The relationship between the immunological efficacy of a dried meningococcal group-A polysaccharide vaccine and the molecular parameters of the group-A polysaccharide

This work deals with the problem of relationship between the molecular parameters of group A meningococcal polysaccharide and its immunological effectiveness for laboratory animals and humans. The depolymerization of group A polysaccharide contained in the vaccine leads to a decrease in its capacity of inducing the production of hemagglutinating (19S and 7S) and bactericidal IgA antibodies in humans, as well as inducing an increase in the number of cells producing IgA antibodies in the spleen of immunized mice and the appearance of circulating IgA antibodies in their sera. As shown in this investigation, fully developed immune response to group A meningococcal vaccine may be achieved in humans only if the content of group A high-molecular polysaccharide in the vaccine is not less than 70%. Mice have been recommended as an experimental model for the prognostication of the effectiveness of meningococcal polysaccharide vaccines and for their control in the process of manufacture instead of currently used titration of bacteriolysins in the sera of immunized humans.     

Effect of rapamycin on renal allograft survival in canine recipients treated with antilymphocyte serum, donor bone marrow, and cyclosporine

Rapamycin (Rapa) monotherapy can promote renal allograft survival in dogs, but it is very toxic. To attempt to augment the effectiveness of Rapa and reduce its toxicity in a tolerance induction protocol, canine renal allograft recipients were treated briefly with antilymphocyte serum (ALS), donor bone marrow cells (BMC), and a limited course of cyclosporine (CsA). Rapa had little effect when CsA-treated recipients were given ALS on days -5 to -1 and BMC on day +1. When combined with CsA given days +13 to +42, ALS on days -5 to +7, and BMC on day +10, Rapa at 0.3 mg/kg on day +8 plus alternate days +15 to +39 significantly increased overall survival and was compatible with long-term survival after immunosuppression (6 grafts, 1 graft > 212 days, 1 graft > 470 days). Rapa appeared to prevent early rejections that can occur during treatment with these ALS/BMC/CsA protocols. Little toxicity of Rapa was observed with any treatment.     

Assembly of hair keratins in transfected epithelial cells

To define the interactions required for the filament assembly of differentiation-specific keratins, active copies of mouse hair keratin mHa1 and mHb4 genes were introduced into a rat kangaroo kidney epithelial cell line (PtK2) and a rat stratified squamous epithelial cell line (rat epidermal keratinocyte). In PtK2 transient transfectants, when introduced individually or in combination, mHa1 and mHb4 formed aggregates of ring-like structures of various sizes at the perinuclear region with no evidence of organization into a keratin network. These aggregates altered the distribution of the endogenous keratins and vimentin. In most of the cells carrying the ring-like structures of mHa1 and mHb4 around the nucleus, the endogenous keratin network collapsed and localized around the nucleus. Furthermore, the densely accumulated endogenous keratin surrounded the ring-like aggregates with partial co-localization. However, when transfected into the rat epidermal keratinocytes, mHa1 and mHb4 were able to co-localize with the well-developed cytoskeleton of endogenous keratins. These results showed that, in contrast to keratin pairs K5/K14 and K8/K18, the mHa1/mHb4 pair is unable to develop an extensive keratin network on its own and that there are possible differential abilities among these hair keratins and other keratins to form well-developed cytoplasmic networks.     

Respiratory symptoms in meat pigs: is there a role for porcine respiratory corona virus (PRCV) and porcine reproductive and respiratory syndrome virus (PRRSV) in the etiology?

On a pig farm with about 2000 pigs, respiratory problems regularly developed in fattening pigs 3 to 4 weeks after the start of the fattening period. A postmortem examination was carried out on four pigs during the acute phase of their illness. The animals showed signs of viral pneumonia. In two animals porcine respiratory virus (PRCV) was discovered and in the other two animals porcine reproductive and respiratory syndrome virus (PRRSV). The possible role of these two viruses in the aetiology of the health problems on this farm is discussed in the context of the results of a longitudinal serological study.     

Joint equivalence of means and variances of two populations

To investigate the contribution of oral, gastric and intestinal factors in the control of appetitc, 425 ml (400 kcal) tomato soup was administered either orally, intragastrically (covertly and overtly) or intraduodenally (overtly) to nine healthy, fasted, male volunteers. Ratings of fullness, hunger and desire to eat were recorded over a period of 2 h and gastric emptying was measured after soup fed orally and intragastrically. Infusion of the soup into the small intestine at a rate commensurate with normal gastric emptying exerted no significant suppression of ratings of hunger and desire to eat and no significant production of fullness. Covert, intragastric infusion of the same soup suppressed appetite and this suppression was increased when the subjects were informed of the nature of the infusion, but there were no differences in gastric emptying profiles between covert and overt intragastric infusions of soup. Oral administration of the soup produced the greatest suppression of appetite compared with other conditions and also generated a slower rate of gastric emptying compared with both intragastric soup infusions. Strong correlations were observed between appetite ratings and both gastric and intestinal contents following intragastric infusions of the soup meal and these were enhanced following oral administration of soup. These results indicate how information, orosensory, gastric and intestinal factors can interact to elicit optimal expression of fullness and suppression of hunger. Specifically, the data not only demonstrate how the influence of gastric distension appears to overwhelm any direct influence of intestinal chemostimulation on appetite and how information modulates this effect, but the data also support an important role in appetite suppression for psychophysiological mechanisms stimulated by orosensory mechanisms.     

Human cells arrest in S phase in response to adenovirus 12 E1A

In the present investigation, nuclei of endodermal cells, primary and secondary mesenchyme cells (PMCs and SMCs), and small micromere descendants (SMDs) of the sea urchin Lytechinus variegatus were counted and mapped at five developmental stages, ranging from primary invagination to pluteus larva. The archenteron and its derivatives were measured three dimensionally with STERECON analytical software. For the first time SMC production is included in the kinetic analysis of archenteron formation. While the archenteron lumen doubled in length during secondary invagination, the number of archenteron cells increased by at least 38% (over 50% when SMCs that emigrated from the tip of the archenteron were included). The volume of the archenteron epithelial wall plus the volume of 17 new SMCs increased by 40% over the equivalent volumes at the end of primary invagination. Because secondary invagination involves the addition of archenteron cells and an increase in volume of the archenteron epithelium, we conclude that secondary invagination is not accomplished simply by the rearrangement and reshaping of the primary archenteron cells. Both archenteron cell number and wall volume continued to increase at the same rates from the end of secondary invagination until the 27-h prism stage, although the lumen lengthened more slowly. SMCs were also produced at a constant rate from primary invagination until the prism stage. Because the production of both endodermal and mesodermal cells continues until the late prism stage, we conclude that gastrulation (defined as the establishment of the germ layers) also extends into the late prism stage.