Zinc-Substituted Hemoglobin-Albumin Cluster as a Porphyrin-Carrier for Enhanced Photodynamic Therapy

Apohemoprotein is focused on the field of theranostics, serving as a porphyrin carrier. Hemoglobin (Hb) consists of α2β2 tetramer with iron(II)-protoporphyrin IX (heme) bound to each globin. However, heme-removed Hb (apoHb) causes dissociation at αβ interfaces and aggregation under physiological conditions. We synthesized a stable apoHb derivative comprising intramolecular-crosslinked apoHb (apoXHb) and human serum albumin (HSA), apoXHb-HSA3. ApoXHb-HSA3 engendered no aggregates in the physiological solutions. Moreover, apoXHb-HSA3 was reconstituted with zinc(II)-protoporphyrin IX (ZnP), generating ZnXHb-HSA3, a potent photosensitizer for photodynamic therapy (PDT). The photophysical properties of ZnXHb-HSA3 were identical to those of zinc-substituted XHb (ZnXHb). Cellular uptake behavior was evaluated using various cancer cell lines. ZnXHb-HSA3 released ZnP around the cells, and the free ZnP penetrated cell membranes. In contrast, protein units were not observed within the cells. ZnXHb-HSA3 showed no cytotoxicity under dark conditions and demonstrated superior PDT activity in comparison to naked ZnXHb. ZnXHb-HSA3 acts as an innovative porphyrin carrier for enhanced PDT.

Next-generation sequencing for patients with non-obstructive azoospermia: implications for significant roles of monogenic/oligogenic mutations

Azoospermia affects up to 1% of adult men. Non-obstructive azoospermia is a multifactorial disorder whose molecular basis remains largely unknown. To date, mutations in several genes and multiple submicroscopic copy-number variations (CNVs) have been identified in patients with non-obstructive azoospermia. The aim of this study was to clarify the contribution of nucleotide substitutions in known causative genes and submicroscopic CNVs in the genome to the development of non-obstructive azoospermia. To this end, we conducted sequence analysis of 25 known disease-associated genes using next-generation sequencing and genome-wide copy-number analysis using array-based comparative genomic hybridization. We studied 40 Japanese patients with idiopathic non-obstructive azoospermia. Functional significance of molecular alterations was assessed by in silico analyses. As a result, we identified four putative pathogenic mutations, four rare polymorphisms possibly associated with disease risk, and four probable neutral variants in 10 patients. These sequence alterations included a heterozygous splice site mutation in SOHLH1 and a hemizygous missense substitution in TEX11, which have been reported as causes of non-obstructive azoospermia. Copy-number analysis detected five X chromosomal or autosomal CNVs of unknown clinical significance, in addition to one known pathogenic Y chromosomal microduplication. Five patients carried multiple molecular alterations. The results indicate that monogenic and oligogenic mutations, including those in SOHLH1 and TEX11, account for more than 10% of cases of idiopathic non-obstructive azoospermia. Furthermore, this study suggests possible contributions of substitutions in various genes as well as submicroscopic CNVs on the X chromosome and autosomes to non-obstructive azoospermia, which require further validation.

The dominant non-gibberellin-responding dwarf mutant (D8) of maize accumulates native gibberellins

The endogenous gibberellins (GAs) were examined from young vegetative shoots of the dominant mutant, Dwarf-8, a GA-nonresponder, and normal maize; GA(44), GA(17), GA(19), GA(20), GA(29), GA(1), and GA(8), members of the early-13-hydroxylation pathway, were identified from both kinds of shoots by full-scan mass spectra and Kovats retention indices. In addition, we report the identification of 3-epi-GA(1), GA(3), GA(4), GA(5), GA(7), GA(9), GA(12), GA(15), GA(24), GA(34), and GA(53) by using the same criteria. [1,7,12,18-(14)C(4)]GA(53) and -GA(44), [17-(2)H(2)]GA(19), and [17-(13)C,(3)H(2)]GA(20), -GA(29), -GA(1), -GA(8), and -GA(5) were used as internal standards to determine the endogenous levels of these GAs by measurement of isotope dilution, using capillary gas chromatography and selected ion monitoring. Shoots of Dwarf-8 accumulate relatively high levels of GA(20), GA(1), and GA(8). The accumulation of GA(1) appears to be related to gene dosage. Since Dwarf-8 contains the same pattern of GAs as normals (including GA(1) and GA(3)), the genetic control point probably lies after GA(1) (and GA(3)). Thus Dwarf-8 may be a GA receptor mutant or a mutant that controls a product downstream from the binding of the bioactive GA to a receptor.

[A case of 9p-syndrome identified chromosome 20 on chromosome 9p by M-FISH]

In this report, we describe one-year-old girl diagnosed with 9p-syndrome. Cytogenetic studies of this patient confirmed a karyotype of 46,XX,add(9) (p24) chromosome, but could not find the additional fragment on 9p22 in one allele. Fluorescence in situ hybridization (FISH) studies could not confirm the fragment in the patient using the LIS1 gene probe which mapped to 9p22. The more recently developed M-FISH method clearly showed that the additional fragment was 20p in this patient. These findings suggest that M-FISH analysis may be a useful method for identifying unknown additional and rearranged chromosomes.

Identity of Cypripedium calceolus (Orchidaceae) in Rebun Island: comparative DNA analysis of related species

Cypripedium calceolus was found in 1980 in Rebun Island off the north coast of Hokkaido, Japan, but the origin of this plant has been a controversial issue. In this study, we have made a comparative study by chloroplast DNA sequencing analysis among C. calceolus which occurs in Rebun Island and populations of C. calceolus from western Europe, China and far eastern Russia (Nakhodka), and also as references, C. macranthos in Japan and other Cypripedium species in North America. A Cypripedium cf. "calceolus", found recently in eastern Hokkaido, was also included in this analysis. The C. calceolus samples analyzed were categorized into three groups, i.e., those from Western Europe, from China and far eastern Russia, and from Rebun Island. The C. calceolus in Rebun Island was clearly different from the others in terms of DNA sequence and morphological features. The C. cf. calceolus from eastern Hokkaido and one sample from Nadhodka, Russia, were also classified into the same group as those from Rebun Island, although some differences in their morphological features were observed. It is concluded that the C. calceolus found in Rebun Island is not identical with those growing in Europe and China. In addition, it was found that it may be possible to classify C. macranthos into two groups, namely groups which include or do not include var. rebunense. An unidentified Cypripedium species found in Rebun Island falls into the same group as var. rebunense.

Triiodobenzoic acid, an auxin polar transport inhibitor, suppresses somatic embryo formation and postembryonic shoot/root development in Eleutherococcus senticosus

The effect of auxin polar transport inhibitor on somatic embryo development and postembryonic growth in Siberian ginseng (Eleutherococcus senticosus) was examined. In the presence of 2,3,5-triiodobenzoic acid (TIBA), an auxin polar transport inhibitor, embryo formation from embryogenic cells was suppressed, while cell division was not affected. When globular embryos at different stages were transferred onto medium containing TIBA, development of axial and bilateral polarity was suppressed in a stagespecific manner. In abnormal embryos induced by TIBA, further development of shoot and root apical meristems and vascular differentiation was also suppressed. Thus, abnormal development of embryos induced by inhibition of auxin polar transport resulted in plantlets without shoots and roots.

Rice gibberellin-insensitive gene homolog, OsGAI, encodes a nuclear-localized protein capable of gene activation at transcriptional level

This paper reports isolation and properties of a rice gene, OsGAI, a putative homolog of the GAI of Arabidopsis thaliana. OsGAI encodes a polypeptide of 625 amino acids, which shows 53-55% identity to GAI and RGA from A. thaliana, and 85% identity to wheat rht-D1a and maize d8. Genomic DNA blot analysis indicated the OsGAI to be a single-copy gene in the rice genome. RNA blot hybridization showed that OsGAI transcripts increased within 6h upon GA(3) but not ABA application. This GA-induced increment in OsGAI transcripts did not require de novo protein synthesis. High levels of OsGAI transcripts were detected in nodes, internodes, leaf sheaths and ears of adult plants and leaf sheaths of young seedlings, where GA enhances cell elongation and division. Transiently expressed OsGAI-GFP fusion protein located to the nucleus in onion epidermal cells. Transactivation assays clearly indicated that OsGAI protein is a transcriptional activator or a coactivator.

Gibberellin-responsive genes: high level of transcript accumulation in leaf sheath meristematic tissue from Zea mays L

In order to identify genes that are related to the gibberellin (GA) response in maize (Zea mays L.), mRNA species from wild-type and single-gene dwarf mutants, d5 and D8, were compared by fluorescent differential display. The d5 mutant is unable to produce biologically active GA, but recovers its tall stature on exogenous application of GA. D8 is insensitive to GA, despite the accumulation of a high level of endogenous GA, suggesting it to be a receptor mutant or a mutant in signal transduction pathway(s). After screening 7000 cDNA populations, one clone was isolated, for which transcripts were rare in d5 shoots but accumulated within 1 h after GA3 application. This clone, designated as ZmGR1a, encodes a polypeptide with a relative molecular mass of ca. 13 kDa, which shows significant homology to proline-rich proteins from several plant species. A similar experiment with D8 identified a clone, ZmGR2a, with low transcript levels, but accumulation within 6 h after GA3 treatment of d5 shoots. ZmGR2a encodes a polypeptide with a relative molecular mass of ca. 19 kDa, which shows no significant homology with any known protein. Southern blot analysis indicated that ZmGR1a and ZmGR2a form a small multigene family within the maize genome. In situ hybridization with wild-type seedlings showed transcripts on both to be abundant in leaf sheath meristematic tissue, in which GA enhances cell elongation and cell division.

Definitive radiotherapy combined with high-dose-rate brachytherapy for Stage III carcinoma of the uterine cervix: retrospective analysis of prognostic factors concerning patient characteristics and treatment parameters

PURPOSE

To assess treatment outcome after definitive radiotherapy for Stage III cervical carcinoma retrospective analysis of the clinical data was performed.

METHODS AND MATERIALS

We enrolled 265 patients with Stage III cervical carcinoma who were treated with combined external beam radiotherapy [mean +/- standard deviation (SD), 50.3 +/- 1.8 Gy; range 40-70) and intracavitary brachytherapy (ICBT) (mean +/- SD, 19.8 +/- 2.4 Gy; range 10-32) using a high-dose-rate 60Co source. We retrospectively analyzed, as measures of the therapeutic outcome, the overall survival rate (OAS), relapse-free survival rate (RFS), locoregional event-free rate (LREF), distant metastasis (DM), and late complication.

RESULTS

The 5-year OAS, RFS, and LREF rates (n = 265) were 50.7%, 57.1%, and 71.2%, respectively. Univariate analysis revealed a significant favorable effect on the OAS rate for complete response (CR) (p = 0.024), maximum tumor diameter < 6 cm (SML) (p = 0.0009), Karnofsky performance score > or =70 (p = 0.046), age <75 years (p = 0.0043), hemoglobin (Hb) concentration of > or =9 g/dl (p = 0.0005), and histopathological diagnosis of squamous cell carcinoma (SCC) (p = 0.0089). In the multivariate analysis, Hb, SCC, SML, and CR remained significant prognostic factors. In both univariate and multivariate analysis, SML, Hb, age, and SCC showed significant effects on the RFS rate. Age > or =60 years (p = 0.017), Hb > or =9 g/dl (p = 0.0039), and SML (p = 0.0046) were significant favorable prognostic factors for the LREF rate identified by univariate analysis. In addition, advanced age, SML, and SCC showed significant beneficial effects on the LREF rate in the multivariate analysis. DM developed in 21.1% of patients, and the groups with Hb < 9 g/dl (p < 0.005), Karnofsky performance score of <70 (p < 0.001), and dose at point A in the ICBT < 16 Gy (p < 0.005) developed a significantly greater incidence of DM than did the groups without. The 5-year incidence was 2.6% for major bladder complication and 8.3% for major rectal complication. The radiation dose in the subgroup with rectal complication was significantly greater than that in the subgroup without complications.

CONCLUSION

In patients with Stage III cervical carcinoma, tumor size, concentration of Hb, and histopathological diagnosis are strong prognostic factors for the therapeutic outcome. The ICBT dose in our study was small compared to the reported data, but the outcome was quite comparable. Thus, the dose we used might be the minimum required. However, locoregional control still remains an important problem. It is necessary to attain the optimal dose distribution in both the target volume and in critical organs. In high-risk patients, combined use of chemotherapy is crucial to improve the response to radiation.

Biochemical and serological examination of beta-hemolytic streptococci isolated from slaughtered pigs

A total of 170 beta-hemolytic streptococci isolated from lesions in slaughtered pigs during 1988 to 1995 were identified by biochemical and serological examinations. Of these, 132 strains (77.6%) were Streptococcus (S.) dysgalactiae and 38 strains (22.4%) were S. porcinus. The largest serological group of streptococci was group C (78 strains, 45.9%), followed by group L (43 strains, 25.3%), group U (14 strains, 8.2%), group G (11 strains, 6.5%), group E (5 strains, 2.9%), and group P (5 strains, 2.9%). Most of isolates from endocarditis (61 strains) and arthritis (25 strains) were group C S. dysgalactiae, but about 33.3% of the isolates from lymphadenitis were group L S. dysgalactiae (28 strains), followed by group C (14 strains, 16.7%), group U S. porcinus (14 strains, 14.3%), and group G (10 strains, 11.9%).

Bacterial isolation from slaughtered pigs associated with endocarditis, especially the isolation of Streptococcus suis

Bacterial isolation from slaughtered pigs with endocarditis was carried out from 1985 to 1994. A total of 495 (0.025%) out of 2,006,127 pigs were diagnosed as having endocarditis. Though bacteria were significantly isolated from 399 of the 495 pigs, bacteria could not be isolated in 96 pigs (19.4%). In 11 pigs, 2 bacterial species were isolated from heart lesion. Streptococcus suis was isolated from 127 cases (25.7%), Streptococcus dysgalactiae from 75 (15.2%), Erysipelothrix rhusiopathiae from 63 (12.7%), Actinomyces pyogenes from 39 (7.9%), Pasteurella multocida from 11 (2.2%). Staphylococcus aureus from 10 (2.0%), and Streptococcus porcinus from 8 (1.6%). Among the 99 isolates biochemically identified as S. suis, the major serotype was S. suis type 2 (35.4%). The remainder of the typable isolates were identified as serotypes 1/2 (2.0%) and 9 (1.0%). A total of 61 isolates (61.6%) were untypable.

Comparative preparation methods of sialylated capsule antigen from Streptococcus suis type 2 with type specific antigenicity

The capsular polysaccharide (CPS) of Streptococcus (S.) suis type 2 was isolated from a type strain of S. suis NCTC 10234 by three different preparative methods: (A) lysozyme treatment method, (B) autoclave extraction method, and (C) HCl-extraction method. The structural characteristics of the three CPS (CPS-A, B and C) were examined by gel permeation chromatography, reactivity against rabbit antiserum and proton-nuclear magnetic resonance (1H-NMR). N-Acetylneuraminic acid (NeuAc) residues as sialic acid in CPS-C were partially dissociated or degraded during preparation with a remarkable decrease in the molecular mass and the antigen activity. Although both methods A and B produced intact CPS without releasing NeuAc residues, method B was considered to be a more suitable procedure for preparing the CPS antigen because of time-saving and safety factors. Sugar analysis by high performance liquid chromatography and gas liquid chromatography showed that CPS-B consisted of five kinds of sugars: Rhamnose (Rha), Glucose (Glc). Galactose (Gal), N-acetylglucosamine (GlcNAc) and NeuAc, in a molar ratio of 1.00:0.95:3.68:0.80:1.31. After complete removal of NeuAc residues by mild acid hydrolysis of CPS-B, the reactivity with anti-type 2 serum was not detected. The NeuAc residue in CPS of S. suis type 2 strain was thought to be the antigen epitope portion.

Typing of Rhodococcus equi isolated from submaxillary lymph nodes of pigs in Japan

Isolation of Rhodococcus equi from the submaxillary lymph nodes of pigs, with or without caseous lymphadenitis, and typing of the isolates by two serological methods were carried out. The rate of isolation of the organisms from the lymph nodes of pigs was 5 times higher in the lymph nodes with caseous lymphadenitis than in those without the lesion. Of 219 isolates, 146 (66.7%) were typable by the method of Prescott, while all the 219 isolates (100%) were typable by the method of Nakazawa et al. The most frequently isolated were serotype 2 of Prescott (identical to serogroup 16 of Nakazawa et al.), and serogroup 3 of Nakazawa et al., which did not correspond with any serotypes of Prescott. Serotypes/serogroups of R. equi from pigs were thus first clarified in Japan.

[Clinical effect of combined chemotherapy with UFT, MMC and OK-432 in recurring or advanced cancer of the digestive organs]

The usefulness of UFTMO therapy (combined chemotherapy with UFT, MMC and OK-432) performed in 40 cases of recurring or advanced cancer of the digestive organs was investigated. According the response criteria by Koyama et al., of 40 eligible cases, the treatment was judged effective in 13, 2 CR and 11 PR cases with a response rate of 32.5%, while of the 35 complete cases, 2 CR and 9 PR cases made for 11 effective cases and a response rate of 31.4%. Side effects were observed in 58.3% of the 36 evaluated cases; of the subjective and objective side effects, however, none were serious enough to require cessation of administration, while stopping administration in the cases of abnormal laboratory findings resulted in rapid recovery. UFTMO therapy, therefore, is considered to be one of the beneficial treatments for recurring or advanced cancer of the digestive organs.

[5-FU concentration in tumor tissue and the antitumor effect in patients with gastric cancer after oral administration of UFT]

Serum and tumor tissue concentration of FT, 5-FU and uracil were measured in 23 patients with gastric cancer who were administered UFT preoperatively. The degeneration of cancer cells was evaluated histologically and the correlation between 5-FU concentration in the tumor tissue and the antitumor effect was assessed. The average concentration of 5-FU in tumor tissue (0.122 microgram/g) was significantly higher than that in normal gastric tissues. Serum 5-FU concentration was very low, suggesting no accumulation of 5-FU in blood. A positive correlation between the concentration of 5-FU and uracil in tumor tissues was found. A 5-FU level higher than 0.05 microgram/g was frequently demonstrated in tumor tissue, resulting in moderate degeneration of cancer cells in many cases. When tumors were classified according to histological type, intratumoral 5-FU concentration was not always correlated with degeneration of cancer cells. The above results suggested that UFT was a very effective drug for stomach cancer because of high tumor affinity for 5-FU, but that it is necessary to consider the sensitivity of tumor cells to antitumor drugs in order to obtain an excellent antitumor effect.

Induction of activated natural killer cells from murine spleen cells primed in vivo and subsequently challenged in vitro with the streptococcal preparation OK432

The present study shows that natural killer cell-mediated cytotoxicity of BALB/c mouse spleen cells to syngeneic tumor cells was augmented by in vivo priming or in vitro stimulation with the streptococcal preparation OK432. The augmentation of spleen cell cytotoxicity to syngeneic tumor cells by in vivo priming alone with OK432 was lower than that obtained by in vitro stimulation alone with OK432. When the murine spleen cells primed in vivo with OK432 were rechallenged in vitro with OK432 at various intervals, the natural cytotoxicity was more strongly enhanced than that seen with in vitro stimulation alone. The cell surface phenotype of killer cells activated with OK432 was Thy 1+ and asialo GM1+, suggesting the activated natural killer cell. Next, mice were transplanted with syngeneic colon adenocarcinoma cells, and primed in vivo with OK432. These spleen cells were subsequently challenged in vitro with OK432. These spleen cells displayed a strong cytotoxic activity not only to the transplanted adenocarcinoma cells but also to other syngeneic tumor cells.

[Analysis of intestinal motility by enteric sound recording system--clinical evaluation of aclatonium napadisilate and prostaglandine F2 alpha on intestinal movement]

In patients with so-called postoperative enteroplegia after laparotomy, effects of aclatonium napadisilate (abbreviated as TM-723 hereinafter) and prostaglandine F2 alpha (abbreviated as PGF2 alpha) on intestinal motility were determined using an enteric sound recording system (phonointestinography) and simultaneously the time required for breaking wind after operation was examined. TM-723 was administered at a dose of 50 mg from the intestinal fistula after dissolved in 5 ml of physiological saline, while PGF2 alpha was administered as an i.v. drip infusion at a dose of 2 mg dissolved in 500 ml of 5% glucose solution. Intestinal movement was determined at McBurney point using the enteric sound recording system developed at our department. The time required for breaking wind after operation was determined in three groups received TM-723, PGF2 alpha and placebo, respectively. No significant intergroup difference was observed. As to effect on intestinal motility, TM-723 increased intestinal motility when it was reduced in so-called postoperative enteroplegia phase. Its efficacy became higher with a decrease in motility. On the contrary, TM-723 rather tended to depress intestinal motility when it was increased. On the other hand, PGF2 alpha tended to increase intestinal motility regardless of motility in enteroplegia phase.

Microwave tissue coagulation applied clinically in endoscopic surgery

On the basis of the ample basic knowledge acquired by repeated experiments, we applied our microwave tissue coagulator in endoscopic surgery, in a total of 59 patients with benign and malignant lesions encountered during a period of two years beginning in July, 1981. Hemostasis was achieved in 96.5% of all the cases with bleeding lesions in the digestive tract. Stenosis was alleviated in 86% of the cases with esophageal or rectal stenosis. Furthermore, the technique was successfully used for hemostasis and tumor reduction in inoperable early cancer cases. Our device is unique in that the electrode is thrust into tissue, which assures us of a satisfactory result. In this point, it must be clearly distinguished from an electrocoagulator or a laser coagulator, which is associated with a risk of injuring intact tissue. The range of coagulation is adjustable by changing the length of the monopolar antenna and electric output, and by employing a coaxial cable of appropriate thickness. In conclusion, our microwave tissue coagulator can be used easily and safely in clinical endoscopic surgery.

Palliative surgery for unresectable carcinoma of the head of the pancreas, ampulla, and distal end of the common bile duct in Japan. A statistical review

To elucidate the approximate present status of palliative surgery for unresectable carcinoma of the head of the pancreas, ampulla, and distal end of the common bile duct in Japan, surgical methods in 151 institutions were collected and analyzed. Biliary drainage alone was performed in 144 institutions (95 percent) and in 80 of them, cholecystectomy and choledochojejunostomy with a Roux-Y procedure was adopted. Gastric bypass with biliary drainage was routinely performed in 13 institutions (8.7 percent), whereas in 62 institution (41.3 percent), combined biliary and gastric drainage operations were performed as the primary procedures in selected cases. In over half the institutions, neither gastrectomy nor vagotomy was provided. Some means to alleviate the pain caused by tumor invasion were performed in about a third of the institutions (49), and about 80 percent of them added some manipulations of the celiac plexus.

[Clinical investigation of intratumoral OK-432 administration]

The clinical effect of intratumoral administration of OK-432 was evaluated. The patients with nonresectable advanced cancer were divided into three groups according to administration method of OK-432 at laparotomy: Group I; Intratumoral administration, Group II; Scattering to the abdominal cavity, and Group III; No OK-432, administration. Improvement in suppression of tumor progression was more frequently noticed in the Group I compared to the Group II and III, but there was no significant difference in terms of survival time and rate among the three groups.

Postoperative functioning of the remaining stomach after pyloric sphincter preserving gastrectomy

Pyloric sphincter preserving gastrectomy (SPG) has been used in 120 cases and the results were compared with those obtained in 73 cases who underwent the Billroth-I operation (B-I). No significant differences were observed in postoperative complications or anastomotic dysfunction. SPG patients, however, showed a longer gastric emptying time than the B-I patients, whereas the B-I patients showed a markedly greater increase in duodenogastric reflux than the SPG patients.

Physiological effects of cotyledons on gibberellin-induced cucumber hypocotyl elongation

The cotyledon requirement for gibberellin-induced hypocotyl elongation of light-grown cucumber (Cucumis sativus L. cv. Aonaga-jibae) seedlings was studied. Gibberellin A7 was used. At the saturation dosage, gibberellin-induced elongation was roughly proportional to the amount of the cotyledon retained. The cotyledon dependence of gibberellin-induced elongation was most marked when decotylization was done at the time of gibberellin treatment or at 24 hr after it. However, when the time of decotylization was delayed by more than 24 hr after gibberellin treatment, the effect was not immediate, and gibberellin-induced elongation continued for a while at a higher rate than that of the control. Young hypocotyls were more sensitive to gibberellin than older hypocotyls and their cotyledon requirement for gibberellin-induced elongation was less. Covering the cotyledons with aluminum foil or treating them with N'-(3,4-dichlorophenyl)-N-methoxy-N-methylurea, a photosynthetic inhibitor, reduced the gibberellin effect. There was a quantitative relationship between the magnitude of the covered or the inhibitor-treated area of the cotyledon and gibberellin-induced elongation. This quantitative relationship paralleled that for decotylization. These results suggested that the cotyledon requirement of the hypocotyl for gibberellin-induced elongation is at least partly related to the photosynthetic activity of the cotyledons.