous glands, whereas others accept the presence of isolated parietal cells within the mucous gland (mixed glands). In this study, we have clarified the presence and site of origin of the cardiac mucosa and its histological composition. To do so we studied the microscopic characteristics of the gastric side of the squamous-columnar junction (SCJ) of 77 autopsied fetuses of different gestational ages (prenatal group) and of infants, young children, and adolescents (postnatal group). We evaluated the presence or absence of a transitional zone, defined as the area between the squamous esophageal and oxyntic mucosa, the glandular composition of the transitional zone (i.e., pure mucous and mixed glands), and the presence or absence of inflammation. Our study revealed that a transitional zone with the microscopic characteristics of cardiac mucosa was universally present at the SCJ. The microscopic characteristics of this zone varied with age. Both pure mucous and mixed glands were observed. We conclude that the cardiac mucosa is partially if not entirely the result of normal embryonic gastric development. Both mucous and mixed glands constitute normal components of the cardiac mucosa.

Expression of thyroid transcription factor-1, surfactant proteins, type I cell-associated antigen, and Clara cell secretory protein in pulmonary hypoplasia

Pulmonary hypoplasia (PH) is a developmental abnormality characterized by diminished distal lung parenchyma. Recent studies have demonstrated that thyroid transcription factor 1 (TTF-1), a member of NKx2 family of homeodomain transcription factors, plays an important role in lung organogenesis and lung epithelial gene expression. In order to evaluate whether abnormal expression of TTF-1 contributes to the pathophysiology of PH, we studied the expression of TTF-1, as well as that of the surfactant proteins (SPs), Clara cell secretory protein (CCSP), and type I cell-associated antigen (T1 cell-Ag), in PH. Immunolocalization patterns of these proteins were evaluated in 15 cases of PH with different associated diseases and compared with those of 14 matched controls. Our study demonstrated that the concentration gradient of TTF-1 along the proximal-distal axis in normal fetal lung is disrupted in PH after 24 weeks gestational age, while the expression of the SPs, CCSP, and T1 cell-Ag seemed to be preserved. We conclude that a normal TTF-1 expression pattern might be crucial in the control of distal lung development. Failure to switch off expression of TTF-1 in PH of more than 24 weeks gestational age may be a final common pathway leading to PH associated with the disease processes investigated in this study.

Hypocretin receptor protein and mRNA expression in the dorsolateral pons of rats

The hypocretins (also known as orexins) are hypothalamic peptides that have been implicated in feeding and sleep regulation. Previous reports have described the distribution of the mRNAs encoding two hypocretin receptors (HCRT-R), but the pattern of protein expression has not been investigated. Here we examine the distribution of the mRNA and protein for the HCRT receptor 1 (HCRT-R1) and HCRT receptor 2 (HCRT-R2) in the pontine brainstem and demonstrate that they are present in many pontine nuclei including those associated with REM sleep. Immunohistochemistry indicates that one or both of the receptor subtypes are expressed in the dorsal raphe, the lateral dorsal tegmental (LDT), the pedunculo pontine (PPT), the locus coeruleus (LC), the locus subcoeruleus, pontis oralis, Barrington's, the trigeminal complex (mesencephalic trigeminal and motor nucleus of the trigeminal nerve), the dorsal tegmental nucleus of Gudden (DTG), the ventral cochlear nucleus (VCA), trapezoid nucleus (TZ), pontine raphe nucleus and the pontine reticular formation. These regions have been shown to be involved in mastication, bladder control, gastrointestinal function and in arousal. Given these projection sites and the functions associated with these sites, we suggest that HCRT may play a role in maintaining alertness and vigilance while the animal is engaged in consummatory behavior.

Expression of thyroid transcription factor-1 in congenital cystic adenomatoid malformation of the lung

Congenital cystic adenomatoid malformation (CCAM) is an abnormality of branching morphogenesis of the lung. CCAM types 1, 2, and 3 exhibit a cellular composition that is different from that of CCAM type 4 when evaluated with bronchiolar and alveolar cell markers. Thyroid transcription factor 1 (TTF-1) regulates early lung development. To evaluate the potential role of TTF-1 in the development of CCAM, TTF-1 expression in CCAM was compared to that of fetal lungs at varying gestational ages. Twenty-three CCAM cases (17 type 1, two type 2, two type 3, and two type 4) and 11 fetal lungs (3 pseudoglandular, 4 canalicular, and 4 terminal sac stages) were analyzed using a rabbit polyclonal antiserum to rat TTF-1. Nuclear staining for TTF-1 was observed in ciliated and nonciliated cells of the bronchial and bronchiolar epithelia and in cells lining the distal air spaces by 12 weeks gestational age. By mid-gestation, proximal bronchial cells were TTF-1 negative, except for the basal cells, while TTF-1 staining was maintained in distal bronchiolar and alveolar cells. TTF-1 expression decreased in both bronchial, bronchiolar, and alveolar epithelia with advancing gestational age and cytodifferentiation. At term, TTF-1 expression persisted in a few bronchial and bronchiolar basal cells and in all alveolar type II cells, whereas type I cells were negative. In CCAM, TTF-1 was detected in the nuclei of epithelial cells lining the cysts. TTF-1 was expressed in a majority of the bronchiolar-like epithelial cells of the cysts in CCAM types 1, 2, and 3, where almost 100% of the cells were TTF-1 positive. In contrast, TTF-1 expression in the alveolar-like epithelium of CCAM type 4 cysts was restricted to type II cells and only 30%-60% of the lining cells were TTF-1 positive. These results support the hypothesis that CCAM types 1, 2, and 3 reflect abnormalities in lung morphogenesis and differentiation that are distinct from those for CCAM type 4. The role played by TTF-1 in the development of CCAM, if any, is not clear.

Adenomyoma arising in a meckel diverticulum: case report and review of the literature

We report a case of adenomyoma of the small intestine arising in a Meckel diverticulum. The patient was a 22-month-old boy who presented with signs and symptoms of intussusception. At surgery, a Meckel diverticulum was found and removed. On histologic examination, a tumor consisting of dilated cystic glands and smooth muscle bundles was identified. A diagnosis of adenomyoma arising in a Meckel diverticulum was made. A review of the literature showed that only six other pediatric cases of adenomyoma of the small intestine have been reported. The presence of an adenomyoma in a young patient within a Meckel diverticulum favors the view that adenomyomas are a variant of pancreatic heterotopia.

Sleep and wakefulness in c-fos and fos B gene knockout mice

G-protein coupled receptor (GPCR) stimulation has been implicated in the regulation of sleep. Upon stimulation of a GPCR an intracellular cascade involving second and third messengers is initiated. The latter include the fos-family of immediate early genes (IEGs). Although there is considerable evidence indicating that IEGs are expressed in response to sleep, the effects of their deletion on sleep is not known. The present study examined sleep-wakefulness in mice lacking the c-fos or fos B genes. Null c-fos mice compared to their wildtype (WT) and heterozygote (het) siblings had more wakefulness and less slow wave sleep (SWS); REM sleep was not affected. The null c-fos mice also had increased delta activity (0.3-4 Hz). In contrast, the null and heterozygote fos B mice had less REM sleep, but the time spent in SWS or wakefulness was not different from their wild-type (WT) siblings. In the null c-fos mice, the increased wakefulness and the reduction in SWS could not be due to a systemic alteration in temperature since the core temperature was similar in all mice. By demonstrating that these IEGs are involved in sleep, we suggest that the deletion of specific genes, even within a family of genes, can have a specific effect on sleep.

Vascular apoptosis and involution in gliomas precede neovascularization: a novel concept for glioma growth and angiogenesis

Vascular changes in gliomas were analyzed by implanting fluorescent-labeled glioma 261 cells in the brains of 28 mice. Seven animals were killed each week for 4 weeks. We investigated the expression of angiopoietin-2 (Ang-2) by in situ hybridization and compared it with the distribution of apoptotic cells identified by DNA strand breaks (using the terminal deoxynucleotidyl transferase-mediated biotinylated deoxyuridine triphosphate nick end labeling [TUNEL] method) and transmission electron microscopy (TEM). As early as 1 week after implantation, tumor cells accumulated around vessels, which expressed Ang-2 and were TUNEL negative. TEM showed tumor cells adjacent to the vascular cells "lifting up" the normal astrocytic feet processes away from the endothelial cells and disrupting normal pericytic cuffing. After 2 weeks the number of perivascular glioma cells had increased. No increase in the number of blood vessels was detected at this time. Vascular cells remained positive for Ang-2 and rare ones were TUNEL positive. TEM showed closely packed proliferating perivascular tumor cells. After 3 weeks, there was vascular involution with scant zones of tumor necrosis. Ang-2 was still detected in vascular cells, but now numerous vascular cells were TUNEL positive. In addition, TEM showed apoptotic vascular cells. After 4 weeks, there were extensive areas of tumor necrosis with pseudopalisading and adjacent angiogenesis. Ang-2 was detected in vascular cells at the edge of the tumors in the invaded brain and in vessels surrounded by tumor cells. At both 3 and 4 weeks, most of the TUNEL-positive tumor cells lacked morphological features characteristic of apoptosis and displayed features consistent with necrotic cell death as determined by TEM. Only rare tumor cells appeared truly apoptotic. In contrast, the TUNEL-positive endothelial cells and pericytes were round and shrunken, with condensed nuclear chromatin by TEM, suggesting that vascular cells were undergoing an apoptotic cell death. These results suggest that vascular cell apoptosis and involution preceded tumor necrosis and that angiogenesis is a later event in tumor progression in experimental gliomas. Moreover, Ang-2 is detected prior to the onset of apoptosis in vascular cells and could be linked to vascular involution.

Effect of lesions of the ventrolateral preoptic nucleus on NREM and REM sleep

Neurons in the ventrolateral preoptic nucleus (VLPO) in rats show c-fos activation after sleep and provide GABAergic innervation of the major monoamine arousal systems, suggesting that they may be a necessary part of the brain circuitry that produces sleep. We examined the effects on sleep behavior in rats of cell-specific damage to the VLPO by microinjection of ibotenic acid. Severe lesions of the central cell cluster of the VLPO ( approximately 80-90% cell loss bilaterally) caused a 60-70% decrease in delta power and a 50-60% decrease in nonrapid-eye-movement (NREM) sleep time (p < 0.001). The number of remaining Fos-immunoreactive neurons in the VLPO cell cluster was linearly related to NREM sleep time (r = 0.77; p < 0.001) and total electroencephalogram delta power (r = 0. 79; p < 0.001) but not to rapid-eye-movement (REM) sleep (r = 0.35; p > 0.10). Lesions in the region containing scattered VLPO neurons medial or dorsal to the cell cluster caused smaller changes in NREM sleep time (24.5 or 15%, respectively) but were more closely associated with loss of REM sleep (r = 0.74; p < 0.01). The insomnia caused by bilateral VLPO lesions persisted for at least 3 weeks. Lesions of the VLPO caused no change in mean body temperature or its circadian variation; after small lesions of the ventromedial preoptic nucleus, body temperature showed normal circadian variation but a wider temperature range, and sleep behavior was not affected. These experiments delineate distinct preoptic sites with primary effects on the regulation of NREM sleep, REM sleep, and body temperature.

c-Fos expression in the cholinergic basal forebrain after enforced wakefulness and recovery sleep

The present study used c-Fos expression to examine cellular activity in cholinergic regions in the basal forebrain (BF) following enforced waking and recovery sleep. Cholinergic cells within the vertical and horizontal limbs of the diagonal band of Broca (VDB and HDB, respectively) showed significantly higher c-Fos immunoreactivity after prolonged waking than after recovery sleep. Cholinergic cells within the medial septal nucleus (MS), however, showed no change in c-Fos expression under these conditions. Consistent with our previous findings, c-Fos immunoreactivity in the ventral lateral preoptic area (VLPO) was increased after 1-2h of recovery sleep compared with enforced waking. These results indicate state-specific effects on transcription and subsequent protein expression in cell populations associated with behavioral state and further show that the HDB, VDB and VLPO are good candidates for the further study of intracellular events associated with sleep and wakefulness.

Compensatory sleep response to 12 h wakefulness in young and old rats

There is a pronounced decline in sleep with age. Diminished output from the circadian oscillator, the suprachiasmatic nucleus, might play a role, because there is a decrease in the amplitude of the day-night sleep rhythm in the elderly. However, sleep is also regulated by homeostatic mechanisms that build sleep drive during wakefulness, and a decline in these mechanisms could also decrease sleep. Because this question has never been addressed in old animals, the present study examined the effects of 12 h wakefulness on compensatory sleep response in young (3.5 mo) and old (21.5 mo) Sprague-Dawley and F344 rats. Old rats in both strains had a diminished compensatory increase in slow-wave sleep (SWS) after 12 h of wakefulness (0700-1900, light-on period) compared with the young rats. In contrast, compensatory REM sleep rebound was unaffected by age. To assess whether the reduced SWS rebound in old rats might result from loss of neurons implicated in sleep generation, we counted the number of c-Fos immunoreactive (c-Fos-ir) cells in the ventral lateral preoptic (VLPO) area and found no differences between young and old rats. These findings indicate that old rats, similar to elderly humans, demonstrate less sleep after prolonged wakefulness. The findings also indicate that although old rats have a decline in sleep, this cannot be attributed to loss of VLPO neurons implicated in sleep.

[Research on the biological risk in the hospital environment]

The epidemiological monitoring of injuries due to exposure to potentially infected biological liquids constitutes the indispensable premise for the elaboration of strategies meant to intervene to reduce the incidence. This work shows the results of an epidemiological study relative to the period going from January 1, 1994--December 31, 1998 elaborated by the use of the register of injuries deposited with the Sanitary Direction. The variables shown here allowed us to individualize the prevalence of injuries in the various professional categories, the working zones, the type and form of injury, the use of individual protection devices. The analyses of the data has shown a scarce sense of risk by the sanitary workers and a scarce application of protective measures. It's evident of the need to intervene in the formation of the workers to sensibilize then to the importance of preventive measures.

Choline acetyltransferase expression during periods of behavioral activity and across natural sleep-wake states in the basal forebrain

The present study examined whether the expression of the messenger RNA encoding the protein responsible for acetylcholine synthesis is associated with sleep-wakefulness. Choline acetyltransferase messenger RNA levels were analysed using a semi-quantitative assay in which reverse transcription was coupled to complementary DNA amplification using the polymerase chain reaction. To examine the relationship between steady-state messenger RNA and behavioral activity, rats were killed during the day (4.00 p.m.) or night (4.00 a.m.), and tissue from the vertical and horizontal limbs of the diagonal bands of Broca was analysed. Choline acetyltransferase messenger RNA levels were higher during the day than during the night. The second study examined more closely the association between choline acetyltransferase messenger RNA levels and individual bouts of wakefulness, slow-wave sleep or rapid eye movement sleep. Choline acetyltransferase messenger RNA levels were low during wakefulness, intermediate in slow-wave sleep and high during rapid eye movement sleep. In contrast, protein activity, measured at a projection site of cholinergic neurons of the basal forebrain, was higher during wakefulness than during sleep. These findings suggest that choline acetyltransferase protein and messenger RNA levels exhibit an inverse relationship during sleep and wakefulness. The increased messenger RNA expression during sleep is consistent with a restorative function of sleep.

Demonstration of communication between alveolus and interstitium in persistent interstitial pulmonary emphysema: case report

Persistent interstitial pulmonary emphysema (PIPE) is an uncommon complication of premature infants suffering from hyaline membrane disease who have been treated with mechanical ventilation. The presumed mechanism for the development of the disease is via a break in the bronchioalveolar system that allows air to escape into the interstitium. We report a case of a 9-week-old child who developed the localized form of the disease and underwent a lobectomy. Immunohistochemical stains helped to demonstrate the communication between the airway system and interstitium. This report strengthens the theory that the disease develops from airway rupture at the alveolar level.

Congenital cystic adenomatoid malformation of the lung (CCAM): evaluation of the cellular components

Congenital cystic adenomatoid malformation of the lung (CCAM) is a rare congenital lesion whose pathogenesis is not well defined. It is generally accepted that the various types of CCAMs originate at different levels of the tracheobronchial tree. To further define the pathogenesis of CCAM, we evaluated the cellular composition of different CCAM types by immunohistochemistry. Twenty-two CCAMs (17 CCAM type 1, two type 2, one type 3, and two type 4) were collected. The cellular composition was determined using immunohistochemical stains for type I cell-associated antigen (T1 cell-Ag), surfactant proteins and surfactant protein precursors (SP-A, SP-B, proSP-B, and proSP-C), neuroendocrine cells (GRP), Clara cells (UP-1), and the adhesion molecule CD44v6, a glycoprotein thought to be involved in cell-matrix and cell-cell interactions. Eleven fetal lungs also were analyzed to compare cytodifferentiation of the epithelial-lined cysts of the different types of CCAM with the stages of normal lung development. Our results indicate that CCAM is caused by an arrest in lung development, and, on the basis of cytodifferentiation, two major subtypes can be distinguished. One subtype consisting of CCAM types 1, 2, and 3 that shows a bronchiolar type of epithelium and a second subtype, consisting of CCAM type 4, that has an acinar-alveolar type of epithelium. Our findings also suggest that these two subtypes may arise at different stages of the branching of the bronchopulmonary tree, the first at the pseudoglandular stage and the second at the saccular stage.

Immunohistochemical evaluation of hepatoblastomas with use of the hepatocyte-specific marker, hepatocyte paraffin 1, and the polyclonal anti-carcinoembryonic antigen

The distinction of hepatoblastoma, especially the embryonal type, from other small, round-cell tumors of childhood can sometimes be difficult. Polyclonal anticarcinoembryonic antigen (pCEA) and Hepatocyte Paraffin 1 (Hep Par 1) are immunohistochemical markers that are useful in the diagnosis of hepatocellular carcinomas. We immunohistochemically studied pCEA, monoclonal CEA (mCEA), and Hep Par 1 on 12 hepatoblastomas (3 fetal type, 2 embryonal type, and 7 mixed epithelial type). In addition, we studied the expression of Hep Par 1 on 27 other selected childhood tumors, including 1 hepatocellular carcinoma, 5 germ-cell tumors, 4 peripheral neuroectodermal tumors/Ewing's sarcomas, 3 rhabdomyosarcomas, 5 neuroblastomas, 2 rhabdoid tumors, 3 lymphomas, and 4 Wilms' tumors. All of the hepatoblastomas expressed Hep Par 1 with a characteristic granular intracytoplasmic pattern that was generally less intense in embryonal-type than in fetal-type hepatoblastomas, perhaps reflecting the degree of hepatocyte differentiation. All of the fetal-type hepatoblastomas expressed pCEA with both an intracytoplasmic and bile canalicular pattern. Embryonal type hepatoblastomas were more likely to be pCEA negative or to show focal or no canalicular pattern of expression, again possibly reflecting the degree of hepatocyte differentiation. All of the hepatoblastomas were mCEA negative. All of the nonhepatoblastomas were Hep Par 1 negative, except for the one hepatocellular carcinoma in this study, which was Hep Par 1 positive. We conclude that Hep Par 1 and pCEA are useful markers for hepatoblastomas, as they have been shown to be in hepatocellular carcinomas.

Apoptosis of undifferentiated progenitors and granule cell precursors in the postnatal human cerebellar cortex correlates with expression of BCL-2, ICE, and CPP32 proteins

Naturally occurring apoptotic cells have been demonstrated in the postnatal cerebellum of rodents (Wood et al. [1993] Neuron 11:621-632; Krueger et al. [1995] J. Neurosci. 15:3366-3374). The nature of these cells differs among species: they are considered to be granule cells in mouse and astrocytes in rat. We labeled proliferating and apoptotic cells in the postnatal human cerebellar cortex by using antibodies against the Ki-67/proliferating cell nuclear antigen and the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling method for fragmented DNA. We also immunocytochemically detected some proteins encoded by genes modulating apoptosis and specific markers of neuronal/glial differentiation. Proliferating cells were observed from birth to 4 months, representing 31-35% of cells within the external granular layer (EGL). Apoptotic cells were detected during the first 3 months and corresponded to 5-7% of EGL cells. Much lower percentages were calculated in other cortical layers and white matter. The balance between proliferation and apoptosis was quantitatively favorable to the latter during the first postnatal week. Expression of BCL-2, CPP32, and interleukin-1beta-converting enzyme (ICE) proteins was spatially and developmentally regulated in parallel with apoptosis. Apoptotic cells were often CPP32/ICE immunoreactive but negative for BCL-2. Some apoptotic cells were positive for vimentin and, less frequently, for alpha-internexin or type-III beta tubulin, but never expressed the glial fibrillary acidic protein. This study demonstrates that apoptosis is a significant phenomenon in early postnatal development of human cerebellar cortex and shares some of the regulatory mechanisms described in other vertebrates.