Purification of a receptor for formaldehyde-treated serum albumin from rat liver

A membrane-associated receptor involved in a specific uptake of formaldehyde-treated serum albumin (f-Alb) was purified from rat livers by Triton X-100 solubilization of a 105,000 X g membrane preparation and affinity chromatography on an f-Alb-Sepharose column. The purified receptor exhibited Mr = 125,000, consisting of two noncovalently linked glycoprotein components with Mr = 53,000 and Mr = 30,000, respectively. Incubation of 125I-receptor with f-Alb, but not with native albumin, resulted in a marked shift of pI value from 5.9 to 5.1, reflecting the presence of a specific ligand-receptor interaction. The receptor incorporated into liposomes displayed a saturable binding to 125I-f-Alb and the binding was effectively replaced by the presence of unlabeled f-Alb, with binding parameters being similar to those obtained from 125I-f-Alb binding to the sinusoidal liver cell membrane (Horiuchi, S., Takata, K., and Morino, Y. (1985) J. Biol. Chem. 260, 475-481). Reaction of anti-f-Alb receptor antibody with extracts of sinusoidal cells resulted in a specific precipitation of two proteins whose molecular weights were identical to those for the purified receptor. The anti-receptor IgG fraction effectively blocked 125I-f-Alb binding to the sinusoidal cell membranes. These results indicate that the purified protein represents the membrane-associated receptor which is presumably involved in a specific uptake of this ligand from the circulation.

Characterization of a membrane-associated receptor from rat sinusoidal liver cells that binds formaldehyde-treated serum albumin

When treated with formaldehyde, serum albumin is known to be taken up and degraded by sinusoidal liver cells via adsorptive endocytosis. The present study aimed at characterization and identification of the membrane-associated receptor on rat sinusoidal liver cells. Kinetic studies of binding of 125I-labeled formaldehyde-treated serum albumin (125I-f-Alb) with the membranes of sinusoidal liver cells demonstrated the presence of specific, high-affinity, saturable membrane-bound receptors with an apparent Kd = 8 micrograms of f-Alb/ml and the optimal pH at around 8.0. The 125I-f-Alb binding to the membranes was not inhibited by either native albumin, asialofetuin, methylamine-treated alpha 2-macroglobulin, mannan, or immune complexes. The binding process exhibited independence of calcium and susceptibility both to heat treatment and to destruction by proteases. The binding was inhibited by concanavalin A and the inhibition was effectively reversed by the presence of alpha-methyl-D-glucoside, a haptenic inhibitor for this lectin, indicating the glycoprotein nature of the receptor. The binding protein was extracted from the membrane preparations with octyl beta-D-glucopyranoside and immunoprecipitated by anti-ligand antibody as a complex with the ligand. Sodium dodecyl sulfate-gel electrophoresis of the immunoprecipitate revealed two polypeptide chains with molecular weights of approximately 53,000 and 30,000, respectively.

Isolation of lysosomes from the tail of metamorphosing bullfrog tadpole

A mitochondrial-lysosomal fraction obtained by differential centrifugation of the tail homogenate of metamorphosing Rana catesbeiana tadpoles was fractionated on iso-osmotic self generating gradients composed of modified colloidal silica (Percoll). More than half the activities of most lysosomal hydrolases were recovered to a heavy fraction, which contained little activities of cytochrome oxidase and of catalase. The activities of lysosomal enzymes in the heavy fraction showed latency, and the median density of those was 1.09. These results indicate that intact lysosomes, which are considerably purified, could be obtained by this method.

The 64-kilodalton membrane protein of Bacillus subtilis is also present as a multiprotein complex on membrane-free ribosomes

The 64-kDa membrane protein of Bacillus subtilis is evidently involved in the attachment of secreting ribosomes to membrane. On immunoprecipitation with antibody to this protein, the solubilized particulate fraction, with or without prior chemical cross-linking, yields a complex of four proteins (64, 60, 41, and 36 kDa). This "S complex" was found to be associated with membrane-free ribosomes rather than with membrane, but the 64-kDa protein is also present, without the other proteins of the S complex, in the membrane-ribosome fraction and in the cytosol. Only the form present in the membrane-ribosome fraction is protected from protease. These findings suggest a cycle in which the complex participates in initiation of secretion but not in the later stages. It is not yet clear whether the 64-kDa protein found in the membrane-ribosome complexes is retained from the S complex after initiation and later recycled via the cytosol or whether it is a separate pool.

Conduction of nonconjugative plasmids by F' lac is not necessarily associated with transposition of the gamma delta sequence

A nonconjugative kanamycin-resistant (Kmr) recombinant plasmid, pNR5311, transferred at a low frequency from an Hfr or F' lac Escherichia coli donor to an F- lac- recipient. Among the transconjugants, two types of Kmr plasmids were found: one was indistinguishable from pNR5311 (type A), and the other was a recombinant between pNR5311 and the gamma delta sequence (type B). When the F' lac strain was used as a donor, 5% of lactose-fermenting (Lac+) and 75% of lactose-nonfermenting (Lac-) transconjugants had type A plasmids. A kinetic study revealed that type A plasmids were transferred more readily in short mating periods than were type B plasmids. Involvement of Tn903, which is present in pNR5311, in transfer of type A plasmids was unlikely since there was no discernible change in the F' lac molecule coexisting with the type A plasmid in the transconjugant cells. The non-gamma delta-associated conduction of pNR5311 by F' lac did not require the recA+ function of the donor. Conduction of pBR322 by F' lac was also carried out, and two types of plasmids with and without gamma delta were found, as with pNR5311. These findings suggest that the transfer of nonconjugative plasmids is conducted by a novel pathway which is not associated with translocation of transposable elements into either plasmid.

Estrogen-dependent plasminogen activator in 7,12-dimethylbenz[a]anthracene-induced rat mammary tumors in vivo and in vitro

Hormonal regulation of plasminogen activator in rat mammary tumor induced by 7,12-dimethylbenz[a]anthracene (DMBA) was studied both in vivo and in vitro. Plasminogen activator activity in DMBA-induced tumor (DMBA-tumor) was markedly decreased by ovariectomy, and recovered in a dose-dependent fashion upon estradiol administration, reaching a maximal level at 12 hr. This estrogen-stimulated production of the enzyme was prevented by actinomycin D, cycloheximide, and tamoxifen, indicating that in DMBA-tumor, estrogen might regulate de novo synthesis of plasminogen activator at a transcriptional level via an estrogen receptor system. Furthermore, DMBA-tumor cells in primary culture displayed similar estrogen-dependency toward the production of the enzyme without any cell proliferation. This indicates that the action of estrogen is mediated neither by cell division nor by prolactin, another hormone pastulated to be responsible for the development and growth of DMBA-tumor. Taken together, the present results have led to support the view that the primary function of estrogen is to induce plasminogen activator, which is probably essential to maintain the malignant state of DMBA-tumor.

Mortality estimation from registered deaths in less developed countries

Age-specific population growth rates were introduced to demographic analysis in earlier work by Bennett and Horiuchi (1981) and Preston and Coale (1982). In this paper, we derive a method which uses these growth rates to transform what may be a set of incompletely recorded deaths by age into a life table that accurately reflects the true mortality experience of the population under study. The method does not rely on the assumption of stability and, for example, in contrast to intercensal cohort survival techniques, is simple to implement when presented with nontraditional intercensal interval lengths. Thus we can obtain mortality estimates for less developed countries with defective data, despite departures from stability. Further, we assess the sensitivity of the method to violations in various assumptions underlying the procedure: error in estimated growth rates, existence of non-zero net intercensal migration, age dependence in the completeness of death registration, and misreporting of age at death and age in the population. We demonstrate the use of the method in an application to data referring to Argentine females during the period 1960 to 1970.

[Allergic reaction to CDDP: report of 4 cases]

Four cases of CDDP allergic reaction (CDDP reaction) are reported. CDDP was given intravenously with vinka-alkaloid and bleomycin or cyclophosphamide (CDDP combination therapy). Case 1 was a 59-year-old man with left ureteral squamous cell carcinoma. The tumor was so large and infiltrated into the retroperitoneal space, that he had conservatively undergone only left nephrectomy and tumor biopsy. Post-operative CDDP combination therapy was performed. Soon after the beginning of the 6th CDDP drip-infusion, a reaction to CDDP occurred. Case 2 was a 22-year-old man diagnosed to have left testicular embryonal carcinoma with multiple pulmonary metastases. After radical orchiectomy and retroperitoneal lymphadenectomy, CDDP combination therapy was performed. At the beginning of the 8th CDDP drip-infusion, a reaction to CDDP occurred. Case 3 was a 49-year-old man diagnosed to have non-papillary bladder carcinoma. Although his bladder was tumor free by TUR-Bt, distant lymph node metastases occurred. CDDP combination therapy was performed. At the beginning of the 6th CDDP drip-infusion, a reaction to CDDP occurred. Case 4 was a 64 year-old-man diagnosed to have bladder carcinoma which was recurrent from right renal pelvic tumor. After total cystectomy and ileal conduit, CDDP combination therapy was performed for diffuse retroperitoneal lymph nodes metastases. At the beginning of the 8th CDDP drip-infusion, a reaction to CDDP occurred. Reaction to CDDP developed at the 6th to 8th course of combination chemotherapy with CDDP, i.e., 450 to 700 mg of CDDP in total doses.(ABSTRACT TRUNCATED AT 250 WORDS)

Neoplastic and non-neoplastic lesions in aging Slc: Wistar rats

Spontaneous neoplastic and non-neoplastic lesions in 98 male and 100 female Slc: Wistar rats, which have been widely used in Japan for toxicological studies, were examined. As spontaneous tumors, the most frequent tumors in males were testicular interstitial cell tumors, followed by tumors of the hematopoietic organs, adrenal gland, thyroid gland, preputial gland, pituitary gland, liver and mammary gland. Those in females were tumors of the pituitary gland, mammary gland, hematopoietic organs, uterus and thyroid gland. The organ distribution and histological types of spontaneous tumors observed in Slc: Wistar rats were very similar to those in F-344/DuCrj rats, although the incidences of some tumors differed slightly in the two strains. Various non-neoplastic lesions were also observed in the heart, kidney, liver and many other organs. These results should be useful in evaluating the results of toxicological and carcinogenic studies on this strain of rat.

A 64-kilodalton membrane protein of Bacillus subtilis covered by secreting ribosomes

The complexed (ribosome-bearing) membrane fraction of Bacillus subtilis contains several proteins (CM-proteins) that are virtually absent from the ribosome-free fraction and hence might be components of the apparatus of protein secretion. We have determined, by trypsin digestion and by labeling with a nonpenetrating reagent (diazoiodosulfanilic acid), the accessibility of four of these proteins on the two surfaces of the membrane, as exposed either in protoplasts or in inverted membrane vesicles. The 68-kilodalton protein is a transmembrane protein and the 45-kilodalton protein faces only the external surface, whereas the 31-kilodalton protein is inaccessible from either side. Of particular interest is the 64-kilodalton protein: it can be digested by trypsin, and can bind antibody, on the cytoplasmic surface, but only after the ribosomes have been released. This protein is thus evidently a component of the apparatus of protein secretion, closely covered by secreting ribosomes. Whether the other CM-proteins are also involved in protein secretion is uncertain.

Chronological changes in latent prostatic carcinoma found in surgical specimens from Japanese during 28 years

Out of 1,193 specimens from open prostatectomies in Japanese at Tokyo Teishin Hospital during the 28 years from 1953 to 1980, 38 focal type latent prostatic carcinomas were found. These were classified histologically by Gleason's criteria and subdivided into two groups, a low grade group (patterns 1 and 2) and a high grade group (patterns 3, 4 and 5). The incidence of the focal type of latent prostatic carcinoma in 1967-1980 was significantly higher than that in 1953-1966 (P less than 0.05). The incidence of the high grade group was significantly higher in the recent 14-year period (P less than 0.05), while the incidence of the low grade group was not. The prevalence of latent prostatic carcinoma in the Japanese male population, especially the prevalence of the high grade group, may have increased during these 28 years, which may be associated with the increasing mortality rate for prostatic cancer in the Japanese.

Localization and quantitation of proteins characteristic of the complexed membrane of Bacillus subtilis

We prepared antibodies to four proteins (molecular weights, 68,000, 64,000, 45,000, and 31,000) that are characteristic of the complexed (ribosome-bearing) fraction of the membrane of Bacillus subtilis and found that these proteins are immunologically distinct. Quantitation by immunoprecipitation confirmed that the ribosome-free membrane fraction contains much lower concentrations of these four proteins than the complexed-membrane fraction. The 64-kilodalton protein appeared to be attached more loosely than the other proteins, since it was more readily extracted from the membrane. In addition, this protein was also present in the cytosol in an even greater amount than in the membrane. The 68-, 64-, and 31-kilodalton proteins are present in cells in stoichiometrically equivalent amounts.

Proteins of ribosome-bearing and free-membrane domains in Bacillus subtilis

In lysates of Bacillus subtilis a free-membrane fraction without ribosomes can be separated from the denser membrane-ribosome complexes. As determined by one-dimensional sodium dodecyl sulfate gel electrophoresis, these two fractions differ markedly in protein composition; at least six major bands (molecular weights, 130,000, 92,000, 68,000, 64,000, 45,000, and 31,000) are essentially unique to the complexed-membrane fraction (CM proteins), and two are unique to the free-membrane fraction. After growth was slowed, the proportion of the free-membrane fraction increased, but the composition of this fraction was the same, whereas after puromycin treatment, which abruptly increased the proportion of the free-membrane fraction, this fraction contained CM proteins. Thus, it appears that the two fractions recovered from growing cells represent topographically and functionally distinct domains. In addition, the effect of growth rate suggests that formation of the complexed domain is regulated at least roughly in parallel with the formation of ribosomes. The separation of these membrane fractions should facilitate the study of protein secretion, membrane topography, and morphogenesis in bacteria.