Tenascin-C expression by angiogenic vessels in human astrocytomas and by human brain endothelial cells in vitro.

The expression of the extracellular matrix glycoprotein tenascin-C (TN) is enhanced in human astrocytomas and correlates with angiogenesis. To determine whether vascular cells are able to synthesize TN, we investigated the expression of TN protein and mRNA in nine astrocytomas. Immunogold electron microscopy in two glioblastomas multiforme detected the presence of TN in an extracellular perivascular location and to a lesser extent among tumor cells, confirming light microscopy immunohistochemical findings. In situ hybridization of astrocytomas using a digoxigenin-labeled antisense riboprobe detected strong staining for TN mRNA in vascular cells, especially in hyperplastic vessels, including those at the invasive edge of the tumors but not in vessels of normal brains. We observed weaker staining in tumor cells indicating a higher level of TN mRNA in vascular than in tumor cells. No staining was detected with the sense probe. Moreover, we investigated the ability of human brain microvessel endothelial cells (HBMECs) in primary culture to synthesize TN in vitro. Western blot analysis of the culture supernatants from HBMECs detected large amounts of TN. Immunogold silver staining demonstrated the presence of TN on the surface of HBMECs and in the subendothelial matrix. The distribution of TN mRNA in vascular cells of astrocytomas and the ability of HBMECs to synthesize TN in vitro demonstrate that vascular cells, including endothelial cells, are a major source of TN associated with angiogenesis. Furthermore, our results suggest that TN expression may be associated with endothelial cell activation and may play an important role in angiogenesis.

Tenascin expression in astrocytomas correlates with angiogenesis.

We investigated the expression and distribution of the extracellular matrix protein tenascin (TN) in 59 astrocytomas and 11 samples of normal brain by Western blot analysis and immunohistochemistry using antibodies against human TN. The tumors included 14 juvenile pilocytic astrocytomas (grade 1), 13 low grade fibrillary astrocytomas (grade II), 8 anaplastic astrocytomas (grade III), and 24 glioblastomas multiforme (grade IV). Proliferation indices were calculated by computer-based image analysis after immunostaining with the MIB-1 antibody against the Ki-67 proliferation-associated antigen. Western blot analysis for TN on fresh frozen tumor tissue from 23 of the 59 astrocytomas indicated up to 4-fold higher TN expression in glioblastomas multiforme than in nontumorous control tissues. Enhanced intercellular expression of TN was observed by immunohistochemistry in glioblastomas multiforme. More-over, TN immunostaining was consistently greater within and around the walls of hyperplastic blood vessels than nonhyperplastic vessels of both high grade tumors and juvenile pilocytic astrocytomas. Juvenile pilocytic astrocytomas with increased TN expression by Western blot analysis had vascular hyperplasia by light microscopy. Proliferation indices moderately correlated with tumor grade. Enhanced immunohistochemical expression of TN was associated with higher tumor grade with higher proliferation indices. The strong association of TN and vascular hyperplasia, regardless of tumor grade, suggests that TN may play a crucial role in angiogenesis.

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.

The pancornulins: a group of small proline rich-related cornified envelope precursors with bifunctional capabilities in isopeptide bond formation.

In this report, the pancornulins are identified as members of the spr (small, proline-rich) multigene family by amino acid sequence and mass spectrometry analyses. One of the pancornulins (14.9 kDa) is identical to the protein predicted by spr-1 clone 128. The other pancornulins (16.9 kDa and 22 kDa) are novel members of the spr family. Immunoelectron microscopy of purified cornified envelopes with a pancornulin-specific antibody established these proteins more definitively as cornified envelope precursors. In addition, two-dimensional electrophoretic analyses of keratinocyte extracts labeled enzymatically with dansylcadaverine (to identify amine acceptors) or dansylPGGQQIV (to identify amine donors) showed that both glutamine and lysine residues within the pancornulins participate in the isopeptide linkage characteristic of cornified envelope formation. These results contrasted with those obtained using involucrin, a prominent cornified envelope protein shown capable of acting only as an amine acceptor in this system. Novel partial cDNAs obtained after reverse transcription and polymerase chain reaction amplification of total messenger RNA with pancornulin-specific primers suggest that the spr multigene family may be even larger than previously described. The bifunctional reactivity of the pancornulins in cross-linking and the large number of family members identified to date suggest that the pancornulins and other spr-1-related proteins may be more important in cornified envelope formation than previously considered, perhaps functioning as "bridge" molecules during the early phases of cornified envelope assembly.

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.

Tubular carcinoma and sclerosing adenosis: the use of basal lamina as a differential feature.

Recent ultrastructural studies have shown that tubular carcinoma of the breast lacks basal lamina. This study was undertaken to determine the usefulness of light-microscopic examination of PAS staining for basal lamina in the differentiation of tubular carcinoma and sclerosing adenosis. Ten cases of tubular carcinoma show no basal lamina except for an occasional short segment. Ten cases of sclerosing adenosis show intact basal lamina except for short focal discontinuities. It is concluded that the lack of basal lamina in tubular carcinoma and its presence in sclerosing adenosis is a useful differential feature.

Placental transmogrification of the lung, a histologic variant of giant bullous emphysema. Clinicopathological study of three further cases.

Placental transmogrification of the lung was described by Chesney in 1978 as an unusual cystic lesion involving a single pulmonary lobe (3). We studied three additional cases with identical clinical and pathologic features. The patients were a 33-year-old woman and men aged 24 and 27 years. Each patient was first seen with respiratory distress; one had repeated pneumothoraces. Radiographically, an enlarging cystic lesion was present in a lower (two) or middle (one) lobe. The lesion had been present for 10 years in one patient. In two patients, mediastinal shift was noted. Lobectomy was curative in all instances. Grossly there was a uni- or paucilocular cyst lined by papillary structures. Microscopically, the papillae contained proliferating blood vessels, lymphoid nodules, smooth muscle, and fat. Sclerotic foci obliterated the vessels in some areas. The growth pattern and topography resembled those of placental villi. Systematic review of the histologic features in other lungs with marked emphysema revealed a spectrum of similar changes and suggested that the lesion in our patients may be a complication of bulla formation and is most likely the clinico-pathologic analog of the "vanishing lung" syndrome (idiopathic giant bullous emphysema).

Congenital cystic adenomatoid malformation of the lung in adults.

Congenital cystic adenomatoid malformation of the lung presents mainly in neonates, is rare in children beyond infancy, and has not been reported in adults. Two adult males (aged 24 and 35) had congenital cystic adenomatoid malformation of the right and left lower lobes respectively. A third case, that of a 7-year-old girl, provided the link between the typical neonatal and these adult cases. All three lesions consisted of single or multiple macroscopic cysts, as well as a network of interconnecting spaces (the adenomatoid component). The lining varied from pseudostratified columnar ciliated, to simple mucinous and cuboidal epithelium. Abundant smooth muscle was present in two cases. Cartilage was absent in all three cases. The absence of inflammation is typical of the lesion in neonates. By contrast, all three of our patients had clinical and pathologic evidence of chronic inflammation. We postulate that congenital cystic adenomatoid malformation, when confined to a lobe or segment, may be clinically silent in infancy and may present as pneumonia associated with a cystic lesion on chest x-ray in childhood or later life.

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.

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.

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.

The effect of hypoxia on human trophoblast in culture: morphology, glucose transport and metabolism.

The response to hypoxia of trophoblast isolated from term placenta and maintained in culture was studied. Trophoblast exposed to normoxic (PO2 120-130 mmHg) or hypoxic (PO2 12-14 mmHg) conditions were examined by electron microscopy. After 48 h, the cytoplasm of the hypoxic cells was more electron-dense with increased numbers of mitochondria, lysosomes and vacuoles. Compared to normoxic cells, the surface microvilli of the hypoxic cells were sparse, short and unevenly distributed. [3H]thymidine incorporation by both hypoxic and normoxic trophoblast fell rapidly and equivalently after 2 days in culture. The percentage of cells with the proliferation-associated nuclear antigen, Ki 67, also decreased, but remained higher in hypoxic cells suggesting that hypoxia retarded completion of the cell cycle (normoxia, 10.80 +/- 2.51 s.e.; hypoxia, 19.87 +/- 2.73, P < 0.01). Glucose consumption was elevated in hypoxia (3.73 +/- 1.07 s.e. mumol/10(6) cells/24 h) as compared to normoxia (1.46 +/- 0.83, P = 0.01). Although lactate production was consistently higher in hypoxia, the difference was not statistically significant (hypoxia 5.38 +/- 1.54 mumol/10(6) cells/24 h versus normoxia, 1.52 +/- 0.29, P = 0.07). After 48 h, uptake of [3H]2-deoxglucose ([3H]2DG) by hypoxic cells was reduced to 12 per cent +/- 4.3 s.e. of that in normoxic cells; return to normoxia resulted in recovery within 10 min. Lineweaver-Burk plots of [3H]2DG uptake indicated high affinity (KM 2.2 +/- 0.4 x 10(-4) M) and low affinity transporters (KM 4.5 +/- 1.6 x 10(-3) M). Northern blot analysis identified mRNA for GLUT1 and GLUT3. In hypoxia, steady-state GLUT1 and GLUT3 mRNA were approximately three- and 10-fold higher than in normoxia respectively. Inhibitors of oxidative metabolism of glucose increased the uptake of [3H]2DG within 2 h, whereas hypoxia reduced uptake. Hence, trophoblast in culture survives in extreme hypoxia, but manifests striking changes in morphology and in glucose metabolism and transport. Completion of cell cycle appears to be retarded.

Virus-associated hemophagocytic syndrome due to Epstein-Barr virus.

The clinical and autopsy findings in a case of virus-associated hemophagocytic syndrome in a previously healthy 17-year-old girl are presented. Serum titers to Epstein-Barr viral antigens were unusually elevated. In addition to widespread proliferation of hemophagocytic histiocytes and lymphoid depletion, there were areas of non-suppurative necrosis in lymph nodes and spleen, which have not been previously reported.

Cardiac myxoma with chondroid features: a light and electron microscopic study.

The first case of a cardiac myxoma exhibiting chondroid differentiation is described. The tumor showed lacunar spaces around clusters of typical myxoma cells on light microscopy. Ultrastructurally the tumor cells contained abundant glycogen, and the tumor stroma contained proteoglycan granules identical to those seen in the ground substance of cartilage. These findings lend further support to the belief that the primitive mesenchymal cell is the cell of origin in cardiac myxoma.

Bacillary angiomatosis presenting as a soft-tissue tumor without skin involvement.

A patient with human immunodeficiency virus infection presented with a soft-tissue mass which histologically and clinically mimicked an angiosarcoma. Ultrastructural study, however, revealed bacteria identical to those seen in cutaneous bacillary angiomatosis, but the patient had no skin lesions. To our knowledge, this represents the first report of soft tissue involvement by bacillary angiomatosis without the presence of skin lesions.

Glomerulonephritis in congenital cytomegalic inclusion disease.

Except for renal transplant recipients, glomerulonephritis has only very rarely been associated with renal cytomegalovirus (CMV) infection. The kidneys of five infants with congenital cytomegalic inclusion disease, including renal infection, were examined at autopsy. Two of the infants had glomerulonephritis. The younger, a 4-month-old female, had diffuse proliferative and necrotizing glomerulonephritis; virus was present in nuclei and cytoplasm of glomerular endothelial cells and, possibly, in leukocytes as well. There were no electron-dense deposits. The other infant, a 5-month-old male, had diffuse mesangial and focal segmental proliferative and sclerosing glomerulonephritis; electron-dense mesangial deposits were seen ultrastructurally. Three additional infants (a newborn male, a 2-day-old male, a 6-week-old female), all with CMV in tubules and one with a single glomerular inclusion, had only rare glomerular abnormalities, i.e., mesangial proliferation in less than 10 per cent of glomeruli (one infant) and segmental sclerosis in less than 1 per cent of glomeruli (all three infants). Thus, congenital renal CMV infection was associated with proliferative glomerulonephritis in the two infants who survived the longest. The three with shorter survival times had only minor glomerular alterations.

Pancreatic disorders in pediatric acquired immune deficiency syndrome.

Acute pancreatitis, reported in 17% of pediatric patients with acquired immune deficiency syndrome (AIDS), is said to have a poor prognosis. We describe the pancreatic changes observed at autopsy from 71 children with human immunodeficiency virus (HIV) infection and document their nature, extent, and clinical relevance. The median age at autopsy of the children was 17 months (range, 2 months to 19 years); 38 were boys and 33 were girls. Parental intravenous drug use was the most frequent risk factor for AIDS, followed by blood transfusions. Respiratory failure and sepsis constituted the predominant causes of death. Nonspecific changes, such as edema, inflammation, fibrosis, inspissated material in acini and ducts, and enlarged Langerhans' islet predominated. Acute and chronic pancreatitis were mild except in one instance of a fatal acute probably dideoxyinosine-associated pancreatitis. Pancreatic involvement by opportunistic infections, such as cytomegalovirus (CMV), Mycobacterium avium intracellulare (MAI), and Candida, was focal and rare despite the high prevalence of these infections at autopsy. Focal lymphoplasmacytic infiltration and vascular calcifications were also observed. We conclude that pancreatic changes were frequently noted at autopsy in children with AIDS. They were usually mild, reflected systemic disease states, and were usually not life threatening. The incidence of opportunistic infections of the pancreas was low.

Fibrous hamartoma of infancy: an ultrastructural study.

The fine structures of three fibrous hamartomas of infancy were studied. All three components of these lesions were examined. The principal cells in the fibrous and myxoid areas were fibroblasts. Cells with stellate cytoplasmic projections were more prominent in myxoid areas. Myofibroblasts were abundant in two cases and not in the other. The adipose tissue component was formed by lipocytes and occasional preadipose fibroblasts. Blood vessels were more numerous in myxoid areas. Larger vessels were accompanied by smaller vessels and by clusters of cells with primitive junctions, suggesting early blood vessel formation. Some small vessels were surrounded by concentric layers of mesenchymal cells, as if attempting to form media. Electron microscopy seems to confirm the hamartomatous nature of fibrous hamartomas of infancy. The lesion appears to recapitulate the formation of blood vessels and fat, as seen in fetal tissues. Cellular myxoid areas showed prominent vasoformative proliferation, which decreased in the adipose tissue and was least prominent in the dense fibrous component. The latter may represent the end stage of the fibrous proliferation.

Small intestinal atresia and segmental absence of muscle coats.

The case of a newborn infant with small-intestine atresia coexisting with segmental absence of muscle coats leading to perforation and meconium peritonitis is presented. The theories of pathogenesis of the simultaneous occurrence of segmental absence of gut musculature and atresia are briefly reviewed. A possible etiologic role of vascular accident in utero for both conditions is discussed.

Ultrastructural demonstration of intracellular bacteria in xanthogranulomatous pyelonephritis.

Xanthogranulomatous pyelonephritis is considered to be an unusual cellular response to bacterial invasion. This assumption is based on circumstantial evidence and experimental studies. In our electron microscopic study of five cases of xanthogranulomatous pyelonephritis demonstrated a stratification of the cellular components, somewhat resembling that described in the experimental lesions. The center of the xanthogranulomas was occupied by purulent exudate. Bacteria were identified mainly in polymorphonuclear leukocytes and extracellularly in four cases in which central area were available for electron microscopic studies. Many bacteria were located in cytoplasmic vacuoles. more peripherally, histiocytes predominated, and their cytoplasm contained numerous lipid droplets with and without limiting membranes and phagolysosomes. The latter contained electron dense, granular, and membranous structures. The outermost layer of the lesion demonstrated macrophages with a decreased number of lipid droplets and larger intralysosomal particles. Lymphocytes, plasma cells, and fibroblasts represented an increasing proportion of the infiltrate in this layer. Our study suggests that xanthogranulomatous pyelonephritis is a bacteria induced process. Its histological appearance may be related to incomplete bacterial degradation and altered host response.