Cell kinetics and prognosis in gastric cancer

METHODS

The potential proliferative activity of primary gastric cancer was determined using the in vitro tritiated thymidine labeling index (LI) technique.

RESULTS

The proliferative rate had a wide range (0.1-28.4%) with a median value of 9.3%. The cell kinetics of the primary tumor were not related to clinicopathologic features, such as the patient's age and sex or the tumor's histologic type and stage. The contribution of cell kinetics to prognosis was investigated in a series of 28 patients (median follow-up, 34 months). The 3-year survival rate was 50% for patients with slowly proliferating tumors compared with only 13% for those with rapidly proliferating tumors. Moreover, in patients with high-LI tumors, the risk of death was more than sixfold greater than for those with low-LI tumors.

CONCLUSIONS

These data suggest that cell kinetic studies might be an important discriminant to predict prognosis in gastric cancer.

CD4 epitope masking by gp120/anti-gp120 antibody complexes. A potential mechanism for CD4+ cell function down-regulation in AIDS patients

The in vitro suppressive effect of gp120 and gp120/anti-gp120 antibody is well known but not yet proven to operate in vivo. We report findings consistent with the presence of gp120/anti-gp120 antibody complexes on CD4+ lymphocytes from HIV-infected patients with advanced disease. PBMC from most AIDS patients showed selective masking of the CD4 epitope associated with the gp120 binding site; immunoprecipitation of PBMC with anti-CD4 mAb disclosed high amounts of IgG bound to CD4 receptors. Antibodies against HIV env proteins, but not other HIV products or CD4 Ag, were detected in purified CD4+ cell culture supernatants; in vitro culture was associated with normalization of both CD4 expression in PBMC and the lymphocyte proliferative response to anti-CD3. gp120 presence could not be directly demonstrated, but findings strongly suggested that CD4+ lymphocytes from most HIV-infected patients with advanced disease were covered with gp120/anti-gp120 antibody complexes, which are responsible for down-regulation of surface CD4 expression as well as functional lymphocyte impairment; this event may represent an important mechanism in the pathogenesis of HIV-associated immunodeficiency.

CD4 epitope masking by gp120/anti-gp120 antibody complexes. A potential mechanism for CD4+ cell function down-regulation in AIDS patients

The in vitro suppressive effect of gp120 and gp120/anti-gp120 antibody is well known but not yet proven to operate in vivo. We report findings consistent with the presence of gp120/anti-gp120 antibody complexes on CD4+ lymphocytes from HIV-infected patients with advanced disease. PBMC from most AIDS patients showed selective masking of the CD4 epitope associated with the gp120 binding site; immunoprecipitation of PBMC with anti-CD4 mAb disclosed high amounts of IgG bound to CD4 receptors. Antibodies against HIV env proteins, but not other HIV products or CD4 Ag, were detected in purified CD4+ cell culture supernatants; in vitro culture was associated with normalization of both CD4 expression in PBMC and the lymphocyte proliferative response to anti-CD3. gp120 presence could not be directly demonstrated, but findings strongly suggested that CD4+ lymphocytes from most HIV-infected patients with advanced disease were covered with gp120/anti-gp120 antibody complexes, which are responsible for down-regulation of surface CD4 expression as well as functional lymphocyte impairment; this event may represent an important mechanism in the pathogenesis of HIV-associated immunodeficiency.

In vitro potentiation by lonidamine of the cytotoxic effect of adriamycin on primary and established breast cancer cell lines

Lonidamine is a new potential chemotherapeutic agent, relatively non-toxic, that can positively modulate the efficacy of several antineoplastic drugs. We evaluated the response of two established human breast cancer cell lines (MCF-7 and BRC-230) and of 20 primary breast cancer cell lines to lonidamine, either alone or in combination with adriamycin, the drug most widely used in the management of breast cancer. Different schedules were tested by varying either concentration of the drugs (LND: 10-150 micrograms/ml; ADM: 0.10-0.15 micrograms/ml), or time of exposure (1-96 hours), or sequence of administration (ADM-->LND; LND-->ADM; ADM+LND). Our results indicate slight sensitivity of the cell lines to lonidamine when used alone, whereas an increase of efficacy was noted when lonidamine was added for at least 24 hours after a 4 hour exposure to adriamycin. Such efficacy was significantly greater than that expected from an additive effect between the two drugs. We conclude that lonidamine, when given according to an appropriate schedule, enhances, in vitro, the efficacy of adriamycin. A correct employment of lonidamine in the management of breast cancer might therefore potentiate the therapeutic effect of adriamycin.

Vaccination of pregnant cynomolgus monkeys with whole formalin-inactivated SIVmac251

Five pregnant (two to three and one-half months) Macaca fascicularis seroconverted following immunization with sucrose-gradient purified and formalin-inactivated whole simian immunodeficiency virus (SIVmac251). No untoward effects on fetal maturation were observed during the immunization of the mothers. Antibodies to SIVmac251 (also those with in vitro neutralizing activity) were passively transferred to the offspring but disappeared within two to six months after birth. Antibodies to env glycoprotein (gp130) lasted longer than those against viral gag proteins (p26,p60).

B-cell activation during HIV-1 infection. III. Down-regulating effect of mitogens

Spontaneous in vitro production of HIV-1-specific antibodies, a hallmark of infected subjects, is often down-regulated by the addition of pokeweed mitogen. We observed that a decrease in such ongoing anti-HIV-1 antibody synthesis could also be induced in cultures from most patients by addition of phytohemagglutinin and Concanavalin A, but not by Epstein-Barr virus, a selective B-cell mitogen. In most cases, this down-regulatory effect of mitogens was evident within the first 24 h of culture. The observed mitogen-associated decrease in spontaneous antibody synthesis was prevented by treating peripheral blood mononuclear cells with agents inhibiting non-major histocompatibility complex-restricted cytotoxic activity or by adding third-party cells to the cultures. In most cases, the mitogen-induced effect was also counteracted by removal of T lymphocytes or CD8+ T-cell sub-population. These findings recall a similar phenomenon observed in normal subjects following intentional immunization, and indicate that mitogen-induced down-regulation of spontaneous in vitro anti-HIV-1-antibody production most probably occurs through a lectin-dependent cytotoxic effect on activated B cells.

B cell activation during HIV-1 infection. II. Cell-to-cell interactions and cytokine requirement

This study examined the mechanisms underlying the intense activation of HIV-1-specific B cells observed in peripheral blood of HIV-1-infected subjects. Spontaneous in vitro synthesis of anti-HIV-1 antibodies, as well as total Ig production, were dramatically reduced by accessory cell, but not T cell removal. This fall was counteracted by addition of rIL-6, but not other cytokines, to monocyte-depleted cultures; moreover, antisera against IL-6 suppressed spontaneous anti-HIV-1 antibody synthesis in a dose-dependent manner. Although IL-6 apparently sustained HIV-1-specific B cell activation, no increase in serum IL-6 levels was observed; PBMC from seropositive subjects did not produce increased amounts of IL-6 in vitro, compared to seronegative controls, both spontaneously and in the presence of LPS stimulation; finally, no constitutive expression of IL-6 gene could be documented in freshly isolated PBMC. These findings indicate that IL-6 may play a central role in HIV-1-specific B cell activation in seropositive patients, and further stress the importance of this cytokine during HIV-1 infection.

B cell activation during HIV-1 infection. II. Cell-to-cell interactions and cytokine requirement

This study examined the mechanisms underlying the intense activation of HIV-1-specific B cells observed in peripheral blood of HIV-1-infected subjects. Spontaneous in vitro synthesis of anti-HIV-1 antibodies, as well as total Ig production, were dramatically reduced by accessory cell, but not T cell removal. This fall was counteracted by addition of rIL-6, but not other cytokines, to monocyte-depleted cultures; moreover, antisera against IL-6 suppressed spontaneous anti-HIV-1 antibody synthesis in a dose-dependent manner. Although IL-6 apparently sustained HIV-1-specific B cell activation, no increase in serum IL-6 levels was observed; PBMC from seropositive subjects did not produce increased amounts of IL-6 in vitro, compared to seronegative controls, both spontaneously and in the presence of LPS stimulation; finally, no constitutive expression of IL-6 gene could be documented in freshly isolated PBMC. These findings indicate that IL-6 may play a central role in HIV-1-specific B cell activation in seropositive patients, and further stress the importance of this cytokine during HIV-1 infection.

Antigen detection, virus culture, polymerase chain reaction, and in vitro antibody production in the diagnosis of vertically transmitted HIV-1 infection

Polymerase chain reaction (PCR), virus culture (V), antigen detection (Ag), and in vitro antibody production (IVAP) assays may be useful for the early detection of vertically transmitted HIV-1 infection in infants under 18 months of age, when a diagnosis cannot be based on seropositivity because of maternal antibody persistence. To assess the reliability of these procedures and to correlate diagnostic results with infection status, 101 children born to HIV-1-seropositive mothers were evaluated by all these techniques within the first 6 months of life. The children were then followed up to the age of at least 18 months, when diagnosis was made on the basis of AIDS or AIDS-related complex (ARC) onset or persistence of HIV-1 seropositivity. Out of 27 children classified as infected according to the above criteria, 25 (92.5%) were repeatedly positive in IVAP test, 22 (81.5%) in the first PCR analysis, and only 19 (70.3%) in the initial V assay. On further testing, a total of 24 children (88.9%) were found positive in PCR assay, and 23 (85.2%) in V test. All these assays were found to be more sensitive than antigen detection for HIV-1 infection diagnosis, but the antigenaemia was shown to be a useful prognostic marker of disease onset. We also found that both Ag and IVAP assays could give false-positive results in the first 2 months of life, which severely limits their diagnostic value during this period of time. False-positive results in PCR assay could occur at any time of the tested period and were unrelated to the child's age.(ABSTRACT TRUNCATED AT 250 WORDS)

Immune dysfunction in the elderly: effect of thymic hormone administration on several in vivo and in vitro immune function parameters

The effects of short-term thymic hormone administration on age-associated immune function were evaluated. Two groups of individuals greater than 65 years of age were treated for 30 days with thymic extracts (TP1) or placebo; before and after this treatment a panel of in vitro and in vivo parameters was determined according to a very rigorous experimental protocol. In most individuals, TP1 treatment was associated with an improvement in cutaneous delayed-type response to PPD. Moreover, an increase in a circulating T cell subpopulation bearing the CD45R surface antigen ("virgin" T cells), and in NK cell cytotoxic activity was also observed in some subjects. Finally, lymphocyte responsiveness to PHA tended to increase, while no effect on lymphocyte ability to produce IL-2 following mitogen stimulation was observed. These findings suggest that TP1 treatment may influence age-related alterations in immune function parameters in some subjects.

[Prevention and families. Opinions and attitudes of a group of parents]

Through a questionnaire filled by the children's accompaniers involved in prevention program of the first elementary classes, was emerged a direct involvement of the parents. In the field of the scholastic prevention, the teacher is the principal mediator with the families. It emerges from the answers a frasting attitude of what was performed by our sanitary service, and a direct information adopted by mass media in the prevention field. Up till now it is not totally perceived the importance of the periodic controls to maintain a better oro-dental health of their children.

[Empathy and prevention: from the child's viewpoint. Comments on a school diary developed from dental prophylaxis messages]

The paper presents, explains and comments on the theoretical, practical and applied aspects of a collaborative enterprise between Health Services and a primary school in the context of a dental hygiene and preventive project organised by the USSL no. 19 in Mediobrenta. The enterprise in question concerned the experimental writing, by the children themselves, of a school diary, based on messages regarding dental health and hygiene formulated by the Odontostomatological Service in line with learning processes and communication models used during infancy. The experiment formed part of the general active approach of modern psychological pedagogy, and proved particularly efficacious in introducing medical concepts to an infantile population which would otherwise have met with much greater resistance.

IgG oligoclonal bands in sera of HIV-1 infected patients are mainly directed against HIV-1 determinants

In a series of 60 HIV-1-infected individuals, serum electrofocusing analysis disclosed clonally restricted IgG patterns in 9 patients (15%), most with limited disease progression (stages WR1-WR3). These oligoclonal bands had a very heterogeneous light chain pattern, and most showed specificity for HIV-1 in affinity-driven transfer studies; virus specificity was more clear-cut following adsorption of sera with the relevant antigen. These findings further stress the profound B-cell function derangement in HIV-1 infection; their possible relevance to AIDS-associated lymphoma development is discussed.

Free light chains of immunoglobulins in the cerebrospinal fluid of human immunodeficiency virus type 1-infected patients

The presence of immunoglobulin (Ig) free light chains (FLC) was investigated in the cerebrospinal fluid (CSF) of human immunodeficiency virus type 1 (HIV-1)-infected patients. Intrathecal synthesis of FLC was demonstrated in 80% of the patients, even in the absence of oligoclonal Ig. The FLC patterns were characterized by restricted heterogeneity with regard to both isoelectric point and the molecular weight, and were mainly composed by dimers rather than monomers. A striking prevalence of lambda FLC was also observed. Local production of FLC can be taken as a marker of an ongoing immunopathological process within the central nervous system (CNS) in HIV-1-infected patients. A deregulation of Ig production by intrathecally activated B cells may be hypothesized.

HIV-1-specific B cell activation. A major constituent of spontaneous B cell activation during HIV-1 infection

B cell activation is a well known consequence of HIV-1 infection, and seropositive subjects show high numbers of spontaneously activated Ig-secreting cells in circulation. To better define the importance of the HIV-1-specific response in this phenomenon, we first studied whether in vitro spontaneous anti-HIV-1 antibody production was accompanied by reactivation of memory B lymphocytes. Unstimulated PBL from HIV-1-infected individuals with prior history of hepatitis B and/or EBV infection did not consistently show spontaneous in vitro synthesis of anti-hepatitis B core Ag or anti-EBV antibodies; in addition, PWM-induced synthesis of anti-hepatitis B virus and anti-EBV antibodies was decreased compared to HIV-1-seronegative subjects. Moreover, in comparing the frequencies of activated HIV-1-specific B cell precursors and activated Ig-secreting precursors in limiting dilution experiments, a sizable fraction (20 to 40%) of circulating cells spontaneously secreting Ig produced antibody against HIV-1 determinants. The ratio between the two frequencies fitted in very well with the amount of Ig removed from unstimulated culture supernatants after HIV-1-specific antibody absorption with solid-phase HIV-1. These findings indicate that B cell activation during HIV-1 infection is mainly oriented toward a specific response to HIV-1 determinants; the possible relevance of this phenomenon to lymphomagenesis in AIDS patients is discussed.

HIV-1-specific B cell activation. A major constituent of spontaneous B cell activation during HIV-1 infection

B cell activation is a well known consequence of HIV-1 infection, and seropositive subjects show high numbers of spontaneously activated Ig-secreting cells in circulation. To better define the importance of the HIV-1-specific response in this phenomenon, we first studied whether in vitro spontaneous anti-HIV-1 antibody production was accompanied by reactivation of memory B lymphocytes. Unstimulated PBL from HIV-1-infected individuals with prior history of hepatitis B and/or EBV infection did not consistently show spontaneous in vitro synthesis of anti-hepatitis B core Ag or anti-EBV antibodies; in addition, PWM-induced synthesis of anti-hepatitis B virus and anti-EBV antibodies was decreased compared to HIV-1-seronegative subjects. Moreover, in comparing the frequencies of activated HIV-1-specific B cell precursors and activated Ig-secreting precursors in limiting dilution experiments, a sizable fraction (20 to 40%) of circulating cells spontaneously secreting Ig produced antibody against HIV-1 determinants. The ratio between the two frequencies fitted in very well with the amount of Ig removed from unstimulated culture supernatants after HIV-1-specific antibody absorption with solid-phase HIV-1. These findings indicate that B cell activation during HIV-1 infection is mainly oriented toward a specific response to HIV-1 determinants; the possible relevance of this phenomenon to lymphomagenesis in AIDS patients is discussed.

Sonography of vertebral arteries in De Kleyn's position in subjects and in patients with vertebrobasilar transient ischemic attacks

Two groups of subjects, matched for age, were studied. The first group consisted of 190 healthy subjects, the second, of 60 patients with vertebrobasilar transient ischemic attacks (TIAs), 22 of whom underwent angiography. After it was ascertained that the findings from continuous-wave (cw) Doppler of carotid and vertebral arteries, performed in the standard position, were normal, the examination was then done in De Kleyn's position, the velocity signal being detected at the mastoidal slopes. The abnormal findings were classified into two groups: "loss of diastolic velocity signal" and "absence of velocity signal." In the control group, changes of flow were detected in 6.31%, whereas in the group of patients abnormal Doppler parameters were detected in 33.33%. None of the patients who were submitted to angiography showed abnormal hemodynamic findings. The authors suggest that the detection of the velocity signal of the vertebral arteries in De Kleyn's position could be of help in revealing conditions that could cause, in time, signs and/or symptoms of vertebrobasilar insufficiency in subjects with possible asymptomatic anomalies of the circle of Willis.

CD4 modulation and inhibition of HIV-1 infectivity induced by monosialoganglioside GM1 in vitro

The addition of monosialoganglioside GM1 to serum-free culture medium efficiently and specifically inhibited CD4 antigen expression on normal T lymphocytes from peripheral blood or thymus as well as on cells from H9 and Molt-3 lines; other molecules such as CD3, CD2 and CD8 were not affected. Subsequent addition of fetal calf serum or bovine and human serum albumin blocked GM1 action on CD4 expression, most likely through the formation of ganglioside-albumin complexes. Removal of GM1 from the medium was followed by the prompt reappearance of CD4 on the cell surface. GM1 treatment of H9 and Molt-3 cells greatly reduced HIV-1 infectivity, which was evaluated by reverse transcriptase activity levels in culture supernatants and p24 detection on target cells. GM1 also inhibited syncytial formation in Molt-3 cells even when treatment was initiated 24h after infection. The GM1 effect on HIV-1 infectivity, however, was not long-lasting since removal of the compound was followed by a rapid increase in viral replication, probably due to CD4 re-expression and HIV-1 propagation from a few initially infected cells.

Human monoclonal antibody against a gag-coded protein of human immunodeficiency virus produced by a stable EBV-transformed cell clone

An EBV-transformed lymphoblastoid B cell clone (A12) derived from peripheral blood lymphocytes of an HIV-1-infected individual is described. The immunoglobulin isotype produced by this clone was IgM, and Southern blot analysis of immunoglobulin gene rearrangement showed a monoclonal pattern. The A12 monoclonal antibody was specific for the p24 product of the HIV-1 gag gene. This clone is now in continuous culture for more than 8 months and no changes in its biologic properties have been observed.