Manipulating systemic and mucosal immune responses with skin-deliverable adjuvants

Most medically important bacterial and viral pathogens gain entry into the body either via the skin or a mucosal surface. Vaccination provides a viable and cost-effective strategy for the prevention of such diseases and it has always been a principal aim with vaccinologists, to be able to promote simultaneously, protective immune responses both systemically and at mucosal surfaces. The paradigm that mucosal immunity is best stimulated by exposure to antigen via a mucosal route simply because inductive sites such as Peyer's patches and bronchial associated lymphoid tissues are located in the mucosal epithelium, has promoted a plethora of immunizing strategies aimed at delivering both antigen and adjuvant to mucosal surfaces. We have developed a novel adjuvant system capable of intradermal delivery of antigens complexed in an ISCOSOME delivery vehicle. This adjuvant, referred to as a skin and mucosal adjuvant or SAMA4, was efficacious in eliciting both systemic and mucosal IgG and IgA antibodies in sheep, pigs and mice. SAMA4 does not induce granulomatous lesions at the site of vaccine delivery and can be used to deliver adjuvanted antigens by other routes including intranasal, oral and intravaginal. Using ovalbumin as a test antigen, intradermally delivered ovalbumin-SAMA4 complexes was found to be very effective in promoting a cytotoxic T cell response. Attempts to dissect the mode of action of SAMA4 by flow cytometric analysis of lymphocyte populations from the spleen, lung, liver and thymus revealed an effect of route of vaccine delivery upon the composition of specific lymphocyte subsets in these various organ compartments. From this, it can be inferred that SAMA4 induced a route-dependent re-mobilization and alteration in lymphocyte trafficking patterns. Other mucosal adjuvants such as cholera toxin B and microspheres, when injected intradermally, tended to promote primarily, an IgG and not an IgA response against hte carrier antigen.

Long-term productive human cytomegalovirus infection of a human neuroblastoma cell line

Human neuroblastoma cell line UKF-NB-4 persistently infected with human cytomegalovirus (HCMV) strain AD169 was established to study the effects of long-term HCMV infection on virus production and phenotypic characteristics of tumour cells. The cells designated UKF-NB-4AD169 were subcultured (80 subcultures) over a period of more than 2 years after initiation of infection. UKF-NB-4AD169 cells continued to produce infectious virus in successive passages, with a titre ranging from 9 x 10(3) to 1 x 10(5) and from 2 x 10(1) to 2 x 10(2) plaque-forming units per 10(6) cells and 1 ml culture medium, respectively; 10-20% of the cells produced HCMV-specific antigens, while 6-13% produced infectious virus progeny. The number of HCMV-specific DNA copies ranged from 9 x 10(4) to 9 x 10(6) per 10(6) cells. Transmission electron microscopy confirmed the productive nature of HCMV infection. UKF-NB-4AD169 cultures proliferated, with population doubling time ranging from 24.5 to 26.6 hr (19.5 to 20.3 hr for UKF-NB-4) and cell viability from 79% to 85% (91-96% for UKF-NB-4). Significantly lower amounts of tyrosine hydroxylase and decreased activity for dopamine-beta-hydroxylase than in uninfected cells were observed in UKF-NB-4AD169 cells. However, the expression of N-myc oncoprotein was significantly increased in persistently infected cultures. Our results show that long-term productive HCMV infection of UKF-NB-4 cell line is associated with the modulation of phenotypic properties, which may be related to the biological behaviour of neuroblastoma cells.

The impact of cognitively impaired patients and shift on nursing assistant stress

This study compared the stress experienced by nursing assistants (NAs) under four work conditions: high or low proportion of cognitively impaired patients and day or other shift. Five standard measures of caregiver stress served as the dependent variables in this study; burden, reaction to patient behaviors, workload, and two measures of burnout. A 2x2 multivariate analysis of variance found an interaction effect of type and shift on the stress measures. Univariate tests found that Burden and Depersonalization accounted for this effect. A further multivariate analysis of simple main effects found significant differences for each independent variable within each level of the other independent variable. Univariate analysis found that NAs who care for cognitively impaired patients on the day shift show significantly higher scores on specific stress measures. The article concludes with a discussion of how institutions can respond to the stresses faced by NAs who care for cognitively impaired patients.

Quick purification of recombinant human truncated tau proteins for immunoanalysis

A simple and rapid purification method is described which exploits the heat stability of human tau (tau) protein to prepare truncated forms of this protein derived from bacteria. Bacterial cells expressing tau fragments were pelleted, resuspended in phosphate buffered saline and boiled for 5 min. After centrifugation the supernatant containing thermostable tau was filtered (0.45 microns) and used for immunoanalysis with monoclonal antibodies. The purified tau fragments exhibited identical antigenic properties as fragments isolated by a conventional procedure, based on ion exchange chromatography on phosphocellulose. In contrast to the conventional approach, our method is less complicated, cheaper and significantly reduces the time required for isolation of the recombinant tau fragments.

[Treatment of septic shock in pediatrics]

A significant improvement has been noticed over the last 20 years in children in whom shock syndrome has developed. This has been attained through the application of technological advances in respiratory, cardiovascular, renal, nutritional support and improved antibacterial and antifungal therapy, but mostly through a better understanding of the physiology of shock. Newer concepts of the pathophysiology of sepsis and septic shock are presented, with clinical definitions referring to the pediatric patient. Innovative therapeutic modalities designed to modulate the systemic inflammatory response triggered by bacterial infection are discussed.

The role of plasma exchange in the treatment of severe forms of hemolytic-uremic syndrome in childhood

Therapeutic plasma exchange (PE) or plasma-pheresis has been used in recent years in the treatment of severe hemolytic uremic syndrome (HUS) in children. We analyzed the benefit of PE and peritoneal dialysis (PD) in 9 children, 6 boys and 3 girls, aged 1-10 years, from 1983-1993. All children came from different geographical regions, and all had the sporadic form of the illness. Three patients had the gastrointestinal form, 5 had respiratory prodromes while 1 child developed HUS during the course of varicella. Seven children were hypertensive, but only in 3 was hypertension persistent. The child with varicella had a transient complement decrease. Five children were treated with PE. In 4 children, fresh frozen plasma (FFP) was used as replacement fluid, and human albumin was used in 1 child. Four children were treated with PD and infusions of FFP. Rapid recovery of renal function was observed in 5 patients whereas in 2 oliguric children the recovery of renal function ensued within 1 and 2 months, respectively. Two children developed terminal renal failure (TRF) (in 1 child the treatment was very delayed, and in other child HUS developed following varicella). Only 1 boy had relapses of the disease followed by impairment of renal function from which he gradually recovered. During the 3-10 year follow-up period, only the child with relapses was hypertensive while the others had normal clinical and laboratory parameters. We suggest that PE plays an important role in the early treatment of severe forms of HUS in children.

A case of fatal sepsis in a child due to highly resistant Streptococcus pneumoniae

Infection with Streptococcus pneumoniae continues to be a significant cause of morbidity and mortality. Most of the pneumococci remain exquisitely sensitive to penicillin. However, S. pneumoniae with a reduced susceptibility to penicillin has been reported. To our knowledge, we present the first case in Croatia of fatal sepsis in a child due to Streptococcus pneumoniae that was highly resistant to penicillin.

[Paracetamol poisoning--case report]

A case of paracetamol poisoning in 17-month-old girl is presented. Clinical features and therapeutic procedures are described. Differences in paracetamol metabolism between children and adults are compared. Differences in the incidence of paracetamol poisoning between Croatia and USA are surveyed. The role of a physician in the education of parents and medical stuff on paracetamol toxicity is emphasized.

Phosphate metabolites of Tenebrio molitor (Coleoptera: tenebrionidae) infected with metacestodes of Hymenolepis diminuta

In vivo phosphorus-31 nuclear magnetic resonance (31P NMR) spectra and those of extracts of Tenebrio molitor L. infected with metacestodes of Hymenolepis diminuta R. showed modifications in the amounts of phosphorous-containing metabolites when compared with those of uninfected beetles. Infected females were more affected than infected males, having significantly more glucose-6-phosphate (Glu-6-P), glycerol-3-phosphate (Gly-3-P), and phosphorylethanolamine (PE), but less inorganic orthophosphate (Pi), glycerophosphorylethanolamine (GPE), gylcerolphosphorylcholine (GPC), phosphoarginine (PAr), and adenosine diphosphate (ADP). Infected males had more Glu-6-P and PE, but less Pi, GPE, and GPC. These changes directly reflected the phosphorylation potential of infected hosts, which increased approximately 100% and 50% in infected females and males, respectively.

Alzheimer paired helical filaments, untreated and pronase digested, studied by vertical platinum-carbon replication and high resolution transmission electron microscopy

Untreated paired helical filaments (PHF) and pronase treated PHF filaments have been stereoscopically imaged with a freeze-drying vertical platinum-carbon replication preparation method for TEM. The untreated PHF have an average wide region, W = 22.8 +/- 2.4 nm, a narrow region width, T = 10.6 +/- 1.7 nm, and a helical turn period, L = 78.6 +/- 13.4. The widths of the pronase treated PHF were significantly reduced and had average measurements of W = 14.8 +/- 1.2 nm, T = 5.7 +/- 1.0 nm, with the helical period unchanged, L = 75.4 +/- 17 nm. The surfaces of the untreated PHF contained approximately 1.0 and approximately 0.4 nm strands, the size of normal and denatured tau monomer. The pronase treated PHF contained approximately 1.0 and approximately 0.4 nm strands as well as approximately 2.0 nm strands. The stereoscopic images of the untreated and the pronase digested PHF do not support a double helical morphology for the PHF. The PHF appear to be long helical ribbons. The approximately 1.0 and approximately 2 nm substructure has been organized both parallel and orthogonal to the PHF-core axis for distances less than 80 nm. The most frequent structural appearance is of a disorganized PHF core. The surfaces of the untreated PHF also have a similar disorganized appearance.

Mucosal immunity and strategies for novel microbial vaccines

Infectious diseases continue to be the leading cause of morbidity and mortality worldwide. Increased awareness of the fact that mucosal membranes are the most frequent portals of entry of pathogenic microorganisms has prompted studies aimed at the development of vaccination protocols and antigen delivery systems that would lead to an increased protection of mucosae. Although systemic and strictly local immunizations are of limited effectiveness in the induction of mucosal protection, ingestion or inhalation of antigens results in a generalized immune response manifested by the appearance of specific antibodies of the secretory immunoglobulin (Ig) isotype in external secretions due to the dissemination of IgA precursor cells from IgA-inductive lymphoid tissues. Furthermore, additional inductive sites strategically positioned at the opening of the respiratory and digestive tracts may also be suitable targets for induction of immune responses at desired effector sites. To prevent degradation and the increase of ingested antigens absorption, novel strategies including enclosure of antigens into biodegradable microspheres, liposomes or their expression in viral and bacterial vectors and plants are currently being considered. Forthcoming technological advances in antigen preparation and routes of delivery will undoubtedly have a profound impact on immunization practices in the future.

Replication of human cytomegalovirus in a rhabdomyosarcoma cell line depends on the state of differentiation of the cells

The replication of human cytomegalovirus (HCMV) was investigated in a new human rhabdomyosarcoma cell line (KFR) with morphological and biochemical characteristics of fetal striated muscle precursors (rhabdomyoblasts). KFR cells exhibited the unique property for spontaneous morphological transformation from a poorly-differentiated state into well-differentiated (myotube-like) rhabdomyoblasts. The poorly-differentiated rhabdomyoblasts promoted both complete viral gene expression and the production of infectious virus. In contrast, in well-differentiated rhabdomyoblasts HCMV infection was abortive. The results showed that replication of HCMV in this human rhabdomyosarcoma cell line depended on the state of cellular differentiation.

Aphidicolin induces myogenic differentiation in the human rhabdomyosarcoma cell line KFR

The effects of aphidicolin, a specific inhibitor of DNA polymerase alpha, on cell growth, DNA synthesis and myogenic differentiation in the human alveolar rhabdomyosarcoma cell line KFR were studied. The treatment with aphidicolin at 5 x 10(-6) M concentration, which completely inhibited DNA synthesis and cell growth, induced morphological differentiation of small mononuclear cells to elongated, multinucleated (myotube-like) structures. The morphological differentiation was accompanied by the expression of skeletal muscle myosin; about 30% myosin-positive cells were observed after 14 days of treatment, compared to 2.3% in untreated cultures. The results showed that aphidicolin induces differentiation of human rhabdomyosarcoma cells and that multinucleated myotube-like elements may develop simply by cell fusion without cell division and DNA synthesis.

The boneless neonate: a severe form of achondrogenesis type I

We report a case of a severe form of achondrogenesis type I. Prenatal ultrasonography showed a micromelic fetus; bony structures could not be identified. Postnatal radiographs revealed some foci of ossification in the ossa ilia, the clavicles, the upper and the lower jaw and the base of the skull. The long bones, the vertebral column and the ribs were not visible. The diagnosis was established by histologic examination of the growth plates.

1H NMR study of metabolic alterations in the small intestine of rats infected with Hymenolepis diminuta

1H NMR spectra of the duodenum, jejunum and ileum tissues of the small intestine of a rat showed metabolic gradients. 2. The concentrations of metabolites in these gut regions were altered by the presence of the tapeworm Hymenolepis diminuta. 3. In the infected duodenum there was significantly less glycogen, glucose and phosphocreatine/creatine, but significantly more lactate than in the corresponding controls. 4. Infected jejunum contained significantly less betaine but significantly more succinate, alanine and lactate. 5. Infected ileum had significantly less glycogen and taurine but significantly more alanine and lactate.

Proton nuclear magnetic resonance analysis of liver metabolites from mice infected with Mesocestoides vogae

Proton NMR spectra of liver extracts from mice infected with Mesocestoides vogae for 24 or 133 days showed differences in the concentrations of liver metabolites when compared to those of normal liver. Moderately infected livers (24 d.p.i.) had significantly less glucose and significantly more glycine, cholines, alanine and lactate than uninfected controls. Similar changes in the concentrations of these metabolites were also found in mice with heavily infected livers (133 d.p.i.), and, in addition, there was significantly more succinate in this group than in the other 2 groups. Furthermore, the heavily infected livers contained more taurine and less acetate than the controls. Tetrathyridia extracts were rich in glycogen and contained high levels of betaine.

Metabolic alterations in organs of Meriones unguiculatus infected with Echinococcus multilocularis

1. 1H-NMR spectra of liver, spleen and kidney extracts from Meriones unguiculatus infected with Echinococcus multilocularis showed decreased levels of glucose. In addition, the liver extracts were severely glycogen-depleted. 2. Both livers and spleens contained less glycine, taurine and acetate. Spleens also had fewer cholines and less lactate but more betaine and alanine. 3. In the kidneys, elevated concentrations of succinate, acetate and lactate were found.

Microencapsulated human parainfluenza virus induces a protective immune response

Human parainfluenza type 3 (PI3) virus was incorporated into microspheres composed of a biocompatible and biodegradable DL-lactide and glycolide copolymer. Sera from mice immunized with these microspheres showed an antibody response to the viral glycoproteins and neutralized virus infectivity. The microspheres were also evaluated by intraperitoneal, oral, or intranasal administration to determine their protective efficacy in the hamster. After challenge infection of the intraperitoneally immunized hamsters with live PI3 virus, a significant reduction of virus titers in the respiratory tract was observed, demonstrating the protective efficacy of the microencapsulated viral antigens.