Early Stages Of Progression Research Articles

The Window of Epileptogenesis: Looking beyond the Latent Period

Development of Spontaneous Recurrent Seizures after Kainate-Induced Status Epilepticus. Williams PA, White AM, Clark S, Ferraro DJ, Swiercz W, Staley KJ, Dudek FE. J Neurosci 2009;29:2103–2112. Acquired epilepsy (i.e., after an insult to the brain) is often considered to be a progressive disorder, and the nature of this hypothetical progression remains controversial. Antiepileptic drug treatment necessarily confounds analyses of progressive changes in human patients with acquired epilepsy. Here, we describe experiments testing the hypothesis that development of acquired epilepsy begins as a continuous process of increased seizure frequency (i.e., proportional to probability of a spontaneous seizure) that ultimately plateaus. Using nearly continuous surface cortical and bilateral hippocampal recordings with radiotelemetry and semiautomated seizure detection, the frequency of electrographically recorded seizures (both convulsive and nonconvulsive) was analyzed quantitatively for 100 d after kainate-induced status epilepticus in adult rats. The frequency of spontaneous recurrent seizures was not a step function of time (as implied by the “latent period”); rather, seizure frequency increased as a sigmoid function of time. The distribution of interseizure intervals was nonrandom, suggesting that seizure clusters (i.e., short interseizure intervals) obscured the early stages of progression, and may have contributed to the increase in seizure frequency. These data suggest that ( 1 ) the latent period is the first of many long interseizure intervals and a poor measure of the time frame of epileptogenesis, ( 2 ) epileptogenesis is a continuous process that extends much beyond the first spontaneous recurrent seizure, ( 3 ) uneven seizure clustering contributes to the variability in occurrence of epileptic seizures, and ( 4 ) the window for antiepileptogenic therapies aimed at suppressing acquired epilepsy probably extends well past the first clinical seizure.

The possible evolutionary role of tumors in the origin of new cell types

The ability of tumor cells to differentiate in combination with their ability to express genes that are not expressed in normal tissues, may result in the emergence of new cell types in evolution. Tumors may play an evolutionary role by providing conditions (space and resources) for the expression of newly evolving genes. Genetically or epigenetically predetermined tumors at the early stages of progression, benign tumors, and some tumor-like processes in invertebrates and plants, all of which are modes of excess cell growth which provide evolving multicellular organisms with extra cell masses, are considered as potentially evolutionarily meaningful. Malignant tumors at the late stages of progression, however, are not. The preexisting cell types of multicellular organisms had restricted potential for the expression of newly evolving genes. Because of regulation and gene competition, some of the newly evolving genes may stay silent. Multicellular organisms would need excess cell masses for the expression of newly evolving genes. The preexisting cell types cannot provide such excess cell masses because of limitations imposed on the number of possible cell divisions. Tumors could provide the evolving multicellular organisms with the excess cell masses for the expression of newly evolving genes. We suggest that tumors could be a sort of proving ground (or reservoir) for the expression of newly evolving genes that originate in the course of genome evolution in the DNA of germ cells (i.e., not in tumor cells themselves). The case in which the expression of a newly evolving gene in tumors results in the origin of a new function would be associated with the origin of new feedback and regulatory circuits, as in root nodules in legumes and macromelanophores in Xiphophorus fishes. Tumor cells would differentiate, resulting in a new cell type for the given multicellular species. This cell type would be inherited because of epigenomic mechanisms similar to those in preexisting cell types. Populations of tumor-bearing organisms with genetically or epigenetically programmed tumors could represent the transition between established species of organisms at different stages of progressive evolution. Experimental confirmation of the prediction of the hypothesis of evolution by tumor cells differentiation concerning the expression of evolutionarily new genes and/or silent (neutrally evolving) sequences in tumor cells is presented.

Late progression of renal pathology and cyst enlargement is reduced by rapamycin in a mouse model of nephronophthisis

Because the size of renal cysts in the native kidneys of patients with ADPKD who have been transplanted was found to be reduced when rapamycin was the immunosuppressant, we tested the involvement of the mTOR pathway in cyst enlargement. Here, male pcy mice, with mutation in one of the nephronophthisis genes, were treated with rapamycin at an early (6 to 12 weeks of age) or a later (20 to 30 weeks of age) disease stage by means of slow-release pellets containing placebo or rapamycin. Effectiveness of the rapamycin dose and delivery was shown by the inhibition of insulin-stimulated phosphorylation of p70S6K, a marker of mTOR activity, in skeletal muscle. Early treatment did not affect initial cyst development but when started late, there was a significant reduction in the rate of cyst enlargement, kidney fibrosis, and the progressive loss of renal function as measured by blood urea nitrogen. Kidneys of the mice treated through 30 weeks of age tended to be smaller and have less fibrosis compared with those of untreated or placebo-treated pcy/pcy mice at 20 weeks when treatment was initiated. Our study shows that rapamycin can prevent the late- but not the early-stage progression of renal pathology and deterioration of renal functional in this model of nephronophthisis, presumably by inhibiting mTOR activity.

Detection of cancer clones in human gastric adenoma by increased DNA-instability and other biomarkers.

An immunohistochemical differential staining of cancerous cells with anti-cytidine antibody after denaturation of nuclear DNA by acid hydrolysis with 2N HCl at 30 degree C for 20 min (DNA-instability test) has been used as a marker of malignancy. The test was applied to bioptic tissues of human gastric polyp assessed histopathologically as foveolar hyperplastic polyp (13 cases), mild (58 cases), moderate (86 cases), and severe (20 cases) dysplasia, and adenocarcinomas (14 cases). The serial sections of the same tissues were also subjected to immunohistochemical staining for Ki67, p53, DNA-fragmentation factor (DFF45), and basic fibroblast growth factor (bFGF). The DNA-instability test was positive in 14 (100%) adenocarcinoma cases, 20 (100%) severe dysplasia cases, 52 (60.5%) moderate dysplasia cases, and 12 (20.7%) mild dysplasia cases, indicating malignancy. All foveolar hyperplastic polyps were negative to the DNA-instability testing. Furthermore, the percentage of glands positive in the DNA-instability test steadily increased in going from mild (10%), to moderate (40%), to severe (100%) dysplasia, and adenocarcinoma (100%). All other biological markers tested in the present study showed significantly higher values in the adenoma glands, being positive to DNA-instability testing, irrespective of the dysplasia grade, as compared to those in the adenoma glands that were negative to DNA-instability testing. Furthermore, the former values were comparable to those in adenocarcinoma. These results indicate that cancer cell clones are already present at the adenoma stages showing a positive DNA-instability test, enhanced proliferative activity, p53 mutation, induction of DFF45 and bFGF. These factors allow cancer cell proliferation, producing heterogeneous subclones due to DNA-instability, enhancing their survival by escaping apoptosis, and providing abundant nutrients during the early-stage progression of gastric cancer. Based on these findings, we herein propose the concept of "procancer" (as opposed to "pre-cancer") as being a unique stage during the course of carcinogenesis and cancer progression. We designate the term to cancer clones at the very early stages of malignant progression that do not show distinguishable morphological atypia but do show positive DNA-instability testing and positive staining for various biomarkers such as Ki67, p53, DFF45, and bFGF. We also define the abnormal positive staining of these biomarkers, including the DNA-instability test as "functional atypia", compared to the ordinary morphological atypia.

Differential N-glycosylation of Kallikrein 6 Derived from Ovarian Cancer Cells or the Central Nervous System

Ovarian cancer causes more deaths than any other gynecological disorder. Perturbed glycosylation is one of the hallmarks of this malignancy. Kallikrein 6 (KLK6) elevation in serum is a diagnostic and prognostic indicator in ovarian cancer. The majority of ovarian carcinomas express high levels of KLK6, which diffuses into the circulation. Under physiological conditions, KLK6 is expressed highly in the central nervous system and found at high levels in cerebrospinal fluid from where it enters the circulation. Our aim was to characterize and compare the N-glycosylation status of this protein in ovarian cancer ascites fluid and cerebrospinal fluid. Anion-exchange chromatography was used to reveal different post-translational modifications on the two isoforms. Mobility gel shift Western blot analysis coupled with glycosidase digestion showed that the molecular weight difference between the two isoforms was because of differential glycosylation patterns. The presence of a single N-glycosylation site on KLK6 was confirmed by site-directed mutagenesis. Using a Sambucus nigra agglutinin-monoclonal antibody sandwich enzyme-linked immunosorbent assay approach, it was shown that ovarian cancer-derived KLK6 was modified with alpha2-6-linked sialic acid. The structure and composition of glycans of both KLK6 isoforms was elucidated by glycopeptide monitoring with electrospray ionization-Orbitrap tandem mass spectrometry. Therefore, the extensive and almost exclusive sialylation of KLK6 from ovarian cancer cells could lead to the development of an improved biomarker for the early diagnosis of ovarian carcinoma.

Development of Spontaneous Recurrent Seizures after Kainate-Induced Status Epilepticus

Acquired epilepsy (i.e., after an insult to the brain) is often considered to be a progressive disorder, and the nature of this hypothetical progression remains controversial. Antiepileptic drug treatment necessarily confounds analyses of progressive changes in human patients with acquired epilepsy. Here, we describe experiments testing the hypothesis that development of acquired epilepsy begins as a continuous process of increased seizure frequency (i.e., proportional to probability of a spontaneous seizure) that ultimately plateaus. Using nearly continuous surface cortical and bilateral hippocampal recordings with radiotelemetry and semiautomated seizure detection, the frequency of electrographically recorded seizures (both convulsive and nonconvulsive) was analyzed quantitatively for approximately 100 d after kainate-induced status epilepticus in adult rats. The frequency of spontaneous recurrent seizures was not a step function of time (as implied by the "latent period"); rather, seizure frequency increased as a sigmoid function of time. The distribution of interseizure intervals was nonrandom, suggesting that seizure clusters (i.e., short interseizure intervals) obscured the early stages of progression, and may have contributed to the increase in seizure frequency. These data suggest that (1) the latent period is the first of many long interseizure intervals and a poor measure of the time frame of epileptogenesis, (2) epileptogenesis is a continuous process that extends much beyond the first spontaneous recurrent seizure, (3) uneven seizure clustering contributes to the variability in occurrence of epileptic seizures, and (4) the window for antiepileptogenic therapies aimed at suppressing acquired epilepsy probably extends well past the first clinical seizure.

Transient Increase in Plasma Oxidized LDL During the Progression of Atherosclerosis in Apolipoprotein E Knockout Mice

Plasma level of oxidized low-density lipoprotein (OxLDL) is a risk marker for cardiovascular diseases. The behavior of plasma OxLDL before disease progression has not been studied previously. In this study, we developed a sensitive ELISA procedure for detecting mouse circulating OxLDL using a monoclonal antibody that recognizes oxidized phosphatidylcholine and a rabbit antimouse apolipoprotein B-48 polyclonal antibody. Apolipoprotein E knockout mice were fed on a chow diet for 40 weeks. Oil red O-positive lesions developed gradually by 20 weeks, and the percentage area covered by the lesions increased dramatically after 28 weeks; it covers 33.4% of the surface area by 40 weeks. The OxLDL level, measured after LDL fraction was isolated from each mouse, at 10 weeks was 0.015 ng/microg LDL. It increased 3-fold at 20 weeks of age and then decreased to the basal level by 40 weeks of age, suggesting that OxLDL appears before the development of atherosclerotic lesions. The occurrence of lipid peroxidation products, acrolein and oxidized phosphatidylcholines, in aortic tissue were revealed by immunohistochemical staining as early as 10 weeks. These results suggest that OxLDL might be involved in the early stages of progression of atherosclerotic lesions.

Neuropeptide Y gene therapy decreases chronic spontaneous seizures in a rat model of temporal lobe epilepsy

Temporal lobe epilepsy remains amongst the most common and drug refractory of neurological disorders. Gene therapy may provide a realistic therapeutic approach alternative to surgery for intractable focal epilepsies. To test this hypothesis, we applied here a gene therapy approach, using a recombinant adeno-associated viral (rAAV) vector expressing the human neuropeptide Y (NPY) gene, to a progressive and spontaneous seizure model of temporal lobe epilepsy induced by electrical stimulation of the temporal pole of the hippocampus, which replicates many features of the human condition. rAAV-NPY or a control vector lacking the expression cassette (rAAV-Empty) was delivered into the epileptic rat hippocampi at an early progressive stage of the disease. Chronic epileptic rats were video-EEG monitored to establish pre-injection baseline recordings of spontaneous seizures and the effect of rAAV-NPY versus rAAV-Empty vector injection. Both non-injected stimulated controls and rAAV-empty injected rats showed a similar progressive increase of spontaneous seizure frequency consistent with epileptogenesis. The delivery of rAAV-NPY in epileptic rat brain leads to a remarkable decrease in the progression of seizures as compared to both control groups and this effect was correlated with the NPY over-expression in the hippocampus. Moreover, spontaneous seizure frequency was significantly reduced in 40% of treated animals as compared to their pre-injection baseline. Our data show that this gene therapy strategy decreases spontaneous seizures and suppresses their progression in chronic epileptic rats, thus representing a promising new therapeutic strategy.

A case of multiple diffuse gastric carcinoma with regional expression of mutant E-cadherin

Dear Editors,E-cadherin is a cell adhesion molecule that is normallylocalizedtothecell–cellinterfaceandithasbeenreportedthatdownregulation of E-cadherin expression is associated withinvasion and metastasis of human cancers. About 50% ofdiffuse gastric carcinomas have revealed mutations of the E-cadherin gene and frequently have in-frame skipping of exon9 at the early stage of progression. Becker et al. developed aspecific antibody E-cad delta 9-1 (clone 7E6; D9) against anepitope that spans the fusion junction region between exons8 and 10 of E-cadherin and immunohistochemically demon-strated tumor cells that lacked E-cadherin exon 9 [3]. Usingthis antibody, we examined a case of multiple diffuse gastriccarcinoma and demonstrated the presence and absence ofexon 9 skipping of E-cadherin in several tumor lesions.A 28-year-old woman, whose familial history was notexamined, underwent total gastrectomy due to an advancedcancer. The operation specimen revealed two flat-depressed(IIc type of Japanese Classification of Gastric Carcinoma)lesions,18mmand9mmingreatestdiameter,attheposteriorwall and the anterior wall of the antrum, respectively, as wellas a small ulcerated lesion, 23 mm in greatest diameter, withconverging folds at the posterior wall of the lower corpus.This tumor reached the subserosa. The larger IIc-type tumorfocally invaded the submucosa and the smaller one wasconfined to the mucosa. Additionally, microscopic examina-tion of the background mucosa disclosed more than onehundred minute, intramucosal lesions within 5 mm indiameter (Fig. 1a and b). No lymph node metastasis wasdetected. All the lesions were diffuse carcinomas includingsignet ring cells, but in situ carcinoma as reported byCarneiro et al. in familial diffuse gastric cancer [4] was notdetected. Macroscopically discernible, the three lesions weresubjected to immunohistochemistry with D9 and E-cadherinmonoclonal antibody (mAb) clone 36 (Transduction Labo-ratories, Lexington, MA, USA; 1:1500), recognizing theintracytoplasmic domain common to both mutant and normalE-cadherin. The three lesions and their surrounding non-neoplastic epithelia were positive for mAb clone 36, whereasonly the larger IIc-type tumor, which invaded the submuco-sa, was positive for D9 (Fig. 1c and d). The small ulceratedlesion, which invaded the subserosa, and minute cancerswere negative for D9 (Fig. 1e and f). These findings suggestthat D9-positive cancer is not always aggressive althoughpatients with D9-positive gastric carcinomas often showedpoor survival.Gastric carcinomas are characterized by various growthpatterns. In particular, superficially spreading intramucosalcarcinomas are peculiar to the stomach. Regarding thehistogenesis of superficially spreading tumors, two con-cepts have confronted each other: monoclonal versus field(multiclonal) cancerization. The latter explains a widemucosal lesion to be formed by the fusion of multipletumors that arise independently. Histological studies on thisproblem have given us only circumstantial evidence.Among the diffuse gastric carcinomas, signet ring cellcarcinoma has been reported to arise from the glandular

Long-term survival for 13 years after percutaneous transhepatic cholangioscopic microwave tissue coagulation (MTC) in an inoperable jaundiced woman with bile duct carcinoma

We report a patient with bile duct carcinoma with longer than 13-year survival with no surgical treatment but cholangioscopic MTC.A 67-year-old female who had undergone coronary arterial bypass grafting was referred to our institution because of increased obstructive jaundice with bile duct carcinoma. Because she had undergone the coronary bypass operation using pedicle right gastroepiploic artery, it was not possible to apply pancreatoduodenectomy as radical operation. Therefore, percutaneous transhepatic cholangioscopic and X-ray image-guided MTC using Microtaze® (Heiwa Electronic Industrial Co. Ltd., Osaka, Japan) and 1.8 mm φ spherical, 5 mm φ bullet-shaped antennas was carried out under radiation of 45 watts and repetitions of 3-5 second duration. Serial cholangioscopic examination was conducted once a month for 3 years and sometimes disclosed involvements which were biopsied and shown to be recurrences histologically and followed by retreatment using MTC. The patient has been alive for more than 13 years since onset of jaundice, and is 81 years old. No adverse side effects were noted.Our method uses not only coagulation but also a mild hyperthermic condition with a 5 mm φ antenna on the tumor margin at the depth of invasion as well as on the ductal lumen. MTC may be useful for palliation of inoperable patients with bile duct carcinoma, and sometimes for cure of the patients in the early stage of progression.

Detection of cancer clones in human colorectal adenoma as revealed by increased DNA instability and other bio-markers.

An immunohistochemical differential staining of cancerous cells with anti-cytidine antibody after denaturation of nuclear DNA by acid hydrolysis with 2N HCl at 30 degrees C for 20 min (DNA-instability test) has been used as a marker for malignancy. The test was applied to bioptic tissues of human colorectal polyps assessed histopathologically as hyperplastic polyp (11 cases), tubular adenoma of mild (68 cases), moderate (102 cases), and severe (46 cases) dysplasia, and adenocarcinoma (30 cases). The serial sections of the same tissues were also subjected to immunohistochemical staining for Ki67, p53, DNA-fragmentation factor 45 (DFF45) and vascular endothelial growth factor (VEGF). The DNA-instability test was positive in 30 (100%) adenocarcinoma cases, 46 (100%) severe dysplasia adenoma cases, 36 (35.29%) moderate dysplasia adenoma cases, and 8 (11.76%) mild dysplasia adenoma cases, indicating malignancy. All hyperplastic polyps were negative to the DNA-instability test. Furthermore, the percentage of glands positive in the DNA-instability test steadily increased in going from mild (10%), to moderate (35%), to severe (100%) dysplasia, and adenocarcinoma (100%). All other biological markers tested in the present study showed significantly higher values in those adenoma glands that were positive to the DNA-instability test, irrespective of the dysplasia grade, as compared to the markers in the adenoma glands that were negative to DNA instability testing. Furthermore, the former values were comparable to those in adenocarcinoma. The results indicate that cancer cell clones are already present at the adenoma stages showing positivity to DNA instability testing, enhanced proliferative activity, p53 mutation and induction of DFF45 and VEGF, at a time when the degree of morphological atypia are not yet large enough for them to be identified as cancer. These factors promote cancer cell proliferation, produce heterogeneous subclones due to DNA instability, enhance their survival by escaping apoptosis, and provide abundant nutrients by neovascularization during the early-stage progression of colorectal cancer.

Growth as a corrective force in the early treatment of progressive infantile scoliosis

This prospective study of 136 children with progressive infantile scoliosis treated under the age of four years, and followed up for nine years, shows that the scoliosis can be reversed by harnessing the vigorous growth of the infant to early treatment by serial corrective plaster jackets. In 94 children (group 1), who were referred and treated in the early stages of progression, at a mean age of one year seven months (6 to 48 months) and with a mean Cobb angle of 32 degrees (11 degrees to 65 degrees), the scoliosis resolved by a mean age of three years and six months. They needed no further treatment and went on to lead a normal life. At the last follow-up, their mean age was 11 years and two months (1 year 10 months to 25 years 2 months), 23 (24.5%) were at Risser stages 4 and 5 and 13 girls were post-menarchal. In 42 children (group 2), who were referred late at a mean age of two years and six months (11 to 48 months) and with a mean Cobb angle of 52 degrees (23 degrees to 92 degrees), treatment could only reduce but not reverse the deformity. At the last follow-up, at a mean age of ten years and four months (1 year 9 months to 22 years 1 month), eight children (19%) were at Risser stages 4 and 5 and five girls were post-menarchal. Fifteen children (35.7%) had undergone spinal fusion, as may all the rest eventually.

Mammary intraepithelial neoplasia outgrowths (MINO): MINO and human ductal carcinoma in situ

Mouse models of human mammary intraepithelial neoplasia have been described in a number of contexts. In general, descriptions of early stages of progression in genetically engineered mice that go on to develop invasive and even metastatic carcinomas are compared with human ductal carcinoma in situ (DCIS). In some instances, lesions with phenotypic similarity to human DCIS are compared, even without evidence of progression. The terminology for these processes in the mouse mammary gland requires precise definition. Otherwise, it is impossible to compare the variety of available models for study utility. Experimentally driven operational definitions are optimal. We have studied a series of transplantable mammary intraepithelial neoplasia outgrowths (MINOs) derived from the transgenic mouse mammary tumor virus promoter-driven polyoma virus middle T oncogene FVB mice. We have characterized their behavior experimentally and morphologically. Experimentally, these MINOs meet the most stringent criteria to be considered premalignant. They are capable of orthotopic growth in the gland cleared mammary fat pad, are without being capable of ectopic (subcutaneous) growth, and have a consistent transformation to the fully malignant behavior (capable of ectopic growth)–defined therefore as invasive carcinoma. Morphologically, there is a high degree of heterogeneity both within and between individual MINO lines. Nevertheless, all consistently transform to behaviorally and morphologically similar carcinomas. MINOs therefore compare closely with human DCIS. Human DCIS is similarly defined by its universal potential (if incompletely treated) to progress to invasive carcinoma, despite heterogeneity within a given breast or between individual patients. We extend the comparison using immunophenotypic analysis, and gene expression analysis. Overall, our goal is to better model human DCIS, in a reproducible and robust mouse model system suitable for interventional studies. By creating a serially transplantable series of MINOs we have removed much of the variability which would otherwise confound such study. Derivation of MINOs from a variety of genetically engineered mice backgrounds may provide additional critical reagents for the preclinical study of DCIS.

Ha-ras oncogene mutation associated to progression of papillomavirus induced lesions of uterine cervix.

Epidemiological and virological surveys suggest that the HPV presence is not enough condition to generate anogenital cancer, others factors (genetic, environmental, hormonal, etc) may have an important role. Mutations of ras genes were observed in several human neoplasias, including cervical cancer. The aim of the study was to assess the frequency of Ha-ras oncogene mutations in cervical intraepithelial neoplasia (CIN) grade III and invasive squamous cell carcinomas and to examine this genetic factor in relation to HPV infection and the clinical evolution of cervical lesions. They were selected for (a) evaluation of the frequency of Ha-ras mutations: 39 cases of invasive carcinomas (InCa), 47 CIN III and 12 normal tissues taken from areas adjacent to the tumor (NT). (b) Retrospective follow-up: 18 cases of lesion progression; 9 cases of persistence and 12 of regression to mature or immature metaplasia after specific treatment. All biopsies obtained from each patient during the follow-up done between 5 and 10 years were included. HPV typing and scanning of possible mutations in Ha-ras were made by single-strand conformation polymorphism analysis/polymerase chain reaction. HPV-DNA was detected in 95% of InCa and 84% of CIN III; HPV 16/18 was found in 65% of patients, mainly associated with persistent infection and lesion progression. The undetermined HPV types (18%) could indicate the circulation in our country of types other than those screened (6, 11, 16, 18, 31 and 33). Twenty percent of CIN III and 41% of InCa had patterns compatible with Ha-ras mutations. Mutated Ha-ras was detected in 61 and 44% of progression and persistence cases, respectively, including early stages of progression. Ha-ras mutations were detected in CIN II-III lesions; in mutated cases, the progression took place in under 2 years, then this detection may be an early predictive marker of rapid progression.

Early recognition of Marfan's syndrome.

To describe the classical features of Marfan's syndrome to help nurse practitioners (NPs) diagnose it in the early stages of progression and perhaps prevent many of its deleterious effects. Selected research-based articles in the scientific literature and classic medical texts. The cause of Marfan's syndrome is unknown, but studies have linked it with a disorder of chromosome 15. It is a degenerative connective tissue disorder that affects the musculoskeletal, ocular, integumentary, respiratory, and neurologic systems. The most lethal effect is on the cardiovascular system causing dissecting aortic aneurysms. Early diagnosis is essential for a positive course of management. Marfan's syndrome can have fatal consequences and is often underdiagnosed and misdiagnosed.

Disruption of hematopoiesis and thymopoiesis in the early premalignant stages of infection with SL3-3 murine leukemia virus.

A time course analysis of SL3-3 murine leukemia virus (SL3) infection in thymus and bone marrow of NIH/Swiss mice was performed to assess changes that occur during the early stages of progression to lymphoma. Virus was detectable in thymocytes, bone marrow, and spleen as early as 1 to 2 weeks postinoculation (p.i.). In bone marrow, virus infection was detected predominantly in immature myeloid or granulocytic cells. Flow cytometry revealed significant reductions of the Ter-119(+) and Mac-1(+) populations, and significant expansions of the Gr-1(+) and CD34(+) populations, between 2 and 4 weeks p.i. Analysis of colony-forming potential confirmed these findings. In the thymus, SL3 replication was associated with significant disruption in thymocyte subpopulation distribution between 4 and 7 weeks p.i. A significant thymic regression was observed just prior to the clonal outgrowth of tumor cells. Proviral long terminal repeats (LTRs) with increasing numbers of enhancer repeats were observed to accumulate exclusively in the thymus during the first 8 weeks p.i. Observations were compared to the early stages of infection with a virtually nonpathogenic SL3 mutant, termed SL3DeltaMyb5, which was shown by real-time PCR to be replication competent. Comparison of SL3 with SL3DeltaMyb5 implicated certain premalignant changes in tumorigenesis, including (i) increased proportions of Gr-1(+) and CD34(+) bone marrow progenitors, (ii) a significant increase in the proportion of CD4(-) CD8(-) thymocytes, (iii) thymic regression prior to tumor outgrowth, and (iv) accumulation of LTR enhancer variants. A model in which disrupted bone marrow hematopoiesis and thymopoiesis contribute to the development of lymphoma in the SL3-infected animal is discussed.

SUPPRESSIVE EFFECT OF PULMONARY HYPERTENSION AND LEUKOCYTE ACTIVATION BY INHALED PROSTAGLANDIN E 1 IN RATS WITH MONOCROTALINE-INDUCED PULMONARY HYPERTENSION

The effect of long-term prostaglandin E 1 (PGE 1) aerosol was investigated in rats with chronic pulmonary hypertension induced by monocrotaline (MCT). Six-week-old Sprague-Dawley rats were separated into groups of 6 and administered 1 mL of saline (group A) or 60 mg / kg of MCT. The MCT-treated mice were then administered either nothing (group B) or 5 mL of PGE 1 (4 μ g/mL) via a nebulizer every day for 1 week (group C), 2 weeks (group D), 3 weeks (group E), or 4 weeks (group F) after MCT injection. The pulmonary artery medial wall thickness was measured and the weight ratio of the right ventricle to the intraventricular septum plus the left ventricle (RV ratio) was determined 1 month after saline or MCT injection. Leukocytes positive for the activation markers CD18, CD49d, CD62L were determined in each group every week for 1 month. The pulmonary artery medial wall thickness and RV ratio gradually decreased in proportion to the duration of PGE 1 inhalation. In groups E and F, the level of CD62L-positive leukocytes gradually decreased after MCT injection in proportion to the duration of PGE 1 inhalation. We conclude that long-term inhalation of PGE 1 is very useful therapy in chronic pulmonary hypertension and that the antileukocyte effect of PGE 1 is associated with the suppression of CD62L-positive leukocytes at an early stage of progression.

Clinical features of symptomatic Rathke's cleft cyst

To investigate the clinical features of Rathke's cleft cysts (RCCs), we retrospectively analyzed 15 cases with histologically confirmed RCCs. All patients underwent formal testing of visual field, endocrinological evaluation and magnetic resonance imagings. As overall presenting symptoms, endocrine disturbance was the most common symptoms, followed by visual disturbance and headache. Among the endocrine disturbances based on adenohypophysial dysfunction, hyperprolactinemia was most common. Considering the size of RCCs, RCCs could induce hyperprolactinemia only when the cysts became large enough to compress the infundibular system. Our series showed relative high incidence of pituitary dwarfism and diabetes insipidus (DI). These facts indicated that RCCs could evoke hyposecretion of growth hormone in young patients and DI in aged patients by direct compression of the pituitary gland in the early stage of progression. All cases who had headache had no other symptoms. We could not prove the evidence that RCCs could induce headaches in these cases. This might be suggested that headache could not be a sole symptom in cases of RCCs.

Amplotyping of microdissected, methanol-fixed lung carcinoma by arbitrarily primed polymerase chain reaction.

The arbitrarily primed polymerase chain reaction (AP-PCR) was used to detect somatic genetic alterations in lung carcinomas. DNA fingerprints generated by a single arbitrary primer were compared between normal and tumor tissues of the same individuals. We adapted the technique to the use of tissue fixed with methanol, which allowed the analysis of small areas of tissue by microdissection. This improvement of the fingerprinting technique permitted the study of tumors at early stages of progression. Loss of sequences from chromosome 7 was detected in 41.7% of adenocarcinomas and from chromosome 22 in 84.6% of small-cell carcinomas. Gains of sequences from chromosomes 1, 8 and 13 were detected in more than 40% of adenocarcinomas and in chromosome 2 in 63.3% of squamous-cell carcinomas. Our results indicate that allelic imbalances at these chromosomal regions are common genetic abnormalities in lung carcinomas. Loss of sequences from chromosome 22q13.3, found in 11 of 13 small-cell carcinomas, were confirmed by microsatellite PCR analysis. We show that the use of our improved AP-PCR fingerprinting permits the detection of both losses and gains of novel chromosomal regions early during lung cancer development. Our results indicate that early-stage tumors tend to have more allelic imbalances than relatively advanced tumors, suggesting a high tumor genetic heterogeneity in the early stages of lung tumor progression.

Structure formation and dynamic properties of physical gels produced with thermoplastic elastomer and monomer

We propose new non-aqueous polymer physical gels prepared with a small amount of semi-crystalline thermoplastic elastomers (nearly 10% concentration) and a large amount of monomers of low molecular weight. The gels have a three-dimensional continuous polymer network whose unit structure, a spherical cell of a few tens micrometer is mutually connected with holes, i.e. the tunnels. The structure formation initiated as spinodal decomposition but the mechanism changes into the nucleation and growth in an early stage of progression. Droplets of monomer-rich phase are discharged from the homogeneous polymer-rich phase. For operating such a mechanism in the system, it is of importance to be the big difference between the mobility of polymer and monomer. In particular, the molecular weight of the monomer to be less than a few thousands is an essential factor. The super-structure thus formed can be fixed and stabilized only when the system is cooled down below its melting temperature in the semi-crystalline polymer and monomer system. In the non-crystalline polymer and monomer system, although the super-structure is also formed and increases in size, the structure finally collapses and becomes droplets which disperse in the monomer-rich matrix during the cooling process. The physical gels are quite stable thermally and dynamically and give the feel of gelatin, flesh and others depending on species of polymer and oil and their composition. The gels are now applied to industrial products as very soft non-aqueous gels. Copyright © 2000 John Wiley & Sons, Ltd.