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Molecular hybridisation using cloned hepatitis B virus DNA (HBV DNA) was applied to liver and serum samples from 46 children (39 with liver diseases and seven controls) for detection of HBV DNA sequences, free and integrated into the liver cell genome. HBV DNA integration was observed in 10 children. The young age of some of these cases indicates that such integration can occur early in liver disease and is not related to the duration of viral infection. Thirteen children exhibited serological evidence of active viral multiplication. All but one had free HBV DNA in liver tissue and integrated HBV DNA sequences were found in four cases. Integrated HBV DNA sequences alone were also detected in three children with neither HBV-antigens nor HBV DNA in serum. One had inactive cirrhosis, and the two others, chronic active hepatitis. Consequently DNA hybridisation may be useful for diagnosis, in the absence of serological signs of HBV infection; its specificity was enhanced in the present investigation by negative results in six children with autoimmune chronic active hepatitis. Taken together, the above results imply that HBV-DNA integration can occur in both active and inactive liver disease. Integrated HBV DNA was also observed in the liver of three children with fatal hepatic failure who presented with antibodies to HBsAg and/or to hepatitis B core antigen in the serum. This finding raises the question of the relationship between the host immune factors and the state of HBV DNA. [ABSTRACT FROM PUBLISHER]

Background: Incidence of breast cancer is rising in Asian countries, and breast cancer is the most common cancer among Asian women. However, there are few recent descriptive reports on the epidemiology of breast cancer among Eastern and Southeastern Asian populations., Methods: We examined incidence trends for invasive breast cancer in women aged ≥20 years from 15 registries in Eastern (China, Japan, the Republic of Korea, Taiwan) and Southeastern Asia (the Philippines, Singapore, Thailand) for the period 1993-2002 mainly using data from Cancer Incidence in Five Continents, Volumes VIII and IX. We compared trends in annual incidence rates and age-specific incidence curves over a 10-year period. We also compared the incidence rates of Asian-Americans with the rates of their Asian counterparts., Results: Breast cancer incidence rates increased gradually over time in all study populations. Rates were relatively high in Southeastern Asia and became progressively lower along a south-to-north gradient, with a fourfold geographic variation within the study populations. Age-specific incidence curves showed patterns that gradually changed according to incidence rates. Breast cancer incidence among Asian women living in the United States was 1.5-4 times higher than the corresponding incidence rate in the women's respective countries of origin., Conclusion: Breast cancer incidence is expected to continue to increase for the next 10 years in Asia and may approach rates reported among Asian-Americans. The number and mean age of breast cancer cases is expected to increase as the female Asian population ages, the prevalence of certain risk factors changes (early menarche, late menopause, low parity, late age at first live birth, and low prevalence of breastfeeding), and as Asian countries introduce mass screening programs.

Breast cancer risk is increasing in most Asian female populations, but little is known about the long-term mortality trend of the disease among these populations. We extracted data for Hong Kong (1979-2005), Japan (1963-2006), Korea (1985-2006), and Singapore (1963-2006) from the World Health Organization (WHO) mortality database and for Taiwan (1964-2007) from the Taiwan cancer registry. The annual age-standardized, truncated (to > or =20 years) breast cancer death rates for 11 age groups were estimated and joinpoint regression was applied to detect significant changes in breast cancer mortality. We also compared age-specific mortality rates for three calendar periods (1975-1984, 1985-1994, and 1995-2006). After 1990, breast cancer mortality tended to decrease slightly in Hong Kong and Singapore except for women aged 70+. In Taiwan and Japan, in contrast, breast cancer death rates increased throughout the entire study period. Before the 1990s, breast cancer death rates were almost the same in Taiwan and Japan; thereafter, up to 1996, they rose more steeply in Taiwan and then they began rising more rapidly in Japan than in Taiwan after 1996. The most rapid increases in breast cancer mortality, and for all age groups, were in Korea. Breast cancer mortality trends are expected to maintain the secular trend for the next decade mainly as the prevalence of risk factors changes and population ages in Japan, Korea, and Taiwan. Early detection and treatment improvement will continue to reduce the mortality rates in Hong Kong and Singapore as observed in Western countries.

Immediate loading of oral implants has been reported as a beneficial treatment protocol in implant dentistry that increases the comfort of the patient. However, documentation in the literature is poor regarding the clinical outcome and the peri-implant bone response of immediately loaded implants compared with the conventional loading protocol placed in different bone qualities. The aim of this report was to present the role of bone quality in the survival rate of implants using conventional or immediate loading according to the literature. A literature search analysis was performed to demonstrate the survival rate of immediately loaded implants, as well as data from the histologic and histomorphometric evaluation in comparison with conventional loaded implants. This analysis showed high survival rates of immediately loaded implants along with osseointegration, with high percentages of bone-to-implant contacts based on histologic evaluation from human and animal studies of immediately and conventionally loaded implants. This study may provide histologic and clinical evidence of the immediate loading protocol for different bone qualities.

We sought to determine the pathway of HIV-1 entry into human astrocytes and the fate of HIV-1 by detecting viral DNA and GFP-tagged HIV-1 in HIV-1-infected primary astrocytes. Immunochemistry and FACS analysis were used to assess the expression of DC-SIGN in human purified cultures of astrocytes. HIV-1 LTR was detected by PCR in infected cultures of human embryonic astrocytes at their third passage. GFP-Vpr-labeled R5 tropic HIV-1 was used to infect astrocytes, and was followed by confocal microscopy. Forty percent of astrocytes expressed DC-SIGN at the membrane level. Viral DNA was detected 5 days after infection in human astrocytes, but not in the presence of anti-CCR5 and anti-DC-SIGN mAbs. T20, NH4Cl, and bafilomycin had no effect on viral DNA detection. We found that 67% of the fluorescent GFP-Vpr-labeled R5 tropic HIV-1 viruses were present in the endosomes of astrocytes at 24 h, but not in the presence of anti-CCR5 or DC-SIGN mAbs. Bafilomycin and NH(4)Cl each increased the amount of fluorescent HIV-1 detected outside endosomes. Titers of p24 remained low from day 1 to day 5 postinfection, in the presence or absence of NH4Cl. Astrocytes express DC-SIGN and HIV-1 penetrates into these cells through CCR5- and/or DCSIGN- mediated endocytosis, via a pH-dependent pathway, with a delayed reverse transcription after infection without productive infection.

Within the brain, glial cells are target cells for human cytomegalovirus (HCMV) and HIV. We infected cultures of unstimulated human microglial cells and astrocytes of embryonic origin and of monocyte-derived macrophages (MDM) with HCMV strain AD169 and observed down-regulation of the plasma membrane expression of CCR5 in the three cell types, and of CXCR4 and CD4 in microglial cells only. Cells were then coinfected simultaneously or at a 24-h interval with both AD169 and two different HIV-1 monocytotropic strains. HCMV late antigens and HIV-1 tat protein colocalized in the cytoplasm of 5-10% of microglia and MDM. p24 antigen levels decreased 10- to 40-fold in supernatants of MDM and the reduction was greater when HCMV infection was performed 24 h before HIV-1 infection. These data suggest that HCMV-induced reduction in the cell-surface expression of the primary co-receptor of HIV-1 monocytotropic strains may impair the ability of HIV to infect these cells.

The regulation of the thyroid gland by TSH is mediated by a heterotrimeric G protein-coupled receptor. Nonthyroid effects of TSH have been reported, and expression of its receptor has been described in adipocytes and lymphocytes. We have previously reported the existence of specific and saturable binding sites of TSH and specific TSH effects in primary cultured rat brain astroglial cells. We now report expression of the TSH receptor gene in these cells; the coding sequence of the corresponding complementary DNA is identical to that previously established in thyroid. Using specific antisense RNA probe, expression of this gene was detected in some isolated or clustered glial fibrillary acidic protein-positive primary cultured cells by in situ hybridization. With this technique, we further detected TSH receptor messenger RNA (mRNA) expression in rat brain cryoslices in both neuronal cells and astrocytes. Its presence predominated in neuron-rich areas (pyriform and postcingulate cortex, hippocampus, and hypothalamic nuclei) and was mostly colocalized with neuron-specific enolase. In astrocytes, this mRNA was detected in the ependymal cell layer and the subependymal zone, and several isolated cells were also found in the brain parenchyma. We also detected TSH receptor mRNA and protein in primary cultured human astrocytes. The protein was detected as well in both rat and human brain cryoslices. Together, these findings clearly demonstrate the expression of the TSH receptor gene in the brain in both neuronal cells and astrocytes.

Oxidative stress is suggested to be involved in several neurodegenerative diseases. One mechanism of oxidative damage is mediated by peroxynitrite, a neurotoxic reaction product of superoxide anion and nitric oxide. Expression of two cytokines and two key enzymes that are indicative of the presence of reactive oxygen intermediates and peroxynitrite was investigated in brain tissue of AIDS patients with and without AIDS dementia complex and HIV-seronegative controls. RNA expression of IL-1beta, IL-10, inducible nitric oxide synthase, and superoxide dismutase (SOD) was found to be significantly higher in demented compared with nondemented patients. Immunohistochemical analysis showed that SOD was expressed in CD68-positive microglial cells while inducible nitric oxide synthase was detected in glial fibrillary acidic protein (GFAP)-positive astrocytes and in equal amounts in microglial cells. Approximately 70% of the HIV p24-Ag-positive macrophages did express SOD, suggesting a direct HIV-induced intracellular event. HIV-1 infection of macrophages resulted in both increased superoxide anion production and elevated SOD mRNA levels, compared with uninfected macrophages. Finally, we show that nitrotyrosine, the footprint of peroxynitrite, was found more intense and frequent in brain sections of demented patients compared with nondemented patients. These results indicate that, as a result of simultaneous production of superoxide anion and nitric oxide, peroxynitrite may contribute to the neuropathogenesis of HIV-1 infection.

Although evidence for human immunodeficiency virus 1 (HIV-1) presence in the central nervous system (CNS) of infected patients is well established, the intensity of viral replication within the brain is not usually known. In vitro, human embryonic microglial cells internalized HIV-1 through a CD4-dependent pathway but were not permissive to viral replication. We observed that HIV replication was induced when CNS cell cultures were stimulated for 14 days by a combination of proinflammatory cytokines including IFNgamma, IL1beta, and TNFalpha. After long-term cytokine stimulation, morphologically differentiated glial cells appeared, in which HIV-1 tat antigen was detected after infection. Thus, variations in the stage of maturation/activation of CNS cells under inflammatory conditions probably play a major role in facilitating massive production of HIV-1. We then studied the effect of prolonged cytokine stimulation on the secretion of inflammatory mediators by glial cells. An early increased secretion of prostaglandin F2alpha and chemokines (RANTES>>MIP-1alpha>>MIP-1beta) was observed, due to both microglia and astrocytes. In contrast to persistent PGF2alpha production, an extinction of RANTES and MIP-1beta but not of MIP-1alpha secretion occurred during the 14 days of stimulation and was inversely correlated with the ability of glial cells to replicate HIV-1. The study of the secretory factors produced in response to a persistent inflammation could provide a better understanding of the modulation of HIV replication in glial cells.

Detection of apoptotic neurons and microglial cells in the brains of human immunodeficiency virus type 1 (HIV-1)-infected patients has suggested that programmed cell death may be implicated in the physiopathology of HIV-1 encephalopathy. To analyze in vitro the intracellular signals induced by HIV-1 in human neurons and the associated neuronal death, we tested cultured human central nervous system (CNS) cells for apoptosis induced by HIV-1 and gp120 and for signaling pathways activated by gp120. HIV-1 and gp120 induced apoptosis of neurons and microglial cells but not of astrocytes or transformed microglial cells. Gp120 activated c-Jun N-terminal kinase (JNK) and p42 extracellular-regulated kinase (ERK) in primary CNS cells, with an early peak of activation at 2 to 5 minutes that was not present when pure microglial or astrocyte cultures were tested, followed by a late and sustained activation (10 and 60 minutes) in primary and enriched glial cell cultures as well as in transformed microglial cells. This demonstrates that gp120 could be an effector of HIV-1-induced apoptosis in the CNS and act directly on neuronal and glial cells.

Apart from the unique changes characteristic of "HIV encephalitis", the productive infection of central nervous system by HIV, which involves predominantly the white matter and basal ganglia, evidence is accumulating that the cerebral cortex may also be affected in AIDS patients. Neuronal loss, suspected at microscopical examination, has been demonstrated by a number of morphometric studies. However, the cause and mechanism of neuronal damage in HIV infection, are still unclear. In an attempt to look for an apoptotic process at the origin of neuronal loss in AIDS, we examined samples of frontal cortex, temporal cortex and basal ganglia from 12 patients who died from AIDS and 4 HIV-positive asymptomatic cases using in situ end labelling to demonstrate characteristic DNA fragmentation. These were compared with 5 seronegative asymptomatic controls, and 2 seronegative patients with Alzheimer's disease. We demonstrated neuronal apoptosis in all the AIDS cases and in the Alzheimer's cases. Positive in situ end labelling was usually associated with morphological changes suggestive of neuronal apoptosis. Semiquantitative appreciation of the density of apoptotic neurons showed that neuronal apoptosis was more severe in atrophic brains. In contrast, no correlation was found between the density of apoptotic neurons and the presence of HIV encephalitis or a history of cognitive disorder. Only occasional apoptotic neurons were found in one asymptomatic, HIV-positive case. Apoptosis was never observed in asymptomatic seronegative cases. Experimental studies tend to support our in vivo findings. Infection by HIV of primary cultures of human embryonic central nervous system induced frequent apoptosis of neurons. No apoptotic cell was identified in non infected control cultures.

Neuropathological studies have shown that human immunodeficiency virus type 1-infected cells within the brain express several markers characteristic of macrophages and could either be microglial cells, or monocytes invading the CNS, or both. To better define the target cells of human immunodeficiency virus type 1 within the brain, we have studied human microglial cells, both in vivo and in vitro, and compared them to monocytes for their antigenic markers and their susceptibility to human immunodeficiency virus type 1 infection. Brain-derived macrophages were isolated from primary cortical and spinal cord cultures obtained from 8 to 12-week-old human embryos. The isolated cells presented esterase activity, phagocyted zymosan particles, expressed several (Fc receptors, and CD68/Ki-M7 and CD11b/CR3 receptors) of the macrophagic antigenic markers, and appeared to be resident microglial cells from human embryonic brain. Conversely, brain-derived macrophages did not express antigens CD4, CD14, or CD68/Ki-M6, which are easily detected on freshly isolated monocytes. Using these antigenic differences between isolated microglial cells and monocytes, we have observed that two populations of macrophages could be individualized. In the normal adult brain, microglial cells were numerous in both the gray and the white matter. The infrequent cells sharing antigens with monocytes were found almost exclusively around vessels. In 8 to 12-week-old human embryos, microglial cells were found in both the parenchyma and the germinative layer. Cells sharing antigens with monocytes were only found at the top of and inside the germinative layer. In brain tissue from patients with human immunodeficiency virus type 1 encephalitis, cells sharing antigens with monocytes are abundant not only around the vessels but also in the parenchyma. In double-labeling experiments, human immunodeficiency virus type 1-infected cells showed monocyte antigens. Finally, microglial cells also differ from monocytes in their in vitro susceptibility to human immunodeficiency virus type 1 infection; after stimulation by r-TNF alpha or GmCSF, monocytes but not microglial cells can replicate human immunodeficiency virus type 1. This in vitro difference in human immunodeficiency virus type 1 susceptibility between monocytes and microglial cells together with the presence of monocytic antigens within the brain tissue of human immunodeficiency virus type 1-infected patients suggest that human immunodeficiency virus type 1-infected cells within the brain are either monocytes that have crossed the blood-brain barrier and spread through the tissue or perivascular microglial cells that, after phagocyting infected blood lymphocytes, subsequently contain viral antigen and migrate to brain tissue.

A simplified spot method for determination in serum of hepatitis B virus DNA (HBV DNA) by molecular hybridization is proposed. For simultaneous testing of 30 serum samples, it reduced to about 1 hr the duration of the steps preceding hybridization proper. The method also greatly reduced the loss of DNA during these steps and allowed more sensitive detection in samples of only 25 or 50 microliters. HBV DNA was determined in 181 serum samples by this method, and the results were pooled with 67 previous determinations by the Southern blot technique. Results for the pool were then compared to those obtained with radioimmunoassay for serological HBV markers. Ninety-six of the 248 samples were HBV DNA positive. Eleven others gave variable or inconclusive results, probably due to low viral particle titers. Seventy-two HBsAg- and HBeAg-positive sera contained HBV DNA, confirming that HBeAg is a marker of active viral replication. Fourteen other HBsAg- and HBeAg-positive sera, obtained from eight patients, were either HBV DNA negative or oscillated between negative and positive, or, again, were weakly positive; serological follow-up in 7 patients showed seroconversion to anti-HBe in 5, 3 of which became HBsAg negative. Eight of the HBsAg-positive sera were negative or borderline for HBeAg but contained HBV DNA and may, therefore, have been infective; seven of these sera had anti-HBe. Six HBsAg-negative sera contained HBV DNA and may also have been infective; five of these exhibited HBV antibodies. These results indicate that molecular hybridization not only provides a more sensitive and direct method for detecting hepatitis B virus in serum but also defines additional serological patterns with predictive or epidemiological value.