An ultrasonographic method to study reproductive seasonality in ewes isolated from rams

In studies concerning the seasonality in sheep, the effect of the teaser-ram, which can by itself induce oestrus as well as the development of ovary function bodies, has not been considered. In this study, a method is developed to determine ovarian activity during the year while excluding a possible influence of the ram. The study was carried out on 10 German Blackhead Mutton ewes (GBM) and 10 German Mutton Merino ewes (GMM) and lasted for 14 months. The ewes were kept without contact with any ram, and once a week a transrectal ultrasonography was conducted to determine ovary function bodies (corpora lutea, follicles) and a blood sample was taken to analyse progesterone (P4) concentration. In both breeds, the number of ovulating ewes, the ovulation rate (OR), the size of the corpora lutea (CL) and P4-concentrations showed significant seasonal fluctuations. During the main breeding period (September-February), the OR was higher (2.0 +/- 0.4) than during the rest of the year (1.6 +/- 0.5). Outside the main breeding season (March-August), approximately 40% GBM ewes and only approximately 15% GMM ewes produced CL. The cycle and the related seasonal changes in the P4-concentration coincide with different ultrasonically diagnosed CL (developing or regressing, insufficient, no CL). Between the volume of fully developed CL and P4-concentration, correlations of 0.57 (GMM) and 0.45 (GBM), respectively, were found. On average, P4-concentration in September to February was by approximately 1.60-1.66 nmol/l in the GMM and by approximately 1.80-1.86 nmol/l in the GBM higher than in spring and summer. Considering the OR, the P4-values corresponded with the CL volumes, i.e. in the months from August to February the CL values were significantly larger than in the months March to August. The ultrasonic ovarian diagnosis is a useful method to determine the ram-uninfluenced seasonality of reproduction in sheep.

Hypochlorous acid-induced stress on human spermatozoa

The fertilising ability of human spermatozoa may be impaired by inflammations of the genital tract, although details of these processes are still unknown. Hypochlorous acid (HOCl), an important product of myeloperoxidase released from stimulated neutrophils, induces a concentration-dependent increase in externalisation of phosphatidylserine in ejaculated human spermatozoa as revealed by fluorescence-activated cell sorting (FACS) analysis. The increase of annexin-V binding cells starts already at about 10(-5) mol/l HOCl, while a formation of lysophosphatidylcholines as detected by matrix-assisted laser desorption and ionisation time-of-flight mass spectrometry (MALDI-TOF MS) is only found at HOCl concentrations higher than 10(-4) mol/l. Thus, changes in lipid composition of spermatozoa are unlikely responsible for the phosphatidylcholine (PS)-externalisation. These data gave concomitant evidence that HOCl itself leads to a dramatic damage of the cell membrane. Thus, the neutrophil-derived HOCl contributes to the deterioration of spermatozoa leading to diminished fertilisation ability.

Cholesterol esterase action on human high density lipoproteins and inhibition studies: detection by MALDI-TOF MS

The modification of lipoproteins by lipolytic enzymes such as cholesterol esterase (CEase) is assumed to play an important role in the pathogenesis of atherosclerosis. However, details of the activation and inhibition of CEase are still unknown. In this study, matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to investigate the extracts of human lipoproteins after treatment with CEase and to monitor the effects of the inhibitor 2-(diethylamino)-6,7-dihydro-4H,5H-cyclopenta[4,5] thieno[2,3-d][1,3]oxazin-4-one (DOT-3). This approach has the advantage that all lipid classes can be independently detected; therefore, conclusions on the mechanism of the applied enzyme are possible. Besides the expected decrease of cholesteryl esters (CEs) in HDL, a significantly enhanced content of lysophosphatidylcholine (LPC) was also detected, confirming the broad substrate specificity of CEase. It was also demonstrated that DOT-3 significantly inhibited the CEase-catalyzed cleavage of CEs in HDL. Phospholipid (PL) vesicles prepared from phosphatidylcholine (PC) or PC and cholesteryl linoleate were treated with CEase, and the changes in lipid composition were investigated. From the analysis of the generated LPC species in HDL and in the isolated lipid mixtures, it is evident that CEase catalyzes the cleavage of the fatty acid residues in both the sn-1 and sn-2 positions of the PLs. These effects are obvious in the absence as well as in the presence of detergents.

Matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) mass spectrometry in lipid and phospholipid research

The interest in the analysis of lipids and phospholipids is continuously increasing due to the importance of these molecules in biochemistry (e.g. in the context of biomembranes and lipid second messengers) as well as in industry. Unfortunately, commonly used methods of lipid analysis are often time-consuming and tedious because they include previous separation and/or derivatization steps. With the development of "soft-ionization techniques" like electrospray ionization (ESI) or matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF), mass spectrometry became also applicable to lipid analysis. The aim of this review is to summarize so far available experiences in MALDI-TOF mass spectrometric analysis of lipids. It will be shown that MALDI-TOF MS can be applied to all known lipid classes and the characteristics of individual lipids will be discussed. Additionally, some selected applications in medicine and biology, e.g. mixture analysis, cell and tissue analysis and the determination of enzyme activities will be described. Advantages and disadvantages of MALDI-TOF MS in comparison to other established lipid analysis methods will be also discussed.

Analysis of the lipid composition of human and boar spermatozoa by MALDI-TOF mass spectrometry, thin layer chromatography and 31P NMR spectroscopy

Alterations in the phospholipid (PL) composition of spermatozoal membranes occur during the fertilization process. Furthermore, membrane lipid composition is of high interest with respect to cryopreservation. The PL and fatty acid compositions of human and boar spermatozoa are compared by using matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) in combination with thin-layer chromatography and 31P NMR spectroscopy. The extreme sensitivity of alkenyl-linked PL against acid treatment was used to estimate the plasmalogen content of spermatozoa. Compared with humans, boar spermatozoa are characterized by a lower variability of their PL and fatty acid composition. Additionally, boar spermatozoa contain much higher moieties of alkyl-linked compounds, e.g. 1-palmityl-2-docosapentaenoyl-sn-glycero-3-phosphocholine and 1-palmityl-2-docosahexaenoyl-sn-glycero-3-phosphocholine as well as the corresponding phosphatidylethanolamine (PE), while human spermatozoa are characterized by high contents of diacyl-PL, e.g. 1-palmitoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine and 1-palmitoyl-2-docosahexaenoyl-sn-glycero-3-phosphoethanolamine. A considerable plasmalogen moiety, for instance 1-palmitenyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine is a typical feature of both, human and boar spermatozoa. It will be shown that these differences in PL composition can be very rapidly and conveniently assessed by MALDI-TOF MS in combination with TLC and also by 31P NMR.

Analysis of the lipid composition of bull spermatozoa by MALDI-TOF mass spectrometry—a cautionary note

In this study we demonstrated the combination of MALDI-TOF MS and TLC as a fast and powerful tool to investigate the phospholipid (PL) composition of organic extracts of bull spermatozoa. Since phosphatidylcholine (PC) is the dominant PL species, an adequate resolution of MALDI-TOF spectra for sphingomyelin (SM) or phosphatidylethanolamine (PE) was achieved only after previous PL separation by TLC. We found a poor diversity especially for PE and PC, mainly containing ether-linked fatty acids which were 1-palmityl-2-docosahexaenoyl-PL and the corresponding alkenyl-acyl compound (plasmalogen) 1-palmitenyl-2-docosahexaenoyl-PL. For PC, both lipids were quantified after phospholipase A2 digestion to represent 44.2 and 37.2%, respectively, of the total PC. In contrast, the diacyl-PC content of bull spermatozoa was comparatively low (18.6% of total PC). In the presence of trifluoroacetic acid (TFA), which is routinely added to the MALDI-TOF matrix to improve the signal to noise ratio, a high lysophospholipid (LPL) content was detected in the PL extracts of bull spermatozoa, whereas TLC did not reveal significant amounts of LPL. The TFA mediated hydrolysis of the acid-labile alkenyl-acyl PL to the corresponding LPL was shown to cause this discrepancy. This assumption was verified by analysing the PL composition by MALDI-TOF MS before and after (i) digestion of sperm cell lipids with phospholipase A2 and (ii) exposition of spermatozoa to HCl fumes. We conclude that the analysis of samples containing alkenyl-acyl-PL by MALDI-TOF has to be performed with great caution.

Deterioration of spermatozoal plasma membrane is associated with an increase of sperm lyso-phosphatidylcholines

Spermatozoa with plasma membranes that lost their asymmetry or permeability for larger molecules can be identified by binding of annexin V to membrane phosphatidylserine (PS). Paramagnetic annexin-V-conjugated microbeads (AN-MB) can be used to eliminate these spermatozoa by magnetic activated cell sorting (MACS). Semen samples of six healthy volunteers with normal spermiogram parameters were divided into two sperm fractions by MACS as a function of bound AN-MB, and their individual lipid compositions were examined by matrix-assisted laser desorption and ionisation time-of-flight mass spectrometry (MALDI-TOF MS). As a model system, liposomes composed of phosphatidylcholines (PC) from egg yolk were digested by phospholipase A2 (PLA2). The MALDI-TOF mass spectra of organic extracts of both sperm subpopulations differed significantly. The ratio between lyso-phosphatidylcholine LPC 16 : 0 and PC 16 : 0/22 : 6 was approximately 2.5-4.7-fold higher (median 2.9) in the sperm group binding AN-MB than in spermatozoa with intact membrane unable to bind AN-MB. The ratio between LPC 22 : 6 and PC 16 : 0/22 : 6 was also enhanced in the spermatozoa with impaired membrane structure (factor in the range: 1.9-3.9; median 2.6). These alterations corresponded to the effects of PLA2 on artificial phospholipids. It is concluded that spermatozoa with deteriorated membrane and exposed PS are characterized by an increased lyso-phosphatidylcholine content that is likely generated by phospholipases.

CsCl as an auxiliary reagent for the analysis of phosphatidylcholine mixtures by matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS)

Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) is mainly used for protein and peptide analysis. However, there is growing evidence that also phospholipids like phosphatidylcholines (PC) can be easily analyzed by MALDI-TOF MS. In MALDI-TOF methodology, the sample is cationized by the addition of inorganic ions. This process is strongly dependent on the corresponding ion concentration. In biological samples various cations are present (mainly H+, Na+ and K+) and, therefore, a mixture of different adducts is formed. Since phospholipids exhibit a wide distribution of different fatty acid residues a considerable peak overlap may occur. This is a major problem since the peak assignment in a mixture will be often unclear. In this paper we demonstrate that this problem can be easily overcome by mixing the analyte with caesium chloride (CsCl). This yields naturally non-occurring Cs+ adducts that are apparent due to the large shift of the molecular mass. The proposed method facilitates the clear assignment of most peaks. Besides that, we will show that CsCl can also be used for the determination of the relative fatty acid composition of a given PC sample. For this purpose naturally occurring mixtures of PCs as well as organic extracts of human lipoproteins-that are mainly composed of PC and sphingomyeline-are used.

[Real-time ultrasonographic (B-mode) pregnancy diagnosis in sheep. 4. Results of a field study in Germany]

Between January 1993 and April 1998 in a total of 27,378 sheep an ultrasonographic early pregnancy diagnosis was done. The determined pregnancy rates (mean = 82.2%) were related to the mating systems, duration of mating season and time of the year. The benefits of scanning are described. If the pregnancy rate is lower than 97% the early pregnancy diagnosis is economical to flock management. Cases of uterine and fetal pathology (fetal mortality, maceration, hydrometra, pyometra) are presented.

[Ultrasonic pregnancy diagnosis (B-mode) in sheep. 2. Comparative studies using transcutaneous and transrectal pregnancy diagnosis]

The aim of this study was to check the earliest time for the ultrasonic pregnancy diagnosis in flock management of sheep after finishing the mating season. Therefore a transcutaneous pregnancy diagnosis (5 MHz) took place on a total of 1060 German merino-mutton sheep between day 10 and 90 after mating (a.m.) and a transrectal diagnosis (5 MHz) took place on a total of 1442 German merino-mutton sheep between day 10 and 70 a.m. At the beginning of the third week a.m. the accuracy of transrectal diagnosis was over 95% and increased to 100% on day 35 a.m. At that time the accuracy of transcutaneous diagnosis was 80% and reached 100% on day 60 a.m. Considering the reached accuracies the pregnancy diagnosis should not take place before day 35 after the end of the breeding season. After day 35 a.m. it is advisable to combine the transcutaneous and the transrectal pregnancy diagnosis. That means that at first all animals are examined by transcutaneous sonography and in the second step the so-called "non-pregnant sheep" are checked by transrectal ultrasound. From the beginning of the third month a.m. a single transcutaneous pregnancy diagnosis is sufficient.

[Purpura fulminans with extensive skin necroses]

Purpura fulminans must be treated as an emergency in internal medicine and dermatology. Its characteristic features are the sudden development of progressively enlarging haemorrhagic skin necrosis, severe disseminated intravascular coagulation with consumption of anticoagulant factors, and signs of shock. Purpura fulminans can be classified into a neonatal form with inherited protein C deficiency and an acquired type for which multiple causes are known. Clinically it is characterized by massive ecchymosis with haemorrhagic blebs and acral necrosis. Histologically the lesions show widespread extravasation of erythrocytes and thrombosis of small vessels. Thrombocytopenia, decrease of coagulation factors, the presence of fibrinogen split products and fragmented erythrocytes in the blood smear help to confirm the diagnosis. The therapy includes fresh-frozen plasma, heparin, antibiotics and surgical debridement of necrotic areas. It is important to recognize the disease promptly because the mortality rate is about 30-40% and only quick intervention helps to save the life of the patient.

[Hematogenous contact eczema cause by phytogenic drugs exemplified by kava root extract]

The increasing promotion of herbal drugs may lead to allergic problems. A case of systemic contact-type dermatitis after oral administration of kava extract illustrates this special problem. The kava plant is a member of the black pepper family; an intoxicant beverage prepared from the roots of this plant is used ceremonially by many traditional societies of the Southern Pacific. The beverage induces relaxation, enhances a sense of sociability and promotes sleep. These effects are utilized in herbal drugs containing kava, which are sold for insomnia, nervousness and depression. The ichthyosiform kava dermopathy is a well-known side effect of excessive use of kava; in this case report we describe an acute allergic side-effect of kava extract.

Characteristic but unfamiliar--the cowpox infection, transmitted by a domestic cat

An 11-year-old girl had been suffering from 2 recently developed reddish ulcerated nodules on the right side of her neck and, concomitantly, from a very hard swelling as well as from painless lymphadenopathy. Subsequently, thick black eschars appeared on the surface of the ulcers. Using the negative staining technique, an orthopox virus infection could be identified by electron microscopy. The patient's characteristic history as well as her close contact with a cat frequently hunting nice indicated the diagnosis of a cowpox infection, which was unequivocally confirmed by identification of both the viral culture and specific antibodies in the serum of the patient.

[Kaposi-Irgang lupus erythematosus profundus. Lupus erythematosus panniculitis]

Lupus panniculitis is a rare variant of cutaneous lupus erythematosus. Two typical cases demonstrate the association of lupus panniculitis with signs of discoid lupus erythematosus and systemic lupus erythematosus. Clinically it is characterised by subcutaneous nodules or plaques, which may ulcerate leaving depressed atrophic scars. Histologically the lesions show lobular panniculitis. A positive immunofluorescent band test with deposition of IgG, IgM and C3 at the dermal-epidermal junction and blood vessel walls helps to confirm the diagnosis. The knowledge of the clinical features and histopathology of the disease is important because lupus panniculitis may precede systemic lupus erythematosus by some years.

Increased expression of epidermal IL-8 receptor in psoriasis. Down-regulation by FK-506 in vitro

IL-8 is a chemotactic cytokine with proinflammatory and growth-promoting activities. Recently it has been shown to influence several functions of keratinocytes, including HLA-DR expression, chemotaxis, and proliferation by binding to a specific receptor. Because psoriasis vulgaris is characterized by epidermal hyperproliferation and infiltration of inflammatory cells, we investigated the expression of IL-8 and its receptor in normal and psoriatic epidermis using semiquantitative reverse-transcriptase-polymerase chain reaction. In addition the mRNA levels of the proto-oncogenes c-ras, c-raf, c-myc, and HER-2 were also investigated as potential growth-promoting stimuli in psoriatic epidermis. IL-8 mRNA was only detected in lesional psoriatic epidermis, and IL-8R-specific mRNA was found to be 10 times increased in lesional psoriatic epidermis. There was no significant difference in the protooncogene mRNA levels. In order to test the relevance of the massively increased IL-8R levels in psoriatic epidermis, we investigated the effect of the antipsoriatic drug FK-506 on specific IL-8 and IL-8R mRNA expression. FK-506 dose dependently inhibited IL-8R expression and function. Our data suggest that in psoriatic skin, elevated IL-8 levels and markedly increased IL-8R expression may act in concert to induce the cardinal signs of psoriasis--epidermal hyperproliferation and leukocyte infiltration. IL-8R may prove a molecular target for antipsoriatic drugs such as FK-506.

Increased expression of epidermal IL-8 receptor in psoriasis. Down-regulation by FK-506 in vitro

IL-8 is a chemotactic cytokine with proinflammatory and growth-promoting activities. Recently it has been shown to influence several functions of keratinocytes, including HLA-DR expression, chemotaxis, and proliferation by binding to a specific receptor. Because psoriasis vulgaris is characterized by epidermal hyperproliferation and infiltration of inflammatory cells, we investigated the expression of IL-8 and its receptor in normal and psoriatic epidermis using semiquantitative reverse-transcriptase-polymerase chain reaction. In addition the mRNA levels of the proto-oncogenes c-ras, c-raf, c-myc, and HER-2 were also investigated as potential growth-promoting stimuli in psoriatic epidermis. IL-8 mRNA was only detected in lesional psoriatic epidermis, and IL-8R-specific mRNA was found to be 10 times increased in lesional psoriatic epidermis. There was no significant difference in the protooncogene mRNA levels. In order to test the relevance of the massively increased IL-8R levels in psoriatic epidermis, we investigated the effect of the antipsoriatic drug FK-506 on specific IL-8 and IL-8R mRNA expression. FK-506 dose dependently inhibited IL-8R expression and function. Our data suggest that in psoriatic skin, elevated IL-8 levels and markedly increased IL-8R expression may act in concert to induce the cardinal signs of psoriasis--epidermal hyperproliferation and leukocyte infiltration. IL-8R may prove a molecular target for antipsoriatic drugs such as FK-506.

Gastric carcinoma metastatic to the site of a congenital melanocytic nevus

Cutaneous metastasis from gastric carcinoma is uncommon. We describe a patient with a metastasis from gastric carcinoma to a congenital melanocytic nevus. The diagnosis was confirmed by positive immunohistochemical staining for cytokeratin 20 and lack of cytokeratin 7.

Interleukin-8 receptors in normal and psoriatic polymorphonuclear leukocytes

Polymorphonuclear leukocyte (PMNL) infiltration is an important characteristic in psoriatic lesions. The proinflammatory 8-kD peptide interleukin-8 (IL-8) is present in psoriatic scales and possesses a high chemotactic activity on human neutrophils, which may relate to its role in psoriasis. Its chemotactic activity is mediated via specific receptors on PMNL. The goal of our work was to ascertain whether PMNL infiltration in psoriasis can be accounted for by functional abnormalities of the circulating PMNL due to alterations in the IL-8 receptor density or affinity (or both). Results of radioligand binding studies performed in 10 psoriatic patients, 10 patients with atopic eczema and 11 normal controls showed no difference in receptor affinity (Kd) between the groups. However, a slight but significant elevation in IL-8 receptor density was seen on PMNL from psoriatic individuals (31,230 +/- 3,237 binding sites per cell) compared to those from normal volunteers (24,152 +/- 2,643) and atopic eczema patients (24,092 +/- 2,743). Increased number of IL-8 receptors may, besides elevated cutaneous IL-8 concentrations, contribute to the intraepidermal accumulation of PMNL in psoriasis.

[The effect of a restriction of the feed intake on the composition of the blood and on the development and composition of different tissues of sheep during growth. 2. The development of different tissues and the concentration of protein, DNA and RNA]

The concentration of protein in the cerebrum of sheep after a period of feed restriction (group 2) was lower (94.5 +/- 10.2) than in normally fed sheep of group 4 (101.4 +/- 9.4 mg/g wet weight). In the group 2 the concentration of protein in the M. longissimus dorsi and in the M. semimembranosus was also smaller. A high DNA-concentration was determined in the intestinal lymph nodes, in the spleen and in the lung. The DNA-concentration of the testes of group 2 (7.17 +/- 2.92) was higher than that of the group 4 (4.46 +/- 1.70 mg/g w. w.), also that of the renal fat tissue (0.39 +/- 0.18 resp. 0.20 +/- 0.09). The highest protein: DNA-relation in group 4 was found in the fat tissue (203.5: 1) and the lowest in the spleen (15.3: 1). A high RNA-concentration was analysed in the lymph nodes, in the spleen and in the lung. The RNA-concentration in the fat tissue of group 2 (0.34 +/- 0.13) was higher that that in group 4 (0.15 +/- 0.08 mg/g w. w.).

[The effect of a restriction of nutrient intake on the composition of the blood and on the development and composition of different tissues of sheep during growth. 1. The level of the hematocrit and hemoglobin in the blood, that of protein, alpha amino-N, remaining N, glucose, FFA, insulin, beta-hydroxybutyrate, Na, K, Ca, Mg, Pa, Fe, iron-binding capacity, Cu and Zn and the activities of ALT, AST, LDH, GGT and AP in plasma at slaughter]

In lambs after weaning with a body weight of 16.3 +/- 1.5 kg (group 1) and in sheep after a period of fattening with an increase of the body weight of 72.2 +/- 13.6 (group 2), of 184.4 +/- 12.2 (group 3) respectively of 302.1 +/- 24.3 g per day (group 4) the concentration of the components mentioned in the title was analysed in blood and plasma. The hematocrit, the concentration of Hb in the blood and that of total protein, of nonprotein-N, of Na, of Ca, of the iron-binding capacity and of Zn as well as the activity of the 5 enzymes in the plasma of the sheep of group 4 were higher than that of the group 2. Stress by the transport and stunning increased the concentration of free fatty acids in the plasma. The significance of the results for the clinical-chemical diagnosis is discussed.

Regulation of 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE) binding sites on human epidermal cells by interferon-gamma

We recently detected specific high-affinity binding sites for 12(S)-HETE, the main arachidonic acid metabolite in skin, on epidermal cells. The putative receptor is involved in keratinocyte chemotaxis toward 12(S)-HETE, which points to its participation in wound healing. In an effort to further characterize the 12(S)-HETE receptor, we investigated its regulation by various cytokines. Of the tested cytokines, only interferon (IFN)-gamma led to a massive induction of the 12(S)-HETE receptors. The effect was dose and time dependent and blocked by cycloheximide. The up-regulation of 12(S)-HETE receptors by IFN-gamma may represent an amplification mechanism of the assumed role of 12(S)-HETE in skin wound repair.

Cytotoxic T-cells and antibody-producing cells isolated from liver and spleen of immunized rats

Liver, strategically positioned within the circulation system, is a major trap for circulating tumor cells. Trapping and killing of tumor cells may be mediated by Kupffer cells and natural killer cells. In addition to these spontaneously cytotoxic cells, we isolated T-killer cells and antibody-producing cells from the liver after immunization with xenogeneic cells. Since tumor surveillance may include T-killer cells and antibody-dependent killer cells, the liver is able to attack tumor cells by "natural" and "induced" cytotoxic mechanisms.

Natural cytotoxic cells from rat liver and spleen kill human glioma cells

Natural cytotoxic cells from rat spleen and rat liver, (isolated using the collagenase method) were found to be cytotoxic against different lines of human gliomas: T406, T508, T705, HeRo, HeRoCl 1, HeRoCl 8, and HeRo-SV 7/114. After 18 h the lytic units ranged from 75 to 251 in the liver and from 5 to 24 in the spleen. Analyzing the ratio of lysis at 4 h/18 h, it may be concluded that this natural killing is predominantly macrophage (Kupffer cell)-dependent. Lysis by Kupffer cells cannot be increased by transforming glioma cells with SV40. Experiments with SV40-transformed mouse fibroblasts (3T3) and virus-transformed human cell lines (SV80) suggested a "SV40" receptor on Kupffer cells. Thus Kupffer cells have receptors for glioma cells and SV40-dependent membrane structures.

Tumoricidal cells increased by pulsating magnetic field

Repeated applications of pulsed magnetic fields (right-angle waves, 50 Hz = 135 Gauss, 2 Hz = 262 Gauss) significantly enhanced the number and the tumoricidal activity of nonparenchymal liver cells. The transplantable mouse leukemia L1210 used as a tumor model was not significantly influenced, either directly or during Cyclophosphamide treatment.

Liver as a tumor cell killing organ: Kupffer cells and natural killers

Sinusoidal rat liver cells spontaneously kill tumor cells in vitro. They have the same preferences as do spleen cells for certain types of tumor cells, YAC-1, P815, BSP73Asml, BSP73As, EB, EsB, and L5222. Metastasizing tumor cells are less sensitive than their nonmetastasizing counterparts. Not all effector cells are Kupffer cells. These nonmacrophage killer cells share some features with classical natural killers: (a) fast reactions (4 h); (b) high toxicity against YAC-1 cells; (c) sensitivity to anti-asialo GM1 globulin; (d) similar age dependency; (e) short biological halflife (approximately 1 day) (deduced from radiation experiments); (b) silica particle insensitivity; and (g) nonadherence. The natural killing potency of the liver is higher than that of the spleen. The reduction of tumoricidal capacity of the liver in germ-free animals suggests environmental influences. Tumoricidal capacity (organ capacity) is increased in rats chronically fed thioacetamide, carbon tetrachloride (CC14), dimethylaminoazobenzene, and N-nitrosomorpholin.

New ways in counselling on prenatally diagnosed congenital malformations. An experimental information project using Bildschirmtext/Videotex

A bibliometric analysis of source items recently published in German-language gynaecology journals and one German-language journal covering a broader field of medicine yielded but one publication linked with prenatally diagnosed congenital malformations and their surgical treatment. Thus, journals usually assessed by the gynaecologist are in this respect at present not a useful source of information for the practitioner outside specialised centres. In order to explore the usefulness of Bildschirmtext (BTX, Videotex), a new electronic medium, as an alternative in counselling for congenital malformations and similar rare medical problems, an experimental database was constructed. Pages giving data on diagnostic pathways, incidence, prognosis, specialised treatment centres and suggested further reading on abdominal wall defects were compiled and are stored in a central computer of the German Federal Postal Services. Data are accessible via the regular telephone network and a specially equipped TV set. The method, although still experimental, is considered useful for offering medical intelligence to the medical professional outside specialised centres.

Tumor cells adhere to intraperitoneal injection sites

Tumor cells injected intraperitoneally form cell plaques at injection sites in the abdominal wall of mice within a few minutes. Tumor cells appear to be transported passively and chemotactic factors are not involved. Dihydrocortisol blocks cell adherence and silica particles , assumed to destroy macrophages, abolish cell plaque formation.

Liver as a tumor-cell-killing organ

Lymphoma cells (Eb and ESb, the metastasizing variant) were injected via a mesenteric vein. 85% to 95% of these cells were trapped in the liver. Most of the Eb cells (81%) were destroyed within 18 hours, ESb cells prove to be more resistant: only 28% of these cells were destroyed within this time. 51-Chromium release assay (4 hours) revealed a similar sensitivity of these two tumor cell strains.

Studies on intravascular phagocytosis in the lung

In this paper we have shown for the first time endocytosis by intravascular lung phagocytes. Glutaraldehyde-treated erythrocytes (discocytes) homed rapidly to the rat lung as measured by scintigraphic procedures. Transmission and scanning electron microscopy showed that the discocytes are phagocytosed by macrophages, blood monocytes and granulocytes as whole cells. This process could not be inhibited by silica treatment.

Kupffer cells recognize trinitrobenzene-labeled erythrocytes

Chemical-modified erythrocytes (trinitrobenzene-modified erythrocytes (TNB-RBC)) are trapped in vivo rapidly by liver macrophages (Kupffer cells). The liver homing of TNB-RBC is dependent on the concentration of TNB-residues coupled to the surface of RBC. High concentrations induce liver homing, low concentrations spleen homing.

Lectin mediates homing of sialidase-treated erythrocytes of the liver as revealed by scintigraphy

Mammalian erythrocytes loose their normal circulatory pattern following desialylation by sialidase and are trapped in the liver. The mechanism responsible for this phenomenon has been studied by a new scintigraphic method. We report here that the retention of asialo-erythrocytes in the liver is due to the interaction between a lectin-like receptor on Kupffer cells and terminal D-galactosyl residues exposed on erythrocytes after sialidase treatment. The major findings supporting the conclusion are: First, kinetics of asialo-erythrocyte accumulation in the liver are identical in conventional and germfree animals, demonstrating that the presence of serum antibody is not essential. Second, trapping of asialo-erythrocytes can be substantially inhibited by intravenous injection of N-acetyl-D-galactosamine or galactosylated bovine serum albumin, other saccharides or glycoproteins are less or not at all effective. This specificity pattern is characteristic for the D-galactose-specific lectin on Kupffer cells. It therefore appears that the retention of sialidase-treated erythrocytes in the liver is lectin- and not antibody mediated.

Studies of erythrocyte sequestration. I. Spleen homing of heat altered erythrocytes

Heat altered erythrocytes are taken up by spleen macrophages without any signs of mechanical strain as revealed by light and scanning electron microscopy. There was no scintigraphic evidence for changed flow rates within the spleen after sequestration of erythrocytes.

Liver homing in the rat of 111Indium labelled beef and neuraminidase-treated rat erythrocytes (studies with a gamma camera)

The rate of liver homing of 111In-labelled erythrocytes has been measured under a Gamma Camera. Homing of neuraminidase-treated or xenogeneic erythrocytes is delayed by preinjection of glycolipids or glycopeptides.