Protection of liver cells from experimentally induced liver cell injury by glycyrrhizin

Liver cell damage is induced when isolated liver cells coated with specific antibody against the liver cell membrane are cultured with peripheral blood mononuclear cells. Although this antibody-dependent cell-mediated cytotoxicity (ADCC) was induced by closed contact of effector cells with targets via specific antibody, a cytotoxic factor or factors causing inhibition of protein synthesis in liver cells was detected in the culture supernatant of the ADCC reaction. Similarly, peritoneal exudate macrophages activated by endotoxin lipopolysaccharide (LPS) also had cytotoxic effects on isolated liver cells by producing a cytotoxic substance or substances. These liver cell injuries caused by either ADCC or activated macrophage culture supernatants were significantly reduced by pretreatment of the isolated liver cells with glycyrrhizin before the addition of the cytotoxic culture supernatants. These results suggest that glycyrrhizin may protect liver cells from immunological injuries.

Coronary spasm and allergy. Retrospective study of the incidence of allergic history in patients with variant angina

Despite a large number of papers concerning coronary spasm, its mechanism still remains unsolved. Several cases have been reported in which coronary spasm was triggered by allergy. Since histamine is one of the causative substances released in allergic reactions, we speculated on some involvement of an allergic mechanism in the pathogenesis of coronary spasm. We retrospectively examined by questionnaire the incidence of allergic history in patients with variant angina (n = 47) and compared it with that in patients with non-ischemic heart diseases (n = 83). We could not find any relationship between coronary spasm and allergy. Furthermore, we have not experienced any case in which myocardial ischemia was provoked by an allergic reaction. Accordingly, allergy could not be a major cause of coronary spasm in our present experience.

Sectional prostheses connected by samarium-cobalt magnets

Large acquired defects with undercuts can be restored with sectional prostheses. Sections of the prosthesis can be connected with small Sm-Co magnet pairs. The advantages of Sm-Co magnets are that (1) sections of prostheses can be connected by magnets less than 1 cm in size, (2) they can be embedded in thin sections of acrylic resin, (3) they are easy to place, (4) insertion is easy (magnetic attraction enhances), (5) hollow obturators can be used, and (6) tissue undercuts can be used for additional retention of prostheses.

Identification of the minimal essential region for the replication origin of miniF plasmid

The minimal replication origin of miniF plasmid was found to lie within a region of 217 bp in length. This region contains an AT cluster and the four 19 bp direct repeats responsible for incompatibility, termed incB. Its location coincides with hat of ori2 of plasmid F, previously inferred to be the replication starting point by electron microscopic analysis (Eichenlaub et al. 1981).

Modulation of cholestatic factor production by serum components

When lymph node cells from sensitized guinea pigs were stimulated in vitro with a specific antigen and their culture supernatant was injected into the mesenteric vein of rats, a marked decrease in bile flow was demonstrated. The treatment of activated lymphocytes with a higher molecular weight fraction of normal human serum Fr-1 and Fr-2 was shown to decrease the reduction of bile flow. Conversely, a lower molecular weight fraction of serum (Fr-3) was found to augment the reduction of bile flow. These findings suggest that the serum components may regulate the production of a factor (or factors) causing the decrease in bile flow from the activated lymphocytes.

Lipid peroxide formation in isolated hepatocytes by cytotoxic factors produced from lymphokine-activated macrophages

When peripheral blood lymphocytes from patients with chronic active hepatitis were stimulated with liver specific lipoprotein (LSP), considerably higher frequencies of lymphocyte transformation and MIF production were induced. Peritoneal macrophages from guinea pigs were activated by lymphokine-containing lymphocyte culture supernatant and produced a cytotoxic (or cytostatic) factor acting on isolated hepatocytes in culture. The cytotoxic (or cytostatic) factor, which was fractionated by Sephadex G-75 column gel filtration followed by DEAE-cellulose column chromatography, had cytotoxic effect on isolated liver cells and produced a significant amount of lipid peroxide. These results suggested the possibility that the cytotoxic effects may be caused at least partially by the lipid peroxide formation.

Role of nine repeating sequences of the mini-F genome for expression of F-specific incompatibility phenotype and copy number control

An autonomously replicating 2,248-base-pair DNA segment of the mini-F plasmid carries nine 19-base-pair repeating sequences. Five of the repeats are arranged in one direction and form the right cluster, whereas the remaining four repeats are arranged in the opposite direction and form the left cluster (Murotsu et al., Gene 15:257-271, 1981). Each cluster, cloned separately into the multicopy plasmid vector pBR322, exhibited a strong F-specific incompatibility phenotype (FIP). These clusters were thought to be responsible for the expression of IncB and IncC phenotypes, causing a switchoff function on mini-F replication. Mini-F DNA fragments containing two, three, or more than four repeats were inserted into pBR322. Cells carrying these recombinant plasmids exhibited, respectively, no, intermediate, and strong FIP intensity. Cloning of five repeats into pSC101, whose copy number is about 6 in contrast to 20 for pBR322, resulted in an FIP of intermediate intensity. Thus, the intensity of FIP reflects the dosage of repeats in a cell. The five repeats in the right cluster were eliminated from the mini-F derivative without impairing its autonomous-replicating ability (Bergquist et al., J. Bacteriol. 147:888-889, 1981; Kline and Palchavdhuri, Plasmid 4:281-289). Such deletion, however, caused a sixfold elevation of the copy number. When the eliminated cluster of repeats was reinserted in the derivative, the copy number was lowered to the original value, viz., 1 to 2. The position and orientation of this insertion was not important in the copy number control. Thus, the repeats are also related to copy number control. A model to account for the role of the repeating sequences in the control of copy number and FIP is discussed.

Modulation of the macrophage hepatocytotoxicity and plasminogen activator activity of activated macrophages from guinea pigs by serum components from normal human and patients with liver diseases

Activated macrophages (m phi) exhibited cytotoxic effects on isolated liver cells and produced plasminogen activator (PA) in vitro. A high molecular weight fraction of normal human serum (Fr-1) was shown to reduce the m phi-mediated hepatocytotoxicity and enhance the PA activity of activated m phi. Conversely, a lower molecular weight fraction of serum (Fr-3) was found to enhance the hepatotoxic potential and decrease the PA activity of activated m phi. Although similar effects were seen with serum fraction prepared from patients with acute hepatitis, somewhat different influences were observed with serum components from patients with chronic active hepatitis or liver cirrhosis: Fr-1 from patients with chronic active hepatitis was less active in reducing m phi-mediated hepatocytotoxicity, and and Fr-3 was more active in enhancing it, in comparison with fractions from individuals or patients with active hepatitis. Fr-3 from patients with liver cirrhosis was shown to be remarkably less active in enhancing m phi-mediated hepatocytotoxicity. Furthermore, Fr-1 from patients with liver cirrhosis reduced PA activity, Fr-3 was less active in decreasing such activity. These findings suggest that the serum components may regulate m phi-mediated hepatocytotoxicity as well as PA secretion of activated m phi. Our studies also suggested the possibility that relative doses of these serum components may differ in various pathological conditions of the liver.

Induction of liver cell injury by antibody-dependent monocyte-mediated cytotoxicity in vitro

The isolated liver cells coated with the anti-liver cell membrane antibody were damaged by incubation with the peripheral blood mononuclear cells. This was demonstrated by measuring the reduction of protein synthesis in the target liver cells. Adherent cells from the peripheral blood mononuclear cells were shown to have a sufficient capacity acting on the isolated liver cells as an effector when they were separated from the peripheral blood of normal and patients with acute or chronic active hepatitis. However, those from patients with liver cirrhosis or hepatoma did not show such effector activity in antibody-dependent cell-mediated liver cell damage. These results suggest that possibly antibody-dependent macrophage-mediated cytotoxicity may play some role in the induction of liver cell injury because the anti-hepatocyte membrane antibody is frequently detected in patient's sera, especially in those with chronic active hepatitis.

Studies on the mechanism of liver injury by macrophage-mediated cytotoxicity--partial purification of cytotoxic factor detected in the culture supernatant of activated macrophages

The culture supernatant of activated lymphocytes was shown to contain macrophage activating factor (MAF), a kind of lymphokine, which activated the peritoneal macrophages prepared from guinea pigs. When the culture fluid of the MAF-activated macrophages was added to the isolated liver cells, a significant inhibition of their albumin biosynthesis was demonstrated. The active material was recovered in a definitive fraction by gel filtration using a Sephadex G-75 column and this was further fractionated into two fractions by DEAE-cellulose column chromatography, suggesting that at least two kinds of active substances existed. By isoelectric focusing electrophoresis it was shown that these two active principles were substances having different isoelectric points, by isoelectric focusing electrophoresis. These results suggest that some cytotoxic or cytostatic materials are produced from the lymphokine-activated macrophages and they may participate in the occurrence of liver injury at least partially.

Role of the nongravid part of the uterus in the regulation of corpus luteum function in pregnant rats

The effect of the nongravid part of the uterus on corpus luteum (CL) activity was studied in rats bearing a single conceptus during midpregnancy. On day 7 (day 1 = insemination), the number of conceptuses was reduced to one by aspirating all but one conceptus (the aspiration group), by removing all of of the uterus except that containing a single conceptus (the hysterectomy group), or by aspirating conceptuses, as in the aspiration group, plus ligating the uterus, as in the hysterectomy group, but without removing the uterus (the sham hysterectomy group). Rats with a full complement of conceptuses (the intact control group) served as additional controls. Blood samples were obtained on days, 10, 12, and 15, to determine the effects of these procedures on the increase in serum progesterone that normally occurs between days 12 and 15 and to observe any related changes in serum LH between days 10 and 15. On day 15, the mean serum prgesterone concentrations and weights of the CL in the aspiration and sham hysterectomy groups were significantly lower than those in the intact control group. In the hysterectomy group, however, serum progesterone was even higher than in the intact control group, although the CL were significantly smaller than in the intact control group and were not different from those in the aspiration or sham hysterectomy groups. Serum LH on day 10 was significantly lower in the hysterectomy group than in any of the other groups; the latter were not significantly different from each other. By day 15, serum LH in the intact group had fallen to less than 50% of the value on day 10, while in the aspiration group, it remained as high as on day 10. In the hysterectomy group, there was no significant difference in serum LH concentrations between days 10 and 15. These results suggest that the nongravid part of the uterus inhibits progesterone secretion, and that in its absence, even a single conceptus can increase progesterone secretion after day 12 as much as can a full complement of conceptuses, but without also increasing the size of the CL. The uterus may exert this effect either through the pituitary or in cooperation with a pituitary factor, possibly LH.

Value of tumor-antigen (TA-4) of squamous cell carcinoma in predicting the extent of cervical cancer

The value of a tumor-antigen (TA-4) of squamous cell carcinoma in evaluating the extent of disease was studied in patients who primarily had surgical treatments with a diagnosis of cervical squamous cell carcinoma. Pretreatment serum TA-4 levels were determined by a radioimmunoassay method. The extent of disease was determined by surgical evaluation and postoperative histologic examinations. Furthermore, all patients were followed for at least two years, and those patients who developed recurrence at the sites which were unresectable by radical hysterectomy were retrospectively regarded as the unresectable case. It was found that serum TA-4 levels reflected the extent of disease, and that high pretreatment TA-4 levels indicated the presence of the widespread tumor which was unresectable by radical hysterectomy.

Construction of a composite thin-element TLD using an optical-heating method

A composite thermoluminescent dosimeter (TLD), composed of four, thin TL elements with a high-speed reader, has been developed by employing an optical-heating method. Each TL element, which is 15 mg/cm2 thick with a 3 mm dia., is prepared by applying Li2B4O7:Cu or CaSO4:Tm to a plastic substrate 14 mg/cm2 thick. Each element can be heated to 350 degree C within 0.8 sec. by IR radiation from a tungsten lamp. The characteristics of this TLD system include the following: (1) the detection limit of the Li2B4O7:Cu is 3 mR and the limit for CaSO4:Tm is 0.1 mR; (2) the energy-dependence curves are similar to the dose-equivalent curve, showing slight under-responses by 15% near 70 KeV for Li2B4O7:Cu and over-responses by 50% at high energies for CaSO4:Tm; (3) despite quick heating, the residual dose is as low as 0.1% of the last exposure signal; (4) responses are very stable for more than 1,000 cycles of repeated exposure readings; (5) no false signal could be detected, even in the cases of sweat or soil contamination; (6) the thin Li2B4O7;Cu element can be used for skin dose monitoring; and (7) the processing time of the automatic reader for the composite dosimeter is 3 hr/500 dosimeters. This TLD system can be applied to personnel dosimetry, gate monitoring and environmental monitoring.

[The double contrast hysterography using CO2 insufflation (author's transl)]

The double contrast hysterography, which was performed by the continuous CO2 insufflation with the ordinary HSG, was applied to 162 infertile patients. Forty-nine of 162 patients showed the abnormal findings by this method. Hysteroscopic or histological examinations revealed that 26 of these patients had hyperplasia, 15 had polyp, 2 had myoma and 1 had intrauterine foreign body. When these results were compared with those obtained by ordinary HSG, it was found that the double contrast hysterography would be more useful to investigate the detailed intrauterine changes such as hyperplasia or polyp than the ordinary HSG, and, therefore, would be a useful aid in the clinical care.

Cytotoxicity of Pd-Co dental casting ferromagnetic alloys

The biocompatibility of three kinds of Pd-Co dental casting ferromagnetic alloys was assessed in a toxicity test in vitro. The test showed that the Pd-Co binary alloy may have weak cytotoxicity, while the Pd-Co-Cr and Pd-Co-Ni ternary alloys may be less cytotoxic. The Pd-Co-Ni alloy was least cytotoxic of the three.

Replication control and switch-off function as observed with a mini-F factor plasmid

Mini-F is a fragment of the F plasmid, consisting of 9,000 base pairs, which carries all of the genes and sites required for replicon maintenance and control. Its copy number is one to two per chromosome. This plasmid is joined to ColE1, whose copy number is 16 to 20. Under normal circumstances the composite plasmid replication exhibited ColE1 characteristics, maintaining a high copy number. However, when ColE1 replication was inhibited by deoxyribonucleic acid polymerase I inactivation, its replication exhibited mini-F characteristics, maintaining a low copy number. These observations are in complete agreement with those of Timmis et al. (Proc. Natl. Acad. Sci. U.S.A. 71:4556-4560, 1974), who examined the behavior of a recombinant plasmid formed between pSC101 and ColE1. The transition from high to low copy number allowed us to examine the control system acting in cells carrying plasmids exhibiting intermediate copy numbers. The initiation of the mini-F replication system as represented by deoxyribonucleic acid synthesis of the composite plasmid was completely blocked when there were multiple copies of mini-F in a cell. It was not restored until the copy number was lowered to one to two, after which replication was first detected. ppF, a mini-F replicon packaged in a phage lambda head behaved similarly: its replication was completely shut off when the resident mini-F genome copy number was high and was inhibited partially when the resident mini-F genome copy number was low. These experiments clearly demonstrate that there is a switch-off mechanism acting on deoxyribonucleic acid synthesis (initiation) in a cell carrying mini-F, and its intensity is related to the plasmid copy number. This result supports the "inhibitor dilution model" proposed by Pritchard et al. (Symp. Soc. Gen. Microbiol. 19:263-297, 1969). The nature of the hypothetical inhibitor is discussed.

Pd-Co dental casting ferromagnetic alloys

Three kinds of Pd-Co alloys have been newly developed. Their magnetic and physical properties and corrosion resistances have been examined. As a result, it was found that they are available as the dental casting ferromagnetic alloy which can be used in combination with Sm-Co magnets, overcoming such problems as non-castability and brittleness.

Studies on the Sm-Co magnet as a dental material

The Sm-Co magnet has superior and convenient magnetic properties as compared with conventional ones used hitherto in prosthesis, and even very small pieces can provide the force necessary in dentistry. Also, the magnet has high corrosion resistance and is innocuous to tissues. Therefore, it can be used as a dental material, overcoming the limitations in past applications.