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The development of an active immunization against malaria is a major goal of scientific research for the last 10 years. While basic information about immunologic relevant epitopes for vaccine development are already available it must be conceded that there is a far way to a clinically available vaccine which is effective, well tolerated and--cheap. This review deals with the present difficulties for vaccine development and their approach to reality. It is tempting to speculate that control and eradication of malaria by the use of vaccines will be a challenge for the next 2 generations at least.

This is a pilot study concerning the question, whether herniorrhaphy is associated with the production of spermaantibodies. The influence of operation or trauma in production of spermaantibodies was investigate as well as the question, whether preexistant spermaantibodies disappear after herniorrhaphy. The following statement was done: 1. Patients with inguinal hernia have no increased coincidence of spermaantibodies in comparison with other men. 2. There is a tendency of more frequent appearance of spermaantibodies in patients after operation or trauma including herniorrhaphy, but no significancy. 3. After herniorrhaphy spermaantibodies appear in about 20%. 4. Preexisting spermaantibodies may frequently disappear after herniorrhaphy.

We investigated the capacity of conjugated bile salts to remove the membrane, a barrier to lipolysis, from milk fat globules. Cow, goat, and human globules were subjected to varying concentrations of the bile salt taurodeoxycholate at 37 degrees C for 2 min, and the released material was obtained by centrifugation at 2 degrees C and 50,000 g for 1 h. Sedimented pellets were analyzed for phospholipid and protein and were characterized further by sodium dodecylsulfate-polyacrylamide gel electrophoresis. Pellets were examined in the electron microscope. Measurable amounts of membrane were sedimented from globules incubated at 37 degrees C for 2 min in 0.5 mM taurodeoxycholate. Taurocholate also exhibited this membrane-releasing ability. However, disintegration of milk fat globule membrane appears to be the principal effect of these salts at 37 degrees C. Our results show that conjugated bile salts within their normal concentration range (2-6 mM) in digesta of term and preterm infants are capable of removing membrane from milk fat globules.

The effect of various antigen concentrations on the surface of target cells on IgG-mediated cytotoxicity of nonsensitized lymphocytes was studied using benzylpenicilloyl (BPO)-coated chicken erythrocytes as target cells, anti-BPO rabbit IgG, and human lymphocytes as effector cells. The number of antigenic sites on the target cell was calculated. The results indicate that a critical density of antigenic sites and consequently a close association of the Fc-parts of the antibody molecules is necessary for the induction of cytotoxicity.

A procedure is described for preparing rabbit antiserum to goat milk fat globule membrane. This membrane is derived from the secretory surface of the lactating cell. Immunoelectrophoresis and enzyme-linked immunosorbent assay showed that antibody development reached maximal levels in about 6--8 weeks. Infusion of 5--10 ml of this antiserum into the lactating mammary gland of goats via the teat canal depressed milk yields temporarily on the infused side to 60--80% of normal. Ordinary serum from rabbit, goat or human did not evoke such a response and rabbit complement was not essential for the effect. Fractionation showed that the globulin fraction of the antiserum contained the milk-suppressing principle. Milk from the antiserum-infused side of the udder showed extensive and tenacious clumping of fat globules on standing 12--24 h. The inhibition of milk flow by antibodies to the secretory membrane resembles a previously observed inhibition following infusion of concanavalin A or its succinyl derivative. Binding of antibodies or lectins which recognize specific surface protein components of the lactating cell appears to be involved in the suppression mechanism. The possible relevance of our findings to autoimmune suppression of exocytosis is noted.

Fat droplet development in rat mammary tissue was evaluated morphometrically in electron micrographs of 200 typical lactating cells. Droplets in the extreme basal area of the cells averaged .6 μm in diameter, increased to 1.3 μm in the extreme apical region, and increased further to a totally protruding (but still connected to the cell) size of 3.5 μm. The basal to apical growth was linear with a slope of .09. The expansion in droplet diameter during secretion also was linear (slope 1.06) and involved a 20-fold increase in volume. No droplets were observed coalescing. Massive lipid accumulation in the apical region of the cell is implied both by the growth and numbers of fat droplets in this region. Observation with the light microscope on lactating cells of three other species (rabbit, cow, and cat) also showed substantial volume increases as fat droplets were being secreted, In view of data on the time required to synthesize a milk fat droplet, droplet secretion may be a relatively slow process requiring up to several hours from the time the droplet first contacts the plasmalemma until it is completely clear of the cell.

Whole hemolytic complement activity (C’H50) was determined in samples obtained from the anastomosed hypogastric artery and the renal vein within the first 12 min after revascularization of 26 primary

During the passage of the egg down the oviduct, the egg shell membrane has essentially three sizes of particles on the outer surface. Membranes from the mid-isthmus have small surface grains, visible only with staining, that range in size from one to ten microns. They occur at approximately 270 per mm.2 increasing to approximately 2700 grains per mm.2 in the posterior isthmus. These grains give a positive reaction for glyoxalbis-(o-hydroxyanil) and a negative reaction for carbonate. The grains are acid soluble and seem loosely attached since they seem to agglomerate during staining. They diminish in number when the egg has progressed into the tubular shell gland and are rarely found once the egg has reached the shell gland. Possibly the grains act as nuclei for the depositions of the secretions of the tubular shell gland. The particles on the egg shell membrane in the tubular shell gland range from 28 to 90 micronsin in diameter. These are the mammillae which are enmeshed in the fibers of the outer shell membrane. They give a positive reaction for carbonate. The mammillae on membranes from the shell gland range from 60 to 150 microns in diameter. They stain uniformly with nine different histochemical stains, showing a relatively even chemical composition. They grow in size during deposition of shell mineral and eventually touch each other, forming small irregular gaps which become part of the pores of the finished shell.

Sera from guinea pigs and rats with chronic experimental allergic encephalomyelitis were injected into the cerebrospinal fluid (CSF) of normal recipient rats. Guinea pig sera induced demyelination in the central and (or) peripheral nervous system, whereas injection of rat sera resulted in demyelination in the peripheral nervous system only. Control sera did not induce demyelination. Demyelinating activity in guinea pig sera was confined to the IgG-fraction; in rat sera the IgG- as well as the IgM-fraction were able to induce demyelination. The demyelinating activity was abolished when the sera were absorbed with with sensitising antigen (guinea pig spinal cord tissue) or when immunoglobulins were removed from the sera. When chronic EAE sera from rats were injected into the CSF of rats, complement was not required for the induction of demyeLination. The presence of complement, however, augmented the demyelinating activity. Decomplemented chronic EAE sera from guinea pigs failed to induce demyelination after injection into the CSF of rats. Injection of control and non-demyelinating or demyelinating EAE sera into the subarachnoid space of normal recipient rats induced a weak inflammatory response with increased numbers of large mononuclear cells in the meninges. It is discussed that in vivo a complex interaction of antibodies, complement and effector cells is responsible for induction of demyelination.

Cytotoxic action against K562-tissue culture cells was investigated under various conditions with a Chromium-release-assay. When amoebae and target cells were centrifuged together, pathogenic strains of amoebae induced a very fast increase of target cell lysis (up to 50% of maximum lysis after 10 minutes). Only a minor degree of target cell lysis resulted, however, when amoebae and K562 cells were kept in suspension. When amoebae were eliminated selectively by addition of complement 10 minutes after starting the experiment, this fast increase of lysis could not be prevented. These observations suggest that the cytotoxic action might take place in two distinct phases. The first step ("lethal hit") seems to be temperature-independent, whereas a temperature of 37 degrees C is necessary for the second step to occur during which cytoplasmic material is released (chromium release). The presence of amoebae is not necessary for the second step. When amoebae together with and target cells are kept in suspension, amoebae lost their capability of setting the "lethal hit" with increasing time of coincubation. It seems, as if the "lethal hit" cannot be accomplished effectively under the conditions of suspension: cytotoxic substances released by the amoebae cannot be transferred to the target cells and are lost in the fluid phase. Thereby, the amoebae are depleted of such substances. Thus, a stable contact between amoebae and target cells for at least a few minutes seems to be necessary for the expression of cytotoxicity.

The hapten density on the surface of sheep red cells, coated with benzylpenicilloic acid (BPO) was determined. This was achieved by comparison of the inhibitory capacity of the test cells with that of a standard cell preparation of known antigen density. IgG-induced hemolysis was much more affected by the recution of haptenic sites/cell than IgM-induced hemolysis. It was concluded that more than 18,000 protein islets on the sheep red cell surface bearing at least four haptenic sites were necessary for IgG-induced lysis. Target cells with 190,000 BPO groups/cell could be protected by anti-BPO-IgG against the lytic effect of simultaneously added IgM. Using target cells with 240,000 haptenic groups/cell or more a synergistic hemolytic action of IgG- and IgM-anti-BPO antibodies could be observed.

A case of dense intramembranous deposit disease, partial lipodystrophy, hypocomplementemia, and nephritic factor-like activity in the serum is presented. Recurrence of underlying renal disease was noted in two consecutive renal allografts. The first transplant was lost 7 months after implantation, chronic renal rejection being an additional cause of graft failure. A favourable clinical course, however, was observed after the second renal transplantation. 22 months after surgery, the patient was fully rehabilitated and transplant function only slightly reduced despite electron microscopic evidence of typical dense intramembranous deposit lesions. Low C3-serum complement and normal C4-serum complement levels were constant findings throughout observation time. The case supports the assumption that patients with dense intramembranous deposit disease should not be excluded from renal transplantation As shown in the literature, maintenance of satisfactory graft function is usually obtained for a long period of time despite recurrence of original disease.

An overview is given dealing with global significance, clinical course and chemotherapie of some important helminthic and protozoal infections of human intestine.

Native normal human serum is capable of inhibiting the cytotoxic action of Entamoeba histolytica against K562 tissue culture target cells assessed by a 51Cr-release test. It is suggested that a part of the inhibitory activity on amoebae's cytotoxic action is represented by the complement system which is known to lyze trophozoites by activation of the alternative pathway. For the rest of the serum's inhibitory activity on amoebic cytotoxic action molecule(s) is (are) responsible which act(s) independently of Mg2+ and Ca2+. The serum components have to act before the trophozoites have come in contact with the target cells. The opsonization of trophozoites with antiamoebic antibodies led to an inhibition of amoebae's cytotoxic action (ACA) in a dose-dependent manner. The inhibitory components of normal human serum and antiamoebic antibodies potentiated each other in their capacity to inhibit ACA. It is suggested that opsonization of amoebae with C3b via its metastable binding site leads to redistribution phenomena on the amoebae's surface similar to the effects observed with antiamoebic antibodies, both events leading to inhibition of ACA.

Hyperacute renal allograft rejection is described in a patient suffering from mesangio-proliferative glomerulonephritis. The transplanted kidney was HL-A identical and the direct cytotoxic cross-match between the recipient's serum and donor lymphocytes was negative. Intrarenal consumption of C 3, but not of C 1 q, C 4, total haemolytic complement, IgG or Igm was demonstrated. Immunofluorescence studies exhibited dense granular deposits of C 3, but not of IgG, IgM C 1q or C 4. These findings together with the observation of beta 1 C-beta 1A converting activity in the patient's serum, raised the possibility that the alternative pathway of complement activation induced by nephritic factor could have operated in this case. Further studies will be necessary to clarify the question whether hyperacute rejection of renal allografts is only antibody mediated or not.

When in 1972 the Walter Reed Army Institute of Research introduced the quinolinemethanol mefloquine, many specialists thought that our problems concerning resistance of Plasmodium falciparum would be solved for the next few years.

The time dependency of the cytotoxic action of E. histolytica against tissue culture cells of mammalian origin was assessed in a 51Cr-release assay. Obviously, the amebae-dependent cytotoxic activity within the first 30-60 min of the assay against K562 (an erythroleukemic cell line) and MH1C1 (a rat hepatoma cell line) correlated with the pathogenicity of the respective amebae in vivo as measured by the hamster liver infectivity test. The in vivo apathogenic strain of E. histolytica (HK9) exhibited a delayed cytotoxic action in comparison with the in vivo pathogenic strain (SFL3), which revealed approximately 50% of maximum 51Cr-release after 10 min of the assay. Peripheral blood lymphocytes and HeLa cells proved to be not suitable to discriminate between pathogenic and apathogenic strains in vitro. Human antibodies directed against E. histolytica were capable of inhibiting the cytotoxic action of pathogenic amebae against K562 and MH1C1 within the first 30-60 min of the assay, revealing a kinetic pattern nearly identical with that observed with apathogenic amebae against K562. Possibly, this antibody-mediated inhibition of the cytotoxic action of E. histolytica against target cells reflects one of the defence mechanisms of the host against invasive amebiasis.

After arriving in Austria a 10 month old Nigerian infant fell sick with malaria tropica and survived after specific antiparasitic therapy. Early diagnosis and immediate begin of treatment are stressed.

Traveller's diarrhea is the most common tourist's disease in the tropics. Therefore epidemiological data for the evaluation of factors influencing the attack rates and the severity of the disease are being required. This paper deals with the data of 1058 Austrian tourists travelling to warm climate countries. 47.3% of all travellers suffered from an episode of traveller's diarrhea during their stay. However, it could be evaluated that besides the destination seasonal influences were very important. Factors like individual hygiene and accommodation did not influence the attack rates. Age and environmental conditions, however, did partially influence the frequency of diarrhea. Furthermore, additional symptoms were interpreted and it could be seen that suspected heterogenicity of etiology leads to a similar pattern of clinical symptoms. Clinical evaluation proves that traveller's diarrhea is commonly not severe, but due to the incidence and duration of the disease it is a major health problem in modern tourism.

26 pig kidneys were perfused in a "Gambro" kidney perfusion machine. The perfusates used were unmodified canine plasma and serum, as well as complement-free plasma, gamma-globulin solutions obtained from dogs immunized against pig leucocytes (ALG) and 2-mercapto-ethanol treated ALG (2 ME-ALG). The typical pig-to-dog xenograft rejection was reproduced by ex vivo perfusion with native dog plasma and serum. Using complement-free dog plasma, ALG and 2 ME-ALG pig kidneys could be perfused for several hours without significant increase in perfusion resistance. 22 pig kidneys, pretreated by perfusion for 2 hours with complement-free dog plasma, ALG and 2 ME-ALG, were transplanted on to the vessels of the neck of recipient dogs. Grafts pretreated with decomplemented dog plasma and 2 ME-ALG were rejected in the usual fashion within 5 to 20 min. Pretreatment with ALG resulted in a prolongation of graft function for 80 to 100 min. It is suggested that ALG exerted a transient blocking effect on the cytotoxic action of recipient IgM resembling passive enhancement; this phenomenon may be limited to sites with low antigen density, corresponding to in vitro findings of passive enhancement on cells with low surface antigen density.

The size, cellular location, and identity of surface-associated components were determined for lipid droplets in lactating cells. Transmission electron-microscopic measurements were made involving 3801 droplets in approximately 211 cells from three rats and 1197 droplets in 66 cells from a mouse. For the purposes of droplet evaluation, cells were divided into seven locations ranging from basal to secreting positions. Droplets were also categorized with respect to contact with other droplets, basolateral plasma membrane, mitochondria, Golgi apparatus, secretory vesicles, and endoplasmic reticulum-cytoplasm (ERC). Data on droplet size showed that droplet growth occurs mainly in the secretory position, confirming previously published findings. Lipid droplets from mouse tissue, although somewhat smaller in size showed similar growth trends to those of the rat. Data on numbers of droplet contacts and percentages of droplet circumferences involved in associations with other cell components showed that the dominant interaction of lipid droplets was with the ERC. However, intimate association of droplets with mitochondria was noted in all cellular locations. In addition, nursed animals exhibited a greater proportion of droplet surface association with secretory vesicles and less in contact with mitochondria in comparison to those not nursed. The significance of these relationships to milk synthesis and secretion is discussed.

The effects of colchicine on ultrastructure of the lactating mammary cell in the rat and goat were studied by electron microscopy. Changes in tissue of the rat were examined over time (1, 2 and 4 h). The goat gland was evaluated by comparing ultrastructure of tissue at the time of maximum milk flow suppression induced by the drug with that of untreated tissue. Colchicine produced notable changes in the tissue of both species: 1) the secretion of lipid droplets and Golgi vesicle contents (exocytosis) was inhibited and the droplets and vesicles became randomly distributed throughout the cell, 2) the Golgi apparatus was significantly reduced in size, 3) casein and lipid continued to be synthesized as evidenced by greater numbers of secretory vesicles and increased sizes of casein micelles and lipid droplets, 4) secretory vesicles showed a propensity to cluster around lipid droplets, 5) isolated microtubules were found occasionally in the control tissue, ordinarily in the vicinity of the Golgi apparatus, but rarely in the colchicine-treated tissue. These observations indicate that colchicine has two effects leading to suppression of exocytosis in the mammary cell: one involves early interference with capacity of secretory vesicle membranes to fuse and a further effect, related to higher concentrations of colchicine, causes intracellular disorganization and loss of polarity. Microtubules were not seen as directly involved in the mechanisms of exocytosis. The secretion of milk fat globules is coupled to exocytosis and thereby is also inhibited by colchicine.

The plant lectin, concanavalin A (Con A) suppresses milk secretion when infused into the mammary gland or when incubated with lactating tissue in vitro. Toward defining its mode of action, we infused Con A into rat and goat mammary glands via the teats and observed effects on lactating cells. Lectin dosages were 2 and 25 mg per gland for rats and goat, respectively. Tissue samples were taken 1 and 3 h post infusion for rats and at 24 h for the goat. Control and Con A-treated tissues were observed by light microscopy and by both thin section and freeze fracture electron microscopy. In comparison to controls, Con A-treated tissues of both species exhibited alveoli with enlarged cells and relatively empty lumina; cells were distended with secretory vesicles and fat droplets. Apical plasma membranes of lectin-affected cells of the rat displayed a marked reduction in the number of microvilli, and exhibited an atypical branching and folded structure. Morphometry was employed to quantitate changes in cell and secretory product parameters in both rat and goat tissue. Microtubule numbers and distribution did not appear to be altered by Con A but considerable changes were noted in the arrangement of microfilaments associated with the secretory surface of lectin-treated epithelial cells. Various related ultrastructural changes and the role of Con A in perturbing the microfilament system are discussed.

In peripheral human blood lymphocytes the uptake and metabolism of adenine, guanine, and hypoxanthine was investigated. This was achieved by incubation of purified lymphocytes with 14C-purine bases, separation of cells from the incubation medium by a rapid filtration technique, and subsequent separation of the acid soluble material by thin-layer chromatography. No perferential uptake for one of the purine bases was observed. In all cases only traces of 14C-purine bases not added originally and labeled nucleosides could be demonstrated. Approximately 2/3 of adenine and 1/2 of guanine or hypoxanthine were converted to nucleotides. Separation of formed nucleotides showed that adenine and guanine were metabolized mainly to their corresponding nucleotides; hypoxanthine was converted to a considerable amount to adenine nucleotides and only to a small proportion into its own nucleotides. These results demonstrate the predomonance of adenine nucleotide formation in normal human lymphocytes.

Different kinds of IgM antibodies were tested for their activity in antibody-dependent cellular cytotoxicity (ADCC): firstly an anti-benzylpenicilloyl (BPO) IgM antibody from immune rabbit serum purified by affinity, ion exchange, and molecular-sieving chromatography, secondly two monoclonal rat anti-BPO IgM antibodies and thirdly a human antidextran antibody prepared from a patient showing restriction of anti-dextran antibodies to the IgM class. Human lymphocytes or purified monocytes served as effector cells. While the two monoclonal rat and the human IgM antibodies showed no ADCC-mediating capacity, ADCC was induced by the rabbit anti-BPO IgM antibody when high antibody concentrations were used. This activity was abolished by further purification using an anti-rabbit IgG (Fc) immunosorbent. The initially observed activity was shown to be likely due to traces of aggregated anti-BPO IgG, which cannot be detected by the methods commonly used. Preincubation of lymphocytes for 24 hr increased the number of EA (IgM)] rosette forming cells but failed to induce IgM-mediated ADCC. Furthermore, evidence for amplification of low-dose IgG-ADCC by IgM could not be found.

The effect of 2-ME treatment of IgG on its ability to induce cytotoxicity in non-committed lymphocytes was studied. An IgG fraction of a rabbit anti-BPO serum was tested with BPO-coated chicken erythrocytes as target cells and human peripheral blood lymphocytes as effector cells. 2-Mercaptoethanol alters the properties of the Fc fragment of the IgG antibody molecule by cleaving inter-H-chain-disulfide bonds. Treatment of the antibodies with 2-ME resulted in a significant reduction of their capacity to induce cytotoxicity of lymphocytes against the respective antigen-antibody complex. 2-Mercaptoethanol treatment may prevent conformational changes of the Fc part of the antibody molecule essential for its interaction with the Fc receptor on the effector lymphocyte.

The observation that concanavalin A can inhibit milk secretion was evaluated in an in vitro system employing minced mammary gland or isolated alveoli from lactating rats. Release of milk constituents (casein, lactose and fat globules) into the medium in the presence and absence of concanavalin A was measured during 1 or 2 h incubations. The effect of concanavalin A on glucose uptake and CO2 production of the minced tissue was also studied. Concanavalin A suppressed release of milk components at a concentration as low as 80 micrograms/ml of medium. Respiration of minced mammary tissue in the presence of concanavalin A (100 micrograms/ml of medium) was essentially the same as that of the control. The data are evidence that concanavalin A acts directly on the mammary cell in suppressing milk secretion and that the effect is not due to cytotoxicity.

Three anesthetics – Nembutal, Ketaset, and T61 – produced extensive large vacuolization of endoplasmic reticulum in lactating goat mammary tissue. This was observable with either light or electron microscopy. No normal looking cells were seen at the electron microscope level. These changes rendered the tissue unusable for morphological and autoradiographic studies. Comparable doses (weight adjusted) of the same anesthetics did not produce cellular distortion in the lactating tissue of rats as observed with light or electron microscopy. This species difference seems to involve susceptibility of the endoplasmic reticulum to swelling. Effects of anesthetics on morphology of lactating tissue from other species is not known but may constitute an important variable.

Sheep erythrocytes were coated with bencylpenicilloyl-(BPO)groups. Different incubation periods resulted in erythrocyte preparations with different hapten density. Complement dependent lysis induced by IgM or IgG antibodies was studied with the cell preparations. The calculation of hapten density on the erythrocyte surface was not possible by direct measurement of coupled radioactive BPO since more than 90% of radioactive material was found in the soluble supernatant after osmotic cell lysis and less than 10% was fixed to the cellular membrane. Measurement of membrane bound immunologically relevant BPO-groups was achieved, therefore, by comparison of the inhibitory capacity of the test cells with that of a standard cell preparation. The latter consisted of tannic acid treated erythrocytes coated with protein complexed radioactive BPO. Surface hapten density of the different target cell preparations varied between 1.9 x 10(5) and 4.8 10(5) BPO-groups per cell depending on the time of incubation. Complement dependent antibody mediated cell lysis was significantly reduced by reduction of haptenic sites per target cell, IgG induced lysis being much more affected than hemolysis induced by IgM antibodies. Statistical calculations led to the conclusion that 18,000 protein islets per cell bearing 4 or more BPO-groups are not sufficient for hemolysis induced by IgG antibodies. 48,000 protein islets with this hapten density are necessary for "optimal" sensitization. IgG antibodies must be apparently bound to the cell surface in bivalent form.