bluuebunny/crossref_metadata_2025 huggingface dataset:
Acclimation of the respiration/photosynthesis ratio to temperature: insights from a model
Authors: Dewar Roderick C. , Medlyn Belinda E. , Mcmurtrie Ross. E.
Published: March 2003

Based on short‐term experiments, many plant growth models – including those used in global change research – assume that an increase in temperature stimulates plant respiration (R) more than photosynthesis (P), leading to an increase in the R/P ratio. Longer‐term experiments, however, have demonstrated that R/P is relatively insensitive to growth temperature. We show that both types of temperature response may be reconciled within a simple substrate‐based model of plant acclimation to temperature, in which respiration is effectively limited by the supply of carbohydrates fixed through photosynthesis. The short‐term, positive temperature response of R/P reflects the transient dynamics of the nonstructural carbohydrate and protein pools; the insensitivity of R/P to temperature on longer time‐scales reflects the steady‐state behaviour of these pools. Thus the substrate approach may provide a basis for predicting plant respiration responses to temperature that is more robust than the current modelling paradigm based on the extrapolation of results from short‐term experiments. The present model predicts that the acclimated R/P depends mainly on the internal allocation of carbohydrates to protein synthesis, a better understanding of which is therefore required to underpin the wider use of a constant R/P as an alternative modelling paradigm in global change research.
Influence of elevated ozone and limited nitrogen availability on conifer seedlings in an open‐air fumigation system: effects on growth, nutrient content, mycorrhiza, needle ultrastructure, starch and secondary compounds
Authors: Kainulainen Pirjo , Utriainen Jarkko , Holopainen Jarmo K. , Oksanen J.A.R.I. , Holopainen Toini
Published: March 2003

Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies Karst.) seedlings were exposed to realistically elevated O3 levels in open‐air experiments over three growing seasons. The total O3 exposure doses were 1.2 × (1991), 1.5 × (1992) and 1.7 × (1993) ambient levels. During the 1992 and 1993 growing seasons pine and spruce seedlings received two different levels of nitrogen supply. Effects on growth, mycorrhiza formation, needle ultrastructure, primary and secondary compounds were studied. Ozone exposure had only slight effects on biomass production, growth height and nutrient content of studied conifers. Higher nitrogen availability improved growth of the seedlings and resulted in higher concentration of nitrogen in needles. In Scots pine O3 exposure did not have effects on quantity of total mycorrhizas and short roots, while higher nitrogen availability decreased quantity of mycorrhizas and short roots. In both tree species O3 exposure induced O3‐related ultrastructural symptoms, e.g. granulation and dark staining of the chloroplast stroma in the needle mesophyll cells, at both nitrogen availability levels. Ozone exposure and nitrogen availability did not have significant effects on starch concentrations in either tree species. Concentrations of some individual terpenes were higher in O3‐exposed needles, while concentrations of individual and total resin acids, total phenolics and catechins were not affected by O3 exposure. Nitrogen availability did not have substantial effects on concentrations of monoterpenes. By contrast, concentrations of some individual and total resin acids were lower in pine needles and higher in spruce needles with higher nitrogen availability, while phenolic concentration in spruce needles decreased at higher nitrogen availability. The results suggest that realistically elevated levels of O3 in the field can have some negative effects on the mesophyll ultrastructure of conifer needles, but carbon allocation to root and shoot growth and secondary metabolites are not affected substantially.
Ozone effects on wheat in relation to CO2: modelling short‐term and long‐term responses of leaf photosynthesis and leaf duration
Authors: Ewert Frank , Porter John R.
Published: March 2003

A combined stomatal–photosynthesis model was extended to simulate the effects of ozone exposure on leaf photosynthesis and leaf duration in relation to CO2. We assume that ozone has a short‐term and a long‐term effect on the Rubisco‐limited rate of photosynthesis, Ac. Elevated CO2 counteracts ozone damage via stomatal closure. Ozone is detoxified at uptake rates below a threshold value above which Ac decreases linearly with the rate of ozone uptake. Reduction in Ac is transient and depends on leaf age. Leaf duration decreases depending on accumulated ozone uptake. This approach is introduced into the mechanistic crop simulation model AFRCWHEAT2. The derived model, AFRCWHEAT2‐O3, is used to test the capability of these assumptions to explain responses at the plant and crop level.

Simulations of short‐term and long‐term responses of leaf photosynthesis, leaf duration and plant and crop growth to ozone exposure in response to CO2 are analysed and compared with experimental data derived from the literature. The model successfully reproduced published responses of leaf photosynthesis, leaf duration, radiation use efficiency and final biomass of wheat to elevated ozone and CO2. However, simulations were unsatisfactory for cumulative radiation interception which had some impact on the accuracy of predictions of final biomass. There were responses of leaf‐area index to CO2 and ozone as a result of effects on tillering which were not accounted for in the present model. We suggest that some model assumptions need to be tested, or analysed further to improve the mechanistic understanding of the combined effects of changes in ozone and CO2 concentrations on leaf photosynthesis and senescence. We conclude that research is particularly needed to improve the understanding of leaf‐area dynamics in response to ozone exposure and elevated CO2.
Sub‐saharan desertification and productivity are linked to hemispheric climate variability
Authors: Oba Gufu , Post Eric , Stenseth Nils C.
Published: March 2003

Vegetation productivity and desertification in sub‐Saharan Africa may be influenced by global climate variability attributable to the North Atlantic Oscillation (NAO) and El Niño Southern Oscillation (ENSO). Combined and individual effects of the NAO and ENSO indices revealed that 75% of the interannual variation in the area of Sahara Desert was accounted for by the combined effects, with most variance attributable to the NAO. Effects were shown in the latitudinal variation on the 200 mm isocline, which was influenced mostly by the NAO. The combined indices explained much of the interannual variability in vegetation productivity in the Sahelian zone and southern Africa, implying that both the NAO and ENSO may be useful for monitoring effects of global climate change in sub‐Saharan Africa.
UV‐B effect onQuercus roburleaf litter decomposition persists over four years
Authors: Newsham K. K. , Anderson J. M. , Sparks T. H. , Splatt P. , Woods C. , Mcleod A. R.
Published: March 2003

The effects of elevated UV‐B (280–315 nm) radiation on the long‐term decomposition ofQuercus roburleaf litter were assessed at an outdoor facility in the UK by exposing saplings to elevated UV‐B radiation (corresponding to a 30% increase above the ambient level of erythemally weighted UV‐B, equivalent to that resulting from ac. 18% reduction in ozone column) under arrays of cellulose diacetate‐filtered fluorescent UV‐B lamps that also produced UV‐A radiation (315–400 nm). Saplings were also exposed to elevated UV‐A radiation alone under arrays of polyester‐filtered fluorescent lamps and to ambient solar radiation under arrays of nonenergized lamps. After 8 months of irradiation, abscised leaves were placed into litter bags and allowed to decompose in the litter layer of a mixed deciduous woodland for 4.08 years. The dry weight loss of leaf litter from saplings irradiated with elevated UV‐B and UV‐A radiation during growth was 17% greater than that of leaf litter irradiated with elevated UV‐A radiation alone. Annual fractional weight loss of litter (k), and the estimated time taken for 95% of material to decay (3/k) were respectively increased and decreased by 27% for leaf litter exposed during growth to elevated UV‐B and UV‐A radiation, relative to that exposed to UV‐A alone. The present data corroborate those from a previous study indicating that UV‐B radiation applied during growth accelerates the subsequent decomposition ofQ. roburleaf litter in soil, but indicate that this effect persists for over four years after abscission.
Nitrogen deposition and atmospheric CO2interactions on fine root dynamics in temperate forests: a theoretical model analysis
Authors: Rasse Daniel P.
Published: March 2003

Fine root turnover is a critical component of below‐ground forest ecology, which regulates nutrient dynamics, forest net primary productivity, carbon input to soils, and soil respiration. Understanding fine root responses to changing environmental conditions is critical for predicting the productivity and carbon sequestration potential of forest ecosystems during the 21st century. The first objective of this study is to demonstrate that a mechanistic model can realistically simulate spatial and temporal fine root demography in temperate forests on the basis of two hypotheses: (1) absorption of mineral N (N) stimulates the production of new roots, and (2) fine root longevity decreases with increasing N availability. Based on this model, my second objective is to predict fine root responses to changing atmospheric CO2levels and N deposition rates. To meet these objectives, an extensive description of the N cycle and the new fine root module were implemented in the ASPECTS model. In agreement with a wide body of literature information, the new model predicted: (1) a preferential colonisation by fine roots of the uppermost soil layer, and (2) a flush of fine root growth in the spring. The simulations indicate that fine root biomass will increase in response to elevated CO2under the double effect of (1) an increase in root longevity due to increased N stress, and (2) larger amounts of assimilates available to the growth of plant tissue due to increased photosynthesis. Although the simulated total fine root biomass increased under both increasing N deposition rates and atmospheric CO2concentrations, the model predicts that the distribution of fine roots among soil layers will be altered. This suggests that experimental studies must consider the full depth of the root system in order to accurately assess effects of environmental changes on fine root dynamics. The model also suggests that fine root longevity is a plastic parameter, which varied from less than 1 year to more than 3 years depending on forcing values of N deposition rates and atmospheric CO2concentrations. Finally, the model indicates that the increase in net ecosystem exchange (NEE) and soil respiration in temperate forests under elevated CO2will be proportional to the amount of available N, with little to no response in low N conditions and up to +28% for both NEE and soil respiration under the highest deposition rate (7.0 g N m−2 y−1).
Effect of springtime solar ultraviolet‐B radiation on growth of Colobanthus quitensis at Palmer Station, Antarctica
Authors: XIONG FUSHENG S. , RUHLAND CHRISTOPHER T. , DAY THOMAS A.
Published: March 2003

We examined the influence of solar ultraviolet‐B radiation (UV‐B; 280–315 nm) on the growth of Colobanthus quitensis plants by placing them under contrasting UV‐B filters at Palmer Station, along the Antarctic Peninsula. The filters reduced diurnal biologically effective UV‐B (UV‐BBE) either by 83% (‘reduced UV‐B’) or by 12% (‘near‐ambient UV‐B’) over the 63 day experiment (7 November 1998–8 January 1999). Ozone column depletion averaged 17% during the experiment. Relative growth and net assimilation rates of plants exposed to near‐ambient UV‐B were 30 and 20% lower, respectively, than those of plants exposed to reduced UV‐B. The former plants produced 29% less total biomass, as a result of containing 54% less aboveground biomass. These reductions in aboveground biomass were mainly the result of a 45% reduction in shoot biomass, and a 31% reduction in reproductive biomass. Reductions in shoot biomass were owing to an 18% reduction in branch production by main shoots, while reductions in reproductive biomass were the result of a 19% reduction in individual capsule mass. Total plant leaf area was reduced by 19% under near‐ambient UV‐B, although total leaf biomass was unaffected because leaves had a greater specific leaf mass. The reduction in plant leaf area under near‐ambient UV‐B was attributable to: (1) production of 11% fewer leaves per main shoot system and plant, which resulted from an 18% reduction in branch production by main shoots. Leaf production per individual main shoot or branch was not affected; (2) shorter leaf longevity—main shoots contained 14% fewer green leaves at a given time; and (3) smaller individual leaves—leaf elongation rates were 14% slower and mature leaves were 13% shorter.
A mechanism of abiotic immobilization of nitrate in forest ecosystems: the ferrous wheel hypothesis
Authors: Davidson Eric A. , Chorover Jon , Dail D. Bryan
Published: March 2003

Forest soils, rather than woody biomass, are the dominant long‐term sink for N in forest fertilization studies and, by inference, for N from atmospheric deposition. Recent evidence of significant abiotic immobilization of inorganic‐N in forest humus layers challenges a previously widely held view that microbial processes are the dominant pathways for N immobilization in soil. Understanding the plant, microbial, and abiotic mechanisms of N immobilization in forest soils has important implications for understanding current and future carbon budgets. Abiotic immobilization of nitrate is particularly perplexing because the thermodynamics of nitrate reduction in soils are not generally favorable under oxic conditions. Here we present preliminary evidence for a testable hypothesis that explains abiotic immobilization of nitrate in forest soils. Because iron (and perhaps manganese) plays a key role as a catalyst, with Fe(II) reducing nitrate and reduced forms of carbon then regenerating Fe(II), we call this ‘the ferrous wheel hypothesis’. After nitrate is reduced to nitrite, we hypothesize that nitrite reacts with dissolved organic matter through nitration and nitrosation of aromatic ring structures, thus producing dissolved organic nitrogen (DON). In addition to ignorance about mechanisms of DON production, little is known about DON dynamics in soil and its fate within ecosystems. Evidence from leaching and watershed studies suggests that DON production and consumption may be largely uncoupled from seasonal biological processes, although biological processes ultimately produce the DOC and reducing power that affect DON formation and the entire N cycle. The ferrous wheel hypothesis includes both biological and abiological processes, but the reducing power of plant‐derived organic matter may build up over seasons and years while the abiotic reduction of nitrate and reaction of organic matter with nitrite may occur in a matter of seconds after nitrate enters the soil solution.
Urea supplementation effects on the utilization of low‐quality forage and lamb production in patagonian rangelands
Authors: Golluscio R. A. , Paruelo J. M. , Mercau J. L. , Deregibus V. A.
Published: March 2003

The effect of feeding a urea‐based supplement for the last 8 weeks of pregnancy was examined on ewes grazing the grass‐shrub steppes of NW Patagonia, Argentina. The productivity of ewes and lambs and the utilization rate of the major, less preferred, grass species (Stipa speciosa, 27% cover) was analysed. In a paddock‐scale experiment, ewes grazed two areas of 450–500 ha from 15 August to 15 February at a stocking rate of 0·5 ewes ha−1. From 15 August to 10 October, one group of ewes was given access to a urea‐based supplement containing 300 g kg−1 urea, 320 g kg−1 salt, 30 g kg−1 molasses and 300 g kg−1 bone meal. Average supplement consumption was 3·5 g ewe−1 d−1. The performance of 100 ewes in each of the two areas was evaluated. Supplemented ewes gained 4·2 kg more live weight than the control ewes between 15 August and 10 October (prepartum) (liveweight gain was 10·3 vs. 6·1 kg ewe−1, P < 0·05). The number of live lambs at 8 weeks of age, as a proportion of ewes mated, was 15% higher in the supplemented than in the control group (0·634 vs. 0·553, P < 0·05). A similar increase in the live weight of lambs at 8 weeks of age in the supplemented group compared with the controls was also observed (12·1 vs. 10·6 kg, P < 0·05). In the paddock with the supplemented ewes, there was a significant increase in the proportion of Stipa speciosa plants defoliated (0·62 vs. 0·38, P < 0·05) and in the intensity of defoliation of these plants. It was concluded that urea‐based supplements increased productivity of ewes and that this was likely to be associated with an increase in the intake, and possibly digestibility, of the less preferred species such as Stipa speciosa.
The quantitative assessment of Listeria monocytogenes growth in a laboratory ensiling system allowing limited aerobic spoilage
Authors: Fenlon  , Wilson
Published: March 2003

Listeria monocytogenes contamination is associated with silage that has been subjected to aerobic deterioration. A laboratory ensiling system based on plastic tube silos, which permit aerobic spoilage to take place in a controlled manner, is described. This system gives a high degree of consistency between replicates. Parameters measured over a 90‐d ensiling period were pH, L. monocytogenes and Enterobacteriaceae counts and percentage spoilage. The system may be suitable for assessing the effectiveness of additives on parameters, such as aerobic spoilage and L. monocytogenes, which are not easily measurable in field studies. The study confirmed the relationship between the presence of Listeria spp. and Enterobacteriaceae in aerobically spoiled silage, showing that the latter group of bacteria may be useful as indicators of the potential risk of L. monocytogenes contamination of silage.
Plant growth functions and possible spatial and temporal scaling errors in models of herbivory
Authors: Parsons A. J. , Schwinning S. , Carrère P.
Published: March 2003

Recent studies have provided detail of the mechanisms by which plants and animals interact, but attempts to apply this knowledge to understand function at the scale of whole fields or grazed ecosystems can be fraught with difficulties. Faced with a plethora of detail, and yet demands to make models more comprehensive, modellers face pressure to revert to simplified accounts for what are assumed to be well‐established biological phenomena, for example, for describing plant growth and intake, but this raises the risk that important insights may be lost, or that the analyses may face errors of scaling.

The predictions of a previously described spatial model are compared with those of a non‐spatial rendition of the same model to identify the differences in predictions and the sources of these differences. In particular, the use of the conventional empirical growth functions and their interaction with temporal and spatial scaling errors are examined. The comparison exposed how substantial errors could be made in predicting yield and stability under grazing. It is proposed that such errors might be avoided by ensuring that the functional responses used capture the insights of more detailed studies, and by recognizing the difficulties of scaling‐up from the level of processes to the field scale and beyond.
Characterization of the effect of high salinity on roots of Chloris gayana Kunth: carbohydrate and lipid accumulation and growth
Authors: Córdoba A. , Seffino L. García , Moreno H. , Arias C. , Grunberg K. , Zenoff A. , Taleisnik E.
Published: March 2003

Branched nodal roots comprise the largest portion of the root system mass in Chloris gayana Kunth and the effects of high salinity on nodal root appearance and elongation rates were analysed in cv. Boma in greenhouse experiments. Roots from salt‐treated plants (0·2 mol l–1 NaCl) were smaller than controls, and accumulated higher concentrations of soluble sugars and reserve lipids. The number of nodal roots was reduced by the saline treatment. Leaf, tiller and nodal root appearance were delayed by salinity but the correlation among these processes was maintained, indicating that the developmental pattern was not altered by this level of salinity, only its rate. Initial nodal root growth rates varied as a function of plant size and were decreased by salinity only after 2 weeks of treatment. When shoots of non‐salinized plants were cut, a drastic reduction in nodal root appearance was observed, suggesting emerging leaves were stronger sinks than roots for available reserves. However, when the shoots of salt‐treated plants were cut, the already depressed root appearance rate was not further reduced. This suggests that, under salinity, alterations in root ability to metabolize reserves could have been more significant than reserve availability for controlling elongation.
Effect of long‐term changes in relative resource availability on dietary preference of grazing sheep for perennial ryegrass and white clover
Authors: Rook A. J. , Harvey A. , Parsons A. J. , Penning P. D. , Orr R. J.
Published: March 2003

Three replicate paddocks, each of 0·235 ha, containing adjacent monocultures of perennial ryegrass or white clover [50:50 by ground area, 6 cm sward surface height (SSH) at start of experiment] were continuously stocked with three yearling and four mature non‐lactating, non‐pregnant Scottish halfbred ewes for 12 weeks. Herbage intake, grazing behaviour and dietary selection were measured on seven occasions. Clover SSH declined rapidly over the first 5 weeks then stabilized at 1·2–1·6 cm, whereas perennial ryegrass SSH rose slightly initially, then declined gradually. Animals initially included proportionately c. 0·6 white clover in their diet but, by the end of the experiment, this had fallen to 0·3. Total daily herbage intake declined over the 12 weeks from 1·8 kg dry matter (DM) day–1 at the start to 1·0 kg DM day–1. Total grazing time increased from 561 min day–1 to 649 min day–1 at the end of the experiment. The results suggest that, despite overall herbage depletion and a greater depletion of white clover than perennial ryegrass as a result of the initial partial preference for white clover, the animals traded‐off a reduced total intake and an increased grazing time in an attempt to maintain their initial preferred dietary composition.
Gasless laparoscopic ovarian cystectomy with minilaparotomy during pregnancy
Authors: Inoue Hiromi , Nabuchi Kaoru , Ishihara Yuki , Fukumoto Yumiko , Kobayashi Masaru
Published: March 2003

Objective

Recently there have been many reports of laparoscopic surgery during pregnancy, despite serious concerns about the possible consequences of fetal damage caused by the pneumoperitoneum and anaesthetics, or the risk of the trauma to the enlarged uterus. We have attempted gasless laparoscopic surgery with extra‐abdominal cystectomy under regional anaesthesia for ovarian cysts in pregnancy to avoid or minimize such risks.

Interventions

We report three cases of laparoscopically assisted abdominal cystectomy during early pregnancy using a gasless method (Laparolift in two cases and surgical wire in one case) and combined spinal‐epidural anaesthesia (CSE). Extra‐abdominal cystectomy was performed after a minilaparotomy directly above the ovarian cyst.

Results

In all three cases, there were no intraoperative complications and postoperative recoveries were rapid and uneventful for both the mother and the fetus. Intra‐abdominal procedures in gasless laparoscopy are more difficult than those with pneumoperitoneum because of the limited visual field. In respect to anaesthesia, all the patients experienced discomfort with the head‐down tilt during the operation, although this position was maintained for the shortest possible period of time. However, the procedures were performed smoothly and with relative ease with extra‐abdominal cystectomy. All the patients were discharged on the second postoperative day and subsequently completed their normal pregnancies with spontaneous vaginal delivery of healthy full‐term babies.

Conclusion

Gasless laparoscopic cystectomy with a minilaparotomy in early pregnancy may be an alternative approach to ovarian cysts in pregnancy, considering the absence of fetal risk from CO2 pneumoperitoneum and a relatively low risk of trauma to the enlarged uterus. With regard to the choice of anaesthesia in this approach, general anaesthesia may be preferable.
Laparoscopic anterior resection of the rectum and hysterectomy in a patient with extensive pelvic endometriosis
Authors: Reich Harry , Wood Carl , Whittaker Mark
Published: March 2003

Objective

To assess the feasibility of excising rectal endometriosis using laparoscopic techniques and reanastomosing the rectum using a circular stapling device.

Subject

A 41‐year‐old woman with recurrent stage IV endometriosis (revised American Fertility Society classification).

Interventions

Laparoscopic excision of stage IV endometriosis, laparoscopic hysterectomy, right salpingo‐oöphorectomy, appendicectomy, anterior rectal resection and reanastomosis with circular stapler.

Main outcome measures

Surgical outcome, involvement of endometriosis, operative time, duration of hospital stay, complications, histological involvement of organs with endometriosis and 1‐year follow up.

Results

The procedure was uncomplicated and took 3 h to complete. The patient was discharged home on day 4. Histological analysis revealed endometriotic involvement through to the rectal mucosa and also of the appendix. The uterus revealed adenomyosis. At 1‐year follow up, the patient was free from the symptoms associated with her pelvic endometriosis

Conclusions

Laparoscopic anterior resection of the rectum using a stapler fashioned to provide an end‐to‐end anastomosis was performed in association with a total laparoscopic hysterectomy. Advanced rectovaginal endometriosis may involve the full thickness of the rectal wall, the endometriosis may be excised laparoscopically and the rectal disease can be excised without performing a laparotomy. By avoiding the need for laparotomy, this allows the patient the advantages of reductions in pain, hospital stay and duration of convalescence.
Present status of conventional cytoreductive operations
Authors: Heintz
Published: March 2003

Objective

To evaluate the present status of cytoreductive operations in the treatment of advanced ovarian carcinoma.

Design

Review of the relevant literature.

Result

At present it is still accepted that the maximum diameter of the largest tumour mass remaining should optimally not exceed 1.0–1.5 cm because of its influence on survival. Other biological factors may be of equal or greater importance to the outcome as is the extent of surgery. A clear restriction of the procedure is that extensive debulking procedures, such as peritoneal stripping technique, or bowel resections, have so far demonstrated no improvement in survival. In particular, patients with mainly extensive stage III or IV disease, have fared no better after optimal cytoreductive surgery than patients who still had residual disease at the completion of surgery. This observation underlines that the initial tumour burden as well as the tumour residue influences prognosis. It also seems that the particular group of patients with largely irresectable large disease in the abdomen, does not benefit at all from cytoreductive surgery. For this reason intervention cytoreductive surgery after at least three courses of chemotherapy and a proven partial response, seems to be a logical option.

Conclusions

At present it is clear that the residual tumour mass and the initial tumour mass are important factors for prognosis. It seems logical that, especially in patients with large initial tumour masses, neoadjuvant chemotherapy is an option that should seriously be considered. A randomized trial is needed to study the real value of this approach.
Assessment of tissue damage associated with laparoscopic and conventional hysterectomies
Authors: Holub  , Jabor  , Fischlová  , Palásek
Published: March 2003

Objective

To assess and compare damage to tissue during laparoscopic and conventional hysterectomies.

Design

Prospective clinical study.

Setting

Department of Gynaecology, Baby‐Friendly Hospital, Kladno, Czech Republic.

Subjects

95 women who had undergone laparoscopic, abdominal or vaginal hysterectomy

Main outcome measures

The operative trauma and tissue damage were assessed using the enzymatic activity of creatine kinase (CK). Serum levels of CK were measured in 85 patients who had undergone hysterectomy, and the activities of CK, isoenzyme CK‐MB and aspartate aminotransferase (AST) were investigated in seven patients of an additional group.

Results

The rate of CK activity was significantly greater in 28 patients who underwent abdominal hysterectomy (P < 0.005) compared with that in the patients who underwent laparoscopic or vaginal hysterectomies (34 and 23 patients, respectively). The CK levels in the latter two groups were also significantly different (P < 0.025).

Conclusion

Following total abdominal hysterectomy, tissue damage, as assessed by the activity of creatine kinase, is statistically significantly greater than that following laparoscopic and vaginal hysterectomies. Clinical experience and metabolic changes indicate that the perioperative stress in patients undergoing laparoscopic hysterectomy is lower than that in patients where an abdominal approach is used. Large prospective studies are needed to evaluate the surgical trauma and metabolic changes induced by laparoscopic hysterectomy.
Blind endometrial biopsies: insufficient for diagnosis in women with intrauterine pathology
Authors: Kent Andrew S. H. , Haines Pat , Manners Brian T. B. , Coats Percy M.
Published: March 2003

Objective

To evaluate blind and directed endometrial biopsies for histological diagnosis in the presence of intrauterine pathology.

Design

A prospective study comparing the information obtained at outpatient hysteroscopy with undirected endometrial biopsy with subsequent pathological findings obtained after transcervical resection (TCR) of intrauterine polyps.

Setting

The Department of Obstetrics and Gynaecology, The Royal Surrey County Hospital, Guildford, 1991–1996.

Subjects

414 women who were diagnosed as having intrauterine abnormalities, 177 of whom opted for transcervical resection.

Main outcome measures

Outcomes of referrals to a ‘one‐visit clinic’, with particular reference to that group of patients undergoing TCR. Comparisons between the histological findings obtained from blind endometrial biopsy and those from TCR specimens.

Results

414/1022 women had intrauterine abnormalities identified by flexible hysteroscopy, and 177 (42.8%) opted for TCR. The histological findings from the TCR specimens differed from the endometrial biopsies by 30% overall, and the discrepancies included two carcinomas and three complex hyperplasias with atypia.

Conclusion

We suggest that, in women with abnormal uterine bleeding, the use of blind endometrial biopsy alone as a screening technique should be questioned. Outpatient hysteroscopy should be offered to women with abnormal uterine bleeding, with directed biopsy or transcervical resection for those in whom intrauterine polyps have been identified.
The availability of training in the laparoscopic management of ectopic pregnancy
Authors: Bancroft Karen , Whittaker Mark D. , Clayton Richard D. , Garry Ray
Published: March 2003

Objective

To assess the availability of laparoscopic treatment for ectopic pregnancy, and the availability of training in such laparoscopic techniques, in the Yorkshire Deanery (training region).

Design

A postal questionnaire was distributed to all trainees in the Yorkshire Deanery with a national or visiting training number (denoting eligibility for CCST).

Results

60 trainees were identified of whom 59 (98%) returned completed questionnaires. Whilst the majority of trainees had observed or assisted with laparoscopic surgery for ectopic pregnancy in their current hospital, only 37% had performed such surgery themselves and only 36% considered that they would be able to achieve appropriate training at that hospital. One or more consultants were offering laparoscopic treatment for ectopic pregnancy in 13 out of the 15 hospitals in the deanery. However, in only five of these hospitals did the majority of trainees consider that they would be able to achieve appropriate training in these techniques.

Conclusion

Although the majority of hospitals have at least one consultant able to undertake laparoscopic surgery for the management of ectopic pregnancy, this is not being translated into a routinely available service or into training opportunities for specialist registrars in the Yorkshire Deanery.
A survey of laparoscopic workshops
Authors: Chang Timothy , Maher Peter , Cooper Michael , Wong Felix
Published: March 2003

Objective

To assess the usefulness of workshops in basic laparoscopic skills in promoting the use of laparoscopy in gynaecological surgery.

Design

Prospective observational survey.

Setting

Department of Obstetrics and Gynaecology, Liverpool Hospital, Sydney, New South Wales and Department of Obstetrics and Gynaecology, Mercy Hospital, Melbourne, Victoria, Australia.

Results

Between 1993 and 1996 12 laparoscopic workshops have been conducted, with eight participants in each course. Of the participants, 82.5% were male, and 72.3% were over the age of 45 years. Out of 62 respondents to a questionnaire, 60 (96.8%) were performing more laparoscopic procedures after the course, with 38/62 (61.3%) performing more complex procedures.

Conclusions

Laparoscopic surgery does have a place in gynaecological practice, and laparoscopic workshops are useful for the introduction of laparoscopic techniques to the gynaecologist.
Conservative treatment of interstitial pregnancy
Authors: Broome Jonathan D. , Vancaillie Thierry G. , Torode Hugh
Published: March 2003

Objective

To report a case of interstitial pregnancy diagnosed and treated laparoscopically by cornual resection, and to review the literature in order to provide a perspective on alternative treatment options for this condition.

Case report

A 42‐year‐old woman with persistent pelvic pain, elevated levels of beta‐human chorionic gonadotrophin (β‐hCG) and a negative ultrasound scan had an initial negative diagnostic laparoscopy. Symptoms continued and repeat ultrasound suggested an asymmetric fundal pregnancy. Repeat laparoscopy revealed an interstitial pregnancy and laparoscopic cornual resection was undertaken. Recovery was uneventful and she was discharged 2 days postoperatively.

Current perspective

When interstitial pregnancy is detected early, treatment options include expectant management, systemic methotrexate, or local injection of methotrexate, potassium chloride or prostaglandin into the gestational sac. Surgical intervention by hysteroscopic removal or laparoscopic cornual excision/cornuostomy can be employed in the case of failed medical treatment or advanced pregnancy.

Conclusion

The early diagnosis of interstitial pregnancy should enable a conservative approach, whether medical or surgical, to be undertaken when treating this rare and potentially fatal condition.
A review of 2581 out‐patient diagnostic hysteroscopies in the management of abnormal uterine bleeding
Authors: Alexopoulos Evangelos D. , Fay Toby N. , Simonis Chantal D.
Published: March 2003

Objective

To evaluate the clinical efficacy, reliability and acceptability of out‐patient diagnostic hysteroscopy at a large teaching hospital.

Setting

The Women's Endoscopy Unit at Nottingham City Hospital, Nottingham, UK.

Subjects

Between 1994 and 1997, 2581 women were referred for menstrual problems and abnormal uterine bleeding. The endocervical canal and endometrial cavity were assessed using either a 4‐mm rigid or a 3.5‐mm flexible hysteroscope, according to the preference of the operator. All hysteroscopies were performed by consultants or experienced registrars. Endometrial biopsy was taken when indicated.

Results

The main indications for referral for diagnostic hysteroscopy included menorrhagia (37.5%), postmenopausal bleeding (33.4%), intermenstrual bleeding (26.7%) and metrorrhagia (8.8%). Less common indications included treatment with tamoxifen, review of previous endometrial pathology or abnormal glandular cells on cervical cytology, and investigation for infertility. The mean age of patients referred was 49.3 years. Hysteroscopy was completed successfully in 96.8% of all patients, with pain being the main reason for failure to complete the procedure. Local anaesthesia with paracervical infiltration was used in 34% of all patients. Submucous fibroids were the commonest cause of intrauterine pathology (11.4%) with the highest incidence found in women referred for menometrorrhagia (17.2%). Endometrial polyps were detected in 10.6% of all the patients. The endometrium was characterized by the hysteroscopist as atrophic, thickened, polypoid, haemorrhagic or malignant. Endometrial Pipelle biopsies were taken in 48.6% of all cases. Abnormal histological findings were reported in 61 cases including 11 instances of endometrial adenocarcinoma. The concordance rate between hysteroscopic and histological findings for all abnormalities was 63.9%. Further medical treatment was offered to 406 patients (16.3%), while 185 patients (17.3%) needed additional surgery as in‐patients.

Conclusion

Out‐patient hysteroscopy is a safe, acceptable and well‐tolerated procedure that provides useful information about the uterine cavity. Endometrial biopsy improves the diagnostic accuracy of hysteroscopy in detecting endometrial pathology.
Laparoscopically assisted hysterectomy for the large uterus
Authors: Clayton Richard D. , Hawe Jeremy A. , Garry Ray
Published: March 2003

Objective

To assess the results of performing laparoscopically assisted hysterectomy on uteri greater in size than 12 weeks.

Design

A prospective observational study.

Setting

South Cleveland Hospital, Middlesbrough, and St James' University Hospital, Leeds, UK.

Subjects

21 consecutive women undergoing wholly laparoscopic or laparoscopically assisted total or subtotal hysterectomy with or without bilateral salpingo‐oöphorectomy.

Main outcome measures

These included uterine size and weight, techniques used to perform hysterectomy, surgical outcome, operative time, additional pathological conditions found, blood loss, intra‐ and postoperative complications and duration of hospitalization.

Results

Laparoscopically assisted hysterectomy was completed in all cases. The mean uterine weight was 522 g with a range of 390–785 g. The mean operating time was 144 min with a range of 78–330 min. Four of the patients had additional pathological conditions. None of the patients required a blood transfusion. Three patients suffered complications: a functional ileus, a small port‐site haematoma and a ureteric injury. The mean hospital stay was 4.3 days (range 2–8 days).

Conclusion

Laparoscopic surgery can be used to avoid abdominal hysterectomy even with significant uterine enlargement, and allows the diagnosis and treatment of coexisting pelvic pathological conditions which cannot be adequately treated at vaginal hysterectomy. However the advantages must be weighed against the possible risk of increased complications.
Is routine preoperative preparation necessary for hysteroscopic endometrial resection?
Authors: Trivedi Prakash , Rocha Ivan , Padhye Asima
Published: March 2003

Objective

To assess whether routine preoperative preparation of the endometrium with danazol or GnRH analogues is really necessary for transcervical resection of the endometrium (TCRE).

Design

A prospective open trial.

Setting

Specialized arrangements in a private minimal access gynaecological centre and a research institute, in Mumbai, India.

Participants

665 women who presented with excessive menstrual bleeding.

Interventions

Random allocation into groups receiving either no preoperative preparation, or danazol or gonadotrophin‐releasing hormone (GnRH) analogues, or progesterones for preoperative preparation, followed by hysteroscopic resection of the endometrium.

Main outcome measures

These included assessment of relief of symptoms, failures and satisfaction rate. Total operating time, amount of fluid used and absorbed, as well as complications observed over a period of 7 years were also recorded.

Results

The results of 665 TCRE procedures evaluated over a period of almost 7 years suggest that outcomes were not influenced by preoperative endometrial preparation. Lack of endometrial preparation was not associated with any increase in the complication rate, in procedures carried out by an experienced hysteroscopist. Routine endometrial preparation is not necessary, and it substantially increases the overall cost of the procedure, which is an important consideration in developing countries. Preoperative endometrial preparation is necessary only occasionally, when large submucous (>3 cm) fibroids are to be resected, as it may reduce the operating time and complication rate significantly. Relief from excessive menstrual bleeding occurred in 88% of patients, of whom 39% had amenorrhoea. Repeat TCRE was necessary in only 3% of patients, and 3% finally underwent hysterectomy.

Conclusions

TCRE can be conveniently performed by an experienced hysteroscopist without routine endometrial preparation with danazol/GnRH analogues. Our study shows that the incidence of complications was low, with successful results in 88% of patients with excessive menstrual bleeding.
Peritoneal hyperdistention for trocar insertion
Authors: Reich Harry , Rasmussen Carsten , Vidali Andrea
Published: March 2003

Introduction

Most laparoscopic complications occur at the time of Veress needle and trocar insertion. Although they are not very frequent, they increase the morbidity and mortality of both diagnostic and operative laparoscopic procedures. The currently recommended techniques of trocar insertion have not completely eliminated the risk of injury.

Technique

After Veress needle insertion we recommend creating peritoneal hyperdistention up to 25–30 mmHg pressure. At this point a short trocar is inserted in the deepest part of the umbilicus without elevation of the anterior abdominal wall. The result is a parietal peritoneal puncture directly beneath the umbilicus. As soon as safe abdominal entry is established, the pressure is lowered to 15 mmHg.

Experience

In our large series utilizing peritoneal hyperdistention there was but one vascular bowel injury related to umbilical trocar insertion. Maintaining an increased intra‐abdominal pressure for the length of time required for trocar insertion did not result in patient morbidity.

Conclusion

Peritoneal hyperdistention at trocar insertion is safe and may reduce the rate of trocar‐related complications.
Laparoscopic management of ovarian cysts
Authors: Wong Yat‐May , Amer Saad , Li Tin‐Chiu , Cooke Ian D.
Published: March 2003

Objective To review the various techniques of laparoscopic management of ovarian cysts and specimen retrieval.

Design Medline search on topics related to ovarian cysts, ovarian endometrioma, medical and surgical management.

Results Transvaginal scanning and measurement of CA 125 level are useful preoperative investigations. The value of preoperative Doppler ultrasound is yet to be established. In the absence of any features of malignancy, ovarian cysts of more than 5 cm may be safely removed laparoscopically. In ovarian endometrioma, drainage followed by ablation of the cyst wall is acceptable, although recent randomized data suggest that cystectomy produces better results. Rupture of stage 1a ovarian carcinoma does not worsen the prognosis if the laparoscopy is converted to laparotomy immediately.

Conclusion The optimal outcome of laparoscopic management of ovarian cysts depends on careful patient selection and the ability to remove the cyst intact without spillage of its contents. A timely conversion from laparoscopy to laparotomy in cases of malignancy will not worsen the eventual prognosis.
Ovarian remnant syndrome
Authors: Richlin Spencer S. , Rock John A.
Published: March 2003

Objective

To review different diagnostic and surgical procedures for ovarian remnant syndrome and suggest that complete primary resection is the only method to avoid recurrence.

Data sources

Sources include original articles and reviews on various ovarian remnant surgical techniques, on comparisons of laparotomy with laparoscopy and on the employment of possible medical methods for treatment, and reviews of methods and techniques for diagnosing ovarian remnant syndrome. The technical sources dated from 1953 to the present.

Methods of study selection

Studies of methods and follow up of ovarian remnant techniques currently used. Review articles including surgical and medical techniques with long‐term outcomes and patient selection criteria were utilized to formulate a strategy for appropriate selection of ovarian remnant removal.

Data extraction and synthesis

The methods reviewed include clinically applied surgical and medical techniques. Articles including surgical and nonsurgical treatment for ‘remnant removal’ were utilized with a review of laparotomy and laparoscopy data.

Conclusions

Complete excision of ovarian remnants via exploratory laparotomy affords patients the best option for avoiding future corrective surgery for pelvic pain from persistent ovarian remnants.
Rectosigmoid integrity after excision of nodular endometriotic disease: do we test appropriately?
Authors: Gordon Simon J. , Maher Peter J. , Healey Martin
Published: March 2003

Objective

To highlight the necessity of adequately testing rectosigmoid integrity after resection of infiltrating endometriosis.

Subject

A 25‐year‐old woman with a past history of ablative treatment for endometriosis, symptoms suggestive of disease progression, and a palpable anterior rectal nodule.

Interventions and outcomes

Excisional treatment of all visible disease, including the rectal nodule was carried out. Rectal integrity was confirmed intraoperatively via the ‘Betadine’ test. The patient presented again 3 days later with clinical findings suggestive of a bowel perforation. Repair of the defect and a de‐functioning colostomy were performed.

Conclusion

Although clinical bowel perforation is an uncommon event, the sequelae have far‐reaching consequences for the patient's quality of life. The use of electrosurgical dissection may have contributed to delayed tissue necrosis and the subsequent rectal perforation. Current methods for testing colorectal integrity are reviewed.
Initial training model for endometrial ablation
Authors: Dunkley M. Peta , Brown Lorna H. , Robinson Judith M. , Parkin David E.
Published: March 2003

The development and evaluation of a model for use in the initial training of gynaecologists in endometrial ablation techniques.

A series of prototypes, created according to theoretical specifications, were evaluated by practitioners experienced in endometrial ablation, and modified accordingly. The final model was evaluated by both trainers and trainees.

An endoscopic training unit.

The Faculty of the Scottish Diagnostic and Operative Hysteroscopy Course (12 consultants) and course participants (88), the majority being trainees from Scottish hospital trusts.

A model was developed for use in laboratory training or for individual practice, which is inexpensive, made of readily available materials and easy to prepare.

The materials, method of preparation and presentation of the model are reported and the advantages and disadvantages of its use are discussed.