Posterior auricular artery free flap reconstruction of the retroauricular sulcus in microtia repair

BACKGROUND

Autologous repair using costal cartilage grafts remains the most widely accepted method of microtia reconstruction. A major complication of current techniques is loss of ear shape caused by scarring, contracture and cartilage absorption. We present a new surgical technique utilizing the posterior auricular artery free flap in microsurgical reconstruction of the retroauricular sulcus in microtia.

METHOD

Reconstruction is performed in two stages. In the first stage, a fabricated costal cartilage framework is inserted into a skin pocket as described by Nagata. In the second stage, the ear framework is elevated from the scalp and held by an additional cartilage wedge. Following indocyanine green angiography perforator mapping, a posterior auricular artery perforator flap is harvested from the contralateral (normal) ear and used to reconstruct the posterior auricular sulcus covering the cartilage framework and elevating wedge.

RESULTS

The technique was applied to three patients aged 11-15 years with a follow-up time of 8 months to 3 years. The average flap artery diameter was 0.73 mm and the vein was 0.7 mm. Venous congestion occurred in one case and was resolved with a vein graft leading to complete flap recovery. Good ear shape, elevation, projection, skin color and texture were achieved in all the cases.

CONCLUSION

Posterior auricular artery flap reconstruction of the retroauricular sulcus in microtia repair is a useful alternative to the current skin graft and tissue expander-based techniques. It provides the ideal skin color and texture match and may improve the overall results of microtia reconstruction by enhancing vascularity.

P1802 Prevalence and prognostic significance of pulmonary artery aneurysms in patients with pulmonary artery hypertension

Background

Pulmonary artery aneurysm (PAA) occurs in some patients with pulmonary arterial hypertension (PAH) and can be accompanied by various complications.

Objective

The aim of the this study is to evaluate the characteristics of cardiac dysfunction and the prognostic impact of PAA by analysing the outcome of patients with PAH complicated by PAA.

Methods

We performed echocardiography and right-heart catheterization in 130 PAH patients. We measured the maximum dimensions of the main pulmonary artery (MPA) trunk. We evaluated the right ventricular (RV) function and the five-year prognosis of patients with PAA.

Results

The maximum MPA trunk diameter of >40 mm by echocardiography was defined as PAA. PAA appeared in 32 of the 130 PAH patients (24.6%: Group PAA), other 98 patients were defined as Group non-PAA. Systolic pulmonary artery pressure (76 ±18 vs. 61 ± 21 mmHg, P = 0.0008) and mean right atrial pressure (10.0 ± 8.1 vs. 5.4 ± 3.8 mmHg, P < 0.0001) were significantly higher in Group PAA than in Group non-PAA. RV end-diastolic area index was significantly larger (37.3 ± 8.8 vs. 32.3 ± 7.8 mmHg, P = 0.0048), and RV fractional area change (32 ± 8 vs. 36 ± 9 %, P = 0.0176) and RV longitudinal strain amplitude (-16 ±5 vs. -20 ± 6, P = 0.0017) were significantly lower in Group PAA than those in Group non-PAA. During the five-year follow-up period, 20 patients (15%) died. The five-year mortality rate was significantly higher in Group PAA compared to Group non-PAA (30% vs. 10%, P = 0.007).

Conclusion

In PAH patients with PAA, RV dysfunction was more severe and the prognosis was poor. Assessment of PAA can be a useful index for the extraction of high-risk PAH patients.

Establishment of supermicrosurgical lymphaticovenular anastomosis model in rat

BACKGROUND

Lymphaticovenular anastomosis (LVA) is becoming a choice of treatment for compression-refractory lymphedema. However, LVA requires highly sophisticated microsurgical technique called supermicrosurgery, and no training model for LVA has been developed. This study aimed to develop and evaluate feasibility of a new LVA model using rat thigh lymphatic vessels.

METHODS

Ten Sprague-Dawley rats were used for the study. After preoperative indocyanine green (ICG) lymphography, lymphatic vessels in posteromedial aspect of the thigh were dissected. In right limbs, the largest lymphatic vessel was anastomosed to the short saphenous vein or its branch, and the remaining lymphatic vessels were ligated (LVA group). In left limbs, all lymphatic vessels were ligated (control group). Anastomosis patency was evaluated intraoperatively and at postoperative 7 days.

RESULTS

Courses of lymphatic vessels in the thigh were constant; lymphatic vessels run along the short saphenous vein. The mean diameter of lymphatic vessel used for LVA was 0.240 ± 0.057 mm, and the mean diameter of vein was 0.370 ± 0.146 mm. All lymphatic vessels were translucent and very thin like human intact lymphatic vessels. In LVA group, intra- and post-operative anastomosis patency rates were 100% (10/10) based on ICG lymphography. In control group, intra- and post-operative patency rates were 0% (0/10).

CONCLUSIONS

Rat lymphatic vessels are thin, translucent, and fragile similar to intact human lymphatic vessels. The LVA model uses easily accessible lymphatic vessels in the thigh, and is useful for training of supermicrosurgical LVA. © 2014 Wiley Periodicals, Inc. Microsurgery 37:57-60, 2017.

Comparative validity of the WHO-5 Well-Being Index and two-question instrument for screening depressive symptoms in patients with type 2 diabetes

A simple tool consisting of two questions for screening depressive symptoms has been shown to be useful in primary care settings, but its validity in patients with diabetes has yet to be evaluated. We compared the test performance of this two-question instrument with that of WHO (The World Health Organization)-5. We consecutively enrolled 153 patients with type 2 diabetes who visited a diabetes clinic in Japan. Using the Center for Epidemiologic Studies Depression Scale as a reference standard of depressive symptoms, we calculated the sensitivity and specificity of the two-question instrument and WHO-5, and compared the area under the ROC curves of these tests. The two-question instrument had a sensitivity of 53.6% (95% CI, 39.7-67.0%) and specificity of 67.7% (95% CI, 58.1-74.9%). With the conventional cutoff point equal to or less than 13 points, the WHO-5 had a sensitivity of 57.1% (95% CI, 43.2-70.3%) and specificity of 82.5% (95% CI, 81.9-94.9%). The area under the ROC curve for the WHO-5 and two-item questionnaire, an indicator of discriminatory power, was 0.81 and 0.73, respectively, showing a statistically significant difference (P = 0.0453). The two-question instrument had statistically lower discriminatory power than the WHO-5 in screening depressive symptoms in patients with diabetes. We do not recommend the use of the two-question instrument for screening depressive symptoms in patients with diabetes.

Decreased pregnancy rate is linked to abnormal uterine peristalsis caused by intramural fibroids

BACKGROUND

The relationship between fibroids and infertility remains an unsolved question, and management of intramural fibroids is controversial. During the implantation phase, uterine peristalsis is dramatically reduced, which is thought to facilitate embryo implantation. Our aims were to evaluate (i) the occurrence and frequency of uterine peristalsis in infertile women with intramural fibroids and (ii) whether the presence of uterine peristalsis decreases the pregnancy rate.

METHODS

Ninety-five infertile patients with uterine fibroids were examined using magnetic resonance imaging (MRI). Inclusion criteria were as follows: (i) presence of intramural fibroids, excluding submucosal type; (ii) no other significant infertility factors (excluding endometriosis); and (iii) regular menstrual cycles, and MRI performed at the time of implantation (luteal phase day 5-9). The frequency of junctional zone movement was evaluated using cine-mode-display MRI. After MRI, patients underwent infertility treatment for up to 4 months, and the pregnancy rate was evaluated prospectively.

RESULTS

Fifty-one patients fulfilled the inclusion criteria, and 29 (57%) and 22 (43%) patients were assigned to the low (0 or 1 time/3 min) or high frequency (≥ 2 times/3 min) uterine peristalsis group, respectively. Endometriosis incidence was the same in both groups. Ten out of the 29 patients (34%) in the low-frequency group achieved pregnancy, compared with none of the 22 patients (0%) in the high-frequency group (P< 0.005). Comparing pregnant and non-pregnant cases, 4 of 10 patients (40%) and 9 of 41 patients (22%), respectively, had endometriosis (not significant).

CONCLUSIONS

A higher frequency of uterine peristalsis during the mid-luteal phase might be one of the causes of infertility associated with intramural-type fibroids.

p19/Arf and p53 suppress sentinel lymph node lymphangiogenesis and carcinoma metastasis

The ability of tumor cells to metastasize is increasingly viewed as an interaction between the primary tumor and host tissues. Deletion of the p19/Arf or p53 tumor suppressor genes accelerates malignant progression and metastatic spread of 7,12-dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced squamous cell carcinomas, providing a model system to address mechanisms of metastasis. Here, we show that benign pre-metastatic papillomas from wild-type mice trigger lymphangiogenesis within draining lymph nodes, whereas there is no growth of primary tumor lymphatic vessels. Lymph node lymphangiogenesis is greatly accelerated in papilloma-bearing p19/Arf- or p53-deficient mice, which coincides with the greater propensity of these tumors to progress to carcinomas and to metastasize. The extent of accumulation of B cells within the tumor-draining lymph nodes of wild-type mice predicted the level of lymph node lymphangiogenesis and metastatic potential. Arf or p53 deficiency strongly accelerated lymph node immune cell accumulation, in a manner that was associated with the extent of lymph node lymphatic sinus growth. This immune cell accumulation and lymph node lymphangiogenesis phenotype identifies host anti-tumor responses that could drive metastatic spread of cancers via the lymphatics.

GER1, a GDSL motif-encoding gene from rice is a novel early light- and jasmonate-induced gene

The reaction of the rice mutant HEBIBA differs from that of wild-type rice in that the mutant responds inversely to red light and is defective in the light-triggered biosynthesis of jasmonic acid (JA). Using the wild type and the HEBIBA mutant of rice in a differential display screen, we attempted to identify genes that act in or near the convergence point of light and JA signalling. We isolated specifically regulated DNA fragments from approximately 10 000 displayed bands, and identified a new early light- and JA-induced gene. This gene encodes an enzyme containing a GDSL motif, showing 38 % identity at the amino acid level to lipase Arab-1 in Arabidopsis thaliana. The GDSL CONTAINING ENZYME RICE 1 gene (GER1) is rapidly induced by both red (R) and far-red (FR) light and by JA. The results are discussed with respect to a possible role for GER1 as a negative regulator of coleoptile elongation in the context of recent findings on the impact of JA on light signalling.

Detailed images of asteroid 25143 Itokawa from Hayabusa

Rendezvous of the Japanese spacecraft Hayabusa with the near-Earth asteroid 25143 Itokawa took place during the interval September through November 2005. The onboard camera imaged the solid surface of this tiny asteroid (535 meters by 294 meters by 209 meters) with a spatial resolution of 70 centimeters per pixel, revealing diverse surface morphologies. Unlike previously explored asteroids, the surface of Itokawa reveals both rough and smooth terrains. Craters generally show unclear morphologies. Numerous boulders on Itokawa's surface suggest a rubble-pile structure.

Microbiological contamination in genetically modified animals and proposals for a microbiological test standard for national universities in Japan

The Biosafety Committee of the Japanese Association of Laboratory Animal Facilities of National Universities (JALAN) investigated recent episodes of microbiological contamination in genetically modified mice (GMM), and the countermeasures taken when the contaminated GMM were introduced into animal facilities, by questionnaires addressed to 53 animal facilities belonging to JALAN and serological tests. Although almost all of the contaminated GMM were accepted with conditions such as rederivation after or before reception and housing in designated rooms, contamination with a spectrum of microorganisms was demonstrated in GMM transferred domestically and from abroad. In serological tests, Mycoplasma pulmonis, mouse parvovirus, and mouse encephalomylitis virus were detected in GMM transferred from domestic facilities and from abroad. The present results of the questionnaires and serological tests suggest that GMM are highly and widely contaminated with microorganisms compared with mice from commercial breeders. Thus, we propose a microbiological requirement, including microbiological status--excellent, common, and minimum--as a guide for the transfer and procurement of mice and rats in Japan.

Analyses of matrix metalloproteinases and their inhibitors in cyst fluid of serous ovarian tumors

OBJECTIVES

Expression of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) in serous tumors of the ovary was investigated to determine whether and how these proteolytic enzymes are associated with the progression of these tumors.

METHODS

Cyst fluid of 24 serous ovarian tumors (8 adenocarcinomas, 2 borderline tumors and 14 adenomas) was analyzed using gelatin/casein zymography and enzyme-linked immunosorbent assay.

RESULTS

Concentrations of MMP-9 and MMP-2 were statistically higher in serous adenocarcinomas than in serous adenomas (p < 0.01, p < 0.05, respectively), while the concentrations of TIMP-1 and TIMP-2 showed no significant difference between adenocarcinomas and adenomas. The molar ratio of TIMP-2/MMP-2 was lower in adenocarcinomas than in adenomas (p < 0.05). With gelatin zymography, the MMP-9 band was detected in all serous adenocarcinomas, but only in 8 of 14 serous adenomas (p = 0.05). Using casein zymography, MMP-7 was more frequently detected in serous adenocarcinomas (7/8) than in serous adenomas (4/14; p < 0.05).

CONCLUSIONS

These observations indicate that matriolytic enzymes such as MMP-2, MMP-7 and MMP-9 are secreted into cyst fluid from serous adenocarcinoma tissues. In part, the aggressive invasion of serous carcinoma cells may be explained by the expression of matriolytic enzymes.

Detection of species of the subgenus Leishmania parasites using polymerase chain reaction and southern blotting

In this study, an attempt was made to identify different Leishmania species by polymerase chain reaction (PCR). Fourteen Leishmania strains from stock were tested by PCR and Southern blotting. A pair of primers were employed that anneal to the kinetoplast DNA sequence conserved among subgenus Leishmania. Of the 14 Leishmania strains used in this study, six showed strong bands of approximately 170 bp, and all the positive strains belonged to the species of the subgenus Leishmania viz., Leishmania (Leishmania) garnhami, L. (L.) amazonensis, L. (L.) pifanoi, L. (L.) mexicana, L. (L.) chagasi, and L. (L.) major All the species belonging to the subgenus Viannia used in this study were negative by PCR. These results suggest that the primer pair may be useful for identification of the species belonging to the subgenus Leishmania of the New World as well as to distinguish subgenus Leishmania from subgenus Viannia.

Technical advance: an automated device for cryofixation of specimens of electron microscopy using liquid helium

Metal-contact rapid freezing using liquid helium is theoretically the best method for preserving the fine structure of living cells with high temporal resolution in preparation of tissue samples for electron microscopy. However, this method is not commonly used, because of its technical difficulty and low reproducibility. We have designed and constructed an automatic device which allows simple, rapid and reproducible preparation of high-quality electron microscopic specimens by the non-specialist. We assessed the quality of cryofixation in samples prepared using this device by examining the preservation of cellular ultrastructure in relation to distance from the freezing block, and found that the region within 10 microm of the metal-contact plane was fixed with the highest quality. We applied this device, in combination with freeze-substitution methods and immunocytochemical techniques, to two phenomena involving rapid movement of subcellular components: (1) active movement of subcellular structures in the papillar cells of stigma and (2) light-induced rapid subcellular translocation of phytochrome A. Considering the importance of understanding subcellular processes of living cells for molecular and cell biology, this device will be a useful tool for diverse biological applications in the near future.

Clinical and pharmacological studies on liver diseases treated with Kampo herbal medicine

Hepatitis C virus (HCV) infection frequently causes chronic hepatitis, which is linked to the development of liver cirrhosis and hepatocellular carcinoma. Most physicians who practice Kampo medicine in Japan have observed that Kampo medicine can be as effective as interferon therapy in the treatment of chronic hepatitis C. In the present study, to evaluate the effect of Kampo medicine on chronic hepatitis C, clinical treatment was assessed in short-term and long-term study, and it was shown that ninjin-yoei-to (Formula ginseng compositae: TJ-108) was very effective. Therefore, to find the most active herbal component of TJ-108 in the treatment of HCV, Citrus Unshiu Peel, Schisandra Fruit, and Polygala Root, which are specific to TJ-108, were screened using an in vitro HCV infection model. Among the three herbs, Schisandra Fruit was found to be most active. In the next step, Gomisin A, an active component of Schisandra Fruit, was studied using an in vitro model with MOLT-4 cells and an animal model of immunologically induced acute hepatic failures. It is concluded that the therapeutic effect of TJ-108 on chronic hepatitis C is from the inhibitory effect on HCV infection, and also from the protective effect on immunological hepatopathy of Schisandra Fruit and its lignan component, Gomisin A.

Discovery of a non-peptide small molecule that selectively mimics the biological actions of calcitonin

Calcitonin (CT), a 32-amino acid peptide hormone secreted mainly from the thyroid gland, plays an important role in maintaining bone homeostasis. To discover non-peptide small molecules with biological actions similar to those of CT, a cell-based screening of an in-house chemical library was performed and a pyridone derivative (SUN B8155) was identified. Like CT, it elevated cyclic AMP (cAMP) levels in T47D and UMR106-06 cells which endogenously express human and rat CT receptor, respectively. SUN B8155 also stimulated cAMP formation in cells expressing recombinant human CT receptor, but not in those expressing human parathyroid hormone/parathyroid hormone-related peptide receptor. Accumulation of cAMP in T47D cells was blocked by a selective antagonist of CT receptor, salmon CT(8-32), whereas SUN B8155 did not displace the specific binding of [(125)I]CT to the receptor. Our results suggested that the compound selectively interacts with the CT receptor by a mechanism similar to but probably different from that of CT itself. In rats, intraperitoneal administration of SUN B8155 significantly lowered serum calcium levels, like CT. Our results demonstrate, for the first time, that the biological activities of the newly identified small molecule can mimic that of CT, acting via the CT receptor.

Evidence for type II phytochrome-induced rapid signalling leading to cab::luciferase gene expression in tobacco cotyledons

We studied the activation of cab gene expression by phytochrome-induced intercellular signalling and report insights into the mechanism of induction and outspread of a plant internal signal. By micro-beam irradiation techniques and use of a photon-imaging charge-coupled device (CCD) camera system we monitored cab::luciferase reporter gene expression in cotyledons of transgenic tobacco (Nicotiana tabacum L. cv. Xanthi) plants. We found that (i) the photoreceptor triggering intercellular signalling and reporter-gene expression is type II but not type I phytochrome, (ii) phytochrome in its far-red-absorbing (Pfr) form is necessary for the induction but not for the outspread of the signalling, (iii) red/far-red reversibility is restricted to the red-irradiated cells, and (iv) the phytochrome-induced signal spreads rapidly throughout the cotyledon and reaches its target cells within minutes.

In vitro assembly of phytochrome B apoprotein with synthetic analogs of the phytochrome chromophore

Phytochrome B (PhyB), one of the major photosensory chromoproteins in plants, mediates a variety of light-responsive developmental processes in a photoreversible manner. To analyze the structural requirements of the chromophore for the spectral properties of PhyB, we have designed and chemically synthesized 20 analogs of the linear tetrapyrrole (bilin) chromophore and reconstituted them with PhyB apoprotein (PHYB). The A-ring acts mainly as the anchor for ligation to PHYB, because the modification of the side chains at the C2 and C3 positions did not significantly influence the formation or difference spectra of adducts. In contrast, the side chains of the B- and C-rings are crucial to position the chromophore properly in the chromophore pocket of PHYB and for photoreversible spectral changes. The side-chain structure of the D-ring is required for the photoreversible spectral change of the adducts. When methyl and ethyl groups at the C17 and C18 positions are replaced with an n-propyl, n-pentyl, or n-octyl group, respectively, the photoreversible spectral change of the adducts depends on the length of the side chains. From these studies, we conclude that each pyrrole ring of the linear tetrapyrrole chromophore plays a different role in chromophore assembly and the photochromic properties of PhyB.

Clear cell variant of malignant melanoma of the uterine cervix: a case report and review of the literature

BACKGROUND

A rare variant of malignant melanoma of the uterine cervix mimicking clear cell carcinoma or clear cell sarcoma is described.

CASE

A 33-year-old Japanese woman was admitted to the hospital complaining of genital discharge and lower back pain. The stage was FIGO IIB and radical hysterectomy and pelvic lymphadenectomy were done. Pathological examination, immunohistochemical studies of melanin granules, and molecular analysis of the EWS/ATF-1 fusion gene were also done. A diffuse proliferation of amelanotic clear cells was detected in the uterine cervix. Tumor cells were positive for HMB 45, Melan-A (MART-1), and S-100 protein and negative for epithelial markers. The EWS/ATF-1 fusion gene was not detected.

CONCLUSION

This is apparently the first report of a case of clear cell melanoma of the uterine cervix. Despite its rarity, this variant of malignant melanoma should be considered when diagnosing clear cell neoplasms of the uterine cervix.

Isolation and characterization of rice phytochrome A mutants

To elucidate phytochrome A (phyA) function in rice, we screened a large population of retrotransposon (Tos17) insertional mutants by polymerase chain reaction and isolated three independent phyA mutant lines. Sequencing of the Tos17 insertion sites confirmed that the Tos17s interrupted exons of PHYA genes in these mutant lines. Moreover, the phyA polypeptides were not immunochemically detectable in these phyA mutants. The seedlings of phyA mutants grown in continuous far-red light showed essentially the same phenotype as dark-grown seedlings, indicating the insensitivity of phyA mutants to far-red light. The etiolated seedlings of phyA mutants also were insensitive to a pulse of far-red light or very low fluence red light. In contrast, phyA mutants were morphologically indistinguishable from wild type under continuous red light. Therefore, rice phyA controls photomorphogenesis in two distinct modes of photoperception--far-red light-dependent high irradiance response and very low fluence response--and such function seems to be unique and restricted to the deetiolation process. Interestingly, continuous far-red light induced the expression of CAB and RBCS genes in rice phyA seedlings, suggesting the existence of a photoreceptor(s) other than phyA that can perceive continuous far-red light in the etiolated seedlings.

Clarification of the active gelatinolytic sites in human ovarian neoplasms using in situ zymography

Tissues from 26 human ovarian common epithelial tumors were examined to determine where and how gelatinolytic activity was present, in relation to tumor-stromal interaction and histologic types. For this purpose, we used in situ zymography, a newly developed technique using gelatin-coated film. Gelatinolytic activity was evident in ovarian carcinomas and in borderline tumors. Benign tumors had no or only weak activity. Four tissue localization patterns of gelatinolysis were identified: pattern A, tumor cytoplasm; pattern B, tumor-stromal junction; pattern C, stroma; and pattern D, cystic fluid. Mucinous cystadenocarcinomas showed A and/or D patterns. One mucinous and one serous adenocarcinoma and one mucinous borderline tumor had a B pattern. Most serous and all clear cell adenocarcinomas showed strong gelatinolysis of C pattern, especially in the desmoplastic stroma, an area where the tumor cells were dispersed. Immunohistochemically in 12 adenocarcinomas and 3 borderline tumors, the tumor cytoplasm was positive for matrix metalloproteinases (MMP-2) (5 cases), MMP-7 (9 cases), and MMP-9 (6 cases). Stromal components were positive for MMP-2 in 5 cases and for MMP-9 in 3 cases, but they were not positive for MMP-7. MMP antigens were mostly distributed in an almost identical pattern consistent with that seen with in situ zymography. In situ zymography clarified the cellular localization of active gelatinolysis in human ovarian neoplasms, a finding which supports the view that interaction between tumor and stroma is critical for tumor growth. This newly developed method contributes to a better understanding of biologic features of ovarian malignancies.

Anti-angiogenic treatment for peritoneal dissemination of pancreas adenocarcinoma: a study using TNP-470

We established peritoneal dissemination-prone subcultures (PCI-43p3) using nude mice by a repetitive in vivo selection of intraperitoneally inoculated PCI-43, a pancreas adenocarcinoma cell line. The subcultures showed upregulated expression of matrix metalloproteinase (MMP)-9, but not MMP-2 in culture supernatants. They also produced increased amounts of vascular endothelial growth factor (VEGF), which was not associated with alterations in isoforms of VEGF mRNA. PCI-43p3 cells attached to cultured mesothelial cell monolayers more readily than did the parent PCI-43 cells. The angiogenesis inhibiting agent, TNP-470, at 30 mg / kg was administered to the model mice, resulting in a prominent suppression of the establishment of peritoneal nodules. The suppression was dependent on the duration of TNP-470 treatment. TNP-470 treatment significantly suppressed proliferation of tumor cells in disseminated nodules, assessed in terms of immunostaining for proliferating cell nuclear antigen (PCNA). TNP-470 did not affect the in vitro attachment between PCI-43p3 and mesothelial cells. The combined data show that anti-angiogenic treatment profoundly suppresses the in vivo process of peritoneal dissemination.

Phytochrome regulation of nuclear gene expression in plants

The photoregulation of gene expression in higher plants was extensively studied during the 1980s, in particular the light-responsive cis -acting elements and trans -acting factors of the Lhcb and rbcS genes. However, little has been discovered about: (1) which plant genes are regulated by light, and (2) which photoreceptors control the expression of these genes. In the 1990s, the functional analysis of the various photoreceptors has progressed rapidly using photoreceptor-deficient mutants, including those of the phytochrome gene family. More recently however, advanced techniques for gene expression analysis, such as fluorescent differential display and DNA microarray technology, have become available enabling the global identification of genes that are regulated by particular photoreceptors. In this paper we describe distinct and overlapping effects of individual phytochromes on gene expression in Arabidopsis thaliana.

Glutathione and a UV light-induced glutathione S-transferase are involved in signaling to chalcone synthase in cell cultures

UV irradiation stimulates expression of the gene encoding the key enzyme chalcone synthase (CHS), which leads to the generation of protective flavonoids in parsley cell cultures. CHS transcripts increase after 3 to 4 hr, and early genes are involved in the signal transduction to the CHS promoter. By using the fluorescent differential display technique in a large-scale screening, several early UV light-induced genes were isolated. Of these, a novel glutathione S-transferase (PcGST1) is induced within 2 hr and precedes CHS expression. Overexpression of PcGST1 in transformed cell lines containing a CHS promoter/luciferase reporter (CHS-LUC) affected the onset of LUC transcription. Supplementing these cell lines with glutathione immediately stimulated CHS-LUC expression within 2 hr in dark-incubated cells and resulted in a biphasic induction profile in UV-irradiated cells. Our data indicate the involvement of glutathione and PcGST1 in early events of a UV light-dependent signal transduction pathway to CHS. In this context, the oxidative status of a cell acts as a central regulating element.

Glutathione and a UV light-induced glutathione S-transferase are involved in signaling to chalcone synthase in cell cultures

UV irradiation stimulates expression of the gene encoding the key enzyme chalcone synthase (CHS), which leads to the generation of protective flavonoids in parsley cell cultures. CHS transcripts increase after 3 to 4 hr, and early genes are involved in the signal transduction to the CHS promoter. By using the fluorescent differential display technique in a large-scale screening, several early UV light-induced genes were isolated. Of these, a novel glutathione S-transferase (PcGST1) is induced within 2 hr and precedes CHS expression. Overexpression of PcGST1 in transformed cell lines containing a CHS promoter/luciferase reporter (CHS-LUC) affected the onset of LUC transcription. Supplementing these cell lines with glutathione immediately stimulated CHS-LUC expression within 2 hr in dark-incubated cells and resulted in a biphasic induction profile in UV-irradiated cells. Our data indicate the involvement of glutathione and PcGST1 in early events of a UV light-dependent signal transduction pathway to CHS. In this context, the oxidative status of a cell acts as a central regulating element.