bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of functional lox sites in the plastid genome
Authors: Corneille Sylvie , Lutz Kerry A. , Azhagiri Arun K. , Maliga Pal
Published: September 2003

Our objective was to test whether or not cyclization recombination (CRE), the P1 phage site‐specific recombinase, induces genome rearrangements in plastids. Testing was carried out in tobacco plants in which a DNA sequence, located between two inversely oriented locus of X‐over of P1 (loxP) sites, underwent repeated cycles of inversions as a means of monitoring CRE activity. We report here that CRE mediates deletions between loxP sites and plastid DNA sequences in the 3′rps12 gene leader (lox‐rps12) or in the psbA promoter core (lox‐psbA). We also observed deletions between two directly oriented lox‐psbA sites, but not between lox‐rps12 sites. Deletion via duplicated rRNA operon promoter (Prrn) sequences was also frequent in CRE‐active plants. However, CRE‐mediated recombination is probably not directly involved, as no recombination junction between loxP and Prrn could be observed. Tobacco plants carrying deleted genomes as a minor fraction of the plastid genome population were fertile and phenotypically normal, suggesting that the absence of deleted genome segments was compensated by gene expression from wild‐type copies. The deleted plastid genomes disappeared in the seed progeny lacking CRE. Observed plastid genome rearrangements are specific to engineered plastid genomes, which contain at least one loxP site or duplicated psbA promoter sequences. The wild‐type plastid genome is expected to be stable, even if CRE is present in the plastid.
Expression of a stress‐induced hemoglobin affects NO levels produced by alfalfa root cultures under hypoxic stress
Authors: Dordas Christos , Hasinoff Brian B. , Igamberdiev Abir U. , Manac'h Nathalie , Rivoal Jean , Hill Robert D.
Published: September 2003

Transgenic alfalfa root cultures expressing sense and antisense barley hemoglobin transcripts were examined under varying levels of atmospheric oxygen. Root cultures overexpressing the hemoglobin gene (Hb+) maintained root growth when placed under 3% oxygen, whereas control cultures or cultures underexpressing hemoglobin (Hb−) experienced 30–70% declines in growth under the same conditions. ATP levels and ATP/ADP ratios for Hb+ lines did not significantly differ in 40 and 3% oxygen, whereas the ATP levels and ATP/ADP ratios in control and Hb− lines were significantly lower under 3% oxygen. Large increases in the production of nitric oxide (NO) were measured in root cultures grown under hypoxic conditions compared to aerobic conditions. The amount of NO accumulated in an Hb− line was 2.5‐fold higher than that in the Hb+ line. Treatment of transgenic root lines under 40% oxygen with NO resulted in significant declines in the ATP levels and ATP/ADP ratio of an Hb− line and the control line, with no significant change in an Hb+ line. The root cell structure of an Hb− line showed evidence of cell breakdown under hypoxic growth, whereas an Hb+ line had no evidence of cell breakdown under similar growth conditions. These results lead us to hypothesize that NO is involved in the response of plants to hypoxia and that hemoglobin modulates the levels of NO in the hypoxic cell.
The transcriptional response of Arabidopsis to genotoxic stress – a high‐density colony array study (HDCA)
Authors: Chen I‐Peng , Haehnel Urs , Altschmied Lothar , Schubert Ingo , Puchta Holger
Published: September 2003

A genome‐wide transcription profiling of Arabidopsis upon genotoxic stress has been performed using a high‐density colony array (HDCA). The array was based on a library of 27 000 cDNA clones derived from Arabidopsis cells challenged with bleomycin plus mitomycin C. The array covers more than 10 000 individual genes (corresponding to at least 40% of Arabidopsis genes). After hybridisation of the HDCA with labelled cDNA probes obtained from genotoxin‐treated (bleomycin plus mitomycin C, 6 h) and untreated seedlings, 39 genes revealed an increased and 24 genes a decreased expression among the 3200 highly expressed clones (representing approximately 1200 individual genes because of redundancy of the cDNA library). Of the 4900 clones with a low transcriptional level, the expression of 500 clones was found to be altered and 57 genes with increased and 22 genes with decreased expression were identified by sequence analysis of 135 identified clones. The HDCA results were validated by real‐time PCR analysis. For about 80% of genes (34 out of 42), alteration in expression was confirmed, indicating the reliability of the HDCA for transcription profiling. DNA damage and stress‐responsive genes encoding, for instance transcription factors (myb protein and WRKY1), the ribonucleotide reductase small subunit (RNR2), thymidine kinase (TK), an AAA‐type ATPase, the small subunit of a DNA polymerase and a calmodulin‐like protein were found to be strongly upregulated. Also, several genes involved in cell cycle regulation revealed significant alteration in transcription, as detected by real‐time PCR analysis, suggesting disturbance of cell cycle progression by mutagen treatment.
IMB1, a bromodomain protein induced during seed imbibition, regulates ABA‐ and phyA‐mediated responses of germination in Arabidopsis
Authors: Duque Paula , Chua Nam‐Hai
Published: September 2003

We report the characterization of a plant gene encoding a member of the BET subgroup of bromodomain proteins, a novel class of putative transcription factors. Imbibition‐inducible 1 (IMB1) appears to be a nuclear protein as suggested by subcellular localization in onion epidermal cells using an IMB1–yellow fluorescent protein (YFP) fusion protein. In Arabidopsis thaliana, IMB1 is expressed at very low levels in dry seeds, but is markedly induced during seed imbibition. In addition, IMB1 transcript levels are down regulated during germination. Seeds of a loss‐of‐function mutant allele, imb1, show impaired cotyledon greening during germination in abscisic acid (ABA) and express higher levels of ABI5 protein than the wild type. Moreover, imb1 seeds are deficient in the phytochrome A (phyA)‐mediated very‐low‐fluence response of germination. Microarray analysis revealed that genes included in different functional categories, such as cell‐wall metabolism or plastid function, are repressed in imbibed imb1 seeds. Mutant imb1 plants appear normal, indicating that IMB1 is involved in regulating a specific developmental stage. Taken together, these results show that IMB1 plays a role in the promotion of seed germination by both negatively and positively regulating the ABA and phyA transduction pathways, respectively. In imbibed seeds, IMB1 modulates the transcription of a battery of genes, providing clues on its mode of action.
A role for glycine in the gating of plant NMDA‐like receptors
Authors: Dubos Christian , Huggins David , Grant Guy H. , Knight Marc R. , Campbell Malcolm M.
Published: September 2003

The amino acid glycine has a well‐established role in signalling in the mammalian central nervous system. For example, glycine acts synergistically with the major excitatory neurotransmitter, glutamate, to regulate the influx of ions such as calcium, through N‐methyl‐d‐aspartate (NMDA) receptors. Plants possess NMDA‐like receptors, generically referred to as glutamate receptors (GLRs), named on the basis of their presumed ligand, glutamate. Previously, glycine has not been implicated in plant GLR activity or any other aspect of plant signalling. Using transgenic Arabidopsis seedlings expressing aequorin to monitor ligand‐mediated changes in the cytosolic concentration of Ca2+ ([Ca2+]cyt), the data presented herein show that glutamate and glycine act synergistically to control ligand‐mediated gating of calcium in plants. Glutamate and glycine synergism also regulates hypocotyl elongation. Transient increases in [Ca2+]cyt mediated by glutamate and glycine, as well as hypocotyl elongation, were inhibited by 6,7‐dinitroquinoxaline‐2,3 dione (DNQX), a competitive inhibitor of animal GLRs. Using a multiscale docking algorithm in combination with a molecular model of the ligand‐binding domain of plant GLRs, evidence is provided indicating that glycine, and not glutamate, is likely to be the natural ligand for most plant GLR subunits. These findings uncover a hitherto unconsidered role for glycine signalling in plants, and suggest that the synergistic action of glutamate and glycine at NMDA‐like receptors predates the divergence of plants and animals.
Metastatic cutaneous squamous cell carcinoma to the parotid: the role of surgery and adjuvant radiotherapy to achieve best outcome
Authors: Dona Eddy , Veness Michael J. , Cakir Burcu , Morgan Gary J
Published: September 2003

Background:  Australia has the highest incidence of cutaneous squamous cell carcinoma in the world. The majority of lesions occur in the head and neck with metastases to the parotid gland lymph nodes reflecting an uncommon, but aggressive, manifestation. Parotidectomy ± neck dissection followed by adjuvant radiotherapy should be considered as best practice.

Methods:  Between 1983 and 2000, seventy‐four patients were treated for metastatic cutaneous squamous cell carcinoma to the parotid with surgery and adjuvant radiotherapy at Westmead Hospital, Sydney. Relevant data were extracted from patient files and a prospectively maintained database. Patterns of relapse and outcome were analysed.

Results:  Median age at diagnosis was 65 years (34−93 years) in 63 men and 11 women. Median follow‐up duration was 41 months (12−188 months). All patients underwent parotidectomy with 52 undergoing a simultaneous neck dissection. Twelve patients required sacrifice of the facial nerve (4) or one or more branches (8). All received adjuvant radiotherapy to the parotid region with 56 also receiving radiotherapy to the ipsilateral neck. Despite treatment, 24% developed locoregional recurrence, with a median time to relapse of 7.5 months. The most common site for recurrence was the treated parotid region and upper neck. Most relapsed patients died. No variable independently predicted for locoregional recurrence on multivariate analysis. The 5‐year absolute and cause‐specific survival rates were 58% and 72%, respectively.

Conclusion:  Parotid gland lymph node metastases from cutaneous squamous cell carcinoma are associated with a high rate of recurrence and cause‐specific mortality despite current best practice (surgery and high dose adjuvant radiotherapy). The role of more aggressive surgery, altered fractionation or chemotherapy to enhance locoregional control remains unclear.
Chemoprevention of gastrointestinal malignancies
Authors: Garcea Giuseppe , Dennison Ashley R. , Steward Will P. , Berry David P.
Published: September 2003

Background:  There has been considerable interest in the use of chemical or dietary agents to suppress or inhibit the development of tumours in the early stages of carcinogenesis. This concept is known as chemoprevention and although the potential for such agents is tremendous, evaluating their clinical benefit is beset with difficulties.

Aims:  Using selected agents, such as curcumin and indole‐3‐carbinol, as examples, the present review will discuss the possible mechanisms of chemoprevention and the problems encountered in developing these agents into clinical drugs.

Methods:  A review of the published literature from 1985 to the present day was performed using Medline and Web of Science search engines. Key words used were ‘gastrointestinal cancer’ and ‘chemoprevention’.

Conclusion:  A huge number of agents with possible chemopreventive action has been identified. Pilot trials using molecular signatures of cancer activity can be used to select which agents should be included in large‐scale phase III clinical trials. Publications concerning chemoprevention are concentrated in the scientific and oncological literature but surgeons with their greater exposure to premalignant gastrointestinal disease need to be aware of current concepts in this rapidly expanding field. This knowledge would allow collaboration between oncologists and surgeons in clinical trials to further evaluate chemopreventive compounds and ascertain their clinical impact.
Postoperative confusion assessed with the Short Portable Mental Status Questionnaire
Authors: Eissa Amirarsalan , Andrew Marie J. , Baker Robert A.
Published: September 2003

Background:  Confusion is a common occurrence after cardiac surgery. However, there is great variability in the reported incidence of confusion in patients following cardiac surgery, mainly due to the diagnostic methods and instruments employed in assessing confusion.

Methods:  Forty‐eight cardiac surgery patients were assessed for postoperative confusion by a non‐structured physician interview, and by the short portable mental status questionnaire (SPMSQ) administered by a medical student.

Results:  The non‐structured ward interviews detected confusion in one of the 48 patients (2%), whereas the SPMSQ diagnosed confusion in 15 of the 48 patients (31%).

Conclusion:  Unlike a subjective ward interview, the SPMSQ is a brief and objective diagnostic tool that can be used to measure accurately both the presence and severity of confusion in postoperative cardiac surgery patients.
Management practices of Australian surgeons in the treatment of venous ulcers
Authors: Kruger Allan J. , Raptis Spero , Fitridge Robert A.
Published: September 2003

Introduction:  Venous ulcers will affect 2% of the general population during the course of their lives causing significant morbidity. The aim of the present paper was to review assessment and treatment regimes used by surgeons throughout Australia and compare these with published guidelines.

Methods:  A structured questionnaire was sent to all general and vascular surgeons in Australia. Questions detailing practice demographics, initial treatment, investigation and surgical intervention were asked. Responses were analysed using Fisher's exact test.

Results:  A response rate of 36% was obtained from 1390 surgeons. This included 30% of the general surgeons and 67% of the vascular surgeons surveyed. Three hundred and seventy‐one of these surgeons managed patients with venous ulcers. Vascular surgeons recorded ankle‐brachial pressures (88%vs 55%; P < 0.0001) more frequently and used compression therapy more often than general surgeons (99%vs 61%; P < 0.0001). Superficial vein ablation was performed by 95% in the presence of superficial vein reflux and a normal deep system, 46% also performed this procedure in the setting of an incompetent deep system. Antibiotics were prescribed by 15% of surgeons with no evidence of infection.

Conclusions:  Initially venous ulcers are well managed in Australia; however, antibiotics are overprescribed in their treatment. The current rate of compression therapy use is low for some groups of surgeons and should be improved. The failure to use compression in all cases of venous ulcers and the overprescription of antibiotics in the absence of cellulitis suggests that significant improvements can be made in the management of venous ulcers in Australia.
Hand‐assisted laparoscopic lymphadenectomy: a novel approach to a difficult area
Authors: Sutherland Andrew , Wright Gavin
Published: September 2003

Background:  Hand‐assisted laparoscopic surgery (HALS) is an emerging technique that is gaining acceptance for a wide range of abdominal procedures. We drew upon our growing experience with hand‐assisted laparoscopic and thoracoscopic surgery to manage a case that was felt to require a major thoracoabdominal incision if it were to be completed by conventional open surgery.

Methods:  A technique is described that combines the advantages of both laparoscopic and open surgery in the form of hand‐assisted laparoscopic surgery to permit safe dissection of a retrocrural mass extending into the chest.

Results:  We used this technique successfully to completely resect a nodal deposit of metastatic embryonal carcinoma previously thought to be inaccessible to surgical resection.

Conclusion:  The use of hand‐assisted laparoscopic surgery improves tactile and visual feedback for the operator. This allows complex procedures involving delicate dissection to be completed safely and with less morbidity than open surgery.
Unusual case of Morgagni hernia associated with malrotation
Authors: . Court Fiona G , Wemyss‐Holden Simon A. , Fitridge Robert , Maddern Guy J.
Published: September 2003

Morgagni herniae are rare congenital diaphragmatic hernia, which normally present late in adult life with minimal symptoms. They are always associated with a peritoneal hernial sac, and often contain transverse colon or stomach. We present an unusual case of a Morgagni hernia containing caecum in an 81‐year‐old woman, post ruptured aortic aneurysm repair.
Clinical and molecular aspects of adrenocortical tumourigenesis
Authors: Sidhu Stan , Gicquel Christine , Bambach Christopher P. , Campbell Peter , Magarey Christopher , Robinson Bruce G. , Delbridge Leigh W.
Published: September 2003

Adrenal masses are a common problem affecting 3−7% of the population. The majority turn out to be benign adrenocortical adenomas, which may be functional or non‐functional. Much more rarely, these masses represent a primary adrenal carcinoma. It is becoming increasingly recognized that of the benign functioning adenomas or hyperplasias, the majority will hypersecrete aldosterone and this will be more frequently detected when hypertensive populations are screened for this disease. In contrast, the incidence of primary adrenocortical carcinoma has remained steady and for this disease, surgery represents the mainstay of treatment. The advent of laparoscopic adrenal surgery has lowered the threshold size for recommending surgery for asymptomatic adrenal masses and as such, an increased proportion of adrenocortical cancers are being resected and detected at an earlier stage. Recent progress has been made in our understanding of the key genetic changes which underpin the biology of this disease. Progression from adrenal adenoma to carcinoma involves a monoclonal proliferation of cells which, among other defects, have undergone chromosomal duplication at the 11p15.5 locus leading to overexpression of the IGF2 gene and abrogation of expression of the CDKN1C and H19 genes. TP53 is involved in progression to carcinoma in a subset of patients and the frequency of ACTH receptor deletion needs to be more fully explored. Other key oncogenes and tumour suppressor genes remain to be identified although the chromosomal loci in which they lie can be identified at 17p, 1p, 2p16 and 11q13 for tumour suppressor genes and chromosomes 4, 5 and 12 for oncogenes.
Methodological index for non‐randomized studies (MINORS): development and validation of a new instrument
Authors: Slim Karem , Nini Emile , Forestier Damien , Kwiatkowski Fabrice , Panis Yves , Chipponi Jacques
Published: September 2003

Background:  Because of specific methodological difficulties in conducting randomized trials, surgical research remains dependent predominantly on observational or non‐randomized studies. Few validated instruments are available to determine the methodological quality of such studies either from the reader's perspective or for the purpose of meta‐analysis. The aim of the present study was to develop and validate such an instrument.

Methods:  After an initial conceptualization phase of a methodological index for non‐randomized studies (MINORS), a list of 12 potential items was sent to 100 experts from different surgical specialities for evaluation and was also assessed by 10 clinical methodologists. Subsequent testing involved the assessment of inter‐reviewer agreement, test‐retest reliability at 2 months, internal consistency reliability and external validity.

Results:  The final version of MINORS contained 12 items, the first eight being specifically for non‐comparative studies. Reliability was established on the basis of good inter‐reviewer agreement, high test‐retest reliability by the κ‐coefficient and good internal consistency by a high Cronbach's α‐coefficient. External validity was established in terms of the ability of MINORS to identify excellent trials.

Conclusions:  MINORS is a valid instrument designed to assess the methodological quality of non‐randomized surgical studies, whether comparative or non‐comparative. The next step will be to determine its external validity when used in a large number of studies and to compare it with other existing instruments.
Effects of ursodeoxycholic acid, glutamine and polyclonal immunoglobulins on bacterial translocation in common bile duct ligated rats
Authors: Aldemir Mustafa , Faruk Geyik M. , Faruk Kökoğlu Ö. , Büyükbayram Hüseyin , Hoşoğlu Salih , Yağmur Yusuf
Published: September 2003

Background:  The present study was conducted to investigate the effects of ursodeoxycholic acid (UDCA), glutamine and i.v. polyclonal immunoglobulins (IVIG) on the bacterial translocation (BT) and intestinal integrity of obstructive jaundice (OJ) in an animal model.

Methods:  Fifty rats were randomized into five groups containing 10 rats each. All procedures were performed aseptically under general anaesthesia using intramuscular ketamine (25 mg/kg). The abdomen was opened and the common bile duct was identified, mobilized, doubly ligated using 5−0 silk and divided. In group 1 (the ‘sham’ group), the rats had a similar incision followed by mobilization of the common bile duct (CBD), without ligation or division. In group 2 rats, only common bile duct ligation (CBDL) was performed. In group 3, CBDL was performed and UDCA was administered by orogastric intubation once daily. In group 4 rats, CBDL was performed and glutamine was given by orogastric intubation once daily. Therapeutic substances were started orally on the day CBDL was fulfilled and were continued for 7 days. In group 5, IVIG was administrated via a femoral vein catheter just before CBDL. The animals were killed at the end of the 7th day, and serum levels of total bilirubin (TB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and gamma‐glutamyl transpeptidase (GGT) were measured. Mesenteric lymph nodes (MLN), liver, spleen and blood were cultured. The terminal ileum specimens were examined histopathologically.

Results:  Bacterial translocation significantly increased in the MLN and spleen of rats in group 2 as compared to groups 3, 4 and 5 (P < 0.05, P = 0.001, P = 0.001, respectively). The BT of the liver in group 2 was significantly higher than that of group 5 (P < 0.05). In the blood, the BT was significantly higher in group 2 than groups 3, 4 and 5 (P < 0.05). The bacterial counts, colony‐forming units per gram tissue (cfu/g), were found significantly higher in MLN, liver and spleen of rats in group 2 than those of groups 3, 4 and 5 (P = 0.000). The average villus height in the group 4 was significantly higher than that of groups 2, 3 and 5 (P = 0.000).

Conclusion:  The present experimental study has demonstrated that the administration of glutamine, UDCA and IVIG reduce the incidence of BT and additionally glutamine preserves intestinal mucosal integrity.
Retrospective, 5‐year surgical audit comparing breast cancer in indigenous and non‐indigenous women in Far North Queensland
Authors: Shaw Ian M. , Elston Timothy J.
Published: September 2003

Background:  Breast cancer is the third leading cause of cancer deaths in Aboriginal women after cervical and lung cancer.

Methods:  A retrospective 5‐year surgical audit comparing breast cancer in indigenous and non‐indigenous women in Far North Queensland was undertaken.

Results:  The mean age at diagnosis was similar for indigenous (54.0 years) and non‐indigenous (55.4 years) women. Indigenous women presented with slightly larger tumours (mean 32.2 mm vs 23 mm; P = 0.07). More indigenous women had involved lymph nodes (P = 0.03). Despite larger tumour size, indigenous women were considered suitable for breast conservation surgery at a rate similar to the non‐indigenous population.

Conclusions:  Indigenous women present with more advanced breast cancer in Far North Queensland despite similar detection rates among the screened indigenous and non‐indigenous population. Indigenous women received similar rates of breast conservation surgery. Differences in mortality rates will require further study.
Breast reconstruction following mastectomy: current status in Australia
Authors: Sandelin Kerstin , King Elizabeth , Redman Sally
Published: September 2003

Background:  Although breast reconstruction provides some advantages for women following mastectomy, few Australian breast cancer patients currently receive reconstruction. In Australia, the routine provision of breast reconstruction will require the development of specific health service delivery models. The present paper reports an analysis of the provision of breast reconstruction in eight sites in Australia.

Methods:  A semi‐structured telephone interview was conducted with 10 surgeons offering breast reconstruction as part of their practice, including nine breast or general surgeons and one plastic surgeon.

Results:  Surgeons reported offering breast reconstruction to all women facing mastectomy; the proportion of women deciding to have breast reconstruction varied between sites with up to 50% of women having a reconstruction at some sites. Most sites offered three types of reconstruction. Two pathways emerged: either the breast surgeon performed the breast surgery in a team with the plastic surgeon who undertook the breast reconstruction or the breast surgeon provided both the breast surgery and the reconstruction. Considerable waiting times for breast reconstruction were reported in the public sector particularly for delayed reconstruction. Surgeons reported receiving training in breast reconstruction from plastic surgeons or from a breast surgery team that performed reconstructions; a number had been trained overseas. No audits of breast reconstruction were being undertaken.

Conclusions:  Breast reconstruction can be offered on a routine basis in Australia in both the private and public sectors. Women may be more readily able to access breast reconstruction when it is provided by a breast surgeon alone, but the range of reconstruction options may be more limited. If access to breast reconstruction is to be increased, there will be a need to: (i) develop effective models for the rural sector taking account of the lack of plastic surgeons; (ii) address waiting times for reconstruction surgery in the public sector; (iii) review costs to women in the private sector; (iv) develop a better understanding of women's views and how best to communicate about breast reconstruction; and (v) improve training in breast reconstruction.
Factors determining the return to normal activity after appendicectomy
Authors: Wagener Jenny , Windsor John
Published: September 2003

Background:  The ability of a patient to return to their normal activities is an important outcome of an operation. The present study was designed to identify and rank factors that are important in determining this return to normal activity (RTNA) after appendicectomy.

Methods:  Consecutive patients were identified prospectively following appendicectomy at North Shore Hospital between February and April 2000. Data regarding 25 different factors were obtained by a structured patient interview before and after discharge from hospital and by review of the medical records. Statistical analysis involved analysis of variance and logistic regression analysis.

Results:  There were 98 patients (median age 28, range 15−69 years, male : female ratio 48:50) who had an appendicectomy. An open appendicectomy was performed in 74 patients, a laparoscopic appendicectomy in 22 patients and a laparotomy in two patients. This includes the 16 patients who were converted from laparoscopic to open appendicectomy (conversion rate 42% 16/38). Acute appendicitis was confirmed by histology in 67 (68%) patients. The significant independent variables identified by anova were ranked by logistic regression analysis. The most important determinant for the time to RTNA was what the doctor advised (χ‐squared 43.7, P < 0.0001). The other determinants were the physical activity of their primary occupation (χ‐squared 21.5, P < 0.017), the need for strong postdischarge analgesia (χ‐squared 21.1, P < 0.13), the American Society of Anesthesiologists (ASA) category (χ‐squared 13.6, P < 0.018) and the total sick leave obtained (χ‐squared 9.6, P < 0.08).

Conclusion:  It has been shown that the most significant factor in determining the RTNA after appendicectomy was the advice given by the doctor, and that this was more important than the surgical approach, pathology, complications, age or occupation of the patient.
Cardiac surgery in Australian octogenarians: 1996−2001
Authors: Hewitt Timothy D. , Santa Maria Peter L. , Alvarez John M.
Published: September 2003

Background:  The number of octogenarians receiving cardiac surgery is increasing. Concerns regarding the outcomes and significant expense required to provide this service have not been addressed because no prospective medium term outcomes of Australian octogenarians have been published.

Methods:  Prospective analysis was undertaken of octogenarians having cardiac surgery from 1996 to 2001 in three hospitals of moderate case volume (400 patients per year) by: in‐hospital audit and data acquisition, 1‐year direct patient follow up in rooms, and a final follow up in late 2001 directly with the patient either in rooms or via telephone questionnaire.

Results:  Sixty‐four patients had cardiac surgery. All patients were severely disabled by symptoms (CCVS: III−IV, NYHA: III−IV) preoperatively, 14% were advised not to proceed with a surgical option but did so. Total operative in‐hospital mortality was 6.3% (elective: 0%, urgent: 10.5%, P = 0.05), major complications were few 10.9% (seven patients; stroke: 1.6%, deep sternal infection: 1.6%, myocardial infarction: 1.6%, reoperation: 4.8%). At 1 year, despite 95% being free of significant cardiovascular symptoms (CCVS/NYHA: I−II), nearly one in five (19%) would not have proceeded with the surgery. However, at the final follow up (mean time: 2.8 years), freedom from cardiovascular symptoms remained high (95%), 94% remained independent and their quality of life was significantly better than before surgery. Although 59% suffered worsening of additional medical conditions, these conditions had a minor impact on their quality of life. Ninety‐eight per cent would recommend cardiac surgery. Actuarial survival for all patients and for hospital survivors at 4 years was 67.9 ± 4.1% and 74.2 ± 4%, respectively.

Conclusion:  Medium‐term follow up of Australian octogenarians who were offered cardiac surgery revealed that 94% remain independent and with an excellent quality of life. Age alone must not be a barrier to access to cardiac surgery.
Total thyroidectomy: the evolution of surgical technique
Authors: Delbridge Leigh
Published: September 2003

The present paper outlines the development of thyroid surgery from early times to the twenty‐first century. The significant changes that have occurred in the past few decades in relation to the evolution of techniques for safe and effective total thyroidectomy are then summarized. In the last 25 years total thyroidectomy has replaced bilateral subtotal thyroidectomy as the preferred option for the management of all patients with bilateral benign multinodular goitre, Graves’ disease, and all but very low‐risk thyroid cancer patients. The principal change in operative technique has been the move from ‘lateral dissection’ to ‘capsular dissection’. Associated with that has been a focus on ‘encountering’ the recurrent laryngeal nerve (RLN), recognizing sympathetic‐laryngeal nerve anastomoses, and routinely identifying the external branch of the superior laryngeal nerve (EBSLN). Completeness of resection has been assured by moving from an anatomically based approach to an embryologically based approach. This requires an awareness of the vagaries of thyroid development including attention to pyramidal remnants, to abnormalities associated with the tubercle of Zuckerkandl, and to thyrothymic thyroid rests. Preservation of parathyroid function has moved from the time‐consuming technique of dissection of a vascularized pedicle in all cases, to initially selective, and then routine, parathyroid autotransplantation. These changes have ensured that total thyroidectomy can now be offered as a safe and efficacious procedure with a minimal complication rate.
Clinical and angiographic outcome after Guglielmi detachable coil embolization of intracranial aneurysms
Authors: Darwish Balsam , Rajak Saul , Wickremesekera Agadha , Hunn Martin , Balakrishnan Venkatraman , Braithwaite Douglas , FitzJohn Trevor
Published: September 2003

Background:  Between July 1997 and April 2001, forty patients underwent Guglielmi detachable coil (GDC) embolization of intracranial aneurysms at Wellington Hospital.

Methods:  The clinical notes and imaging were reviewed retrospectively.

Results:  Complete initial occlusion was achieved in 28 patients (70%). Eleven patients (27.5%) had small residual neck (>90% occlusion) and one patient (2.5%) had substantial filling of the aneurysm. Follow up angiographic assessment was obtained in 28 patients (70%) of whom 24 patients (85.7%) had no recurrence or stable residual neck and four patients (14.3%) had recurrence or enlargement of the residual neck. Stable occlusion was achieved in 100% of small and medium sized aneurysms and 50% of large and giant aneurysms. Technical complications occurred in 10% including aneurysms perforated in two patients (5%) and presumed parent artery occlusion in another two (5%).

Conclusions:  The findings of the present study demonstrate the safety of GDC embolization. The initial clinical grade at presentation strongly predicted the clinical outcome. Although the number of patients in this study is small, there is evidence that the angiographic outcome is better for small and medium sized aneurysms. Our results are comparable to other published series.
Nutrients obtained from leaf litter can improve the growth of dipterocarp seedlings
Authors: Brearley Francis Q. , Press Malcolm C. , Scholes Julie D.
Published: September 2003

• In tropical rain forests the rate of litterfall is high, and is the most important nutrient cycling pathway in these ecosystems. We tested two hypotheses using seedlings of dipterocarp species: (1) addition of leaf litter improves growth; (2) and litter addition affects both ectomycorrhizal (ECM) colonization and community structure.

• Three dipterocarp species with contrasting ecologies (Parashorea tomentella, Hopea nervosa and Dryobalanops lanceolata) were grown in a nursery in forest soil with or without the addition of litter.

• Litter addition improved the growth of all three species. There was no effect of litter addition on total percentage ECM colonization but ECM diversity and percentage colonization by Cenococcum geophilum were lower with litter addition. Foliar δ15N was lower in two of the three species grown in the presence of litter, reflecting the lower δ15N of the litter compared with the soil. There was a negative correlation between δ15N and percentage ECM, suggesting a role for ECMs in accessing litter‐derived N sources.

• This study shows that litter addition improved the growth of dipterocarp seedlings and that the ECM associations of dipterocarps facilitated access to this organic nutrient source. This has implications for the successful regeneration of seedlings in the rain forest understorey.
Biochemical traits of lichens differing in relative desiccation tolerance
Authors: Kranner Ilse , Zorn Margret , Turk Boris , Wornik Sabine , Beckett Richard P. , Batič Franc
Published: September 2003

• Oxidative stress arises when desiccation restricts photosynthesis and light energy is transferred from photo‐excited pigments onto ground state oxygen. We tested whether a highly desiccation tolerant lichen, Pseudevernia furfuracea, displays better protection against oxidative stress than more sensitive species, Lobaria pulmonaria and Peltigera polydactyla.

• We rehydrated lichens after desiccation periods of 2, 7 and 9 weeks and assessed their viability by measuring CO2 exchange using IRGA. During desiccation and rehydration, photosynthetic pigments and the antioxidant α‐tocopherol were analysed by HPLC, and peroxidases by spectrophotometry.

•  Pseudevernia furfuracea contained considerably lower chlorophyll, α‐tocopherol and β‐carotene concentrations and peroxidase activity than the two other lichens. However, it recovered photosynthesis rapidly, even after remaining in the desiccated state for 2 months while there was a significant delay in the onset of photosynthesis in L. pulmonaria and P. polydactyla.

• We conclude that high antioxidant concentrations do not necessarily indicate better adaptation to desiccation. Rather, the ability to rapidly re‐establish the species‐specific normal antioxidant concentrations during rehydration, even after longer desiccation times, is a characteristic of well‐adapted species.
Extreme events as shaping physiology, ecology, and evolution of plants: toward a unified definition and evaluation of their consequences
Authors: Gutschick Vincent P. , BassiriRad Hormoz
Published: September 2003

Here we consider how extreme events, particularly climatic and biotic, affect the physiology, development, ecology and evolution of organisms, focusing on plants. The marked effects on organisms are of increasing interest for ecological prediction, given the natural and anthropogenic changes in spectra of extreme events being induced by global change. Yet there is currently a paucity of knowledge or even a common world‐view of how extreme events shape individuals, communities and ecosystems. We propose that extreme events need be defined in terms of organismal responses of acclimation and of de‐acclimation or hysteresis. From this definition we proceed to develop a number of hypotheses, including that fitness effects of extreme events occur primarily during recovery. We review evidence that, on the evolutionary time scale, selection is virtually absent except during extreme events; these drive strong directional selection, even to trait fixation and speciation. We describe a number of new tools, both conceptual and technological, that are now at hand or that merit rapid development.

Contents

I.
Introduction
22

II.
Moving to an organismally based definition of extreme events
22

III.
Features to discern in extreme events
26

IV.
Additional challenges in the study of extreme events
27

V.
Evolutionary dimensions
29

VI.
The mandate for new conceptual tools for ecological and evolutionary prediction
34

VII.
Tools in hand, and tools needed, to study extreme events
35

VIII.
Conclusions
37

Acknowledgements
37

References
38
Editorials: Sodium Balance in Hemodialysis Therapy
Authors: Kooman Jeroen P. , Van Der Sande Frank , Leunissen Karel , Locatelli Francesco
Published: September 2003

Water and sodium overload is the predominant factor in the pathogenesis of hypertension in dialysis patients. In many dialysis patients, dry weight is not reached because of an imbalance between the interdialytic accumulation of water and sodium and the brief and discontinuous nature of routine dialysis therapy. During dialysis, sodium is removed by convection and to a lesser degree by diffusion. However, with supraphysiologic dialysate sodium concentrations, diffusive influx from dialysate may occur, especially in patients with low predialytic plasma sodium concentrations. Measuring sodium removal during dialysis is difficult and hampered by the variability in conventional sodium measurements. Ionic mass removal by continuous measurement of conductivity in the dialysate ports appears to be a promising tool for the approximation of sodium removal during dialysis. While the beneficial effects of concomitant water and sodium removal on blood pressure control in dialysis patients are undisputed, it is less well known whether a change in hydrosodium balance solely by reducing dialysate sodium is beneficial. Considering the inherent dangers of such an approach (intradialytic hemodynamic instability), the beneficial effects of strict dietary sodium restriction appear to be of much larger clinical benefit. It has become possible to individualize dialysate sodium concentration by means of online measurements of plasma conductivity and adjustment of dialysate conductivity by feedback technologies. The clinical benefits of this approach deserve further study. Still, reducing dietary sodium intake remains the most important tool in improving blood control in dialysis patients.
Ethical Issues in Dialysis Alan Spital, Series Editor: Organ Allocation: A Case for not Transplanting the Violent Criminal
Authors: West John C. , Chao Stan , Kelley Stephen E. , Schwartz Jan A. , Bertsch David J. , Marsh James F.
Published: September 2003

As organ transplantation outcomes become ever more successful, vigilance as to appropriate recipient selection must be ensured, for without careful monitoring the already great disparity between organ supply and demand will continue to grow. There is a public perception that justice requires equal access to treatment for all, but this is not always the case. We suggest that, while violent felons do not account for a large number of transplant recipients, transplanting even one such individual should be deemed inadvisable—and could well be fraught with irreparable public repercussions.
Review Articles: Management Options for Hydrothorax Complicating Peritoneal Dialysis
Authors: Chow Kai Ming , Szeto Cheuk Chun , Li Philip Kam‐Tao
Published: September 2003

Hydrothorax as a result of pleuroperitoneal communication occurs in approximately 2% of continuous ambulatory peritoneal dialysis (CAPD) patients. Although our understanding of its mechanisms is incomplete, it is apparent that the key to successful therapy is obliteration of a transdiaphragmatic route of dialysate leakage (pleuroperitoneal communication), possibly coupled with reduction of intra‐abdominal pressure. This review corroborated the findings from 10 major population‐based case series in which 60 of the 104 cases (58%) were able to resume long‐term peritoneal dialysis (PD). Temporary interruption of PD alone was successful in half of them. As compared to this conservative approach, as well as chemical pleurodesis via intercostal chest drain, video‐assisted thoracoscopic intervention (including direct pleurodesis and diaphragmatic repair) has shown a promising role. Efficacy of thoracoscopic treatment has been confirmed by several case series from various centers and the demonstration of a success rate in excess of 90%. With accumulating experience using the thoracoscopic technique, it remains to be seen whether this mode of treatment will obviate the traditional closed pleurodesis.
Dialysis Rounds A Dialysis Case Presentation and Discussion Edited by Roger A. Rodby: Bloody Ascites in a Patient After Transfer from Peritoneal Dialysis to Hemodialysis
Authors: Pollock Carol A.
Published: September 2003

A 65‐year‐old woman with end‐stage renal disease (ESRD) presented with bloody ascites. She had been maintained on peritoneal dialysis (PD) for 7 years and had eight episodes of peritonitis. She was eventually transferred to hemodialysis (HD) because of ultrafiltration failure. This was associated with “high” peritoneal transport by peritoneal equilibration test (PET). A period of “peritoneal rest” did not improve PET results. Within a year of transfer to HD, ascites developed, which was hemorrhagic upon evaluation. A computed tomography (CT) scan suggested encapsulating sclerosing peritonitis, which was confirmed upon peritonoscopy. The patient was treated with prednisone and tamoxifen. Encapsulating peritoneal sclerosis (EPS) is a devastating complication of PD. Although it is rare and its development often unpredictable, this case demonstrates several clinical features commonly observed in the condition. These include more than 6 years on PD, a high transporter status, recurrent peritonitis, and the development of blood‐stained dialysis effluent (or ascites if PD has been discontinued, as was the case in this patient). The initial presentation is often incipient with vague abdominal pain. Symptoms are progressive, however, and EPS has a high mortality rate, with most patients dying within 1 year of diagnosis, usually from malnutrition and sepsis. Treatment options include systemic immunosuppression and regular peritoneal irrigation after transfer to HD. Response to treatment is more likely to occur in the early inflammatory stage of EPS, when symptoms are nonspecific and imaging is relatively normal. Hence a high degree of suspicion for the diagnosis should be present in patients “at risk” of this condition, as early diagnosis is essential if progressive encapsulation of the abdominal viscera is to be prevented.
Combined Antiplatelet Therapy in Atrial Fibrillation:
Authors: HOHNLOSER STEFAN H. , CONNOLLY STUART J.
Published: September 2003

Atrial fibrillation (AF), the most commonly encountered cardiac rhythm disorder, affects approximately 1% of the general population and is associated with serious complications, most notably ischemic stroke. AF‐associated stroke occurs at an annual rate of 4.5%. Anticoagulation therapy with warfarin has been demonstrated in randomized controlled trials to reduce the risk for AF‐related stroke by two thirds, but warfarin therapy is markedly underused in clinical practice because of its narrow therapeutic window and its implications on quality of life. This article reviews the present knowledge and potential future research avenues for the role of antiplatelet therapy in AF as an alternative to anticoagulation with warfarin for prevention of AF‐associated stroke. Antiplatelet therapy recently has been shown to be protective against thrombotic events related to blood stasis. There is ample evidence from experimental and clinical studies that a combination of different antiplatelet agents may increase antithrombotic efficacy compared to monotherapy. Accordingly, a series of randomized controlled trials (ACTIVE [Atrial fibrillation Clopidogrel Trial with Irbesartan for prevention of Vascular Events]) has been designed to vigorously examine the role of combined antithrombotic therapy for prevention of vascular events, including stroke in high‐risk AF patients. The ACTIVE program began patient enrollment in spring 2003. (J Cardiovasc Electrophysiol, Vol. 14, pp. S60‐S63, September 2003, Suppl.)
Resynchronization Therapy is an Important Advance in the Management of Congestive Heart Failure:
Authors: JESSUP MARIELL
Published: September 2003

The antagonist portion of the debate acknowledges that cardiac resynchronization therapy (CRT) is an important advance in the management of congestive heart failure, but the eligible treatment population currently is small relative to the whole. The impact of CRT on mortality without an implantable cardioverter defibrillator (ICD) probably is not significant, although a beneficial effect on morbidity associated with heart failure has clearly been achieved. The costs of CRT are not negligible. The morbidity and mortality of the procedure to implant these devices must be considered in future trial design. (J Cardiovasc Electrophysiol, Vol. 14, pp. S30‐S34, September 2003, Suppl.)