Expression of AoNHX1 increases salt tolerance of rice and Arabidopsis, and bHLH transcription factors regulate AtNHX1 and AtNHX6 in Arabidopsis

Expression of AoNHX1 from the mangrove Avicennia increases salt tolerance of rice and Arabidopsis, and specific bHLH transcription factors regulate AtNHX1 and AtNHX6 in Arabidopsis to mediate the salinity response. Improving crop plants to better tolerate soil salinity is a challenging task. Mangrove trees such as Avicennia officinalis have special adaptations to thrive in high salt conditions, which include subcellular compartmentalization of ions facilitated by specialized ion transporters. We identified and characterized two genes encoding Na⁺/H⁺ exchangers AoNHX1 and AoNHX6 from Avicennia. AoNHX1 was present in the tonoplast, while, AoNHX6 was localized to the ER and Golgi. Both NHXs were induced by NaCl treatment, with AoNHX1 showing high expression levels in the leaves and AoNHX6 in the seedling roots. Yeast deletion mutants (ena1-5Δ nha1Δ nhx1Δ and ena1-5Δ nha1Δ vnx1Δ) complemented with AoNHX1 and AoNHX6 showed increased tolerance to both NaCl and KCl. Expression of AoNHX1 and AoNHX6 in the corresponding Arabidopsis mutants conferred enhanced NaCl tolerance. The underlying molecular regulatory mechanism was investigated using AtNHX1 and AtNHX6 in Arabidopsis. We identified two basic helix-loop-helix (bHLH) transcription factors AtMYC2 and AtbHLH122 as the ABA-mediated upstream regulators of AtNHX1 and AtNHX6 by chromatin immunoprecipitation. Furthermore, expression of AtNHX1 and AtNHX6 transcripts was reduced in the atmyc2 and atbhlh122 mutants. Lastly, transgenic rice seedlings harboring pUBI::AoNHX1 showed enhanced salt tolerance, suggesting that this gene can be exploited for developing salt-tolerant crops.

Cost Benefits of the Drug and Poison Information Centre in Preventing Unnecessary Hospitalisation: The Singapore Experience

Background

The Drug and Poison Information Centre (DPIC) in Singapore was piloted as a new service in April 2004. This study evaluated the cost benefits of its interventions in the first two years of its operation.

Method

A two-year retrospective review of DPIC call records was performed and the following outcome measures were noted: (A) proportion of patients who were managed onsite and hence did not need to attend the emergency department (ED); and (B) proportion of patients who were managed in the ED without the need for admission. Cost savings were calculated based on admission costs for patients with poisoning, including other out-of-hospital costs. This amounted to savings of S$1390 and S$1170 for patients who fulfilled outcome measures A and B respectively. Savings for the hospital was S$1477 per case. The cost of operating the DPIC over the same period was S$507,922.

Results

There were 831 calls on acute toxic exposures over the study period. Of these, 115 and 405 patients fulfilled outcome measure A and B respectively with consequent cost savings of S$159,850 (115 x S$1390 per patient), and S$473,850 (405 x S$1170 per patient). The hospitals saved S$768,040 (520 x S$1477) from prevented admissions. Excluding operating cost, this gave net savings of S$893,818 over the two years from DPIC interventions.

Conclusion

The cost savings from DPIC services is evident from this study. This translates to more effective use of limited healthcare resources.

Nephrotoxicity Associated with Acute Paracetamol Overdose: A Case Report and Review of the Literature

A 29-year-old, 65 kg, Chinese man presented to hospital 10 hours after ingesting 30 g of paracetamol (462 mg/kg body weight). The blood paracetamol level was 145 µg/ml at 10 hours post-ingestion. He had no known risk factors for hepatotoxicity and was treated with intravenous N-acetylcysteine (NAC). Serum creatinine level rose to a maximum of 455 µmol/L on day 8; it gradually declined without the need for dialysis. Little is known of the risk factors for nephrotoxicity, which may occur with or without concurrent liver damage, suggesting possible primary toxic effects on the kidney. The use of NAC in this case may have prevented the progression to liver failure and reduced the severity of the nephrotoxic effects.

Proteomic analysis of plasma membrane and tonoplast from the leaves of mangrove plant Avicennia officinalis

In order to understand the salt tolerance and secretion in mangrove plant species, gel electrophoresis coupled with LC-MS-based proteomics was used to identify key transport proteins in the plasma membrane (PM) and tonoplast fractions of Avicennia officinalis leaves. PM and tonoplast proteins were purified using two-aqueous-phase partitioning and density gradient centrifugation, respectively. Forty of the 254 PM proteins and 31 of the 165 tonoplast proteins identified were predicted to have transmembrane domains. About 95% of the identified proteins could be classified based on their functions. The major classes of proteins were predicted to be involved in transport, metabolic processes, defense/stress response, and signal transduction, while a few of the proteins were predicted to be involved in other functions such as membrane trafficking. The main classes of transporter proteins identified included H(+) -ATPases, ATP-binding cassette transporters, and aquaporins, all of which could play a role in salt secretion. These data will serve as the baseline membrane proteomic dataset for Avicennia species. Further, this information can contribute to future studies on understanding the mechanism of salt tolerance in halophytes in addition to salt secretion in mangroves. All MS data have been deposited in the ProteomeXchange with identifier PXD000837 (http://proteomecentral.proteomexchange.org/dataset/PXD000837).

Data in support of the proteomic analysis of plasma membrane and tonoplast from the leaves of mangrove plant Avicennia officinalis

The data provides information in support of the research article, Proteomics 2014, 14, 2545–2557 [1]. Raw data is available from the ProteomeXchange Consortium via the PRIDE partnerRepository [2] with the dataset identifier PXD000837. Plasma membrane and tonoplast proteins from the leaves of Avicennia officinalis were identified using gel electrophoresis (one and two dimensional) combined with LC–MS analysis. Based on GO annotation, identified proteins were predicted to be involved in various biological processes.

Proteome profile of salt gland-rich epidermis extracted from a salt-tolerant tree species

Preparation of proteins from salt-gland-rich tissues of mangrove plant is necessary for a systematic study of proteins involved in the plant's unique desalination mechanism. Extraction of high-quality proteins from the leaves of mangrove tree species, however, is difficult due to the presence of high levels of endogenous phenolic compounds. In our study, preparation of proteins from only a part of the leaf tissues (i.e. salt gland-rich epidermal layers) was required, rendering extraction even more challenging. By comparing several extraction methods, we developed a reliable procedure for obtaining proteins from salt gland-rich tissues of the mangrove species Avicennia officinalis. Protein extraction was markedly improved using a phenol-based extraction method. Greater resolution 1D protein gel profiles could be obtained. More promising proteome profiles could be obtained through 1D-LC-MS/MS. The number of proteins detected was twice as much as compared to TUTS extraction method. Focusing on proteins that were solely present in each extraction method, phenol-based extracts contained nearly ten times more proteins than those in the extracts without using phenol. The approach could thus be applied for downstream high-throughput proteomic analyses involving LC-MS/MS or equivalent. The proteomics data presented herein are available via ProteomeXchange with identifier PXD001691.

Proteomic Characterisation of the Salt Gland-Enriched Tissues of the Mangrove Tree Species Avicennia officinalis

Plant salt glands are nature’s desalination devices that harbour potentially useful information pertaining to salt and water transport during secretion. As part of the program toward deciphering secretion mechanisms in salt glands, we used shotgun proteomics to compare the protein profiles of salt gland-enriched (isolated epidermal peels) and salt gland-deprived (mesophyll) tissues of the mangrove species Avicennia officinalis. The purpose of the work is to identify proteins that are present in the salt gland-enriched tissues. An average of 2189 and 977 proteins were identified from the epidermal peel and mesophyll tissues, respectively. Among these, 2188 proteins were identified in salt gland-enriched tissues and a total of 1032 selected proteins were categorized by Gene Ontology (GO) analysis. This paper reports for the first time the proteomic analysis of salt gland-enriched tissues of a mangrove tree species. Candidate proteins that may play a role in the desalination process of the mangrove salt glands and their potential localization were identified. Information obtained from this study paves the way for future proteomic research aiming at elucidating the molecular mechanism underlying secretion in plant salt glands. The data have been deposited to the ProteomeXchange with identifier PXD000771.

Identification of salt gland-associated genes and characterization of a dehydrin from the salt secretor mangrove Avicennia officinalis

BACKGROUND

Salt stress is a major challenge for growth and development of plants. The mangrove tree Avicennia officinalis has evolved salt tolerance mechanisms such as salt secretion through specialized glands on its leaves. Although a number of structural studies on salt glands have been done, the molecular mechanism of salt secretion is not clearly understood. Also, studies to identify salt gland-specific genes in mangroves have been scarce.

RESULTS

By subtractive hybridization (SH) of cDNA from salt gland-rich cell layers (tester) with mesophyll tissues as the driver, several Expressed Sequence Tags (ESTs) were identified. The major classes of ESTs identified include those known to be involved in regulating metabolic processes (37%), stress response (17%), transcription (17%), signal transduction (17%) and transport functions (12%). A visual interactive map generated based on predicted functional gene interactions of the identified ESTs suggested altered activities of hydrolase, transmembrane transport and kinases. Quantitative Real-Time PCR (qRT-PCR) was carried out to validate the expression specificity of the ESTs identified by SH. A Dehydrin gene was chosen for further experimental analysis, because it is significantly highly expressed in salt gland cells, and dehydrins are known to be involved in stress remediation in other plants. Full-length Avicennia officinalis Dehydrin1 (AoDHN1) cDNA was obtained by Rapid Amplification of cDNA Ends. Phylogenetic analysis and further characterization of this gene suggested that AoDHN1 belongs to group II Late Embryogenesis Abundant proteins. qRT-PCR analysis of Avicennia showed up-regulation of AoDHN1 in response to salt and drought treatments. Furthermore, some functional insights were obtained by growing E. coli cells expressing AoDHN1. Growth of E. coli cells expressing AoDHN1 was significantly higher than that of the control cells without AoDHN1 under salinity and drought stresses, suggesting that the mangrove dehydrin protein helps to mitigate the abiotic stresses.

CONCLUSIONS

Thirty-four ESTs were identified to be enriched in salt gland-rich tissues of A. officinalis leaves. qRT-PCR analysis showed that 10 of these were specifically enriched in the salt gland-rich tissues. Our data suggest that one of the selected genes, namely, AoDHN1 plays an important role to mitigate salt and drought stress responses.

Role of root hydrophobic barriers in salt exclusion of a mangrove plant Avicennia officinalis

Salt exclusion at the roots and salt secretion in the leaves were examined in a mangrove, Avicennia officinalis. The non-secretor mangrove Bruguiera cylindrica was used for comparative study of hydrophobic barrier formation in the roots. Bypass flow was reduced when seedlings were previously treated with high salt concentration. A biseriate exodermis was detected in the salt-treated roots, along with an enhanced deposition of hydrophobic barriers in the endodermis. These barriers reduced Na(+) loading into the xylem, accounting for a 90-95% salt exclusion in A. officinalis. Prominent barriers were found in the roots of B. cylindrica even in the absence of salt treatment. A cytochrome P450 gene that may regulate suberin biosynthesis was up-regulated within hours of salt treatment in A. officinalis roots and leaves, corresponding with increased suberin deposition. X-ray microanalysis showed preferential deposition of Na(+) and Cl(-) in the root cortex compared with the stele, suggesting that the endodermis is the primary site of salt exclusion. Enhanced salt secretion and increased suberin deposition surrounding the salt glands were seen in the leaves with salt treatment. Overall, these data show that the deposition of apoplastic barriers increases resistance to bypass flow leading to efficient salt exclusion at the roots in mangroves.

Dynamic secretion changes in the salt glands of the mangrove tree species Avicennia officinalis in response to a changing saline environment

The specialized salt glands on the epidermis of halophytic plants secrete excess salts from tissues by a mechanism that is poorly understood. We examined the salt glands as putative salt and water bi-regulatory units that can respond swiftly to altering environmental cues. The tropical mangrove tree species (Avicennia officinalis) is able to grow under fluctuating salinities (0.7-50.0 dS m(-1)) at intertidal zones, and its salt glands offer an excellent platform to investigate their dynamic responses under rapidly changing salinities. Utilizing a novel epidermal peel system, secretion profiles of hundreds of individual salt glands examined revealed that these glands could secrete when exposed to varying salinities. Notably, rhythmic fluctuations observed in secretion rates were reversibly inhibited by water channel (aquaporin) blocker, and two aquaporin genes (PIP and TIP) preferentially expressed in the salt gland cells were rapidly induced in response to increasing salt concentration. We propose that aquaporins are involved and contribute to the re-absorption of water during salt removal in Avicennia officinalis salt glands. This constitutes an adaptive feature that contributes to salt balance of trees growing in saline environments where freshwater availability is limited.

A simple, rapid method to isolate salt glands for three-dimensional visualization, fluorescence imaging and cytological studies

BACKGROUND

Some plants inhabiting saline environment remove salts via the salt glands embedded in the epidermal tissues. Cytological studies of salt glands will provide valuable information to our understanding of the secretory process. Previous studies on salt gland histology relied mainly on two-dimensional microscopic observations of microtome sections. Optical sectioning properties of confocal laser scanning microscope offer alternative approach for obtaining three-dimensional structural information of salt glands. Difficulty in light penetration through intact leaves and interference from neighbouring leaf cells, however, impede the acquiring of good optical salt gland sections and limit its applications in salt gland imaging. Freeing the glands from adjacent leaf tissues will allow better manipulations for three-dimensional imaging through confocal laser scanning microscopy.

RESULTS

Here, we present a simple and fast method for the isolation of individual salt glands released from the interference of neighbouring cells. About 100-200 salt glands could be isolated from just one cm2 of Avicennia officinalis leaf within hours and microscopic visualization of isolated salt glands was made possible within a day. Using these isolated glands, confocal laser scanning microscopic techniques could be applied and better resolution salt gland images could be achieved. By making use of their intrinsic fluorescent properties, optical sections of the gland cells could be acquired without the use of fluorescent probes and the corresponding three-dimensional images constructed. Useful cytological information of the salt gland cells could also be obtained through the applications of fluorescent dyes (e.g., LysoTracker® Red, FM®4-64, Texas Red®).

CONCLUSIONS

The study of salt glands directly at the glandular level are made possible with the successful isolation of these specialized structures. Preparation of materials for subsequent microscopic observations of salt glands could be achieved within a day. Potential applications of confocal fluorescence microscopic techniques could also be performed using these isolated glands. Experiments designed and targeted directly at the salt glands were explored and cytological information obtained herein could be further incorporated towards the understanding of the mechanism underlying secretion in plant salt glands.

Reciprocal function of movement proteins and complementation of long-distance movement of Cymbidium mosaic virus RNA by Odontoglossum ringspot virus coat protein

Complementation of movement and coat proteins of the orchid-infecting potexvirus Cymbidium mosaic virus (CymMV) and tobamovirus Odontoglossum ringspot virus (ORSV) was investigated. Nicotiana benthamiana, which is susceptible to both CymMV and ORSV, was used as a model system. Four transgenic lines, each harbouring one of the movement protein (MP) or coat protein (CP) genes of CymMV or ORSV, were constructed. The MP of CymMV consists of three overlapping open reading frames, together called the triple-gene block (TGB). CymMV and ORSV mutants, each carrying an inactivated MP or CP, were generated from the respective biologically active full-length cDNA clones. Complementation was studied by infecting transgenic plants with in vitro transcripts generated from these mutants. The cell-to-cell movement of a movement-deficient CymMV was restored in transgenic plants carrying the ORSV MP transgene. Similarly, CymMV TGB1 transgenic plants were able to rescue the cell-to-cell movement of a movement-deficient ORSV mutant. ORSV CP transgenic plants supported systemic movement of a CymMV CP-deficient mutant. However, in these plants, neither encapsidation of CymMV RNA with ORSV CP nor CymMV CP expression was detected. Long-distance movement of an ORSV CP-deficient mutant was not supported by CymMV CP. The complementation of MPs and CPs of CymMV and ORSV facilitates movement of these viruses in plants, except for long-distance movement of ORSV RNA by CymMV CP.

Induced mutations in cassava using somatic embryos and the identification of mutant plants with altered starch yield and composition

A cyclic somatic embryogenic system was used to induce mutations in cassava variety PRC 60a in vitro. Globular-stage somatic embryos were selected as suitable experimental materials, and 50 Gy of gamma-rays was determined to be the optimal dose for inducing mutations. During subsequent field trials, more than 50% of the regenerated mutant lines varied morphologically from wild-type plants. Consequently, we used this approach to induce genetic variability for obtaining novel cassava cultivars. Among the different mutant lines obtained, lines S14 and S15 showed large morphological variations. In 10-month-old S14 and S15 mutant lines, storage root yield was reduced 17-fold and 60-fold, respectively, compared to wild-type plants, while the storage roots of S15 mutant plants also exhibited an almost 50% decrease in starch content and a significant reduction (30%) in amylose content. These two features were observed throughout the different developmental stages of the storage roots in S15 plants.

Reliability and validity of the Spielberger State-Trait Anxiety Inventory (STAI) among urological patients: a Malaysian study

To validate the English version of the Spielberger State-Trait Anxiety Inventory (STAI) in a sample of Malaysia patients with and without urinary symptoms. Validity and reliability were studied in patients with lower urinary tract symptoms (LUTS) and patients without LUTS. Reliability was evaluated using the test-retest method and internal consistency was assessed using Cronbach's alpha. Sensitivity to change was expressed as the effect size in the pre-intervention versus post-intervention score in additional patients with LUTS who underwent transurethral resection of the prostate (TURP). Internal consistency was excellent. A high degree of internal consistency was observed for each of the 40 items with Cronbach's alpha value = 0.38 to 0.89 while the Cronbach's alpha for the total scores was 0.86. Test-retest correlation coefficients for the 40 items score were highly significant. Intraclass correlation coefficient was high (ICC=0.39 to 0.89). A high degree of sensitivity and specificity to the effects of treatment was observed. A high degree of significant level between baseline and post-treatment scores was observed across nearly half of the items in surgical group but not in the non-LUTS group (control subjects). The STAI is reliable, valid and sensitive to clinical change in a sample of Malaysian patients with and without urinary symptoms.

Clinical usefulness of tumour markers

Tumour markers are substances related to the presence or progress of a tumour. An ideal tumour marker is (1) detectable only when malignancy is present, (2) specific for the type and site of malignancy, (3) correlates with the amount of malignant tissue present and (4) responds rapidly to a change in tumour size. At present, no tumour marker fulfills all of the above criteria. The first part of the review discusses the clinical usefulness of the commonly requested serum tumour markers, namely, prostate-specific antigen (PSA), CA 19-9, carcinoembryonic antigen (CEA), CA 125, CA 15-3, human chorionic gonadotrophin (hCG) and alpha-foetoprotein (AFP). It is hoped that this review article will decrease the abuse and misuse of these commonly requested serum tumour markers. The second part of the review discusses the clinical usefulness of catecholamines and their metabolites, calcitonin, thyroglobulin, parathyroid hormone, prolactin, adrenocorticotrophic hormone, oestrogen and progesterone receptors, p53, HER-2/c-erbB2, BRCA1 and BRCA2.

Sexual function outcomes following treatment for lower urinary tract symptoms. A one-year study

The aim of this study was to assess the effects of treating lower urinary tract symptoms (LUTS) on the quality of sexual function in a one-year follow up. A total of 116 patients with LUTS received alpha-blocker treatment, 111 patients underwent transurethral resection of the prostate (TURP) and 70 patients with renal stones, with no or mild symptoms served as a control group. The patients were assessed at baseline, three months, six months and twelve months using the International Index of Erectile Function (IIEF-15). The surgical group exhibited some changes in the domain of IIEF-15. Patients in the medical group showed improvement in erectile function and intercourse satisfaction, while orgasmic, overall sexual satisfaction and sexual drive were relatively unchanged. In contrast, the surgical group suffered retrograde ejaculation and overall sexual dissatisfaction after undergoing TURP. TURP has been found to be associated with retrograde ejaculation intercourse and overall sexual dissatisfaction.

Peritoneal implantation of ureter in a cadaveric kidney transplant recipient

We report here a case of a kidney transplant recipient in whom the ureter was initially implanted into the peritoneum. Excessive ultrafiltration volume and reversal of serum vs dialysate creatinine ratio when the patient was recommenced on continuous ambulatory peritoneal dialysis first suggested the diagnosis which was subsequently confirmed by a plain abdominal x-ray demonstrating placement of ureteric stent in the peritoneum. This rare complication was successfully corrected with surgical re-implantation of ureter into the bladder and 5 years later, the patient remains well with good graft function.

The sensitivity of the Malay version of Brief Manual of Sexual Function Inventory in assessing erectile dysfunction secondary to benign prostatic hyperplasia

This study aimed to assess the sensitivity of the Malay version of the Brief Manual Sexual Function Inventory (BMSFI) on patients with and without urinary symptoms in Malaysian population. Validity and reliability were studied in patients with lower urinary tract symptoms (LUTS) and patients without LUTS. Reliability and validity was evaluated by using the test-retest method while internal consistency was assessed by Cronbach's alpha. Sensitivity to change was expressed as the effect size in the pre-intervention versus post-intervention score in patients who underwent transurethral resection of the prostate (TURP). Internal consistency was excellent. A high degree of internal consistency was observed for each of the 11 items and 5 domains (Cronbach's alpha value = 0.67 and higher and 0.73 and higher respectively). Test-retest correlation coefficient for the 11 items scores was highly significant. Intraclass correlation coefficient was high (ICC = 0.68 and above). The sensitivity and specificity showed a high degree of sensitivity and specificity to the effects of treatment. A high degree of significant level between baseline and post-treatment scores were observed across 3 domains in the treatment corresponds cohort but not in the control group. The Mal-BMSFI is a suitable, reliable, valid and sensitive to clinical change in the Malaysian population.

The performance properties of the International Index of Erectile Function (IIEF-15) in assessing erectile dysfunction in patients with lower urinary tract symptoms

To validate the International Index of Erectile Function (IIEF-15) in Malaysian population. Reliability and internal consistency were evaluated using the test-retest method and Cronbach's alpha. Sensitivity to change was expressed as the effect size index. Internal consistency was excellent (Cronbach's alpha value = 0.75 to 0.90) Test-retest correlation coefficient and intraclass correlation coefficient were highly significant (ICC = 0.75 and above) and a high degree of sensitivity and specificity was observed. The IIEF-15 is suitable, reliable, valid and sensitive to clinical change in the Malaysian population.

Genetic variability in the coat protein genes of two orchid viruses: Cymbidium mosaic virus and Odontoglossum ringspot virus

The variability in coat protein gene sequences of Cymbidium mosaic virus (CymMV) and Odontoglossum ringspot virus (ORSV) that naturally infect orchids worldwide was investigated. Samples were collected from Korea, Singapore and Taiwan. The sequence data were compared with available published coat protein gene sequences of CymMV and ORSV, including those from Japan and Thailand. Among CymMV isolates, the homology was 89.1%-99.7% and 93.2%-100% at the nucleotide and amino acid levels, respectively. Among the ORSV isolates, the homology was 95.5%-100% and 93%-100% at the nucleotide and amino acid levels, respectively. No particular region of variability could be defined in either of the viruses. In deduced amino acid sequence, the N-terminal was more conserved than the C-terminal in both CymMV and ORSV. By comparing all sequences determined in this study and those that are published in the GenBank databases, we did not find clustering based on geographical distribution or sequence identity. Such high sequence conservation suggests that both CymMV and ORSV coat protein genes are suitable candidates to provide resistance to orchids cultivated in different geographical locations.

The effects of treating lower urinary tract symptoms on health-related quality of life: a short-term outcome

OBJECTIVES

This study examined the effects of treatment of lower urinary tract symptoms (LUTS) on the health-related quality of life (physical/functional, mental, social and global aspect), pain and prostatic symptoms.

PATIENTS AND METHODS

The study consisted of 123 LUTS patients on medical treatment (alpha blockers) and 52 who underwent surgical treatment (TURP). The patients were assessed one week before and three months after medical and surgical treatment by using the Health-Related Quality of Life (HRQOL-20), the Visual Analogue Scale of Pain (VAS), the Present Pain Intensity (PPI) and the International Prostate Symptom Score (I-PSS) inventories and questionnaires.

RESULTS

Prior to treatment, the surgically treated patients were found to suffer more pain, severe prostatic symptoms, bothersomeness and deterioration in health-related quality of life than the medically treated patients. Postoperatively, the surgical group showed a significant reduction and improvement in all aspects of pain, prostatic symptoms, bothersomeness and overall health-related quality of life, as compared with the medication group. The mean ages of the surgical and medical treated groups were 69.56 years (SD=7.94 years) and 64.62 years (SD=7.94 years) respectively.

CONCLUSIONS

The result showed that operative procedure had significantly improved the overall health-related quality of life of LUTS patients compared to those on medical treatment.

Reliability and validity of the Malay version of the International Index of Erectile Function (IIEF-15) in the Malaysian population

The objective of this study was to validate the Malay version of the International Index of Erectile Function (IIEF-15) in patients with lower urinary tract symptoms. Reliability and validity was assessed by using the test-retest while Cronbach's alpha was used to assess internal consistency. Effect size 5was evaluated to assess the sensitivity to change in the pre-transurethral resection of the prostate (TURP) vs post-TURP. Internal consistency was excellent. A high degree of internal consistency was observed for each of the 15 items and five domains (Cronbach's alpha value=0.56 and higher and 0.74 and higher, respectively). Test-retest correlation coefficient for the 15 items and domains scores showed no significant changes. Intraclass correlation coefficient for 15 items and domains were high (ICC=0.59 and above). It can be concluded that the Mal-IIEF-15 is suitable, reliable, valid and sensitive to clinical change in the Malaysian population.

Reliability and validity of the Malay version of the Health-Related Quality of Life instrument in a Malaysian population

OBJECTIVE

To validate the Malay version of the Health-Related Quality of Life (Mal-HRQOL-20) questionnaire in patients with and without urinary symptoms in a Malaysian population.

PATIENTS AND METHODS

The validity and reliability of the Mal-HRQOL-20 were assessed in patients with and without lower urinary tract symptoms (LUTS). The reliability was evaluated using the test-retest method and the internal consistency using Cronbach's alpha. Sensitivity to change was expressed as the effect size in the score before and after intervention in additional patients with LUTS who underwent transurethral resection of the prostate.

RESULTS

The internal consistency was excellent; there was a high degree of internal consistency for each of the 20 items and for the overall score (Cronbach's alpha > or = 0.57 and 0.79, respectively) in the population study. The test-retest correlation coefficient for the 20 item scores was highly significant. The intra-class correlation coefficient was high (> or = 0.55). The sensitivity and specificity were high for the effects of treatment. There was a very significant agreement between scores before and after treatment across all domains in the treatment cohort, but not in the control group.

CONCLUSION

The Mal-HRQOL-20 is suitable, reliable, valid and sensitive to clinical change in the Malaysian population.

Reliability and Validity of the Malay Version of the General Health Questionnaire (GHQ - 12) Among Urological Patients

The aim of the study was to validate the Malay version of the General Quentionnaire (GHQ-12) in patients with psychiatric morbidity secondary to urological disorder. Validity and reliability were studied in patients with lower urinary tract symptoms (LUTS) and patients without LUTS. Internal consistency was excellent. A high degree of internal consistency was observed for each of the 12 items and total scores (Cronbach's alpha value = 0.50 and higher and 0.65 respectively. Test-retest correlation coefficient for the 12 items scores was highly significant. Intraclass correlation coefficient was high (ICC=0.47 and above). A significant level between baseline and post-treatment scores were observed across 3 items in the surgical group. The Mal-GHQ-12 is a suitable, reliable, valid and sensitive to clinical change in the Malaysian population.

The quality of life outcome following treatment for lower urinary tract symptoms

This study aims to assess the impact of medical and surgical treatment on treating lower urinary tract symptoms (LUTS) on pain, prostatic symptoms, disease-specific quality of life and health-related quality of life. Patients scheduled for medical (alpha-blockers) and surgical treatment (transurethral resection of the prostate, TURP) were recruited in the study. The patients were assessed using the Visual Analogue Scale (VAS), Present Pain Intensity (PPI), International Prostate Symptom Score (I-PSS) and Health-Related Quality of Life (HRQOL) at 3-month, 6-month and 12-month (baseline). Before treatment, most of the patients with LUTS had severe pain, LUTS and deterioration of health-related quality of life. Following treatment, both medical and surgical treatment improved their pain, LUTS and health-related quality of life. Both treatments are effective in relieving the symptoms of pain, LUTS and health-related quality of life.

Induction of early bolting in Arabidopsis thaliana by triacontanol, cerium and lanthanum is correlated with increased endogenous concentration of isopentenyl adenosine (iPAdos)

The effects of triacontanol (TRIA), applied singly or in combination with cerium nitrate and lanthanum nitrate, on bolting of Arabidopsis thaliana were studied. Triacontanol (0.1 to 0.6 microM) added to the culture medium induced early bolting. TRIA (0.3 microM) applied with low concentrations of cerium and lanthanum caused a synergistic stimulation of bolting. In medium containing 0.3 microM TRIA, 0.1 microM cerium nitrate and 0.1 mM lanthanum nitrate, 82% of the plants bolted 20 d after seed sowing compared to only 8.6% in basal medium and 47.8% in medium with TRIA only. The changes in the endogenous concentrations of total cytokinins of the isopentenyl adenine (IP) subfamily in the leaf and root tissues were correlated with TRIA-induced early bolting. The combined treatment of TRIA (0.3 microM), cerium nitrate (0.1 microM) and lanthanum nitrate (0.1 mM) resulted in a significant increase in the endogenous concentrations of total cytokinins of the IP subfamily in the root and leaf tissues compared to plants growing in the basal medium and medium with TRIA. The exogenous application of six natural cytokinins to the plants revealed that only isopentenyl adenosine (iPAdos) was as effective as TRIA on floral bud formation. iPAdos was also found to have similar effects as TRIA on root growth and reproductive growth. These results suggest a correlation between the early bolting induced by TRIA, cerium and lanthanum and the production of higher concentrations of endogenous iPAdos.

Drying rate and dehydrin synthesis associated with abscisic acid-induced dehydration tolerance in Spathoglottis plicata orchidaceae protocorms

Dehydration tolerance of in vitro orchid protocorms was investigated under controlled drying conditions and after abscisic acid (ABA) pretreatment. Protocorms were obtained by germinating seeds on Murashige and Skoog (MS) medium containing 10% (v/v) coconut water, 2% (w/v) sucrose and 0.8% (w/v) agar, and were dehydrated in relative humidities (RH) ranging from 7% to 93% at 25 degrees C. The critical water content of dehydration tolerance was determined, using the electrolyte leakage method. Drying rate affected the critical water content. Slow drying under high RH conditions achieved the greatest tolerance to dehydration. ABA pretreatment decreased the drying rate of protocorms, and increased dehydration tolerance. Improved tolerance to dehydration after ABA treatment was correlated with the effect of ABA on drying rate of protocorms. When critical water content of protocorms dried under different RH was plotted as a function of actual drying rate, no significant difference in tolerance to dehydration was observed between ABA-treated and control protocorms. ABA pretreatment and dehydration of orchid protocorms induced the synthesis of dehydrin, especially under the slow drying conditions. ABA pretreatment also promoted dry matter accumulation such as carbohydrates and soluble proteins and increased the concentration of K(+) and Na(+) ions in protocorms. The ABA-induced decrease in drying rate was correlated with lower osmotic potential, the enhanced maturity of protocorms and the accumulation of dehydrin in protocorms during pretreatment.

Differential expression and characterization of three metallothionein-like genes in Cavendish banana (Musa acuminata)

Metallothioneins (MTs) are cysteine-rich polypeptides that are involved in metal detoxification and homeostasis in both prokaryotes and eukaryotes. In this study, we report the isolation and characterization of three members (MT2A, MT2B and MT3) of the MT-like gene family from ripening banana fruit and their differential expression in various banana organs and during fruit development and ripening. All members of the MT-like gene encode small cysteine-rich polypeptides of 65-79 amino acid residues. MT2A shared a high sequence similarity (54-77%) with several type-2 MTs in plants, while MT3 was highly homologous (51-61%) with type-3 MTs. The three members expressed differentially in various organs but transcripts were generally more abundant in reproductive than vegetative organs. During fruit development, the MT2A transcript was barely detectable in ovary but increased to a high level in young fruit at 20 days after shooting (DAS) and declined gradually thereafter as fruit developed. In contrast, both MT2B and MT3 expressed poorly in young fruits (20-60 DAS) and transcripts were detected only in fruits at later stages of development. As ripening progressed, expression of MT2A decreased but that of MT3 increased. Expression of MT members during ripening appeared to be differentially regulated by ethylene, whose levels were low in FG and TY fruit but surged climacteristically in MG and declined sharply as ripening advanced further. Exogenous application of ethylene at 5 ppm or higher concentrations down-regulated MT2A expression and the inhibitory effect of ethylene could be partially suppressed by the presence of norbornadiene, an inhibitor of ethylene action. Ethylene had no effect on transcript accumulation of MT2B and MT3. However, MT3 expression was greatly enhanced in response to metals such as CdSO4, CuSO4 and ZnSO4. These results suggest that increased MT3 expression may be associated with excess metal ions present in ripening fruit tissues. This study also provided evidence, for the first time, that ethylene and metals play a regulatory role in expression of MT-like genes in banana.

Quality of life assessment before and after transurethral resection of the prostate in patients with lower urinary tract symptoms

OBJECTIVES

The aim of this study was to determine the effects of surgical treatment of lower urinary tract symptoms (LUTS) in a Malaysian population by evaluating the quality of life before and after treatment.

PATIENTS AND METHODS

The study group comprised 111 LUTS patients (age 69.56 +/- 7.94 years, mean +/- SD ) who were assessed 1 week before and at 3, 6 and 12 months after treatment using the health-related quality of life (HRQOL-20) questionnaire, a visual analogue scale (VAS), the present pain intensity (PPI) scale and the international prostate symptom score (I-PSS).

RESULTS

Preoperatively the patients suffered more pain, severe prostatic symptoms, impaired disease-specific quality of life and a reduction in health-related quality of life. Postoperatively the patients showed a significant reduction and improvement in pain, prostatic symptoms, and disease-specific and health-related quality of life.

CONCLUSIONS

The results showed that the operative procedure significantly improved the overall quality of life of patients with LUTS.

Reliability and validity of the General Health Questionnaire (GHQ-12) among urological patients: a Malaysian study

This present study was undertaken to validate the English version of the General Health Questionnaire (GHQ-12) in urological patients. Validity and reliability were studied in patients with lower urinary tract symptoms (LUTS) and patients without LUTS. Reliability was evaluated using the test-retest method and internal consistency was assessed using Cronbach's alpha. Sensitivity to change was expressed as the effect size in the pre-intervention versus post-intervention score in additional patients with benign prostatic hyperplasia (BPH) who underwent transurethral resection of the prostate (TURP). Internal consistency was excellent. A high degree of internal consistency was observed for each of the 12 items with Cronbach's alpha value of 0.37-0.79, while total scores was 0.79 in the population study. Test-retest correlation coefficient for the 12 items score were highly significant. Intraclass correlation coefficient was high (0.35-0.79). It showed a high degree of sensitivity and specificity to the effects of treatment. A high degree of significant level between baseline and post-treatment scores were observed across all 12 items in the treatment cohort but not in the control group. The GHQ-12 is suitable, reliable, valid and sensitive to clinical change in urological disorders.

Beck Depression Inventory (BDI): a reliability and validity test in the Malaysian urological population

This study aimed to validate the Beck Depression Inventory (BDI) in the Malaysian urological population. Reliability and internal consistency were evaluated using the test-retest method and internal consistency was assessed using Cronbach's alpha. Responsiveness was expressed as the effect size. Internal consistency was high (Cronbach's alpha value = 0.56 to 0.87). Test-retest correlation coefficient and intraclass correlation coefficient were significant (ICC = 0.56 to 0.87) and a high degree of sensitivity and specificity. The BDI is thus a reliable and a valid instrument to be used in Malaysia.

A Malaysian Study on the reliability and validity of the Health-Related Quality of Life Questionnaire (HRQOL-20) in urological patients

Main objective of this study is to validate the Health-Related Quality of Life (HRQOL-20) in the Malaysian population. Reliability and internal consistency were evaluated using the test-retest method and Cronbach's alpha. Responsiveness was expressed as the effect size. Internal consistency was excellent (Cronbach's alpha value = 0.68 to 0.87). Test-retest correlation coefficients and intraclass correlation coefficient were significant (ICC = 0.58 and 0.91) as well as the high degree of sensitivity and specificity. The HRQOL-20 is a reliable, valid and sensitive to clinical changes in the Malaysian urological population.

Reliability and validity of the International Prostate Symptom Score in a Malaysian population

OBJECTIVE

To validate the English version of the International Prostate Symptom Score (IPSS) in patients with and without urinary symptoms in a Malaysian population.

PATIENTS AND METHODS

Validity and reliability were assessed in patients with lower urinary tract symptoms (LUTS) and in patients with no LUTS. Reliability was evaluated using the test-retest method and internal consistency using Cronbach's alpha. Sensitivity to change was expressed as the effect size in the score before and after intervention in additional patients with LUTS who underwent transurethral resection of the prostate (TURP).

RESULTS

Internal consistency was excellent; there was a high degree of internal consistency for each of the seven domains and for the total score (Cronbach's alpha > or = 0.60 and > or = 0.79, respectively) in the populations studied. The test-retest correlation coefficient for the seven domain scores was highly significant. The intra-class correlation coefficient was high (> or = 0.59). There was a high level of sensitivity and specificity for the effects of treatment, with a very significant change between the seven scores domains in the treated group but not in the control group.

CONCLUSIONS

The IPSS is suitable, reliable, valid and sensitive to clinical change in the Malaysian population.

The effects of treating lower urinary tract symptoms on sexual function

We prospectively evaluated the effect of the treatment of lower urinary tract symptoms (LUTS) on sexual function. The patients were assessed by using the International Index of Erectile Function (IIEF-15) inventory at baseline and three months after medical (alpha-blockers) or surgical treatment (transurethral resection of the prostate, TURP). Following treatment, there were improvement in erectile function and intercourse satisfaction while orgasmic, overall satisfaction and sexual drive were relatively unchanged in the medication group. Patients who had surgical treatment suffered retrograde ejaculation, dissatisfaction in sexual intercourse and overall sexual satisfaction compared to patients who were on alpha-blockers.

Cucurbit protoplast isolation for the study of plant virus replication

A cucurbit protoplast isolation protocol was established for the study of plant virus replication in vivo. This protocol is applicable to both cucumber and squash leaf tissue with significant increases in yields of viable protoplasts suitable for electroporation, compared to other published methods. A combination of Cellulase RS, Macerozyme R10 and mannitol was used as digestion enzymes and osmoticum. An average of 1.7x10(7) protoplasts per gram of fresh leaf tissue were obtained from cucumber cultivar Bet-alpha. Both cucumber cultivar Shimson and squash cultivar First Taste produced an average yield of 6.0x10(6) protoplasts per g of fresh leaf tissue. Electroporation of 10 microg of Zucchini yellow mosaic potyvirus (ZYMV-S) RNA into the protoplasts resulted in virus replication and synthesis of coat protein (CP). SDS-PAGE and immunoblotting were used to detect the CP 48 h post-electroporation. This protocol is highly reproducible and will assist researchers who require cucurbit protoplasts to study virus replication.

Direct somatic embryogenesis, plant regeneration and in vitro flowering in rapid-cycling Brassica napus

 A simple method to induce somatic embryogenesis from seeds of rapid-cycling Brassica napus is described. Seedlings cultured on Murashige and Skoog (MS) basal medium produced somatic embryos directly on hypocotyls and cotyledons after 2 to 3 subcultures onto the same medium. A low pH of the medium (3.5-5) was more conducive to somatic embryogenesis than a higher pH (6 and 7). Embryogenic potential of the seeds was inversely correlated to seed age: about 41-68% of immature seeds between the ages of 14 and 28 days after pollination (DAP) formed somatic embryos compared to 0-11% of the seeds obtained 29-37 DAP. About 54% of the somatic embryos produced secondary embryos after subculturing onto the same medium. The embryogenic potential of the cultures has been maintained on MS basal medium for 2 years (12 generations) without diminution. Up to 75% of the secondary embryos developed into plantlets on MS medium enriched with 10^-6  M zeatin, and 40% of these produced flowers when transferred to an optimised flower-induction medium. Viable seeds were produced in self-pollinated in vitro flowers.

The psychological effects of treatments for lower urinary tract symptoms

OBJECTIVE

To assess and evaluate the level of depression, anxiety and psychiatric status in patients with lower urinary tract symptoms (LUTS) before and after treatment by surgery or drugs.

PATIENTS AND METHODS

The study included 123 patients (mean age 64.6 years, SD 7. 95) with LUTS who were treated medically (with alpha-blockers, i.e. terazosin, prazosin, doxazosin and alfuzosin), and 52 patients (mean age 69.6 years, SD 7.94) with LUTS and confirmed to have benign prostatic hyperplasia (BPH) who underwent transurethral resection of the prostate (TURP). Both groups were assessed at baseline and 3 months after treatment using standardized questionnaires (the Beck Depression Inventory, the State-Trait Anxiety Inventory and the General Health Questionnaire-12).

RESULTS

Patients before TURP were significantly more depressed, worried and psychiatrically morbid than were those before medical treatment. Three months after medical and surgical treatment, there was significantly less depression, anxiety and psychiatric morbidity in the TURP than in the medication group.

CONCLUSIONS

TURP is a better treatment than medication for minimising anxiety, depression and psychiatric morbidity after treatment in patients with LUTS, but causes greater psychological stress before treatment.

Traditional Chinese medicines as immunosuppressive agents

INTRODUCTION

Traditional Chinese Medicines (TCM) have been used for centuries in China to treat various immune-mediated disorders.

METHODS

This review focuses on the clinical and experimental studies that have been performed with TCM as immunosuppressive agents for the treatment of systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), atopic eczema and solid organ transplantation.

RESULTS

The "thunder god" vine, Tripterygium wilfordii Hook F (TWHf), has been extensively used in China to treat SLE and RA. TWHf not only inhibited mitogen-stimulated lymphoproliferation, but its active derivatives have also been shown to inhibit production of proinflammatory cytokines by monocytes and lymphocytes, as well as prostaglandin E2 production via the cyclooxygenase, COX-2, pathway, a potential mechanism of action in patients with RA. Demethylzelasteral (TZ-93), a triterpenoid isolated from the root cortex of TWHf, the plant alkaloid berbamine, and the hydrophobic extract of a Chinese herbal decoction, CMX-13, were all shown to be active in prolonging allograft survival in experimental animal models of heart, skin and single lung transplants, respectively. There are few well-designed randomised placebo-controlled clinical trials demonstrating the efficacy of TCM in various diseases. Zemaphyte, a decoction of 10 herbs, has been shown to be efficacious in the treatment of atopic dermatitis in both children and adults in two randomised double-blind placebo-controlled trials.

CONCLUSION

There is both laboratory and clinical evidence that the derivatives of many of these herbs may have significant beneficial immunosuppressive effects, however, concerns of toxicity must also be addressed, as exact dosing of the active derivatives is difficult to achieve with the current prescriptions of TCM.

Immunoassay for wheat processing quality: utilization of a sandwich assay incorporating an immobilized single-chain fragment

A single-chain fragment (scFv) was engineered from a monoclonal antibody to high molecular weight glutenin subunits (HMW-GS), wheat flour polypeptides that play a major role in determining the mixing- and extension strength-related properties of dough and its subsequent baking performance. The scFv was expressed in a thioredoxin mutant Escherichia coli strain that allows disulfide bond formation in the cytoplasm and incorporated into a diagnostic test for wheat quality. Although the scFv lacks the more highly conserved antibody constant regions usually involved with immobilization, it was able to be directly immobilized to a polystyrene microwell solid phase without chemical or covalent modification of the protein or solid phase and utilized as a capture antibody in a double-antibody (two-site) immunoassay. In the sandwich assay, increasing HMW-GS concentrations produced increasing assay color, and highly significant correlations were obtained between optical densities obtained in the ELISA using the scFv and the content of large glutenin polymers in flours as well as measures of dough strength as measured by resistance to dough extension in rheological testing. The assay using the scFv was able to be carried out at lower flour sample extract dilutions than that required for a similar assay utilizing a monoclonal capture antibody. This research shows that engineered antibody fragments can be utilized to provide superior assay performance in two-site ELISAs over monoclonal antibodies and is the first application of an engineered antibody to the analysis of food processing quality.

Quantitative studies of the kinetics of 5-aminolaevulinic acid-induced fluorescence in bladder transitional cell carcinoma

Photodynamic therapy is a potential treatment for superficial bladder cancer that utilizes photosensitizer drugs, which are activated by light to cause tissue destruction. However, first-generation photosensitizers cause prolonged phototoxicity, have poor tumour specificity and can accumulate within detrusor muscle, resulting in permanent loss of bladder capacity following treatment. A newer drug, called 5-aminolaevulinic acid (ALA), generates a sensitizer called protoporphyrin IX (PpIX) in situ and has been shown, qualitatively, to be more tumour specific. The fluorescence kinetics of ALA-induced PpIX was investigated in patient biopsies of bladder tumour, normal urothelium and detrusor muscle, both in vitro after incubation of specimens in ALA-rich culture medium for various times and in vivo after instillation of intravesical ALA before endoscopic resection. The fluorescence in tumour tissue was twice that of normal urothelium in vitro and up to tenfold in vivo. There was little ALA-induced fluorescence in detrusor muscle, both in vitro and in vivo. Most importantly, no patients experienced phototoxicity or other adverse events following intravesical instillation of ALA.

Two-coat systems for encapsulation of spathoglottis plicata (Orchidaceae) seeds and protocorms

Complex coacervation of alginate-chitosan and alginate-gelatin were used to develop two-coat systems for the encapsulation of Spathoglottis plicata seeds and protocorms (top-shaped structures formed after seed germination of orchids). Both the seeds and the protocorms could withstand the encapsulation treatments with high viability. About 54% of seeds and 40% of large protocorms (1.6-2.0 mm) were able to tolerate a 6-h desiccation treatment. However, viability of the small protocorms (0.7-0.9 mm) was greatly reduced if they were desiccated before encapsulation. Encapsulation after desiccation significantly increased the percentage viability of seeds and protocorms. Treatment with abscisic acid (ABA, 10(-5) M) before desiccation and encapsulation resulted in high percentage viability in seeds and large protocorms whereas the small protocorms were found to be less tolerant to the treatments. Copyright 1998 John Wiley & Sons, Inc.

Synergism in replication of cymbidium mosaic potexvirus (CymMV) and odontoglossum ringspot tobamovirus (ORSV) RNA in orchid protoplasts

An in vitro orchid protoplast isolation method to study replication kinetics of CymMV and ORSV was developed. This method allows the isolation of viable and raphid-free petal protoplasts from an orchid hybrid, Dendrobium Sonia (Dendrobium Caesar x Dendrobium Tomie Drake). The optimum field strength for both viral RNA to achieve good efficiency of electroporation was 750 V/cm and the optimum viral RNA concentration required was 1 microgram and 4 micrograms per 2 x 10(6) protoplasts for CymMV and ORSV, respectively. Autoradiographs of Northern blots depicting the viral genomic and subgenomic RNA in the extracts, referred to as the "Replication Footprint Profiles" (RFP) of specific CymMV/ORSV virus were prepared at different time intervals. Viral RNA synthesis reached a maximum at 18 h for CymMV and 24 h for ORSV. When CymMV and ORSV viral RNA were electroporated into the protoplasts simultaneously, detection signals of both the positive and negative strand viral RNA increased as compared to the singly infected protoplasts. Thus, synergism in replication of CymMV and ORSV was observed in orchid protoplasts.

Photodynamic therapy of bladder cancer cell lines

OBJECTIVE

To determine the effect of photodynamic therapy mediated by 5-aminolevulinic acid (ALA) on a range of bladder cancer cell lines, including a squamous cancer cell line and a multi-drug resistant cell line.

MATERIALS AND METHODS

Experiments were performed on cells growing in culture: the cell lines studied were the transitional cell cancer lines RT112, T24 and EJ138, the squamous cancer cell line, SCaBER, and the multi-drug resistant transitional cancer cell line, MGH-U1(R), together with its non-resistant parent line, MGH-U1. The kinetics of the ALA-mediated generation of fluorescent photosensitizer were determined using flow cytometry. Photodynamic therapy was performed by incubating cells in ALA followed by exposure to various doses of white light.

RESULTS

The response of the various transitional cancer cell lines to photodynamic therapy depended on dose. The squamous cell line was relatively resistant to photodynamic therapy. There was some cross-resistance of the MGH-U1(R) cell line to photodynamic therapy, although the mechanism of cross-resistance appeared not to be necessarily a property of the drug-resistant phenotype.

CONCLUSION

This study suggests that ALA-mediated photodynamic therapy may be effective in transitional cell carcinoma of the bladder. Based on these findings, this therapeutic method should be further evaluated clinically.

High frequency production of embryos from liquid flask cultures of oilseed rape

As part of the program to scale-up the production of artificial seeds of winter oilseed rape, Brassica napus ssp. oleifera, we established a liquid flask culture system that enables the high frequency production of freely suspended embryos. As many as 4000 embryos could be obtained from 1 mL packed-cell-volume of cells. For initiation of liquid flask cultures, four different types of callus tissues were used. Among them, the most embryogenic cell suspension cultures were obtained from spontaneous callus developed on the surface of secondary embryos precultured in medium supplemented with 2,4-dichlorophenoxyacetic acid (4.52 microM) and kinetin (0.46 microM) (type B callus). Growth curves of the cell suspension were determined and the cell suspension was able to grow in medium without plant growth regulators. Embryos were observed to developed directly from the cells without going through an obvious callus phase. When subcultured to agar medium containing 44.38 microM benzylaminopurine, about 43% of the embryos developed into plants.

The complete sequence of a Singapore isolate of odontoglossum ringspot virus and comparison with other tobamoviruses

The complete sequence of a Singapore isolate of odontoglossum ringspot virus (ORSV-S1) comprises 6609 nucleotides (nt) and four open reading frames (ORFs 1 to 4). The 126/183-kDa RNA-dependent RNA polymerase (RdRp), 33-kDa movement protein (MP) and 18-kDa coat protein (CP) cistrons are located at nt 63-3401/4901, 4807-5718, and 5721-6197 on the genome, respectively. The 5' UTR contains three copies of an 8-base direct repeat and (CAA)n motifs. Characteristic tRNA-like structure and three consecutive homologous regions were present in the 3' UTR. The genomic RNA and MP of ORSV-S1 are one of the longest among all members of the TOV group. Phylogenetic analysis of all four genes indicates evolutionary divergence, but within each gene there are some degrees of evolutionary convergence. The conserved amino acid sequences in the MP can be used for the classification of tobamoviruses.