Inhibition of in vitro granulopoiesis by autologous allogeneic human NK cells

This study demonstrates the ability of human NK cells to inhibit in vitro granulopoiesis of autologous and allogeneic BM cells. NK lytic activity and GM-CFC inhibition was present among nonstimulated lymphocytes from healthy donors and could be increased by treatment of PBL with IFN. Both the cytotoxic NK cells and the GM-CFC inhibitory cells could be enriched for among nonadherent, low-density cells. High-density cells were not cytotoxic, only inhibitory to a small extent, and could become neither cytotoxic nor more inhibitory after IFN treatment. In contrast, low-density cells showed an increased cytotoxic and GM-CFC inhibitory capacity after IFN treatment. The NK mediated GM-CFC inhibition was dependent on cell contact with BM cells, increased with longer preincubation times, and was most efficient against 7-day GM-CFC as compared with 14 day GM-CFC progenitors. In conclusion, these data provide new information about the human NK cell as a potent inhibitor of in vitro granulopoiesis and also as a possible regulator of hematopoiesis in vivo.     

The effects of parasitic water mite larvae (Arrenurus spp.) on zygopteran imagoes (Odonata)

Arrenurus larvae, ectoparasitic on zygopteran imagoes, attach to the host's cuticle and tear it to obtain the host's tissue fluids. Within the host's epidermis, each larval mite produces a feeding device, the stylostome, a narrow gelatinous resilient blind sac. Heavy mite infestation brings about several wounds in close proximity, accompanied by loss of more or less extensive areas of the epidermis. Despite wound repair by congregating hemocytes, local lack of epidermis seems to enfeeble the host, presumably owing to desiccation. Heavily mite-loaded zygopterans have lost the typical agility and are easily caught. A mite-induced mortality seems to exist in zygopteran populations; the infestation contributes to reduced longevity. The study of formation and decline of the arrenurid stylostome in zygopterans renders it possible to trace cellular defence reactions under natural conditions. Most stylostomes seem to thwart the ability of the host to recognize them as foreign bodies. The host's defence appears as a two-step reaction: (1) initial hemolymph clotting and deposition of melanin associated with aggregating hemocytes at the penetration site, (2) occasional subsequent melanization and cellular encapsulation of the stylostome.     

A Comparison of the Polypeptide Pattern Between a Brain Primary Culture and Fractions of Bulk-Isolated Glial Cells

Abstract: This paper reports on the electrophoretic protein/polypeptide pattern of a rat brain primary culture. For comparison, the polypeptide pattern of neuronal and glial enriched fractions from adult rat brain and cerebral hemispheres from newborn and adult rat have been analysed. Water-soluble and SDS-extractable polypeptide fractions appeared and/or increased in amount in the cultures until confluency. The polypeptide pattern of the cultures most resembled that of the glial cell fractions, showing some of this fraction's specificity. Removal of fetal calf serum and addition of 0.1 mM dibutyryl cyclic adenosine monophosphate (dB-cAMP) produced few changes in the electrophoretic pattern. The study thus provides evidence in favour of the astroglial nature of the brain primary culture. It also shows that the cells undergo some maturation in the culture.     

Sterols and steryl esters in some Brassica and Sinapis seeds

The qualitative and quantitative composition of sterols in the free form and esterified to fatty acids was studied in seed oils from Brassica napus, B. campestris, B..iuncea, B. nigra, Sinapis alba and S. aruefisis (Brassica kaber). Sitosterol, followed by campesterol, predominated in both the free and the esterified sterols. The free sterols were richer in brassicasterol (ca 10–20%) than the steryl esters (3–10%). Small amounts of δ⁵-avenasterol and δ⁷-stigmastenol were also found in the Brassica oils, often more in the esterified than in the free form. The quantity of sterols was studied only in Brassica campestris, which had ca 0.3 % in the free as well as in the esterified form. In Sinapis alba, ca 10% of the sterols in the free form and 20 % in the esterified sterols were δ⁵-avenasterol. This compared to only a few per cent in both the free and esterified sterols in the Brassica oils. Similarly, ca 2 % of cholesterol was found among the sterols of Sinapis alba but only traces in the Brassica oils. The similarity of sterol compositions among the cultivated brassicas and wild mustard (Sinapis arvensis), and the specific characteristics of the sterols in white mustard (Sinapis alba) adds further weight to the suggestion that wild mustard should be treated as Brassica kaber and strengthens the generic separation of Sinapis alba.     

Prostaglandins and thromboxanes in amniotic fluid during rivanol-induced abortion and labour

Abortion or delivery were induced by extra-amniotic instillation of Rivanol during the second trimester in twelve patients and during the third trimester in two patients with fetal death and one patient with fetal acrania. Serial sampling of amniotic fluid was performed through a transabdominal catheter and the levels of free arachidonic acid (AA), prostaglandin F₂α (PGF₂α), prostaglandin E₂ (PGE₂), 6-keto-prostaglandin F₁α (6-keto-PGF₁α) and thromboxane B₂ (TXB₂) were determined. The levels of AA, PGF₂α, PGE₂, 6-keto-PGF₁α and TXB₂ in amniotic fluid increased significantly during induction with the exception of AA in fetal death which was high and remained constant during induction. Furthermore, PGF₂α, 6-keto-PGF₁α and TXB₂ were all significantly correlated to AA.These observations suggested that free AA is released during Rivanol-induction of abortion and labour giving an increased synthesis of PGF₂α, PGE₂ prostacyclin and thromboxane A₂ in the fetal membranes and the decidua but not in the fetus. This increase might be relevant for the initiation and progress of abortion and labour in these patients.     

Effect of polyamine on microsomal cytochrome P-450 stimulation of rate and improved coupling of NADPH oxidation to hydroxylation

Elastase-type activities were found associated with lipoprotein fractions in human serum. A metallo-protease hydrolysing Suc(Ala)₃ PNA and soluble elastin peptides was isolated from apoHDL by Sepharose-elastin chromatography. Polyacrylamide gel electrophoresis and immunoelectrophoresis indicated that this elastase-type activity was associated with apoA₁.     

Perchlorate binding to cytochrome c: a magnetic and optical study

1. The effects of perchlorate on cytochrome c have been investigated by 1H and 35Cl NMR, electron paramagnetic resonance and optical spectroscopy. 2. The pK values for the formation and disappearance of the major alkaline conformation were found to be displaced from 9.3 to 8.3 and from 10.4 to 10.9, respectively. The displacement was dependent on the ClO4(-) concentration below 0.1 M. 3. Competition experiments between perchlorate and chloride show that ClO4(-) binds both to the neutral and alkaline forms but with a higher affinity for the latter. The appearance of a new binding site in the alkaline form accounts for the markedly enhanced relaxation rate of 35ClO4(-) in this pH range. Complex formation between cyanide and the alkaline species results in the loss of this binding site, which probably is located close to or within the heme crevice. 4. The neutral form of ferricytochrome c also binds perchlorate strongly as evidence by the unique appearance of a high-spin signal dependent on pH and perchlorate concentration. This signal disappears with the same pK value as the neutral form. The effects of perchlorate on cytochrome c are due to specific binding of this ion.     

Digestion and absorption of trioleoyl-thioglycerol in the rat

A triacylglycerol analogue, rac-1,2-di-O-oleoyl-3-S-oleoyl-3-thioglycerol, was fed to rats and chyle acylglycerols were analyzed. Triacylglycerol was the dominating chyle lipid but X-triacyl-1-thioglycerol constituted approx. 6% of total chyle lipids. Its identity was verified by ultraviolet and mass spectra and its stereochemical structure by ORD and CD. The proportions of triacyl-1-thio-sn-glycerol/triacyl-3-thio-sn-glycerol were $\text{63}\text{37}$ and $\text{78}\text{22}$ in two experiments. Possible reasons for this stereospecificity are discussed. The study shows that the stereochemical configuration of lipids isolated from biological material can be assessed by ORD and CD.