Concentration measurements of a light absorber localized in a scattering medium

Using a time-resolved technique, we have studied two methods of quantifying the concentration of a light absorber localized in a scattering medium. Because some of the transmitted photons pass through the absorber region many times because of complicated photon propagation in the scattering medium, we used the following methods. First, early-arriving photons passing through the absorber approximately once were selected. Using these photons, we quantified the concentration of the absorber by an ordinary spectroscopic method based on the Beer-Lambert law. Second, for later-arriving photons, after empirically determining the distribution of the number of passes through the absorber as a function of detection time, we obtained the concentration by applying this function to the Beer-Lambert law.

NPK15, a tobacco protein-serine/threonine kinase with a single hydrophobic region near the amino-terminus

A cDNA clone (cNPK15) was isolated from tobacco cells in suspension culture, which encodes a predicted protein kinase of 422 amino acids. The predicted NPK15 protein consists of a hydrophobic region near the amino-terminus, a linker domain and the catalytic domain of a protein-serine/threonine kinase in the carboxyl-half. NPK15 was not found to be closely related to any reported protein, but its putative catalytic domain shares some structural similarity with those of receptor-like protein kinases of plants, such as ZmPK1 from Zea mays and TMK1 from Arabidopsis, even though no receptor-like domain is found in NPK15. Recombinant NPK15 expressed in Escherichia coli as a fusion protein was found capable of autophosphorylation and of phosphorylation of the histone H1 protein on both serine and threonine residues. Upon overexpression of cNPK15 under control of the promoter of cauliflower mosaic virus 35S RNA in tobacco cells, into which it had been introduced by Agrobacterium-mediated transformation, the NPK15 gene acted as a "suicide" gene and blocked proliferation of the host cells. By contrast, such a suicide effect was not observed with the gene for a kinase-negative mutant protein in which the nucleotide sequence for the ATP-binding site had been mutated or with a mutant derivative encoding a protein in which the hydrophobic region had been deleted. Thus, the protein kinase activity of NPK15 and the hydrophobic region of the protein are responsible for the suicide effect. The NPK15 protein kinase seems to be associated with specific cellular functions. Southern blot analysis with cNPK15 as the probe detected several fragments in restriction digests of genomic DNAs from both tobacco and other members of the Solanaceae. This results suggests that NPK15-related genes constitute a small gene family in the genomes of Solanaceae.

Characterization of monoclonal antibodies to chitinase A1 and enhancement of chitinase A1 activity by monoclonal antibodies

A total of eleven hybridomas which secrete antibodies against chitinase A1 were established. Among the eleven monoclonal antibodies (MAbs) obtained, six recognized the catalytic domain, three recognized the type III region and two recognized the chitin binding domain of chitinase A1. Of the two MAbs which recognized the chitin binding domain one was found to also react with chitinase D, but none of the other MAbs which recognized either the type III region or the chitin binding domain reacted with chitinase D despite the extensive amino acid sequence similarity between both the type III and chitin binding domains of the two chitinases. Two of the eleven MAbs enhanced chitinase activity significantly, while the other MAbs did not have any significant effect on chitinase A1 activity.

Immunohistochemical localization of estrogen receptors in the submandibular gland tumors of female rats

The localization of estrogen receptors (EsR) in the tumor tissues of submandibular glands was examined in female rats, using the indirect immunoperoxidase method in combination with the in situ hybridization technique. Tumors were experimentally produced by 9,10-dimethyl-1,2-benzanthracene (DMBA), and the tumor tissues were fixed with formalin or paraformaldehyde and then embedded in paraffin. In the DMBA-induced submandibular gland tumors, immunoreactivity to EsR-peroxidase conjugate was found in nuclei of the tumor cells which occupied the peripheral rim of the tumor cell nests. In contrast, the reactivity in the normal submandibular glands without tumor was mostly confined to nuclei of the duct cells. When EsR mRNA expression was analyzed in the tumor tissue by in situ hybridization with a cDNA probe, its distribution was identical with that of immunoreactivity to EsR. These data suggest that the ductal cells of the submandibular gland are responsive to ovarial steroids, and that estrogens may play an important role in the maintenance of growth of the submandibular gland tumors.

Cytochrome P450 2B1 immunoreactivity in bronchiolar and alveolar epithelial cells after exposure of rats to ozone

Pulmonary cytochrome P450 (P450) plays an important role in the metabolism of xenobiotics. We have previously demonstrated that exposure to ozone (O3), a major oxidant of photochemical smog, increases P450 content and xenobiotic metabolizing activities in the rat lung. Therefore, it is conceivable that O3 exposures modify the pattern and potency of xenobiotic metabolism. The aim of this study is to examine the effect of O3 exposure on localization of P450 in the lung. After exposure of rats to 0.4 ppm O3 for 14 days, the concentration of P450 2B1, the main isozyme of P450 in the lung, increased to 214% of the control value. By immunohistochemical analyses, O3 exposure caused hypertrophy and hyperplasia of P450 2B1-positive non-ciliated bronchiolar epithelial (Clara) cells, showing an increase in the cell number to 128% of the control level. At the proximal alveoli, O3 exposure induced hypertrophic epithelial cells that presented immunoreactivity to P450 2B1 and morphological characteristics of both type 1 and type 2 cells. These hypertrophic cells had lamellar inclusion bodies, microvilli, and extended cytoplasm. Typical type 2 cells did not react with anti-P450 2B1 antibody even after O3 exposure. These data suggest that O3 exposure may activate the P450-mediated xenobiotic metabolism in the pulmonary epithelial cells, and that expression of P450 2B1 in the pulmonary epithelial cells might be regulated by the factors involved in the process of the differentiation from type 2 to type 1 cells.

Role of increased DNA synthesis activity of hepatocytes in multicentric hepatocarcinogenesis in residual liver of hepatectomized cirrhotic patients with hepatocellular carcinoma

To examine whether the marked increase in DNA synthesis of hepatocytes in cirrhotic liver might elicit multicentric hepatocarcinogenesis, we examined the relationship between new development of hepatocellular carcinoma (HCC) and the bromodeoxyuridine (BrdU) labeling index (LI) of hepatocytes in the residual liver of hepatectomized patients with liver cirrhosis (LC) and HCC. Eighteen hepatectomized patients with LC and HCC, whose resected liver revealed neither portal nor hepatic vein invasion by histologic examination, were studied (to exclude cases with intrahepatic metastasis). DNA synthesis activity of hepatocytes from the residual cirrhotic liver was measured by a BrdU/anti-BrdU in vitro method. The incidence of HCC recurrence was studied during a 3-year follow-up period. Among 18 patients, 9 patients had recurrence and 9 did not. The average BrdU LI in the recurrent patients was 2.6 +/- 1.3% and was significantly higher than that in patients without recurrence (1.4 +/- 0.5%, P < 0.05). All five patients who had a BrdU LI of 2.4% or above showed recurrence within 3 years, as compared with 4 of 13 (30.8%) patients with BrdU LI of less than 2.4% (P < 0.05). Our data indicate that abnormally high DNA synthesis in hepatocytes in the background cirrhosis might lead to the development of multicentric carcinogenesis in human cirrhotic liver, and in the residual cirrhotic liver of hepatectomized patients with HCC and LC, it may be a predictor of new development of HCC.

An S-alkylating reagent with positive charges as an efficient solubilizer of denatured disulfide-containing proteins

A novel S-alkylating reagent, N-(3-bromopropyl)-N,N,N',N',N'-pentamethyl-1,3-propanedi(ammonium bromide) (TAP2-Br) which carries two positive charges in the molecule, was prepared to increase the solubility or to decrease the hydrophobicity of cysteine-containing denatured proteins (or peptides). S-Alkylation with TAP2-Br introduces two positive charges per cysteine residue, which will effectively shift the net charge of a protein in the positive direction. Disulfide-containing proteins, such as hen egg-white lysozyme, RNase A, BSA, and soybean trypsin inhibitor (Kunitz type), were reduced and S-alkylated with TAP2-Br to evaluate the potential of this reagent compared with other S-alkylating reagents such as monoiodoacetic acid, bromosuccinic acid and (3-bromopropyl)trimethylammonium bromide. The solubilities of these denatured proteins in the pH range of 2-10 indicated that S-alkylation with TAP2-Br effectively solubilized not only basic proteins (lysozyme and RNase) but also an acidic protein containing a fairly large number of cysteine residues (BSA). Moreover, the retentions of cysteine-containing tryptic peptides derived from lysozyme on reversed-phase HPLC were greatly reduced by S-alkylation with TAP2-Br. These results indicate that TAP2-Br is very useful to increase the solubility of some cysteine-containing denatured proteins and to decrease the hydrophobicity of peptides containing cysteine residue(s).

Cell growth on immobilized cell-growth factor. 10. Insulin and polyallylamine co-immobilized materials

Polyallylamine, which is cationic and enhances cell adhesion electrostatically (non-specifically), was co-immobilized with a cell growth factor, insulin, onto a surface-hydrolysed poly(methyl methacrylate) membrane. The adhesion of mouse STO fibroblast cells was accelerated by the immobilization of polyallylamine. The adhesion and growth of the cells were both markedly accelerated by the co-immobilization of the polyallylamine and insulin. The co-immobilized membrane can be applied for a new technique for protein-free cell culture.

Usefulness of the pulmonary vein flow velocity-time profile as an estimate of left atrial storage fraction

During ventricular systole, the left atrium (LA) stores a certain amount of ventricular stroke volume; this is defined as an LA storage volume. From cineangiocardiograms, an LA storage fraction is obtained as the ratio of the LA storage volume to left ventricular stroke volume. From the pulmonary vein (PV) flow velocity-time profile, the LA storage fraction may be estimated as a ratio of the PV flow velocity-time integral during systole (Sa) to a sum of that during systole and diastole (Sa+Da), namely, Sa/(Sa+Da), provided that the PV cross-sectional area remains relatively unchanged during one cardiac cycle and that the PV flow velocity-time profile is similar in any of the PVs draining to the LA. To evaluate usefulness of Doppler echocardiographic method of estimating the LA storage fraction, the authors measured the LA storage fraction from the left upper PV flow velocity-time profile by transesophageal Doppler echocardiography and compared it with the LA storage fraction from conventional cineangiocardiographic volumes. Subjects were 23 patients with a variety of cardiac diseases in normal sinus rhythm, ranging from eighteen to seventy-four years of age. The LA storage fraction was 0.58 +/- 0.12 (mean +/- SD) from cineangiocardiography and 0.64 +/- 0.08 from Doppler echocardiography larger than that from cineangiocardiography (P < 0.01), the correlation was good (r = 0.643). The authors conclude that the left upper PV flow velocity-time profile appears to provide a better correlation with that by cineangiography and may be used as a reliable quantitative estimate of the LA storage fraction.

A possible role of tyrosine kinases in the regulation of muscarinic receptor-activated cation channels in guinea pig ileum

We investigated the effects of inhibitors for tyrosine kinases and phosphatases on the muscarinic receptor-activated nonselective cationic current. With nystatin-perforated whole-cell recording, the tyrosine kinase inhibitor genistein (1 approximately 10 micrograms/ml) reduced the amplitude of currents evoked by iontophoretically applied acetylcholine in a dose-dependent manner, the maximum inhibition being to about 46% of the control. In contrast, daidzein (10 micrograms/ml), an inactive analog of genistein, exerted little effect. These effects were unchanged when the cationic current was activated by internal perfusion of GTP gamma S (50 microM) bypassing the muscarinic receptor. A potent phosphatase inhibitor, orthovanadate (30 approximately 100 microM), on the other hand, increased the GTP gamma S-induced cationic current. These results suggest that tyrosine phosphorylation may be essential to regulate the Ca mobilization associated with muscarinic receptor-operated nonselective cation channels.

Glucocorticoid inhibits cAMP production induced by vasoactive agents in aortic smooth muscle cells

It is well-known that atherosclerotic change and hypertension are common manifestations in patients with glucocorticoid excess. We previously reported that pituitary adenylate cyclase activating polypeptide (PACAP), prostaglandin E2 (PGE2) and carbacyclin, a stable analog of prostacyclin, have suppressive effects on vasopressin-induced DNA synthesis of rat aortic smooth muscle cells through cAMP production (Murase et al., J. Hypertens., 10 (1992) 1505; Oiso et al., Biochem. Cell. Biol., 71 (1993) 156). In the present study, we investigated the effect of glucocorticoid on cAMP production induced by PACAP, PGE2 and carbacyclin in aortic smooth muscle cells. The pretreatment with dexamethasone significantly inhibited cAMP accumulation induced by these vasoactive agents in a dose dependent manner in the range between 10 pM and 10 nM. These inhibitory effects of dexamethasone were dependent on the time of pretreatment up to 8 h. Dexamethasone inhibited cAMP accumulation induced by NaF, a GTP-binding protein activator, and forskolin which directly activates adenylate cyclase. Moreover, forskolin-induced adenylate cyclase activity was significantly reduced in membranes prepared from the cells treated with dexamethasone. These results strongly suggest that glucocorticoid inhibits cAMP production induced by vasoactive agents in primary cultured rat aortic smooth muscle cells and the inhibitory effect is exerted at the level of adenylate cyclase.

Separations of basic amino acid benzyl esters by pH-zone-refining counter-current chromatography

pH-Zone-refining counter-current chromatography was applied to the separation of basic amino acid benzyl esters. The method uses a retainer base in the stationary phase to retain analytes in the column and an eluent acid to elute the analytes in the decreasing order of pKa and hydrophilicity. The preparative capability of the method is demonstrated in the separation of a 10-g quantity of the sample.

A multicenter randomized controlled dose study of ursodeoxycholic acid for chronic hepatitis C

The effect of ursodeoxycholic acid on liver function tests and on bile acid metabolism was investigated in a multi-center randomized controlled dose study for chronic hepatitis C. Twenty, 18 and 19 patients were administered 150, 600 and 900 mg/day, respectively of ursodeoxycholic acid every day for 16 wk. Serum liver parameters and bile acid composition in the treatment groups were compared with 17 control patients. A similarly significant decrease of serum alanine aminotransferase and serum gamma-glutamyltransferase was observed in patients administered 600 and 900 mg of ursodeoxycholic acid. Serum bile acid composition was determined by high-performance liquid chromatography. At entry, the relative proportions of major bile acids were similar to those observed in normal individuals. Maximal concentrations of total ursodeoxycholic acid were 0.30 mumol/L, 5.59 mumol/L, 21.42 mumol/L and 14.73 mumol/L in the control, 150, 600 and 900 mg/day groups, respectively. The fraction of the total ursodeoxycholic acid increased in a dose-dependent manner, and it was significantly higher than in controls (p < 0.001). The hydrophobicity index of bile acids was calculated by the method of Heuman, and its correlation with serum parameter levels was analyzed. In the 600 and 900 mg/day dose groups, serum alanine aminotransferase decreased in the cases in which hydrophobicity index significantly decreased during treatment. The same correlation was observed between the hydrophobicity index and serum gamma = glutamyltransferase in these two groups. There was no correlation between these parameters in the control and 150-mg groups. There was no correlation between reduction rate of serum alanine aminotransferase and initial liver histology.(ABSTRACT TRUNCATED AT 250 WORDS)

[The significance of portal infusion chemotherapy for prevention of recurrence in residual liver after hepatectomy for metastases from colorectal cancer]

We performed portal infusion chemotherapy using a reservoir for prevention of recurrence in residual liver after hepatectomy for metastases from colo-rectal cancer. To study the usefulness of portal infusion chemotherapy, the period from hepatectomy to recurrence in residual liver was investigated by three treatment groups for H2 cases; (a) a group of systemic chemotherapy, (b) a group of arterial infusion chemotherapy and (c) a portal infusion chemotherapy group. Treatment in (a) group was for 204 +/- 98.2 days (n = 6), in (b) group for 343.0 +/- 238.3 days (n = 8) and in (c) group for 961.0 +/- 1,172.4 days (n = 5). There was no statistically significant difference in the three groups, but (c) group had a better result in recurrence in residual liver. As for prevention of recurrence in residual liver after re-hepatectomy, there was no significant difference in the three groups, but (c) group had the longest survival.

Cloning and nucleotide sequencing of L-lactate dehydrogenase gene from Streptococcus thermophilus M-192

The gene encoding L-lactate dehydrogenase (LDH) was cloned from an industrial dairy strain of Streptococcus thermophilus M-192 using a synthetic oligonucleotide probe based on the N-terminal amino acid sequence of the purified enzyme, and its nucleotide sequence was determined. The enzyme was deduced to have 328 amino acid residues with a molecular weight of 35,428 and found to have high sequence similarity to LDHs from other lactic acid bacteria (89.0% to Streptococcus mutans, 76.3% to Lactococcus lactis subsp. lactis, 67% to Lactobacillus casei, and 60% to Lactobacillus plantarum). The gene contained a promoter-like sequence similar to the Escherichia coli promoter consensus, and expression of the S. thermophilus LDH gene was observed in E. coli cells.

Morphological aspects of aging liver: half a century of progress in Japan

The most important morphological aspects of the physiological changes of the liver with age are decreases in the numbers of hepatocytes and their mitochondria, coupled with increases in their volumes. The latter is considered to partially compensate for the decrease in numbers of hepatocytes and mitochondria, but leads to a more limited reserve capacity and thus to a condition in which liver function can be more readily exhausted. The binuclearity and polyploidization of the hepatocytes increase with age and are considered to be due to inhibition of their cell division process. Our studies on the parabiosis between young and old rats and mice, on the implantation of isolated hepatocytes in the spleens of rats of different ages, and on the regenerative process after partial hepatectomy in rats of different ages, suggested the existence of humoral inhibitory factor(s) for the division of the cells and their mitochondria. Morphological studies on the native and Hawaiian Japanese, as well as on the USA Caucasians and the Costa Rican Latinos revealed that a difference in the process of the age-related decrease in hepatocyte number among different ethnicities is mainly due to differences in nutritional conditions rather than to genetic factors. Experimental studies are now being carried out on the effect(s) of various dietary conditions on age-related changes of the liver, and the results obtained support the findings of the geographical studies.

Functional properties of rotation-sensitive neurons in the posterior parietal association cortex of the monkey

We studied the functional properties of rotation-sensitive (RS) neurons of the posterior parietal association cortex in detail. We classified 58 neurons as RS neurons on the basis of statistical analysis, to indicate that their responses to rotary movement were significantly greater (P < 0.01) than those to linear movement of the same stimulus. We calculated rotation index, 1-(L/R), in 82 cells, where L/R is the ratio of net response to linear movement to that to rotary movement. All the RS neurons had rotation index greater than or equal to 0.3. The recording site of these RS neurons was localized in the posterolateral part of area PG (area 7a of Vogt), on the anterior bank of the caudal superior temporal sulcus (STS), in the region partly overlapping the medial superior temporal (MST) area. We compared the response of RS neurons to rotation with that to shearing movement as well as to linear movement. In the majority of RS neurons the ratio of shearing response to rotation response (S/R) was smaller than the ratio of linear response to rotation response (L/R), indicating that the response to rotation was not due to a simple combination of linear movements in the opposite direction. Most of the RS neurons responded to the rotary movement of a single spot as well as that of a slit, although the response was smaller (average 70%) for the former. Most of the RS neurons had large receptive fields (60-180 degrees in diameter) and their responses were independent of the position within the receptive field. The responses of most RS neurons increased monotonically with the increase in angular velocity and were also dependent on the size of the stimulus, although the rate of increase was small when the length was more than 10 degrees. The majority of RS neurons (37/58) responded better to rotation in depth than to that in the frontoparallel plane. Some of them (12/37) responded to diagonal rotation rather than to sagittal or horizontal rotation. We found that some depth RS neurons showed reversal in the preferred direction when we used a trapezoidal window-like plate as the rotating stimulus in the monocular viewing condition, just as occurs in the case of the Ames window illusion. The response of some RS neurons (5/7) was enhanced by tracking eye movement.(ABSTRACT TRUNCATED AT 400 WORDS)

Preparative separation of components of the color additive D&C Red No. 28 (phloxine B) by pH-zone-refining counter-current chromatography

A pH-zone-refining counter-current chromatographic method was developed for the preparative (multigram) separation and purification of components of the commercial color additive D&C Red No. 28 (phloxine B). The chromatography of 3 and 6 g of color additive yielded 1.07 and 4.06 g, respectively, of pure 2',4',5',7'-tetrabromo-4,5,6,7-tetrachlorofluorescein, the principal component of D&C Red No. 28. The importance of the quantity of retainer acid (trifluoroacetic acid) relative to the amount of salt in the color additive is discussed.

Effect of retinoic acid on prostaglandin F2 alpha-induced prostaglandin E2 synthesis in osteoblast-like cells

We previously reported that prostaglandin F2 alpha (PGF2 alpha) stimulates phosphoinositide hydrolysis via pertussis toxin-sensitive GTP-binding protein in osteoblast-like MC3T3-E1 cells (Miwa, Tokuda, Tsushita, Kotoyori, Takahashi, Ozaki, Kozawa and Oiso 1990) and that PGF2 alpha stimulates arachidonic acid release and prostaglandin E2 (PGE2) synthesis, and the activation of protein kinase C (PKC) amplifies the effect of PGF2 alpha in MC3T3-E1 cells (Tokuda, Oiso and Kozawa 1992). In the present study, we investigated the effect of retinoic acid (RA), a vitamin A (retinol) metabolite, on PGF2 alpha-induced PGE2 synthesis in MC3T3-E1 cells. The pretreatment with RA, which by itself had little effect on synthesis, significantly inhibited PGE2 synthesis induced by PGF2 alpha in a dose-dependent manner in the range between 1 nM and 0.1 microM. This effect of RA was dependent on the time of pretreatment up to 8 h. In addition, RA inhibited the amplification of PGF2 alpha-induced PGE2 synthesis by 12-O-tetradecanoylphorbol-13-acetate, known to be a PKC activator. However, RA had little effect on PGE2 synthesis induced by melittin, known as a phospholipase A2 activator. Moreover, pertussis toxin had little effect on arachidonic acid release induced by PGF2 alpha. These results strongly suggest that RA inhibits PGE2 synthesis induced by PGF2 alpha in osteoblast-like cells and the inhibitory effect is exerted at the point prior to the activation of phospholipase A2.

Tissue distribution of isoforms of type-1 protein phosphatase PP1 in mouse tissues and its diabetic alterations

The amounts of four isoforms of the catalytic subunit of type-1 protein phosphatase, PP1 alpha, PP1 gamma 1, PP1 gamma 2, and PP1 delta have been determined in extracts of various mouse tissues including brain, liver, skeletal muscle, kidney, small intestine, heart, lung, spleen, thymus, and testis by Western blot analysis. Immunoreactive bands for PP1 isoforms were detected at 39.5, 38.5, and 40 kDa for PP1 alpha, PP1 gamma 1, and PP1 gamma 2, respectively, and at 39 and 37 kDa for PP1 delta. The amount of PP1 alpha was at comparable levels in all tissues examined except skeletal and heart muscles, in which it was detected slightly or not detectable, respectively. The amount of PP1 gamma 1 was at higher levels in brain, small intestine, and lung, being 2 to 3 times those in other tissues except heart and spleen, in which PP1 gamma 1 was not detectable. The amount of PP1 gamma 2 was extremely large in testis, small in brain, lung, spleen, and thymus, but it was not detectable in the other tissues. The amount of PP1 delta was at comparable levels in all the tissues except skeletal muscle, in which it was at a low but detectable level. Then, the amounts of the four PP1 isoforms were determined in non-obese diabetic (NOD) mice. The amounts of PP1 alpha were progressively decreased in livers of NOD mice as a function of increasing concentrations of blood glucose, whereas the amounts of PP1 gamma 1 and PP1 delta were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)