Best second trimester sonographic markers for the detection of trisomy 21

We analyzed all genetic sonograms obtained during a 6 year period to establish the independent ability of the following sonographic markers of aneuploidy in the diagnosis of trisomy 21: structural anomalies, cardiac abnormalities, nuchal fold thickness of 6 mm or greater, bowel echogenicity, choroid plexus cysts, and renal pyelectasis. With the exception of bowel echogenicity and choroid plexus cysts, the sonographic markers were more common in trisomy 21 than euploid fetuses (all P < 0.001). Logistic regression analysis demonstrated that cardiac anomalies (odds ratio = 255; 95% confidence interval, 25, 2592), other structural anomalies (odds ratio = 25; 95% confidence interval, 6, 97), and nuchal fold thickness of 6 mm or greater (odds ratio = 13; 95% confidence interval, 3, 50) were the only independent predictors of trisomy 21. The false-positive rate and sensitivity were 5.3% (48 of 898) and 59.2% (13 of 22), respectively, when any of the sonographic markers significant at univariate analysis was considered, and 3.1% (28 of 898) and 54.5% (12 of 22), respectively, when any of the predictors at multivariate analysis was present. Because a considerable overlap of sonographic markers exists among trisomy 21 fetuses, use of those that are not independent predictors leads to an increase in false-positive rate without a gain in sensitivity.

Accuracy of prenatal ultrasonographic diagnosis of duplex renal system

Duplex renal system is a rare congenital anomaly of the urinary tract that can be diagnosed in utero. The purpose of this study was to establish the optimal diagnostic criteria for fetal renal duplication in a population undergoing prenatal sonographic screening. Between January 1989 and June 1997 we found 11 cases of duplex renal system, 10 of which were correctly identified in utero at a median gestational age of 28 weeks (range, 20 to 38 weeks), and one of which was a false-negative diagnosis. Prenatal diagnosis of duplex renal system can be made in utero during the second half of pregnancy in the presence of two or more of the following signs: hydronephrosis limited to one pole in a kidney with two separate, noncommunicating renal pelves; ipsilateral megaureter; and ureterocele.

Vitamin D, thyroid hormones and muscle mass influence natural killer (NK) innate immunity in healthy nonagenarians and centenarians

Increasing evidence has demonstrated that the immune system closely interacts with other physiological systems, whose communications are mediated by circulating cytokines and hormones. The aim of our study was to test whether the number and cytolytic activity of NK cells in a group of relatively healthy Italian nonagenarians and centenarians were affected by the modifications of endocrine, metabolic and functional parameters that occur during ageing. Because of the extreme age of the study population, a cross-sectional analysis was performed. This study revealed that the group of oldest subjects with the highest number of NK cells and the best preserved cytolytic function also presented a preserved metabolism of thyroid hormones and vitamin D and integrity of muscle mass. In fact, the NK cell number and/or cytolytic activity of healthy subjects > 90 years old was positively associated with serum levels of vitamin D, while T3, FT4, i-PTH hormones and lean body mass were associated only with NK cell number. In conclusion, our results stress the paramount importance of nutritional evaluation in the clinical assessment of elderly people.

Impact of aging on innate immunity

Immune responses in higher organisms are triggered by the recognition of a limited diversity of microbiological products by cells of the innate or "natural" immune system. As a result, in addition to the direct protective effect of natural immunity, antigen-presenting cells, particularly dendritic cells, are activated to process and present an enormous number of peptide antigens to the T lymphocytes of the adaptive immune system. These, together with the B lymphocytes, then mediate specific immune responses and maintain acquired immunological memory. The aging immune system is less well able to cope with infectious disease than the youthful immune system; this review will briefly consider what is known of the age-associated alterations in innate immunity, and how these may also impact on adaptive immunity.

TNF-alpha but not IL-1 and IL-6 modifies the susceptibility of human osteosarcoma cells to NK lysis

TNF-alpha-treated osteosarcoma cells have an enhanced susceptibility to NK lysis which mostly depends on the increased expression of CD54 molecules. Since IL-1 and IL-6 share overlapping biological properties with TNF-alpha, we investigated whether the treatment of osteosarcoma cells with these cytokines could modify their susceptibility to NK lysis and whether these modifications were related to a different distribution of CD54, CD56 and CD58 molecules. We demonstrated that the expression of CD54 and CD58 on osteosarcomas correlated positively with the susceptibility to NK lysis and that this susceptibility was enhanced by TNF-alpha treatment but not by IL-1 and IL-6 stimulation.

Age-dependent decreases of NK cell phosphoinositide turnover during spontaneous but not Fc-mediated cytolytic activity

The progressive increase in the number of peripheral NK cells found in the elderly does not correlate with a corresponding increase in lytic activity. On the contrary, a decreased function of circulating NK cells purified from old subjects was observed on a per cell basis. Most of the studies on NK cells have focused on late events such as lytic activity. In view of this, little is currently known about the modification of the early signalling pathways of NK cells in elderly people. This study investigated whether the modification of NK lytic activity could be related to differences in the metabolic pattern of activation of these cells in the elderly. NK cells were negatively purified by immunomagnetic depletion from the peripheral blood of selected old and young healthy subjects. Hydrolysis of inositol phospholipids was measured following incubation with K562 target cells and/or CD16 mAb for different times. Our data show that there is a pronounced age-related decrease in the ability to generate total inositol monophosphates and, particularly, inositol trisphosphates by NK cells following K562 stimulation (spontaneous cytolytic activity) together with an attenuated and delayed hydrolysis of phosphatidylinositol bisphosphate, while phosphoinositide turnover is preserved following Fc triggering (antibody-dependent cell-mediated cytotoxicity). These results confirm that, also in old subjects, different biochemical pathways of activation are involved in NK cells when target or antibody-mediated triggering occurs and may aid the development of experimental and therapeutic strategies to counteract declines in cell mediated immune functions associated to advancing age.

Natural immunity and bone and muscle remodelling hormones in the elderly

Increasing evidence has demonstrated that the immune system is closely integrated with two other physiological systems: endocrine and nervous. They communicate through circulating humoral factors such as cytokines, hormones and neurotransmitters. We undertook a cross-sectional analysis in a group of elderly subjects over 90 years to demonstrate that a functional relationship exists among the number and cytolytic activities of NK cells, bone and muscle remodelling hormones, anthropometric parameters and physical ability. Peripheral blood samples collected from 62, 90-106 years-old subjects underwent biochemical (bone and muscle remodelling hormone levels) and immunological determinations (Natural Killer cell distribution and activity), anthropometric and functional assessment. Significant associations were found among NK cell number and cytolytic activity and serum concentrations of vitamin D, anthropometric parameters, while functional independence in daily activity was only associated with NK cell number. In general a high level of physical ability was correlated with preserved body stores and vitamin D levels. In conclusion, our results stress the importance of nutritional evaluation in the clinical assessment of elderly people. The magnitude of the NK immune response, which constitutes the first line of defence against infected and neoplastic cells, is best preserved in oldest-old people with the best hormonal parameters and nutritional measures.

Expression of beta-galactoside alpha 2,6-sialyltransferase does not alter the susceptibility of human colon cancer cells to NK-mediated cell lysis

The extent of processing of N-linked oligosaccharides and the sialylation of the target cell membranes has been positively correlated with resistance to lysis mediated by NK cells, but a conclusive evidence has never been reached. Colon cancer tissues express an increased activity of beta-galactoside alpha 2,6-sialyltransferase (EC 2.4.99.1, alpha 2,6ST), which catalyzed the addition of sialic acid in alpha 2,6-linkage to Gal beta 1,4GlcNAc (N-acetyllactosamine) sequences of glycoprotein N-linked chains. The resulting increased level of membrane alpha 2,6-sialylation appears to be related with a more invasive behavior of cancer cells. This phenomenon may depend on a decreased sensitivity of colon cancer cells to NK cells. To obtain conclusive evidence on the role played by sialylation of N-linked chains in determining the target cell susceptibility to NK-mediated lysis, human colon cancer cell lines not expressing sialyltransferases acting on N-linked chains were transfected with a rat alpha 2,6ST cDNA. Stable transfectants expressed different levels of alpha 2,6ST activity, were reactive with the Sambucus nigra lectin, specific for alpha 2,6-linked sialic acid, and compared with control transfectants, showed a remarkable decrease in the number of unsubstituted Gal beta 1,4GlcNAc terminal sequences. The NK susceptibility of these clones was found to be identical to that of control transfectants, either when unstimulated- or IL-2-stimulated lymphocytes were used as effectors. Neuraminidase treatment of target cells does not result in significant changes to NK susceptibility. Our data demonstrate that sialic acid alpha 2,6-linked to N-linked chains of target cell glycoproteins does not play a major role in recognition of the target by human NK cells.

Epitope specificity of Th0/Th2 CD4+ T-lymphocyte clones induced by vaccination with rHBsAg vaccine

BACKGROUND & AIMS

Different amino acid sequences of hepatitis B virus surface antigen (HBsAg) are involved in the activation of CD4+ lymphocytes needed to induce an optimal antiviral function. The aim of this study was to characterize the CD4-mediated response to immunodominant HBsAg epitopes in hepatitis B virus (HBV) vaccine recipients by defining minimal sequences recognized by T cells, cytokine profiles, and HLA restriction of peptide recognition.

METHODS

T-lymphocyte lines and clones specific for HBsAg were isolated from the peripheral blood of subjects immunized with recombinant HBsAg and stimulated in vitro with synthetic peptides spanning the whole HBsAg sequence.

RESULTS

Four immunodominant epitopes (sequences 21-40, 136-155, 156-175, and 211-226) were identified. Using panels of truncated peptides of different length, sequences 21-28, 165-172, and 215-223 were shown to correspond to the minimal epitopes recognized by T cells. The antigen-specific T-lymphocyte proliferation was HLA class II restricted, and each peptide could be presented in association with different HLA class II determinants. Th0/Th2 cytokine patterns were induced on peptide stimulation.

CONCLUSIONS

These results indicate the presence of at least four immunodominant epitopes within HBsAg that represent potential candidates for the design of anti-HBV synthetic vaccines.

Human osteosarcoma cell susceptibility to natural killer cell lysis depends on CD54 and increases after TNF alpha incubation

Osteosarcoma cell lines vary widely in their susceptibility to natural killer (NK) cell lysis in vitro although it is still unclear why this occurs. In this study we investigated the expression of some cell adhesion molecules on osteosarcomas to determine which of these can modify the susceptibility to NK lysis and we also attempted to modulate the cytolytic susceptibility of these targets with TNF alpha. We found that osteosarcoma lysis induced by NK cells correlates with different expression of the CD54 adhesion molecule on osteosarcomas and the increased susceptibility after TNF alpha treatment mostly depends on the expression of CD54 molecules on target cells.

Application of high-performance liquid chromatography in the analysis of direct dyes in semipermanent hair colouring cosmetics

A method for the identification and the quantification of direct dyes in semipermanent hair colouring cosmetics by using a reversed phase high-performance liquid chromatography (HPLC) with gradient elution and diode array detector (DAD) detection is presented. A standard mixture of 18 commonly marketed dyestuffs (11 nitroderivatives, two anthraquinones and five Arianor dyes) was studied. The major problems in the analysis of the mixture of direct dyes is the different chemical structure and especially the wide range of polarities. However we succeeded in the complete separation of the standard dyes. A qualitative analysis of eight colouring commercial products selected from different shades and a quantitative analysis of three of them was carried out. Materials, methods and results are reported.

Perforins in human cytolytic cells: the effect of age

The ageing process is associated with a progressive increase in the number of circulating NK cells, together with a decreased lytic activity per cell. A similar decrease in activity was also found for CD8 lymphocytes. Cytotoxic T- and NK cells express cytoplasm granules containing cytolytic effector molecules (as perforins, studied here) which can recognize and destroy damaged, infected and/or mutated target cells. To investigate whether an altered distribution of perforins in cytolytic cells or a reduced number of cytolytic cells producing perforins underlies decreased cytolytic activity with advancing age, perforin expression was assessed at the single cell level in T- (CD4 and CD8) and NK (CD16) peripheral blood lymphocytes from elderly subjects by flow cytometry. Perforin distribution at the cellular level in CD8+ and CD16+ cell cytoplasm suggested a similar distribution during ageing and a similar number of cells producing perforins. In addition, perforin utilization was maintained in the generation of cytolytic activity against K562 target cells and perforin synthesis in culture following activation was unabated. These data stress the importance of other factors, such as defective signal transduction for granule exocytosis, that may account for the different pattern of lytic activity found in aged people.

Synthesis and pharmacological activity of some N,N-disubstituted 1-amino-2-phenyl-3H,12H-naphtho[1,2-b]pyrano[2,3-d]pyran-3-ones

The synthesis of some N,N-disubstituted 1-amino-2-phenyl-3H,12H-naphtho[1,2-b]pyrano[2,3-d]pyran-3-ones 4, by reaction of phenylchloroketene with a series of N,N-disubstituted 3-aminomethylene-2,3-dihydro-4H-naphtho[1,2-b]pyran-4-ones, followed by dehydrochlorination in situ of the primary adducts with DBN, is described. Some compounds 4 showed antiarrhythmic and analgesic activities.

Synthesis of ethylammonium iodides of omega-dialkylaminoethyl ethers of 5-(arylmethylene)-1,3,3-trimethyl-2-oxabicyclo [2.2.2.] octan-6-hydroxyimines as potential cosmetic ingredients

The synthesis of nine quaternary ammonium iodides derived from omega-dialkylaminoethyl ethers of 5-(arylmethylene)-1,3, 3-trimethyl-2-oxabicyclo[2.2.2]octan-6-hydroxyimines, as potential cosmetic ingredients, is described. They are routinely prepared starting from cineole aminoethers by reaction with iodoethane and their physics-chemical data are reported. These substances were studied for their UV absorption and three of these compounds were also submitted to microbiological assays on five test organisms. The substances have their UV absorption maxima at 284-321 nm, and one compound is active on Staphylococcus aureus, Streptococcus faecalis and Candida albicans. These preliminary findings seem to indicate that some of these compounds could be considered as potential UV sunscreens; one compound, having a moderate antimicrobial activity, could be considered a potential active compound in cosmetics as deodorants, toothpastes, mouthwashes and other oral care products.

Pattern reversal visual evoked potentials in children with migraine or tension-type headache

Pattern reversal visual evoked potentials were recorded in 71 children with different types of migraine (e.g. migraine with aura, migraine without aura) or tension-type headache and in 19 controls (mean age of both groups 9 years). P100 latencies were comparable in all three groups.

Lytic activity of IL-2 and IL-12 stimulated NK cells against HOS osteosarcoma cell line

NK cells are CD16, CD56 positive lymphocytes that spontaneously lyse tumor or virus infected cells. In this study we investigated whether IL-2 and/or IL-12 stimulated NK cells increased their lytic efficiency against HOS osteosarcoma cell line. Our results demonstrate that both 18 hour and 5 day incubation times enhanced the lytic activity of human PBL against HOS and K562 target cells and that IL-12 appears to be more efficient than IL-2 in augmenting NK cytotoxicity.

Biological parameters influencing the immunological response to plasma derived and recombinant hepatitis B vaccines

Personnel (1856 subjects) belonging to local health units (medical and paramedical staff) that have been vaccinated since 1984 against hepatitis B virus (HBV) with HBsAg plasma purified preparations (Hevac-B and H-B-Vax) or recombinant DNA preparation (Engerix-B) were followed in plasma anti-HBs antibody levels. At the end of the protocols, different seroconversion percentages and different anti-HBs levels were reached: the best results were obtained with Engerix-B. Sex and principally age influenced the antibody production: women generally reached highest protective antibody levels and the 21-30 year group was more responsive than other groups. The injection of a supplementary 4th or 5th dose in low or non-responders could restore the specific immunity in the majority of the subjects and increase the anti-HBs level. The time course after the immunization of antibody levels depended on the level reached at the end of vaccination schedule. These data suggest that different antibody level monitorings of vaccinated subjects, planned on the basis of the antibody level reached at the end of vaccination, could prevent a loss of protection against the HBV infection.

In vitro cytolytic activity of human NK cells against osteosarcoma cell lines

NK lymphocytes present CD16, CD56 and lack CD3 surface molecules and are able to spontaneously lyse tumor or virus infected cells. In this study we evaluated the susceptibility of some human osteosarcoma cell lines to NK cytolytic activity and standardized the assay conditions. NK lymphocytes were used as effector cells in a cytotoxicity test against HOS, U-2 OS and Saos-2 osteosarcoma targets. While HOS cells were susceptible on the contrary U-2 OS and Saos-2 were osteosarcoma resistant lines. Our preliminary results support a model for the study of a possible interaction between the immune system and these tumors.

Visual evoked potentials in NIDDM: a longitudinal study

In order to assess the possible progression of neurological abnormalities over time and the value of visual evoked potential alterations in predicting stability and severity of diabetes-related optic pathway disease, a longitudinal study in non-insulin-dependent diabetic patients was performed. Neurological examination, visual evoked potentials with pattern reversal, motor and sensory nerve conduction velocities and metabolic control were studied in 18 non-insulin-dependent diabetic patients and in 35 normal control subjects at baseline and again after 4.6 +/- 0.8 years (range 4-6). At the first recording the peak P100 wave latencies were significantly delayed in the diabetic patients compared with the control subjects; signs of peripheral neuropathy were detected in five patients, clinical in three and in two there was only neurophysiological alteration without clinical signs. The second recording revealed no significant alterations of P100 latencies in patients compared with baseline, but the number with clinical signs and/or neurophysiological alterations with no clinical signs of peripheral neurological disease was increased to seven. In conclusion, we observed that visual evoked potential alterations were stable over time whereas peripheral neurological disease progressed and correlated positively with metabolic control.