Comparative study of intraocular lens implantation through 3.2- and 5.5-mm incisions

PURPOSE

To prospectively and comprehensively compare the clinical results of two small-incision cataract surgery procedures, silicone intraocular lens (refractive index of 1.46) implantation through a 3.2-mm incision and polymethylmethacrylate intraocular lens implantation through a 5.5-mm incision.

METHODS

Two hundred eyes with cataract randomly were assigned to either procedure. Except for incision size, identical surgical methods were used in every case. Data on uncorrected and corrected visual acuity, keratometry, corneal topography, flare-cell measurement, fluorophotometry, specular microscopy, glare disability measurement, and photographic examination of intraocular lens decentration were analyzed up to 6 months after surgery.

RESULTS

Eyes in the 3.2-mm incision group displayed significantly better uncorrected and corrected visual acuity in the early postoperative period, lower aqueous flare intensity and cell counts immediately after surgery, less operatively induced astigmatism throughout the study period, and less corneal topographic changes taken 3 months after surgery. No significant between-group differences were noted for other parameters. Complications in the two groups were few and comparable.

CONCLUSION

Both procedures of small-incision cataract surgery offered satisfactory clinical results, but 3.2-mm incision cataract surgery allowed significantly earlier recovery of visual function and better preservation of corneal shape.

Low-molecular-size allergens, LM-1s, in feces extract of Dermatophagoides farinae which elicit histamine release from washed blood cells of patients with bronchial asthma

A significant activity to elicit histamine release was found in an ultrafilterable (Mr-cutoff < 10 kD) fraction of a mite feces extract from a spent mite medium. The activity was divided into two fractions (LM1 and LM2) on an Ultrogel AcA 54 column when monitored by histamine release assay using washed peripheral blood cells from mite-allergic patients. The larger-molecular-size antigen, LM1 was further separated into three allergenic fractions by consecutive chromatography on Sephadex G-50, GM-DEAE, and TSKgel ODS-120T. All the purified allergens, LM1s (LM1a, LM1b, and LM1c), which produced positive reactions in skin tests on allergic patients, were glycoproteins (molecular weight: 8 kD on SDS-PAGE; 12.5 kD on Gel filtration) with different carbohydrate contents and pI values ranging from 4 to 5 on an IEF plate. LM1s were cross-reactive with anti-Der f II but not with anti-Der f I. The reaction of LM1c to anti-Der f II serum was completely inhibited with the other antigens, while the reactions of LM1a and LM1b to the serum were partially inhibited with LM1c or the other antigens, respectively.

Phosphorylation of an inhibitory subunit of cGMP phosphodiesterase in Rana catesbeiana rod photoreceptors. II. A possible mechanism for the turnoff of cGMP phosphodiesterase without GTP hydrolysis

In amphibian rod photoreceptor membranes, P gamma, an inhibitory subunit of cGMP phosphodiesterase, is phosphorylated by a protein kinase when P gamma is complexed with the guanosine 5'-O-(3-thiotriphosphate)-bound alpha subunit of transducin (GTP gamma S.T alpha). Five different experiments support the conclusion that the phosphorylated P gamma loses its interaction with GTP gamma S.T alpha. These observations include 1) detection of the inhibitory effect of the GTP gamma S.T alpha.P gamma complex on cGMP phosphodiesterase activity after P gamma in the complex is phosphorylated in a system reconstituted from isolated components, 2) no stimulating effect of GTP gamma S.T alpha on the phosphorylated P gamma-inhibited cGMP phosphodiesterase in the reconstituted system, 3) physical release of phosphorylated P gamma from GTP gamma S.T alpha in the reconstituted system, 4) no inhibitory effect of phosphorylated P gamma on both GTP hydrolysis by T alpha and GTP gamma S/GDP exchange on T alpha in the reconstituted system, and 5) no enhanced activity of cGMP phosphodiesterase by GTP gamma S.T alpha in rod outer segment membranes after incubation of the membranes with the kinase preparation in the presence of ATP. Together with our data that P gamma released with GTP.T alpha is not phosphorylated, and that phosphorylated P gamma inhibits more effectively cGMP phosphodiesterase activity than nonphosphorylated P gamma (Tsuboi, S., Matsumoto, H., Jackson, K. W., Tsujimoto, K., Williams, T., and Yamazaki, A. (1994) J. Biol. Chem. 269, 15016-15023), these observations suggest that, after P gamma is released with GTP.T alpha from catalytic subunits of cGMP phosphodiesterase, P gamma complexed with GTP.T alpha is phosphorylated by a kinase. Then, the phosphorylated P gamma is released from GTP.T alpha and binds to active cGMP phosphodiesterase to inhibit the cGMP hydrolysis. It is suggested that in some G-protein-dependent signal transduction systems G-protein-activated effector may be phosphorylated with a specific kinase and that phosphorylation of the effector results in the turnoff of signal transduction without GTP hydrolysis.

Phosphorylation of an inhibitory subunit of cGMP phosphodiesterase in Rana catesbeiana rod photoreceptors. I. Characterization of the phosphorylation

Interaction between the inhibitory subunit (P gamma) and catalytic subunits of cGMP phosphodiesterase is essential for the regulation of cGMP phosphodiesterase in vertebrate rod photoreceptors. P gamma phosphorylation in vitro has been studied using a kinase which is extracted from amphibian rod outer segments. Various chromatographies of the kinase preparation using ionic exchange, gel filtration, and heparin-Sepharose columns indicate that a kinase with M(r) 70,000 is responsible for the P gamma phosphorylation. The kinase does not require any of the known activators for protein kinases but is inhibited by cGMP in a concentration-dependent manner. Together with analysis by laser-desorption mass spectrometry, measurement of 32P radioactivity in phosphorylated P gamma indicates that P gamma extracted with GTP-bound transducin alpha subunit is not phosphorylated and that a phosphate is incorporated into more than 80% of the P gamma by the kinase. Phosphoamino acid analysis, sequencing of phosphorylated peptides derived from phosphorylated P gamma, and phosphorylation of synthetic peptides indicate threonine 22 in P gamma is phosphorylated by the kinase. Phosphorylated P gamma has a higher inhibitory activity for active cGMP phosphodiesterase than non-phosphorylated P gamma. These data suggest that threonine 22 in P gamma is phosphorylated by a specific kinase and that the P gamma phosphorylation governs the interaction between P gamma and catalytic subunits of cGMP phosphodiesterase in vertebrate rod photoreceptors.

Increase in production of hepatocyte growth factor by human embryonic lung fibroblasts in the process of aging in culture

It was determined whether human hepatocyte growth factor (hHGF)-producing ability would change in the human embryonic lung fibroblast cell strains (MRC-5 and IMR-90) until the cells senesced in culture. The effects of phorbol 12-myristate 13-acetate (PMA), dexamethasone, and transforming growth factor-beta 1 (TGF-beta 1) on hHGF production were also studied in these cell strains. For stimulation of DNA synthesis of adult rat hepatocytes in primary culture, hHGF secreted by MRC-5 cells at 39.9 and 69.8 population doubling levels (PDLs) showed almost the same activity as recombinant hHGF. Secretion of hHGF by MRC-5 cells increased about threefold between 37.3 and 67.8 PDLs. IMR-90 cells also showed about a threefold increase in hHGF secretion with increased passage from 37.8 to 66.0 PDL. Both cell strains showed almost the same ratio of hHGF amount in the cell extracts to that secreted into the medium around 40 and 70 PDLs. Northern blot analysis showed that the transcriptional level of the hHGF gene in MRC-5 cells increased about three-fold from 42.0 to 73.6 PDL in culture. These findings indicated that hHGF production increased in both cell strains with aging in culture. Production of hHGF in both cell strains was remarkably stimulated by treatment with 10 nM PMA. On the other hand, hHGF production in both cell strains was slightly suppressed by treatment with 1 microM dexamethasone. TGF-beta at a concentration of 5 ng/ml prominently inhibited hHGF production in both cell strains. The response of both cell strains to these regulators for hHGF production was almost the same around 40 and 70 PDLs in culture.

[Small incision cataract surgery-silicone intraocular lens vs polymethylmethacrylate intraocular lens]

We compared the postsurgical results of two small incision cataract surgery procedures: silicone intraocular lens implantation through a 3.2 mm incision and polymethylmethacrylate intraocular lens implantation through a 5.5 mm incision. One hundred fifty eyes of 124 patients were randomly assigned to either procedure, and the patients underwent phacoemulsification and intraocular lens implantation without sutures or scleral cautery. Identical surgical techniques were employed in each case except for the size of the incision. Patients in the 3.2 mm incision group showed: (1) better uncorrected and corrected visual acuity in the early postoperative period, (2) lower aqueous flare intensity immediately after surgery, (3) less operatively induced corneal astigmatism throughout the study period up to 3 months after surgery, and (4) less corneal topographic change, i.e., less corneal flattening, 3 months after surgery. There were no significant differences between groups in the corneal endothelial cell loss, blood-aqueous barrier permeability measured by fluorophotometry, or postoperative complications. It was concluded that both procedures offer highly satisfactory clinical results, but that the 3.2 mm incision surgery allows a significantly earlier recovery of visual function and less surgery-induced corneal astigmatism.

Differential E-selectin-dependent adhesion efficiency in sublines of a human colon cancer exhibiting distinct metastatic potentials

Previously we have shown that high metastatic colonic carcinoma cells express relatively more lamp molecules and sialyl Le(x) structures on the cell surface than their corresponding low metastatic counterparts (Saitoh, O., Wang, W.-L., Lotan, R., and Fukuda, M. (1992) J. Biol. Chem. 267, 5700-5711). In the present study, we extended these findings by testing whether these high and low metastatic colonic carcinoma cells differ in their adhesion efficiency to E-selectin-expressing cells. First, it was found that the high metastatic cells, as compared to their low metastatic counterparts, bind more efficiently to activated human endothelial cells that express E-selectin. This was also true when the adhesion was tested for Chinese hamster ovary cells stably expressing E-selectin. In addition, it was found that the high metastatic cells also adhere more efficiently to mouse endothelioma cells after activation with interleukin-1 beta. It was also shown that the adhesion can be inhibited by soluble lamp-1 or soluble leukosialin that contain sialy Le(x) termini. The inhibition was not, however, observed when these soluble glycoproteins lack sialyl Le(x) structures. The results indicate that the efficiency of the E-selectin-mediated binding of colonic carcinoma cells to human and mouse endothelial cells correlates with the metastatic potential of the cells and suggest that this adhesive event may be one of the critical factors for the metastatic spread of tumor cells. Soluble forms of leukosialin or lamp-1 may be useful as therapeutic agents for the inhibition of E-selectin-mediated binding to tumor cells.

Magnesium distribution in human bone

The present study was undertaken to reveal the magnesium distribution in human bone. Sixty human ribs, obtained from subjects aged 10-80 years of age, were used. Transverse sections were prepared from the middle region of the human ribs. Adjacent sections were ground to a thickness of about 1000 microns. One section was used for magnesium determination by atomic absorption spectrophotometry, and the other was used for analysis with X-ray microanalysis. Thirty micron thick samples were abraded continuously from the periosteal and the endosteal surfaces by abrasive microsampling, as previously described by Weatherell et al. Results showed that magnesium concentrations were higher in both the periosteal and endosteal surfaces and did not change with age in general, although it tended to be higher among teenagers and lower over 80 years old.

[A case of early gastric cancer with Virchow's node metastasis, effectively treated by high dose of UFT]

We report a case of early gastric cancer with Virchow's node metastasis. The patient underwent partial gastrectomy and postoperative immunochemotherapy using MMC, 5'-DFUR and PSK, which reduced the Virchow's node. Three years after surgery, we found metastases to the left subclavicular and axillary nodes other than the Virchow's node. Then UFT was administered orally at 600 mg/day, and the metastatic nodes diminished, then vanished. The patient is alive nearly five years after surgery.

Inhibitory effects of S-(1,2-dicarboxyethyl)glutathione on collagen-induced platelet aggregation; enhancements of cyclic AMP level and adenylate cyclase activity in platelets by S-(1,2-dicarboxyethyl)glutathione

S-(1,2-Dicarboxyethyl)glutathione (DCE-GS) in addition to being present in the liver, lens, and heart, also inhibited platelet aggregation. To clarify these inhibitory effects, the role of DCE-GS in the release of ATP and serotonin from platelets was studied, as was thromoboxane A2 formation, cyclic AMP level and adenylate cyclase activity in human platelets. The results are as follows: DCE-GS at a concentration of 1.3 mM inhibited ATP and serotonin release from platelets induced by collagen, by 77.4 +/- 4.3 and 78.7 +/- 6.3%, respectively. At 1.5 mM DCE-GS also inhibited the formation of thromboxane B2 by 79.6 +/- 4.1%. Incubation of human platelet rich plasma with 2 mM of DCE-GS for 10 min increased the cyclic AMP level and the activity of adenylate cyclase by 204 +/- 28 and 211 +/- 11.7%, respectively. These results suggest that the inhibitory effect of DCE-GS on the platelet aggregation induced by collagen is due to an increase in the cyclic AMP level in platelets, which in turn may be due to enhancement of the activity of adenylate cyclase.

Immortalization of epithelial-like cells from human liver tissue with SV40 T-antigen gene

The cells derived from the human embryo liver tissue were transfected with a plasmid pSV3neo containing both the large and small T-antigen gene of the early region of simian virus 40 (SV40), and two cell strains, OUMS-21 and -22, were obtained. OUMS-22 cells, to date, have reached over 100 population doublings through a culture crisis and are considered to have become an immortal cell line. However, OUMS-21 cells failed to become an immortal cell line. Both OUMS-21 and -22 cells were SV40 T-antigen-positive, epithelial-like, and immunoreactive against an anti-keratin 18 monoclonal antibody but against neither an anti-vimentin nor an anti-von Willebrandt factor VIII monoclonal antibody. The staining pattern of cytokeratin in these cells was similar to that in the differentiated human hepatoblastoma and hepatocellular carcinoma cell lines but not to that in the human cholangiocellular carcinoma cell lines. OUMS-21 and -22 cells expressed neither alpha-fetoprotein nor albumin mRNAs. These cells showed no tyrosine aminotransferase activity. However, both OUMS-21 and -22 cells were sensitive to cytotoxicity of aflatoxin B1, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole, and benzo[a]pyrene, whereas human embryo lung fibroblasts were insensitive to the cytotoxicity of these carcinogens. These findings suggest that OUMS-21 and -22 cells may arise from undifferentiated liver stem cells or from hepatocytes that lost their ability to express the liver-specific functions prior to immortalization. Both OUMS-21 and -22 cells expressed glutathione S-transferase pi (GST-pi) mRNA. The expression of GST-pi mRNA highly increased in OUMS-22 cells with their immortalization. Karyotypic analysis showed that numerical and structural aberrations of the chromosomes were profound, but neither specific events nor marker chromosomes were found in OUMS-21 and -22 cells. Both OUMS-21 and -22 cells could grow in soft agar, but they were not tumorigenic when transplanted into nude mice.

Regulation of G protein function by an effector in GTP-dependent signal transduction. An inhibitory subunit of cGMP phosphodiesterase inhibits GTP hydrolysis by transducin in vertebrate rod photoreceptors

The regulation of cGMP phosphodiesterase in vertebrate rod photoreceptors is a typical G protein-dependent signal transduction mechanism. The interaction of P gamma, an inhibitory subunit of cGMP phosphodiesterase, with transducin alpha subunit (T alpha) is essential for the activation of cGMP phosphodiesterase. It has been shown that, in a homogenized preparation of frog (Rana catesbeiana) rods, P gamma interacts with GTP.T alpha and remains tightly bound to GDP.T alpha after GTP hydrolysis on T alpha. Association of this complex with beta gamma subunits of transducin (T beta gamma) triggers the release of P gamma from the complex and the subsequent inactivation of cGMP phosphodiesterase. In a system reconstituted with purified components, both GTP- and GDP-bound forms of T alpha were found to interact with P gamma. Under these conditions, P gamma inhibited GTP hydrolysis by transducin in a noncompetitive manner with a Ki of 92 nM. Binding of an hydrolysis-resistant GTP analog to T alpha was also inhibited by P gamma. These inhibitions of transducin function were resulted from the inhibition of both hydrolysis of GTP bound to T alpha and interaction of GDP.T alpha with membrane-bound T beta gamma. However, after GDP.T alpha reassociated with membrane-bound T beta gamma, the inhibitory effect of P gamma on the binding of an hydrolysis-resistant GTP analog to T alpha was greatly diminished, suggesting that the GTP/GDP exchange on T alpha was not inhibited by P gamma. These data indicate that the T alpha function is altered during complexing with P gamma. G protein functions may be modified by interacting with an effector in the G protein-dependent signal transduction.

Distribution of fluoride in cortical bone of human rib

We describe a detailed study of fluoride distribution with age in the human cortical rib bone. Human ribs were obtained from 110 subjects (M:68, F;42) aged 20-93 years. The fluoride distribution from the periosteal to endosteal surfaces of the ribs was determined by sampling each specimen using an abrasive micro-sampling technique, and the samples were analyzed using the fluoride electrode, as described by Weatherell et al. [1]. The concentration of fluoride was highest in the periosteal region, decreased gradually towards the interior of the tissue where the concentration of fluoride tended toward the plateau, and then rose again towards the endosteal surface. Patterns of fluoride distribution changed with age, and the difference between periosteal and endosteal fluoride levels increased with age. Although average fluoride concentrations increased with age in both sexes, there was a significant difference between males and females at the age of about 55 years (P < 0.05).

[Results of 29-year study of hoya (sea-squirt) asthma in Hatsukaichi, Hiroshima prefecture]

As remarkable improvements have been made to the working environment and working methods of oyster shucking workers during the past 30 years, a study was made on the effects of these improvements on hoya (sea-squirt) asthma and the following results were obtained. 1) The prevalence of hoya (sea-squirt) asthma among oyster shucking workers was 36.0%, 30.1%, 21.7%, 22.0%, 18.0%, and 26.6% in 1963, 1968, 1976, 1984, 1988, and 1992, respectively. Accompanying the improvements made to the working environment and working methods, asthmatic symptoms failed to develop in some of the patients through engaged in oyster shucking work. Thus, those with symptoms actually accounted for 36.0%, 18.7%, 15/8%, 7.4%, 8.4%, and 8.0% of the workers, respectively. 2) The proportion of serious cases among the patients rapidly decreased from 29.2% in 1963 to 0% after 1984. On the other hand the proportion of slight cases was 35.4% in 1963, but after 1988 all the cases were slight cases. 3) During the period from 1984 to 1992, the number of those newly engaged in oyster shucking work was 74. The number of those who developed hoya (sea-squirt) asthma during this period was 8 or 10.1%. All the cases were asthma of the rhinitis type. 4) The number of workers who did not develop asthmatic symptoms though engaged in oyster shucking work was 53 in 1984, 40 in 1988, and 49 in 1992. Of this number, 31% are now under hyposensitization therapy, 57.0% have received this therapy in the past, and 12.0% have not received any therapy.

[Lifestyles related to preserving 20 or more teeth at 80 years of age]

To explore lifestyle factors related to preserving 20 or more teeth at 80 years of age, a total of 114 Japanese persons aged 80 years old (70 with 20 teeth or more (mean teeth: 25.0 +/- 2.8) and 44 with 19 teeth or less (mean teeth: 5.2 +/- 6.3)) were studied. Study subjects received a dental examination and were directly interviewed, using a questionnaire, to collect such information as past episodes of tooth and gingival conditions, past attitude to dental care and several lifestyle habits. The following major findings emerged by statistical analysis. Probability of preserving 20 or more teeth at 80 years of age was significantly high with: (1) strict upbringing in childhood (p < 0.05 in males), (2) no swollen gums around 60 years old (p < 0.01 in males), (3) early visit to a dentist around 40 years old (p < 0.05 in males), and (4) not being fond of sweets in childhood (p < 0.05 in females). The following related to a high tendency toward preserving 20 or more teeth at 80 years of age: (1) graduate from primary school only (in females), (2) having a home dentist around 20 years old (in males), (3) tended to visit a dentist earlier at 20 years old (in males), (4) not eating sweet things at 60 years old (in males), and (5) have not smoked cigarettes (in males).(ABSTRACT TRUNCATED AT 250 WORDS)

Increase of S-(1,2-dicarboxyethyl)glutathione in regenerating rat liver

Changes in the level of S-(1,2-dicarboxyethyl)glutathione (DCE-GS) with time were determined during regeneration of rat liver after partial hepatectomy. The DCE-GS level increased in regenerating rat liver, reaching a maximum level (4.7-fold) on day 2 and reverted to the normal level in 1 week. During the liver regeneration process, the activity of DCE-GS-synthesizing enzyme in the liver retained its control level, while the level of glutathione--a substrate of the enzyme in the liver--fluctuated in parallel with that of DCE-GS.

Crystal structure of papain-succinyl-Gln-Val-Val-Ala-Ala-p-nitroanilide complex at 1.7-A resolution: noncovalent binding mode of a common sequence of endogenous thiol protease inhibitors

Succinyl-Gln-Val-Val-Ala-Ala-p-nitroanilide corresponding to a common sequence of endogenous thiol protease inhibitors is a noncompetitive reversible inhibitor of papain. In order to elucidate the binding mode of the inhibitor at the atomic level, its complex with papain was crystallized at ca. pH 7.0 using the hanging drop method, and the crystal structure was analyzed at 1.7-A resolution. The crystal has space group P2(1)2(1)2(1), with a = 43.09, b = 102.32, c = 49.69 A, and Z = 4. A total of 47,215 observed reflections were collected on the imaging plates using the same single crystal, and 19,833 unique reflections with Fo > sigma (Fo) were used for structure determination and refinement. The papain structure was determined by use of the atomic coordinates of papain previously reported, and then refined by the X-PLOR program. The inhibitor molecule was located on a difference Fourier map and fitted into the electron density with the aid of computer graphics. The complex structure was finally refined to R = 19.6% including 118 solvent molecules. The X-ray analysis of the complex crystal shows that the inhibitor is located at the R-domain side, not in the center of the binding site created by the R- and L-domains of papain. Such a binding mode of the inhibitor explains well the biological behavior that the inhibitor exhibits against papain. Comparison with the structure of papain-stefin B complex indicates that the structure of the Gln-Val-Val-Ala-Gly sequence itself is not necessarily the essential requisite for inhibitory activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Autophagy in yeast demonstrated with proteinase-deficient mutants and conditions for its induction

For determination of the physiological role and mechanism of vacuolar proteolysis in the yeast Saccharomyces cerevisiae, mutant cells lacking proteinase A, B, and carboxypeptidase Y were transferred from a nutrient medium to a synthetic medium devoid of various nutrients and morphological changes of their vacuoles were investigated. After incubation for 1 h in nutrient-deficient media, a few spherical bodies appeared in the vacuoles and moved actively by Brownian movement. These bodies gradually increased in number and after 3 h they filled the vacuoles almost completely. During their accumulation, the volume of the vacuolar compartment also increased. Electron microscopic examination showed that these bodies were surrounded by a unit membrane which appeared thinner than any other intracellular membrane. The contents of the bodies were morphologically indistinguishable from the cytosol; these bodies contained cytoplasmic ribosomes, RER, mitochondria, lipid granules and glycogen granules, and the density of the cytoplasmic ribosomes in the bodies was almost the same as that of ribosomes in the cytosol. The diameter of the bodies ranged from 400 to 900 nm. Vacuoles that had accumulated these bodies were prepared by a modification of the method of Ohsumi and Anraku (Ohsumi, Y., and Y. Anraku. 1981. J. Biol. Chem. 256:2079-2082). The isolated vacuoles contained ribosomes and showed latent activity of the cytosolic enzyme glucose-6-phosphate dehydrogenase. These results suggest that these bodies sequestered the cytosol in the vacuoles. We named these spherical bodies "autophagic bodies." Accumulation of autophagic bodies in the vacuoles was induced not only by nitrogen starvation, but also by depletion of nutrients such as carbon and single amino acids that caused cessation of the cell cycle. Genetic analysis revealed that the accumulation of autophagic bodies in the vacuoles was the result of lack of the PRB1 product proteinase B, and disruption of the PRB1 gene confirmed this result. In the presence of PMSF, wild-type cells accumulated autophagic bodies in the vacuoles under nutrient-deficient conditions in the same manner as did multiple protease-deficient mutants or cells with a disrupted PRB1 gene. As the autophagic bodies disappeared rapidly after removal of PMSF from cultures of normal cells, they must be an intermediate in the normal autophagic process. This is the first report that nutrient-deficient conditions induce extensive autophagic degradation of cytosolic components in the vacuoles of yeast cells.

Effect of continuous circular capsulorhexis and intraocular lens fixation on the blood-aqueous barrier

Permeability across the blood-aqueous barrier to fluorescein was estimated fluorophotometrically in pseudophakic eyes for which a continuous circular capsulorhexis was performed. The permeability index was significantly higher in the in-the-bag fixations than in the out-of-the-bag fixations at 3 and 6 months after surgery, when only bilateral cases were enrolled. Damage to the barrier in eyes with the in-the-bag fixations was attributable to the broad attachment of optics to the anterior capsule, because a positive linear regression was obtained between the permeability index and the doughnut-shaped contact area in eyes with the in-the-bag fixations. The permeability index in eyes with the in-the-bag fixations was as low as that in eyes with the out-of-the-bag fixations when the contact area was small. These results indicate an unfavorable effect of the in-the-bag fixation with broad contact of the optics with the anterior capsule and, thus, suggest either an in-the-bag fixation with a large capsulorhexis or an out-of-the-bag fixation.

Effects of barbiturates with or without liver-tumor-promoting activity on survival and DNA synthesis of suckling and adult rat hepatocytes in serum-free primary culture

The effects of four barbiturates with or without liver-tumor-promoting activity were examined on survival and deoxyribonucleic acid (DNA) synthesis of suckling and adult rat hepatocytes in serum-free primary culture: Of the four barbiturates, two promoters, phenobarbital and barbital, enhanced DNA synthesis of suckling rat hepatocytes at low concentrations of 0.5-2 mM or 0.5 mM, but suppressed it at high concentrations of 3 mM or 1.5-4 mM. DNA synthesis of adult rat hepatocytes was, however, only suppressed by phenobarbital within the dose range tested of 1-3 mM. On the other hand, two remaining non-promoters, barbituric acid and amobarbital, did not increase but only suppressed DNA synthesis of suckling rat hepatocytes within the dose ranges of 0.5-4 mM and 0.05-0.5 mM respectively. Phenobarbital and amobarbital were effective for supporting survival and maintaining morphological features of suckling and adult rat hepatocytes at the relatively high concentrations of 3-4 mM and 0.5-0.75 mM respectively. However, barbital and barbituric acid were ineffective for maintenance of hepatocytes. The results show that the ability to support survival of primary cultured hepatocytes is not a common property of liver-tumor-promoter barbiturates but is a common property of some barbiturates with high lipophilicity, and that the maintenance of hepatocytes by phenobarbital or amobarbital is not due to a counterbalance of stimulated proliferation and death of the cells.

Purification and characterization of formaldehyde dehydrogenase from rat liver cytosol

Formaldehyde dehydrogenase was purified to electrophoretic and column chromatographic homogeneity from rat liver cytosolic fraction by a procedure which includes ammonium sulfate precipitation, DEAE-cellulose-, hydroxyapatite-, Mono Q-chromatography, and gel filtration. Its molecular mass was estimated to be 41 kDa by gel filtration and SDS-PAGE, suggesting that it is a monomer. It utilized neither methylglyoxal nor aldehydes except formaldehyde as a substrate. It has been reported that liver class III alcohol dehydrogenase and formaldehyde dehydrogenase are the same enzyme and oxidize formaldehyde and long chain primary alcohols. However, the enzyme examined here did not use n-octanoi as a substrate. The Km values for formaldehyde and NAD+ were 5.09 and 2.34 microM at 25 degrees C, respectively. The amino acid sequences of 10 peptides obtained from the purified enzyme after digestion with either V8 protease or lysyl endopeptidase were determined. From these results, the enzyme was proved to be different from the previously described mammalian formaldehyde dehydrogenase and is the first true formaldehyde dehydrogenase to be isolated from a mammalian source.

Nonspecific lipid transfer protein in castor bean cotyledon cells: subcellular localization and a possible role in lipid metabolism

The subcellular localization and several biochemical activities of nonspecific lipid transfer protein (nsLTP) were investigated. A section of a castor bean cotyledon cell was labeled with anti-nsLTP serum followed by protein A-gold. Gold particles were more abundant in the glyoxysome matrix and the vessel cell wall than in other areas. Cell fractionation analysis of 6-day-old castor bean cotyledons by sucrose density gradient centrifugation demonstrated that 13% of nsLTP was distributed in the glyoxysomal fraction, identified on the basis of catalase as a marker, and 87% in the soluble fraction near the top of the gradient. The location of castor bean nsLTP in glyoxysomes was further confirmed by in vitro import experiments. The synthesized precursor of nsLTP (pro-nsLTP-C) was incorporated into intact castor bean glyoxysomes and processed to the mature form after import into the glyoxysomes, but it was not imported into canine pancreatic microsomes. Castor bean nsLTP-A was found to possess the ability to bind oleic acid and oleoyl-CoA by means of a method involving Lipidex 1000. The dissociation constants (Kd) for oleic acid and oleoyl-CoA binding to nsLTP-A were 4.8 and 5.0 microM, respectively. The saturated binding capacities (Bmax) for oleic acid and oleoyl-CoA per mol of nsLTP-A were 1.1 and 1.2 mol, respectively. When acyl-CoA oxidase activity was assayed in the glyoxysomal fraction, marked enhancement of the activity was observed in the presence of nsLTP. These results suggest the possibility that nsLTP regulates fatty acid beta-oxidation through the enhancement of acyl-CoA oxidase activity in glyoxysomes. The occurrence of castor bean nsLTP in the vessel wall was discussed.