Connexin43 Expression and Associated Chronic Inflammation Presages the Development of Cerebral Radiation Necrosis

Cerebral radiation necrosis (CRN) is a delayed complication of radiosurgery that can result in severe neurological deficits. The biological changes leading to necrotic damage may identify therapeutic targets for this complication. Connexin43 expression associated with chronic inflammation may presage the development of CRN. A mouse model of delayed CRN was used. The left hemispheres of adult female mice were irradiated with single-fraction, high-dose radiation using a Leksell Gamma Knife. The brains were collected 1 and 4 days, and 1-3 weeks after the radiation. The expression of connexin43, interleukin-1β (IL-1β), GFAP, isolectin B-4, and fibrinogen was evaluated using immunohistochemical staining and image analysis. Compared with the baseline, the area of connexin43 and IL-1β staining was increased in ipsilateral hemispheres 4 days after radiation. Over the following 3 weeks, the density of connexin43 gradually increased in parallel with progressive increases in GFAP, isolectin B-4, and fibrinogen labeling. The overexpression of connexin43 in parallel with IL-1β spread into the affected brain regions first. Further intensified upregulation of connexin43 was associated with escalated astrocytosis, microgliosis, and blood-brain barrier breach. Connexin43-mediated inflammation may underlie radiation necrosis and further investigation of connexin43 hemichannel blockage is merited for the treatment of CRN.

Perfluorocarbon emulsions radiosensitise brain tumors in carbogen breathing mice with orthotopic GL261 gliomas

Background

Tumour hypoxia limits the effectiveness of radiation therapy. Delivering normobaric or hyperbaric oxygen therapy elevates pO₂ in both tumour and normal brain tissue. However, pO2 levels return to baseline within 15 minutes of stopping therapy.

Aim

To investigate the effect of perfluorocarbon (PFC) emulsions on hypoxia in subcutaneous and intracranial mouse gliomas and their radiosensitising effect in orthotopic gliomas in mice breathing carbogen (95%O₂ and 5%CO₂).

Results

PFC emulsions completely abrogated hypoxia in both subcutaneous and intracranial GL261 models and conferred a significant survival advantage orthotopically (Mantel Cox: p = 0.048) in carbogen breathing mice injected intravenously (IV) with PFC emulsions before radiation versus mice receiving radiation alone. Carbogen alone decreased hypoxia levels substantially and conferred a smaller but not statistically significant survival advantage over and above radiation alone.

Conclusion

IV injections of PFC emulsions followed by 1h carbogen breathing, radiosensitises GL261 intracranial tumors.

Variations in the Circumplex Structure of Mood

Typically, researchers have emphasized the similarity of the semantic and self-report mood circumplexes. The purpose of the present study was to investigate systematic differences in these structures. The semantic circumplex is defined by two dimensions: valence and level of arousal. The present study demonstrated that when making judgments of their mood, people weigh the arousal dimension less than the valence dimension, whereas in the semantic structure the two mood dimensions are weighed equally. This reduction in the size of the arousal dimension was directly associated with increases in the correlation between self-reported anxiety and depression. The results are discussed with reference to the meaning of subjective mood ratings.

Influence of SV40 Genome on the Replication of an Adenovirus-SV40 "Hybrid" Population

Feldman, L. A. (Baylor University College of Medicine, Houston, Tex.), J. L. Melnick, and F. Rapp. Influence of SV40 genome on the replication of an adenovirus-SV40 "hybrid" population. J. Bacteriol. 90:778-782. 1965.-Replication of a type 7 adenovirus-SV40 hybrid population in primary African green monkey kidney cells was accompanied by the formation of SV40 tumor antigen, adenovirus antigens, and cytopathic changes characteristic of adenovirus infection. Prior infection of the cultures with SV40 stimulated replication of nonintegrated adenovirus 7 but did not enhance the replication of the hybrid virus. These results suggest that the population of the adenovirus-SV40 hybrid studied contains many particles carrying SV40 information. Replication of SV40 virus was not enhanced by co-infection with nonintegrated adenovirus 7 or with the adenovirus-SV40 hybrid. Cytosine arabinoside strongly inhibited replication of the adenovirus-SV40 hybrid population in African green monkey kidney cells. Enhanced replication of nonintegrated adenovirus 7 by SV40 was blocked by cytosine arabinoside; this block could be reversed by 2-deoxycytidine or deoxycytidine triphosphate.

Minority enrichment programs at the New Jersey Medical School: 26 years in review

In 1971 the New Jersey Medical School formed a task force to address the training of physicians from minority and disadvantaged backgrounds, and in 1972 the Students for Medicine Program (SMP) was launched. The program, one of the first of its kind, provided previews of college science courses to help minority students develop their noncognitive skills and make the transition to medical school. The school has also established other minority programs. The programs have been designed to form a health careers pipeline for college-bound students, beginning in the eighth grade. Grade-specific summer experiences, as well as year-round monthly workshops, are offered to all participants. The workshops for pre-college and college students and their parents are designed to strengthen students' academic skills, address issues such as self-esteem, provide exposure to health professions, and increase parents' knowledge and involvement. From 1972 to 1998, there had been 1,722 participants in the pre-college, 1,875 in the college, and 683 in the prematriculation programs, respectively. They were from the inner city, most of them African American, but with a growing number of Hispanics. From 1987 to 1994, 36% of the SMP participants entered health professions schools. In 1996, the medical school created the New Jersey Partnership for Health Professions Education, a collaboration of high schools, universities, community-based organizations, the federal government, and the health professions schools. It works to strengthen the medical school's "pipeline" for underrepresented minority students while eliminating competition among programs for the same students and simultaneously developing a larger pool.

Minority enrichment programs at the New Jersey Medical School: 26 years in review

In 1971 the New Jersey Medical School formed a task force to address the training of physicians from minority and disadvantaged backgrounds, and in 1972 the Students for Medicine Program (SMP) was launched. The program, one of the first of its kind, provided previews of college science courses to help minority students develop their noncognitive skills and make the transition to medical school. The school has also established other minority programs. The programs have been designed to form a health careers pipeline for college-bound students, beginning in the eighth grade. Grade-specific summer experiences, as well as year-round monthly workshops, are offered to all participants. The workshops for pre-college and college students and their parents are designed to strengthen students' academic skills, address issues such as self-esteem, provide exposure to health professions, and increase parents' knowledge and involvement. From 1972 to 1998, there had been 1,722 participants in the pre-college, 1,875 in the college, and 683 in the prematriculation programs, respectively. They were from the inner city, most of them African American, but with a growing number of Hispanics. From 1987 to 1994, 36% of the SMP participants entered health professions schools. In 1996, the medical school created the New Jersey Partnership for Health Professions Education, a collaboration of high schools, universities, community-based organizations, the federal government, and the health professions schools. It works to strengthen the medical school's "pipeline" for underrepresented minority students while eliminating competition among programs for the same students and simultaneously developing a larger pool.

Distinguishing depression and anxiety in self-report: evidence from confirmatory factor analysis on nonclinical and clinical samples

Psychologists believe that anxiety and depression self-report scales tap distinct constructs. This assumption was tested by using confirmatory factor analysis on mood data from nonclinical samples (K. S. Dobson, 1985a; I. H. Gotlib, 1984; J. Tanaka-Matsumi & V.A. Kameoka, 1986) and a clinical sample (J. Mendels, N. Weinstein, & C. Cochrane, 1972). These analyses provide evidence that anxiety and depression self-report scales do not measure discriminant mood constructs and may therefore be better thought of as measures of general negative mood rather than as measures of anxiety and depression per se.

Distinguishing depression and anxiety in self-report: evidence from confirmatory factor analysis on nonclinical and clinical samples

Psychologists believe that anxiety and depression self-report scales tap distinct constructs. This assumption was tested by using confirmatory factor analysis on mood data from nonclinical samples (K. S. Dobson, 1985a; I. H. Gotlib, 1984; J. Tanaka-Matsumi & V.A. Kameoka, 1986) and a clinical sample (J. Mendels, N. Weinstein, & C. Cochrane, 1972). These analyses provide evidence that anxiety and depression self-report scales do not measure discriminant mood constructs and may therefore be better thought of as measures of general negative mood rather than as measures of anxiety and depression per se.

Restriction of human adenovirus replication in Chinese hamster cell lines and their hybrids with human cells

We have found that the replication of human adenovirus (Ad2) is restricted in multiple Chinese hamster cell lines including CHO and V79. The major site of restriction involves differential accumulation of late viral proteins as demonstrated by immunofluorescence assay and polyacrylamide gel electrophoresis with and without prior immunoprecipitation. Synthesis of fiber and penton base are markedly reduced, whereas others, such as the 100K polypeptide, are synthesized efficiently. This pattern of restriction is similar to that previously reported for Ad2 infection of several monkey cell lines; however, the restriction is more marked in the Chinese hamster cell lines. The restriction is most likely due to a deficient cellular function since stable cell hybrids between V79 or CHO and human cells are permissive for virus replication. By analysis of a series of hybrids with reduced numbers of human chromosomes, fiber synthesis was correlated with the presence of the short arm of human chromosome 3. More hybrids showed restoration of fiber synthesis than production of progeny virus, suggesting that more than one unlinked function is required for the latter.

The effects of measles virus and various strains of SSPE virus on organotypic cultures of nervous tissue

The neurotropic effects, virologic behaviors and morphologic appearances of 4 strains of subacute sclerosing panencephalitis (SSPE) virus have been examined in organotypic cultures of hamster cerebellar tissue and have been compared with the Edmonston strain of measles virus in the same system. While measles virus caused extensive damage to nervous tissue, the SSPE strains, in general, exerted a less deleterious effect. All of the SSPE viruses replicated in this tissue. The SSPE strains showed morphologic variation ranging from normal measles-type virions to apparently nucleocapsid deficient forms. It is speculated that some of these differences between measles and SSPE virus may account for the differences in the in vivo conditions with which they are associated.

Cell-associated subacute sclerosing panencephalitis agent studied in organotypic central nervous system cultures: viral rescue attempts and morphology

Organotypic cultures of hamster cerebellum were exposed to the IP-3-Ca cell line , which contains a cell-associated subacute sclerosing panencephalitis agent. Central nervous system (CNS) cultures were examined by light and electron microscopy as well as standard virological techniques from 3 to 46 days postinfection. The results indicate that although viral nucleocapsid material was transferred to elements of the CNS, cell-free virus could not be detected by virological techniques and by electron microscopy, and budding viral particles were not observed. Attempts to recover cell-free virus from hamster CNS tissue exposed to IP-3-Ca cells were generally negative. However, 2% of the cultures yielded low levels of infectious virus. IP-3-Ca cells were able to transfer the cell-associated viral material to all cell types found in the CNS cultures and were capable of inducing polykaryocytes in the CNS cultures. The role of cell-associated virus-like agents in subacute sclerosing panencephalitis and other chronic CNS infections is discussed.

Ultrastructural study of long-term measles infection in cultures of hamster dorsal-root ganglion

The morphogenesis of the Edmonston strain of measles is described in cultures of hamster dorsal-root ganglion maintained for as long as 63 days postinoculation. The patterns observed confirmed those previously reported in both neural and non-neural tissue. However, in the present tissue, the development of viral material could be followed chronologically within different cell types such as neurons and Schwann cells. Active replication was visualized up to 63 days postinoculation. The appearance of cytoplasmic nucleocapsid preceded that of intranuclear nucleocapsid, the latter occurring after 14 days. These intranuclear inclusions were formed after the transformation of the nucleoli into bizarre pleomorphic bodies which eventually segregated into clumps of nucleocapsid. These intranuclear inclusions mimic those seen in subacute sclerosing panencephalitis, now known to be etiologically related to a measles-like virus.

Ultrastructure of measles virus in cultures of hamster cerebellum

Replication of Edmonston strain of measles virus in cultures of hamster central nervous system tissue was studied by electron microscopy of ultrathin sections. Infected cultures were fixed from 3 hr to 39 days postinoculation (PI). Measles nucleocapsid was first seen within the cytoplasm of giant cells, the latter appearing 5 to 6 days PI. Measles virus particles were most abundant at 10 days PI and appeared to bud off from areas of the cell membrane along which nucleocapsid was aligned. Intranuclear nucleocapsid was more abundant at later stages, and by 39 days PI entire nuclei were seen to be occupied. By this time, the cytoplasmic formations, which had been sequestered by membranes, appeared to lose their regular structure. Budding viral particles at 39 days PI were of a much simplified structure and did not involve the alignment of nucleocapsid about their periphery.

Herpes simplex virus-host cell relationships in organized cultures of mammalian nerve tissues

Studies on the replication of herpes simplex virus in organized cultures of rat central nervous system (CNS) and peripheral nervous system (PNS) tissue demonstrated synthesis of intra- and extracellular virus, as determined by plaque assay on HEp-2 cells. Newly synthesized intracellular virus appeared 12 to 14 hr after inoculation of CNS, followed 10 hr later by the appearance of extracellular virus. In PNS cultures, where higher inputs of virus were introduced, intracellular virus appeared 6 to 8 hr after inoculation, followed by extracellular virus 12 hr later. Polykaryocyte formation was observed in CNS and PNS tissue involving neuroglial, meningeal, or Schwann cells. Neuron somas did not participate in polykaryocyte formation, but they underwent progressive morphological changes starting with increased cytoplasmic granularity followed by nucleolar distortions and disintegration, margination of nuclear chromatin, and the appearance of intranuclear inclusions. Finally, all recognizable cellular detail was lost. Immune serum globulin failed to inhibit both the progressive nature of the cytopathic effect and the synthesis of intracellular virus. These findings are discussed in relation to other in vitro systems, as well as to disease processes in man and animals.

Synthesis of virus deoxyribonucleic acid during abortive infection of simian cells by human adenoviruses

Rapp, Fred (Baylor University College of Medicine, Houston, Tex.), Lawrence A. Feldman, and Manley Mandel. Synthesis of virus deoxyribonucleic acid during abortive infection of simian cells by human adenoviruses. J. Bacteriol. 92:931-936. 1966.-Inoculation of green monkey kidney cells (GMK) with adenovirus types 2 or 12, under conditions where neither infectious virus was synthesized, resulted in an increase in the uptake of H(3)-thymidine into deoxyribonucleic acid (DNA). Extraction of the DNA from infected cells, followed by identification by isopycnic analysis in CsCl gradients, revealed the presence of virus DNA. Cells infected with adenovirus type 2 yielded DNA giving bands with peak densities of 1.699 g/ml [GMK DNA with 40 moles% guanine + cytosine (GC)] and 1.714 g/ml (adenovirus type 2 DNA with 55 moles% GC). Cells infected with adenovirus type 12 also yielded the GMK DNA and a band at 1.706 g/ml (adenovirus type 12 DNA with 47 moles% GC). The rate of synthesis of adenovirus type 2 DNA in KB cells (productive cycle) and in GMK cells infected only with adenovirus (nonproductive cycle) or with adenovirus and simian virus 40 (adeno-productive cycle) was not significantly different.

Interaction of a simian papovavirus and adenoviruses. I. Induction of adenovirus tumor antigen during abortive infection of simian cells

Feldman, Lawrence A. (Baylor University College of Medicine, Houston, Tex.), Janet S. Butel, and Fred Rapp. Interaction of a simian papovavirus and adenoviruses. I. Induction of adenovirus tumor antigen during abortive infection of simian cells. J. Bacteriol. 91:813-818. 1966.-Adenovirus types 2, 7, and 12 undergo an abortive growth cycle in green monkey kidney cells; they induce the formation of adenovirus tumor antigen, but synthesis of adeno capsid antigen and infectious adenovirus was observed only when cultures were concomitantly infected with a simian papovavirus (SV40). Several other viruses, including herpes simplex and measles which replicate in monkey cells, and rabbit papilloma and human wart papovaviruses which do not, failed to stimulate adenovirus replication in the monkey cells. Adenovirus tumor antigen was detected 8 to 10 hr postinfection by immunofluorescent techniques. The antigen induced by adenovirus types 2 and 7 appeared as intranuclear masses; adenovirus type 12 tumor antigen also appeared as cytoplasmic and nuclear flecks. Sera from hamsters bearing tumors induced by adenovirus type 12 cross-reacted with tumor antigens induced by types 2 and 7 but not with antigens induced by SV40.