Xenon exposure in the neonatal rat brain: effects on genes that regulate apoptosis.

BACKGROUND: In the developing rodent brain, exposure to volatile anesthetics causes widespread neuronal apoptosis in several regions of the brain. Increasing evidence points to a possible neuroprotective role for the anesthetic gas xenon, following neuronal injury. To address this gap in understanding, we explored the transcriptional consequences of xenon in the brains of postnatal day 7 (P7) rats exposed to xenon compared to those of air-breathing animals, with particular emphasis on the mRNA transcript levels of Akt and c-Jun N-terminal kinase kinase 1 (JNKK1), which are important for cell survival and the activation of extrinsic neuroapoptotic pathways, respectively. METHODS: P7 Sprague/Dawley rats were exposed to air (75% nitrogen, 25% oxygen) or xenon (75% xenon, 25% oxygen) for 120 min (N=6/group). Forebrains were harvested for reverse transcription polymerase chain reaction, which enabled quantification of Akt and JNKK1 mRNA transcripts. Suppression subtractive hybridization was used to explore the "genetic signature" of xenon exposure. RESULTS: Compared to control air-breathing animals, xenon-breathing rats exhibited a 0.7-fold decrease in Akt mRNA expression (P<0.01) and a 1.6-fold increase in JNKK1 mRNA levels (P<0.05). CONCLUSION: The concomitant decrease in the Akt mRNA expression level and increase in the JNKK1 mRNA transcript level provide evidence that xenon has a neuroapoptotic effect in the developing rodent forebrain. Given these results, further study into the paradoxical neuroprotective and neuroapoptotic effects of xenon is warranted.

Postchemotherapy late recurrence of non metastatic gestational trophoblastic disease following a partiale mole. A case report.

The authors describe a case of a 35-year-old woman who showed elevation of betahCG 13 months after the complete regression of betahCG values following chemotherapy for an incomplete mole. This case outlines the necessity for careful monitoring of betahCG levels in low risk gestational trophoblastic diseases for a period of time longer than one year after achieving the first clinical remission.

Localized (solitary) fibrous tumors of the pleura: an analysis of 55 patients.

BACKGROUND: Localized (solitary) fibrous tumors (LFTPs) of the pleura are rare, slow-growing neoplasms thought to originate from submesothelial connective tissue. The aim of this article is to present 55 new cases of LFTP, and to discuss the treatment of choice and the clinical behavior of such neoplasms. METHODS: From July 1990 to November 1999, 55 patients (32 male, 23 female) with an LFTP were surgically treated at our Institution. Neoplasms were considered to be malignant if one or more of the following histologic features were present: high cellularity with crowding and overlapping of nuclei; high mitotic activity; or mild, moderate, or marked pleomorphism. RESULTS: No operative mortality was reported. Forty-eight of the cases arose from the visceral pleura and seven arose from the parietal pleura. A local removal of the neoplasm with free surgical margins was accomplished by video-assisted thoracic surgery in 39 patients and by standard thoracotomy in 10 patients. Four patients underwent formal lung resections, 1 had thymectomy, and 1 had en bloc chest wall resection. Four malignant variants were identified. One patient developed local recurrence and underwent redo surgery with chest wall resection. One patient died of unrelated disease. The remaining patients are alive and disease free at a median follow-up of 53.2 months. CONCLUSIONS: LFTPs show a benign outcome in most of the cases. Video-assisted thoracic surgery, with intraoperative assessment of the surgical margins, represents the treatment of choice.

Expression and parental imprinting of the H19 gene in human rhabdomyosarcoma.

The expression of Insulin-like Growth Factor 2 (IGF-2) and H19, two genes located on human chromosome 11p15 and provided with cell growth modulating activity, is regulated by parental imprinting, in that the activity of their alleles is dependent on the parental origin. Parental bias in the genetic alterations of chromosome 11p15 observed in several pediatric cancers suggests the involvement of imprinted genes in tumor development. We have previously reported that the number of functional IGF-2 alleles is frequently increased in rhabdomyosarcoma (RMS), as a consequence of either relaxation of imprinting (LOI) or gene duplication. Here we show that the expression of the H19 gene is significantly suppressed with respect to normal muscle tissue in 13 out of 15 rhabdomyosarcomas with embryonal histology (ERMS) and in three out of 11 rhabdomyosarcomas classified as alveolar subtype (ARMS). Since a growth-inhibitory activity has been found associated with the H19 gene, the extinction of its expression can contribute to RMS development. Parental imprinting of the H19 gene was found conserved in all informative RMSs, including those whose ICF-2 imprinting was relaxed, indicating that LOI is a gene-specific event. Seven ERMSs and one ARMS displaying low H19 RNA levels showed an underrepresentation of the expressed allele in their genotype. This result is consistent with the paternal imprinting of the H19 gene and with the preferential loss of the maternal 11p15 alleles in these neoplasms. Low H19 expression was also found in four out of eight RMSs retaining the heterozygosity at 11p15, but showing IGF-2 LOI. These findings suggest that the genetic and epigenetic alterations affecting chromosome 11p15 in a high number of RMSs cause deregulation of more than one imprinted gene, possibly affecting tumor growth, including the extinction of H19 expression and an increase in the number of active IGF-2 alleles.

Sarcomatoid transitional cell carcinoma of the renal pelvis. A report of five cases with clinical, pathological, immunohistochemical and DNA ploidy analysis.

Sarcomatoid transitional cell carcinoma of the renal pelvis is a rare neoplasm with only 7 well illustrated examples reported. These tumours can assume a partial or complete spindle cell pattern of growth, leading to the erroneous classification as sarcomas. We describe the clinic-pathologic features of five additional examples of sarcomatoid carcinoma of the renal pelvis observed in three males and two females. The age ranged from 65-to-82 years-old (mean 71.6). All these patients were treated by nephrectomy and died of disease between 6 and 20 months (mean 11.2) after the onset of symptoms. An immunohistochemical study demonstrated coexpression of keratins, epithelial membrane antigen and vimentin. The image DNA ploidy of all the tumours showed an aneuploid pattern.

Bellini duct carcinoma. A clinical and in vitro study.

OBJECTIVE: Bellini duct carcinoma (BDC) is a rare and highly aggressive renal tumor whose histogenesis is still a matter of debate although a putative origin from collecting ducts has been proposed. METHODS: A primary tumor cell culture was obtained from a BDC of a 57-year-old man who presented with a mass of the right kidney. The patient died from disease progression 18 months after diagnosis. The light and ultrastructural features were consistent with previous reports on BDC. The expression of low (Ker 18) and high (Ker 5, Ker 8, Ker 10) molecular weight keratins was studied. RESULTS: The BDC tumor cells displayed strong positivity for keratins, 5, 8 and 18 but did not react with the anti-keratin 10 antibody. Northern blot analysis of total mRNA revealed expression of the c-erbB-1 oncogene unlike two conventional clear cell carcinomas of the kidney used as control. Cytogenetic analysis revealed an aneuploid karyotype: 53,XY,del(1)(p34),+iso(1q),+iso(5p),+4,+7,+8,-14,del(16)(q22). No submicroscopic deletion on p14-21 and p26 regions of the short arm of chromosome 3 was detected on Southern blot analysis. CONCLUSIONS: The absence of structural changes in the short arm of chromosome 3 (usually present in hereditary and sporadic renal cell carcinomas) in the presence of chromosomal abnormalities observed in malignant lesions of urothelial origin confers to BDC a unique genetic profile among papillary tumors of the kidney.

Retroperitoneal cystic neuroendocrine tumor. A case report.

A 21 cm retroperitoneal cystic mass was excised from a 71 year old woman. The cyst was filled with a hemorrhagic fluid and contained a 5 cm parietal hemorrhagic nodule. On histology, the nodule was composed of a uniform population of round cells arranged in trabeculae and nests. The neoplastic cells were immunoreactive to cytokeratin, EMA, NSE, chromogranin A, pancreatic polypeptide (PP) and Gastrin (G). Ultrastructural observation of neurosecretory granules confirmed the neuroendocrine nature of the tumor. No other lesions were detected and a diagnosis of primary epithelial neuroendocrine tumor was rendered. The histogenesis of the tumor including the possibility of a paraganglionic origin is discussed.

Gastrointestinal stromal tumor: evidence for a smooth-muscle origin.

A gastrointestinal stromal tumor, arising from the rectal ampulla of a 63-yr-old man, was investigated using conventional techniques as well as Western blot analysis of its cytoskeleton proteins. The expression of desmin, muscle-specific actins, vimentin, S-100 protein, chromogranin, neuron-specific enolase, and keratins was studied using the avidin-biotin technique. The tumor cells showed a positive reaction only to antivimentin antibody. Ultrastructural analysis failed to provide conclusive evidence for neural or muscular origin of the tumor. Western blot analysis of the tumor whole-protein extract allowed identification of the presence of gamma-smooth-muscle actin, thus suggesting an enteric smooth-muscle origin of the tumor. This result seems partially to support a parenchymal smooth-muscle origin for S-100 protein and desmin-negative gastrointestinal tumors.

Mono- and bi-allelic expression of insulin-like growth factor II gene in human muscle tumors.

Insulin-like growth factor II (IGF-II) is a mitogen for many cell types and an important modulator of muscle growth and differentiation. IGF-II gene is prevalently expressed during prenatal development and its gene activity is regulated by genomic imprinting, in that the allele inherited from the father is active and the allele inherited from the mother is inactive in most normal tissues. IGF-II expression is activated in several types of human neoplasms and an alteration of IGF-II imprinting has been described in Beckwith-Wiedemann syndrome and Wilms' tumor. Here we show that monoallelic expression of IGF-II gene is conserved in normal adult muscle tissue whereas two or more copies of active IGF-II alleles, arising by either relaxation of imprinting or duplication of the active allele, are found in 9 out of 11 (82%) rhabdomyosarcomas retaining heterozygosity at 11p15, regardless of the histological subtype. Since IGF-II has been indicated as an autocrine growth factor for rhabdomyosarcoma cells, these findings strongly suggest that acquisition of a double dosage of active IGF-II gene is an important step for the initiation or progression of rhabdomyosarcoma tumorigenesis. Among different types of muscle tumors, relaxation of imprinting seems to arise prevalently in rhabdomyosarcomas, since we have detected only one case of partial reactivation of the maternal IGF-II allele out of 7 leiomyosarcomas tested.

Comparison of Ewing's sarcoma of bone and peripheral neuroepithelioma. An immunocytochemical and ultrastructural analysis of two primitive neuroectodermal neoplasms.

Ewing's sarcoma of bone (ESB) and peripheral neuroepithelioma (PN) are frequently considered to be different tumors. Some researchers have suggested that PN is morphologically a neuroectodermal Ewing's sarcoma. We sought to determine the extent of neuroectodermal features in conventional ESB on direct patient material (25 cases) and to compare these tumors with a similar group of readily diagnosed PNs (10 cases). Light microscopic, ultrastructural, and immunophenotypic parameters were assessed and compared for both groups. The avidin-biotin complex method was used. All tumors were antigenically intact since all stained for vimentin or at least one marker. Neuroectodermal antigens (neuron-specific enolase, Leu-7 [HNK-1], neurofilament 200 kd, and S100) were found in nine of 10 cases of PN and in 17 of 25 cases of ESB. In ESB, an atypical light microscopic appearance correlated with the presence of neuroectodermal features in most cases, but neuroectodermal phenotype was more frequent (68%) than morphological evidence of neuroectodermal differentiation (36%). These data support the concept that ESB and PN are both peripheral primitive neuroectodermal neoplasms, differing only in extent of neuroectodermal phenotype and morphological differentiation.

Glycosaminoglycans prevent morphological renal alterations and albuminuria in diabetic rats.

Abnormal glycosaminoglycan metabolism is involved in the onset of anatomo-functional derangements in diabetic nephropathy, and determines the loss of glomerular basement membrane anionic charges leading to albuminuria. Glycosaminoglycan administration was shown to increase the negative electrical potential of the vessel wall, inhibit mesangial cell proliferation, which is an anatomical hallmark of diabetic nephropathy, and slow down the progression to uremia in subtotally nephrectomized rats, a model that shares some pathogenetic key events with diabetic nephropathy. Based on these considerations, we verified the effect of exogenous glycosaminoglycans on renal involvement in streptozotocin diabetic rats. Long-term administration of two glycosaminoglycans (low-molecular weight heparin and dermatan sulphate) prevented glomerular basement membrane thickening, glomerular anionic charge reduction, as well as the onset of albuminuria without affecting glomerular filtration rate and metabolic control of the disease. Our data demonstrate that the long-term administration of glycosaminoglycans has a favorable effect on morphological and functional renal abnormalities in diabetic rats.

Spindle cell rhabdomyosarcoma. A prognostically favorable variant of rhabdomyosarcoma.

Twenty-one cases of embryonal rhabdomyosarcoma, composed mainly of elongated spindle cells arranged in a fasciculated or storiform pattern, were retrieved from the files of the German-Italian Cooperative Soft Tissue Sarcoma Study. The term spindle cell rhabdomyosarcoma is proposed to designate this histotype. Spindle cell rhabdomyosarcoma predilected male patients (18 males, three females) and involved mostly the paratesticular area (12 cases) and the head and neck region (six cases). Histologically, all cases were characterized by a uniform proliferation of elongated spindle cells with eosinophilic and fibrillar cytoplasm mimicking smooth muscle fibers; immunocytochemical studies disclosed high expression of the muscle markers titin, desmin, and myoglobin. Clinical information was available in 17 cases; according to the Intergroup Rhabdomyosarcoma Study (IRS) grouping system, 13 were classified in group I, two in group II, and two in group III. Sixteen patients were well and alive 24 to 100 months after diagnosis; one patient died from disease progression 24 months after diagnosis. Analysis of our results determined that spindle cell rhabdomyosarcoma constitutes a rare variant of the embryonal form, showing a high degree of skeletal muscle differentiation and a low malignant potential; it should therefore be distinguished from classical forms of embryonal rhabdomyosarcoma.

DNA content, nuclear grading and early tumor progression in renal cell cancer: a prospective study on frozen specimens.

Renal cell carcinoma is a neoplasia with an unpredictable behavior. Nuclear grade and pathologic stage are widely accepted as valuable prognostic factors. More recently DNA content has been proposed as an adjunctive parameter of the clinical course of the disease. In order to substantiate these findings we prospectively analyzed 36 frozen specimens from patients submitted to radical nephrectomy for renal cell carcinoma. The study population had a 2:1 male/female ratio with a median age of 57 years. Six of 33 patients died of tumor progression with a median survival time of 11 months. The tumor DNA index (DI) ranged from 0.86 to 2.06 with a mean coefficient of variation of 4.59. Ten cases (27.8%) had a diploid DNA content, whereas 26 (72.2%) showed a distinct aneuploid population. In 10 cases different DI values were observed in different samples from the same tumor. Aneuploidy was significantly associated with advanced pathologic stages, high nuclear grade, and tumor progression.

Fine-needle aspiration cytology of malignant nerve sheath tumors.

Precise preoperative diagnosis of three malignant nerve sheath tumors (MNST) was based on their remarkably uniform and highly characteristic cytologic appearance. The differential diagnosis with benign nerve sheath tumors and other spindle cell sarcomas is addressed, and the possibility of achieving confident diagnosis on cytologic material from at least some soft-tissue sarcomas is confirmed.

Peripheral neuroepithelioma: a light microscopic, immunocytochemical, and ultrastructural study.

Forty-two cases of peripheral neuroepithelioma (PN) retrieved from the files of the National Cancer Institute (Bethesda, MD) and the Pathology Department of Padua University, Italy, were reviewed. No sex predilection was observed (25M/17F) and ages ranged from 7 to 54 yr (median 22 yr). Roughly a third of the tumors were thoracopulmonary ("Askin tumor"), a third were axial, and a third were in extremities. A lobular pattern with rosettes or pseudo-rosettes characterized PN. Seventeen cases showed a strong diastase-sensitive PAS positivity. Transitional areas with an Ewing's-like appearance and, in one case, transition to malignant nerve sheath tumor have been documented. The presence of neuron specific enolase (NSE), S-100 protein, HNK-1, neurofilaments, vimentin, keratin (AE1-AE3), beta 2-microglobulin, chromogranin A, and synaptophysin was investigated using the avidin-biotin technique. Immunocytochemically, NSE (95% of cases), beta 2-microglobulin (77.5%), synaptophysin (73.3%), and S-100 protein (67.5%) were the most consistently positive markers. Ultrastructurally, PN is characterized by a primitive appearance, although it was routinely possible to recognize neural features such as primitive neuritic extensions and dense core granules, either in the cytoplasm or in the cellular processes. In our experience, a light microscopic picture of a primitive round cell tumor with a lobular pattern, and particularly with rosettes when present, with NSE and beta 2-microglobulin positivity by immunocytochemistry, ideally with positive synaptophysin, along with supportive electron microscopy, is required for the diagnosis of PN. Conversely, no one feature alone is generally sufficient for diagnosis, but does allow distinction from extraosseous Ewing's, which (like osseous Ewing's) lacks features of neural differentiation.

Morphometry and the differential diagnosis between peripheral neuroepithelioma and neuroblastoma.

The differential diagnosis based on morphology between neuroblastoma (NB) and peripheral neuroepithelioma (PN) is difficult, since these tumors share many architectural and cytological features. In this study, a morphometrical approach to this diagnosis is made by using nuclear (shape factors) and tissue (volume density of nuclei and stroma) parameters. Quantitative morphological analysis adds important information, which when used with clinical and biochemical data facilitates the distinction. In the majority of cases, nuclei of PN are significantly less round than those of NB and their profile is much more irregular. The density of neoplastic nuclei is significantly higher in PN. However, in a certain number of cases, even the morphometrical study confirms how difficult it may be to differentiate these two neoplastic entities, since the values of parameters are largely overlapping. This suggests the existence of a "continuum" of changing features between NB and PN, which may substantiate the hypothesis of a common histogenesis.

Small-cell carcinoma of gallbladder. An immunocytochemical and ultrastructural study.

An unusual carcinoma of the gallbladder in a seventy-one-year-old woman displayed features of a well-differentiated adenocarcinoma, atypical carcinoid and small cell undifferentiated carcinoma. The patient died from progressive hepatic failure four months after surgery. Autopsy showed bulky liver masses and several peritoneal nodules exclusively composed of small, hyperchromatic cells. The neuroendocrine nature of the small cell component of the tumor was documented by the presence of neurosecretory granules at the ultrastructural level and by immunocytochemical positivity to NSE and Synaptophysin. The epithelial markers, cytokeratin and CEA, were also positive in the carcinoid and in the undifferentiated portions of the tumor. A common endodermal origin is suggested for carcinoid and small cell carcinoma of the gallbladder.

Expression of the dbl proto-oncogene in Ewing's sarcomas.

We have investigated the expression of the dbl proto-oncogene in childhood tumors of known or suspected neuroectodermal origin. We found that while the dbl gene is consistently found expressed in Ewing's sarcoma as a single mRNA species, of approximately 5.0 kb, it is generally absent in two seemingly related categories of tumors, neuroblastoma and neuroepithelioma. The specificity of expression of the dbl proto-oncogene in Ewing's sarcoma supports the concept that Ewing's sarcoma may be differentiated from two closely related tumors, neuroblastoma and neuroepithelioma, on the basis of the presence of specific molecular markers.