A new form of amyloid protein associated with chronic hemodialysis was identified as beta 2-microglobulin

Amyloid fibrils were isolated from amyloid-laden tissue obtained from a chronic hemodialysis patient with carpal tunnel syndrome. After solubilization in guanidine HCl, a significant amount of the protein was located in a homogeneous low molecular weight fraction. The protein was found to be identical to beta 2-microglobulin, with regard to its molecular weight of 11,000, amino acid composition and 16 amino-terminal amino acids: Ile-Gln-Arg-Thr-Pro-Lys-Ile-Gln-Val-Tyr-Ser-Arg-His-Pro-Ala-Glu-. These results demonstrate that the amyloid associated with chronic hemodialysis contains as major component a new form of amyloid fibril protein that is homologous to beta 2-microglobulin.     

Non-equivalent natures of the coordinated imidazole rings of cytochrome c3 from D. vulgaris Miyazaki F as studied by 1H NMR.

All of the C2 proton signals of the coordinated histidine residues in the 1H NMR spectrum of cytochrome c3 from D. vulgaris Miyazaki F were assigned by specific deuteration. They appeared at extremely high fields and scattered in a wide range from -4 to -22 ppm. This clearly shows that the chemical properties of the imidazole groups are quite different from one another. The extremely high-field shift of the C2 signal indicates that some of them must carry the imidazolate-like nature to some extent. This might be responsible for the extremely low redox potentials of the four hemes. On changing temperature, most of them showed Curie-type change. All of the C2 signals showed a small p2H dependence in the range of p2H 4.8-10.0.     

Gibberellin induces endopeptidase activity in detached cotyledons of Pisum sativum

Endopeptidase activity in cotyledons of 5-day seedlings of Pisum sativum increased rapidly during germination. However, the increase of the activity in detached cotyledons was depressed. We examined whether a growth regulator can be substituted for the embryonic axis on the development of endopeptidase activity. As monitored by an assay with azoalbumin, the development of endopeptidase activity from crude extracts of detached cotyledons appeared to be slightly accelerated by incubation with 10^–5 M GA₃. However, the pattern after gelatin-polyacrylamide gel suggested that the activity induced in detached cotyledons during a 5-d incubation at 10^–7 M GA₃ was the same as that in attached ones during germination for 5 days and an even greater increase in activity was obtained with 10^–5 M GA₃. These results suggest that GA₃ from the embryonic axis induces endopeptidase activity in attached cotyledons at the first stage of germination.Abbreviations ABA abscisic acid - IAA indole-3-acetic acid - GA gibberellic acid     

Protection against metastasis by immunization with an allogeneic lymphocyte antigen

Q5 antigens are expressed on the surface of various experimental murine tumor cells. They share partially common antigenicity with Qa-2 alloantigens expressed on normal lymphocytes. For that reason we tested the immunoprotection by anti-Qa-2 immunization of mice against a Q5+ tumor. Nerve fibrosarcoma (NSFA) tumor, which specifically develops metastasis in the lung, has been reported to be poorly immunogenic. However, expression of the Q5 antigen was evident on the surface of NFSA cells. After immunizing (C3H/He x B6.K1)F1 (Qa-2-) mice with B6 (Qa-2+) lymphocytes, the protection against the proliferation of the semi-syngeneic NFSA tumor was examined First, immunization of normal mice induced resistance to NFSA cell transplants. Second, when the tumor cells were transplanted to the hind foot of a mouse and the resulting tumor was removed by amputating the leg, the mice were protected against the development of lung metastasis after immunization by intraperitoneal inoculation of B6 cells 3 days after tumor removal. Immunization with attenuated NFSA cells in this system failed to protect the mice from lung metastasis. On the other hand, inoculation of the mice with B6 cells without removal of the original tumor on the foot showed little effect on the progression of the tumor. Thus, cytotoxic T lymphocytes (CTL), which seemed to be present in an inactive form in the mice from which the tumor had not been removed, were induced in the mice after the removal of the major tumor followed by immunization with B6 lymphocytes. The induction of CTL by the immunization was suppressed in mice bearing large tumors. Cells stimulated by the tumor antigen seemed to be involved in the suppression. It was also shown that the Q5 antigen is the direct recognition target of the CTL since the activity of Q5-specific CTL clones in lysing tumor cells was inhibited by a monoclonal antibody specific for the Q5 antigen. In contrast to immunization with attenuated tumor cells, our novel allogeneic lymphocyte immunization procedure offers high CTL activation, by-passing the induction of T cell unresponsiveness.     

WBN/Kob-Ht Rats Spontaneously Develop Dermatitis under Conventional Conditions: Another Possible Model for Atopic Dermatitis.

WBN/Kob-Ht rats (Ht-rats) raised under conventional conditions spontaneously developed dermatitis. In this study, we carried out histopathological analysis to elucidate the pathological features of the dermatitis in Ht-rats. We then tried to detect Staphylococcus species recovered from the skin lesions of Ht-rats. We also measured the serum levels of total IgE, IL-4 and IFN-gamma in these rats. The histopathological data indicated that inflammatory cells had infiltrated the skin lesions. Staphylococcus aureus was recovered from the skin lesions, and the serum levels of total IgE and IL-4 were elevated in Ht-rats with dermatitis. These results suggest that dermatitis in Ht-rats is similar to that in the DS-Nh mice, which has recently been proposed as an animal model for human atopic dermatitis.     

Auxins induce alpha-amylase activity in pea cotyledons

The report documents how the development of α-amylase activity in detached cotyledons of Pisum sativum cv Alaska is accelerated 2- to 12-fold during incubation with 1 micromolar to 10 micromolar 2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, or with 4-chloroindoleacetic acid, an endogenous auxin from Pisum sativum. It seems probable that auxin from the embryonic axis induces α-amylase in the attached cotyledons during germination.     

The alkaline phospholipase A1 of rat liver cytosol.

1. Rat liver cytosol contains a heat-sensitive phospholipase A1 active against phosphatidylethanolamine, 1-acylglycerophosphoethanolamine and, to a very much lesser extent, phosphatidylcholine and phosphatidylinositol. 2. Activity towards a pure phosphatidylethanolamine substrate is invoked by the presence of water-soluble cations that do not precipitate at the pH optimum of the enzyme (9.5). In this activation bivalent cations, e.g. Mg2+, Ca2+, Mn2+, Sr2+ and Ba2+, are effective at much lower concentrations (2.5-5 mM) than univalent cations K+, Na+ and NH4+ (100 mM). 3. In the absence of such cations the enzyme can be activated by cationic amphiphiles containing quaternary nitrogen or by basic proteins. 4. It is concluded that these agents activate the enzyme by reducing the negative zeta potential on the substrate at the high pH optimum (9.5) and allow interaction with the enzyme whose isoelectric point is at 7.15. 5. The activated enzyme is markedly inhibited by mixing the phosphatidylethanolamine substrate with many other phospholipids that exist in cell membranes, e.g. phosphatidylcholine, phosphatidylinositol. On the other hand, both phosphatidylcholine and phosphatidylinositol can be hydrolysed much more readily if they are mixed with an excess of phosphatidylethanolamine. 6. Such results on the inhibition and substrate specificity of the enzyme, coupled with birefringence measurements, allow the tentative conclusion that phospholipid substrates are only attacked when they exist in a hexagonal or non-bilayer structure and not in the bilayer (lamellar) form.     

Cerebrospinal fluid and plasma corticotropin-releasing hormone in senile dementia.

Cerebrospinal fluid (CSF) levels of corticotropin-releasing hormone (CRH) and ACTH, and plasma levels of CRH, ACTH and cortisol were determined in samples taken simultaneously from 28 patients with dementia including senile dementia of the Alzheimer type (SDAT), multi-infarct dementia (MID), dementia following a cerebrovascular accident (CVD), and the borderline-to-normal state. CRH levels in CSF were significantly reduced in patients with SDAT and CVD, but not in those with MID, as compared with the borderline cases. ACTH levels in CSF were significantly reduced in the patients with SDAT compared to those with MID. Reduced CRH levels in CSF were found in the patients who showed severe dementia and poor activities of daily living (ADL). Plasma levels of CRH, ACTH and cortisol were normal and were not significantly different among the four groups of patients. CRH levels in CSF were positively correlated with ACTH levels in CSF, but not with the levels of plasma CRH, ACTH or cortisol. Plasma CRH levels were positively correlated with plasma ACTH levels. These results suggest that: 1) abnormalities in the extrahypothalamic CRH system play a role in the pathophysiology of senile dementia, which may not be specific to SDAT; 2) CSF CRH is correlated with the severity of dementia and ADL; 3) the levels of CRH in CSF and plasma are independent, and 4) the plasma CRH reflects, at least in part, the activity of the hypothalamic CRH regulating the secretion of pituitary ACTH.     

Novel epoxysuccinyl peptides Selective inhibitors of cathepsin B, in vitro

A series of new epoxysuccinyl peptides were designed and synthesized to develop a specific inhibitor of cathepsin B. Of these compounds, N-(L-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-isoleucyl-L-proline (compound CA-030) and N-(L-3-trans-propylcarbamoyloxirane-2-carbonyl)-L-isoleucyl-L-proline (compound CA-074) were the most potent and specific inhibitors of cathepsin B in vitro. The carboxyl group of proline and the ethyl ester group or n-propylamide group in the oxirane ring were necessary, the ethyl ester group or the n-propylamide group being particularly effective for distinguishing cathepsin B from other cysteine proteinases such as cathepsins L and H, and calpains.