bluuebunny/crossref_metadata_2025 huggingface dataset:
11β‐Hydroxylase deficiency: management of a difficult case by laparoscopic bilateral adrenalectomy
Authors: Nasir Joohi , Royston Christopher , Walton Christopher , White Michael C.
Published: November 2003

A 14‐year‐old girl presented with short stature and progressive virilization. She had not undergone the menarche. On investigation, she had elevated testosterone, androstenedione, dihydroepiandrosterone sulphate and 17α‐hydroxyprogesterone levels, which were all suppressed by overnight dexamethasone to within their normal ranges. An initial diagnosis of 21‐hydroxylase deficiency was revised to 11β‐hydroxylase deficiency after a tetracosactrin stimulation test, which showed only a modest rise in 17α‐hydroxyprogesterone level (from 92 nmol/l at baseline to 133 nmol/l at 60 minutes) and measurement of the basal 11‐deoxycortisol, which was grossly elevated. Treatment with dexamethasone 0.5 mg nocte resulted in suppression of androgens in the daytime, but not in the evening, particularly androstenedione. Treatment with hydrocortisone 10 mg b.d. failed to suppress testosterone or androstenedione over a 24‐hour period. Addition of cyproterone and oestrogen supplements had no effect and significant virilization persisted. Laparoscopic bilateral adrenalectomy was therefore performed as definitive treatment and resulted in remarkable clinical and biochemical improvement. This case illustrates difficulties in correct diagnosis, choice of appropriate steroid regimen and monitoring efficacy of treatment in congenital adrenal hyperplasia due to 11β‐hydroxylase deficiency. More aggressive management with earlier bilateral adrenalectomy may be appropriate in selected cases.
Thyroid hypoechogenicity after methimazole withdrawal in Graves' disease: a useful index for predicting recurrence?
Authors: Zingrillo Matteo , D'Aloiso Leonardo , Ghiggi Maria Rosaria , Di Cerbo Alfredo , Chiodini Iacopo , Torlontano Massimo , Liuzzi Antonio
Published: November 2003

OBJECTIVE A characteristic thyroid ultrasonographic picture with diffuse or scattered low echogenicity has been described in Graves' disease (GD). Thyroid hypoechogenicity in GD at onset has been considered a prognostic index of relapse after medical treatment; moreover, thyroid hypoechogenicity is regularly observed in GD at the onset, but not in patients with ‘burned‐out’ disease. The aim of this study was to evaluate the usefulness of thyroid hypoechogenicity changes in predicting GD relapse.

DESIGN Longitudinal prospective study of previously untreated patients with GD.

PATIENTS Thirty‐nine consecutive patients aged 10–72 years were treated with methimazole (MMI) for 12–24 months on a titration regimen. Evaluation of patients in remission or with relapse was done 12 and 24 months after MMI withdrawal.

MEASUREMENTS Thyroid ultrasonography and TSH receptor antibodies (TRAb) were evaluated in basal conditions and then one month after MMI withdrawal. Thyroid hypoechogenicity score (assessed by the same observer with the same equipment) was graded as: 0 absent; 1 mild; 2 moderate; 3 marked. At the withdrawal evaluation a score < 2 and a TRAb value < 10 U/l were considered as normal.

RESULTS Twelve and 24 months after withdrawal, there were 10 (25.6%) and 17 (44.7%) relapses, respectively. Neither thyroid hypoechogenicity score nor TRAb values evaluated in basal conditions, showed significant differences between patients remaining euthyroid and those who became again hyperthyroid. In the whole group, the thyroid hypoechogenicity score was significantly lower at the withdrawal than in basal conditions (1.1±1.1 vs 2±0.8; P < 0.0001); it was significantly lower in patients in remission (P < 0.001), but not in those who relapsed. The thyroid hypoechogenicity score at withdrawal was normal in 23/29 (79.3%) of patients still euthyroid and in 4/10 (40%) of those who relapsed up to the 12th month (P < 0.05); it was normal in 19/21 (90.4%) of patients still euthyroid and in 7/17 (41.2%) of those who relapsed up to the 24th month (P < 0.05). A normal thyroid hypoechogenicity score at withdrawal of MMI had a higher specificity (0.95) and sensitivity (0.59) with respect to TRAb values (0.86 and 0.53, respectively) for the prediction of the relapse of hyperthyroidism at the 24th month.

CONCLUSIONS Basal thyroid hypoechogenicity cannot be used as an index of relapse of GD. MMI treatment induces evident changes in thyroid hypoechogenicity, mainly in patients who subsequently go into remission. The absence or a low grade of thyroid hypoechogenicity after MMI treatment seems to be a favourable prognostic index of remission of hyperthyroidism in GD.
Helicobacter pylori and non‐Helicobacter pylori bacterial flora in gastric mucosal and tumour specimens of patients with primary gastric lymphoma
Authors: JONKERS D. , GISBERTZ I. , DE BRUINE A. , BOT F. , ARENDS J. W. , STOBBERINGH E. , SCHOUTEN H. , STOCKBRÜGGER R.
Published: November 2003

There is an association between Helicobacter pylori (H. pylori) and gastric mucosa‐associated lymphoid tissue (MALT) and MALT lymphoma. Histologically, mainly non‐specific stains are used to detect H. pylori, such as haematoxylin–eosin (HE) or modified Giemsa (MG). In this study, both a MG and a specific immunohistochemical stain (IMM) for H. pylori (Dako B471) were performed on sequential slides of resected material containing tumour and non‐tumorous gastric mucosa from patients with primary gastric lymphoma (n = 52). Special attention was paid to the presence of non‐H. pylori bacterial flora diagnosed by a positive MG (according to form and localization) and a subsequently negative IMM. On all slides, bacterial density was scored semiquantitatively (grades 0, 1, 2, 3). In total, 32 (61.5%) patients were H. pylori positive using IMM and 34 (65.4%) were non‐H. pylori positive using MG. In 24 out of the 34 patients, the non‐H. pylori flora consisted mainly of cocci in combination with rods in 15 patients, mostly in minor quantities; in another 10 patients, high numbers of both cocci and different types of rods were present. Most non‐H. pylori bacteria were localized superficially, although in 22 patients minor quantities of non‐H. pylori were also seen in the glandular lumina. After all of the patients had been analysed, no differences in the density of H. pylori and of non‐H. pylori flora were found. Only when comparing patients who had a small‐cell lymphoma with those who had a large‐cell lymphoma was a significantly higher density of H. pylori found in the corpus mucosa of large‐cell lymphomas and a higher prevalence of non‐H. pylori was found in tumours, in antrum or corpus, of patients with large‐cell lymphomas. In conclusion, with joint evaluation using MG and a H. pylori‐specific immunohistochemical stains, the proportion of H. pylori‐positive gastric lymphoma patients was lower than in most previous studies but other bacteria were found in a relatively high proportion. The role of the non‐H. pylori intragastric bacterial flora identified in this study has to be further elucidated in the aetiopathogenesis of primary gastric lymphoma.
Intestinal taurine transport: a review
Authors: O'FLAHERTY L. , STAPLETON P. P. , REDMOND H. P. , BOUCHIER‐HAYES D. J.
Published: November 2003

Intestinal uptake of dietary taurine is an important contributor to taurine homeostasis and may become crucial when taurine metabolism is impaired. This review aims to assess the literature documenting taurine transport and review what is currently known about the operation of the enterocyte taurine transport protein. Sources included MedLine searches from the last 10 years and references from original and review articles. The aim was to include human and animal studies directly addressing the subject of taurine uptake by enterocytes. Intestinal taurine transport has been well documented in in vivo studies using many different animal models. The mechanistic/kinetic aspects of the transport system have been extensively documented. However, little is known about what regulates the system. The recent development of a cell culture model of intestinal taurine transport will allow studies to explore the regulation of gut taurine uptake, which promises to be a very exciting area.
Phyllanthus amarus suppresses hepatitis B virus by interrupting interactions between HBV enhancer I and cellular transcription factors
Authors: OTT M. , THYAGARAJAN S. P. , GUPTA S.
Published: November 2003

The Phyllanthus amarus plant suppresses HBV mRNA transcription in vitro and exhibits therapeutic potential in chronic HBV carriers, although further work is necessary to define its mechanism of action. Analysis in HuH‐7 cells with transfected plasmids using a luciferase reporter showed that P. amarus specifically inhibited HBV enhancer I activity. To identify the mechanism of this HBV enhancer I inhibition, liver‐enriched cellular transcription factors were co‐expressed in HuH‐7 cells. The C/EBPα and β, as well as HNF‐3α and β transcription factors, significantly up‐regulated the HBV enhancer I activity. In contrast, co‐transfection of HNF‐1α or β had no effect upon the HBV enhancer I activity. Exposure to P. amarus inhibited C/EBPα‐ and β‐mediated up‐regulation of HBV enhancer I activity in a dose‐dependent manner, whereas HNF‐3α‐ and β‐mediated up‐regulation of HBV enhancer I was unaffected. In vitro gel shifts showed that P. amarus inhibited complexing of C/EBP transcription factors to a consensus oligonucleotide sequence, whereas DNA binding of AP‐1 and SP‐1 transcription factors was unaffected. As P. amarus down‐regulates HBV mRNA transcription by a specific mechanism involving interactions between HBV enhancer I and C/EBP transcription factors, purification and further analysis of the active P. amarus component will advance insights into its antiviral activity.
Hyposensitivity to nerve stimulation in portal hypertensive rats: role of nitric oxide
Authors: SIEBER C. C. , SUMANOVSKI L. T. , MOLL‐KAUFMANN C. , STALDER G. A.
Published: November 2003

Portal hypertension goes along with vascular hyporeactivity, partly mediated by nitric oxide (NO). Interactions between the adrenergic nervous system and NO in portal hypertension are undetermined. We tested (1) whether superior mesenteric arterial beds of portal hypertensive rats have an altered sensitivity to periarterial nerve stimulation (PNS) and (2) the role of NO in modulating nerve‐stimulated responses. Vasopressor responses to PNS (Hz, 2–32) were similar in preparations of partial portal vein‐ligated (PVL, n = 12) and control (CON, n = 12) rats (60.0 ± 6.7 and 47.8 ± 6.1 cmH2O respectively) for 24 Hz (NS), but sensitivity of vessels of portal hypertensive animals displayed a significant right‐ward shift [Hz needed for 50% of maximal response (Hz50) being 15.5 ± 0.4 and 12.9 ± 0.6 for PVL and CON respectively, P < 0.001]. NO formation inhibition by Nω‐nitro‐l‐arginine (10−4 mol L−1) significantly increased responses to PNS (P < 0.05), the absolute values for 24 Hz being 101.4 ± 11.7 cmH2O for PVL (n = 8) and 86.4 ± 11.4 cmH2O for CON (n = 7) (NS). NO formation inhibition reversed the hyposensitivity in preparations of PVL, Hz50 being 13.9 ± 0.5 and 13.2 ± 0.2 for PVL and CON respectively (NS). Adrenergic receptor antagonism with prazosin (10−7 mol L−1) and yohimbine (10−6 mol L−1) inhibited PNS‐mediated vasopressor reactivity (n = 6 per group, P < 0.001), confirming the nervous origin of vasoconstrictor responses. It is concluded that (1) portal hypertension goes along with a significant hyposensitivity to PNS and (2) this hyposensitivity is reversed by NO‐formation inhibition.
Signal transduction pathways of membrane expression of proteinase 3 (PR‐3) in human endothelial cells
Authors: MAYET W.‐J. , SCHWARTING A. , ORTH T. , SIBELIUS U. , HATTAR K. , MEYER ZUM BÜSCHENFELDE K.‐H.
Published: November 2003

At present, the exact mechanism of the pathogenic effect of anti‐PR‐3 antibodies remains unknown. Interaction of anti‐neutrophil cytoplasmic antibodies (ANCAs) with human umbilical vein endothelial cells (HUVECs) may play a key role. Recently we were able to show that ANCAs recognize their target antigen, PR‐3, translocated into the membrane of HUVECs. The objective of this study was to investigate regulation, i.e. signal transduction pathways, of PR‐3 expression in endothelial cells. HUVECs were isolated according to the method of Jaffe et al. and cultured under standard conditions. A cyto‐enzyme‐linked immunosorbent assay (ELISA) with unfixed cells was performed. Membrane‐expressed PR‐3 was detected by affinity‐purified and monoclonal anti‐PR‐3 Ab. Tumour necrosis factor alpha (TNF‐α)‐induced membrane expression of PR‐3 could be blocked with the RNA synthesis inhibitor actinomycin D, the protein kinase C (PKC) and proteinase A (PKA) inhibitor staurosporine, the specific PKC inhibitor calphostin C, the c‐AMP‐dependent PKA inhibitor KT5720 and the tyrosine kinase inhibitor genistein in a dose‐dependent manner. The effect of calphostin C was the most significant. In addition, the effect of phorbol 12‐myristate 13‐acetate (PMA), a mediator of intracellular second messengers, was investigated. In our study, pretreatment of cells with PMA for 48 h led to a down‐regulation of PR‐3 expression. This effect, however, could be overridden by TNF‐α stimulation, i.e. TNF‐α‐induced membrane expression of PR‐3 was resistant to down‐regulation of PKC. In conclusion, our data suggest that translocation of PR‐3 in HUVECs is an active process depending on protein synthesis. PR‐3 expression by HUVECs may involve a PKC reactive to cytokines such as TNF‐α which induces PR‐3 expression at a transcriptional level.
High doses of hydroxyethyl starch and human albumin have similar effects on monocyte function and oncotic pressure
Authors: GUIDET B. , PODEVIN P. , ROBERT A. , CHAUVIN P. , MAURY E. , OFFENSTADT G.
Published: November 2003

The accumulation of hydroxyethyl starches (HES) in monocytes/macrophages has raised concern over their potential detrimental effects on host defences. We assessed prospectively the function of circulating monocytes isolated from patients treated with plasma exchange (PE) using HES. The study was carried out in the medical intensive care unit of a university hospital. Eight patients underwent PE for neurological disorders. Each patient underwent three PEs, 48 h apart. The total exchange volume was 4 L per PE. Only 4% human albumin was used for the first PE. In the second and third PEs, the plasma substitute was 2 L of HES (200 000/6%/0.62) and 2 L of albumin. Mononuclear cells were collected before and immediately after each PE and 48 h after the last PE. They were placed in suspension culture and incubated with lipopolysaccharide (LPS). Monocyte function was assessed in terms of procoagulant activity (PCA) and tumour necrosis factor alpha (TNF‐α) production. LPS‐stimulated PCA increased after the first PE (P < 0.05). Stimulated TNF‐α production increased, but not significantly so. Similar effects were observed after the second and third PE (P < 0.05 for stimulated TNF‐α). Values 48 h after the last PE were similar to those obtained before the second PE, suggesting that repeated infusions of HES had no detrimental effect on monocyte function. Furthermore, plasma oncotic pressure was preserved after PE with HES. These results support the partial replacement of costly human albumin with HES during repetitive PE, and suggest that HES might be a safe plasma expander in septic patients.
Contribution of nitric oxide to exercise‐induced changes in healthy volunteers: effects of acute exercise and long‐term physical training
Authors: POVEDA J. J. , RIESTRA A. , SALAS E. , CAGIGAS M. L. , LÓPEZ‐SOMOZA C. , AMADO J. A. , BERRAZUETA J. R.
Published: November 2003

Endothelium plays a central role in the regulation of regional blood flow through the release of certain vasoactive substances. We conducted this study to test whether an increase in the production of nitric oxide (NO) metabolites, atrial natriuretic peptide (ANP) and plasma and intraplatelet cyclic guanosine 3′:5′ monophosphate (cGMP) is involved in the adaptation to chronic exercise in physically trained people and in the vasodilatation induced by acute physical exercise. We studied one group of 10 trained athletes and another group of 10 untrained people. We measured plasma levels of nitrites, nitrates and cGMP and intraplatelet levels of cGMP, as an indicator of intracellular guanylate cyclase activity, and ANP before and after a maximal treadmill test. Resting cardiac rate (CR) and systolic blood pressure (SBP) were lower in the athlete group than in the control group (73.8 ± 3.6 vs. 92 ± 5.9; P < 0.02 and 110 ± 2.58 vs. 118 ± 3.27; P < 0.02 respectively). SBP did not show differences between groups after the exercise test. Diastolic blood pressure (DBP) at rest was lower in the athlete group (71 ± 1.79 vs. 80.5 ± 3.53; P < 0.03) and the decrease after maximal exercise was more pronounced in this group (64 ± 2.67 vs. 74.5 ± 3.2; P < 0.02). Basal plasma nitrites were 4.9 ± 0.8 in the athlete group and 1.9 ± 0.3 in the control group (P < 0.05). After exercise, test differences between groups remained (P < 0.05). Nitrates were significantly higher in the group of athletes and did not show exercise‐related changes. Plasma levels of cGMP and ANP increased in both groups after the treadmill test, with no differences between groups. Among the athletes, cGMP increased from 1.11 ± 0.1 to 2.6 ± 0.4 (P < 0.001), whereas in the untrained group plasma cGMP rose from 1.14 ± 0.09 to 1.86 ± 0.2 (P < 0.01). There was a significant correlation between the increases in plasma cGMP and the atrial natriuretic peptide in both groups (r = 0.91, P < 0.0002, for athletes; and r = 0.68, P < 0.04, for control group). The intraplatelet concentration of cGMP did not show differences between groups and did not change after exercise. In conclusion, we have found increased basal levels of plasma nitrite and nitrate in trained subjects. Exercise does not produce differences in the increments of these metabolites. Therefore, we speculate the release of nitric oxide is not augmented by exercise in trained athletes.
The relationship between phytoplankton composition and physical–chemical variables: a comparison of taxonomic and morphological–functional descriptors in six temperate lakes
Authors: DE M Vera Lúcia . Huszar , Nina F. Caraco
Published: November 2003

1. The relationship between phytoplankton composition and physical–chemical variables was studied in six temperate lakes, characterizing the phytoplankton taxonomically or by a rarely used morphological–functional approach (m/f approach) developed by Reynolds (1997). This approach divides phytoplankton into three groups (C‐, S‐ and

R‐strategists) by morphological characters thought to be related to light and nutrient acquisition.

2. The lakes ranged from oligotrophic to moderately eutrophic and exhibited both polymictic and dimictic patterns of mixing. Across the trophic gradient total phytoplankton biomass ranged from 0.3 to 4.8 mg (wet weight) L–1 and total phosphorus (TP) from 0.19 to 1.07 μm.

3. The taxonomic groups predominantly represented were cyanobacteria, diatoms, dinoflagellates, chrysophytes and chlorophytes. The m/f group that was dominant (> 50% of total biomass) in five of the six lakes was composed of S‐strategists. In four of the six lakes the second most abundant group comprised R‐strategists. In only one lake was biomass dominated by C‐strategists.

4. Within‐lake seasonal variations in taxonomic and m/f groups were not predicted well from physical or chemical variables. This lack of predictability is probably caused, in part, by the problem of rapid seasonal variation in environmental conditions as compared to the replacement time of phytoplankton. Considering the data as a whole, however, several physical and chemical variables were significantly related to taxonomic and m/f groups. Some correlations agreed with expectations from the literature and some did not.

5. For taxonomic groups, as expected, cyanobacteria were positively associated with temperature, pH and TP and negatively with light and NO3 : TP ratios. Chrysophytes were negatively related to temperature, pH, soluble reactive phosphorus and TP. No other division showed a substantial correspondence to literature expectations.

6. For m/f groups: R‐strategists were correlated with high dissolved nutrients (both N and P) and low light; S‐strategists were correlated with low dissolved N. C‐strategists were generally in low abundance in the study lakes, as might be expected from the generally low nutrients in the six lakes. Opposite to expectations, however, their abundance in the study lakes was negatively correlated to dissolved P.

7. Despite a lack of complete predictive ability, the m/f approach performed better than the taxonomic approach. This suggests that size and shape of phytoplankton may predict their response to physical and chemical conditions better than taxonomy at the division level.
Phosphorus kinetics of planktonic and benthic assemblages in a shallow subtropical lake
Authors: Hwang Soon‐Jin , Havens Karl E. , Steinman Alan D.
Published: November 2003

1. Phosphate uptake kinetics and uptake rates were calculated for planktonic (phytoplankton and bacterioplankton) and benthic (epiphyton and epipelon) assemblages in a large, shallow, subtropical lake. Samples were taken bimonthly over the period of 1 year at three different sites to examine spatial and temporal variability in these processes.

2. Two of the sites, located at the edge of the littoral zone next to the open water (ecotone sites), had low irradiance at the sediment surface and high total phosphorus (TP) concentration (annual mean TP = 112 μg L–1). The third site, located in the littoral marsh zone, had high irradiance at the sediment surface and low TP concentration (annual mean TP = 7 μg L–1).

3. Based on 32P‐PO4 turnover time, P availability varied temporally and spatially. At the two high TP ecotone sites, P concentration was lowest in July and August. At the low TP marsh site, P limited algal production throughout the year.

4. The quotient of maximum uptake rate to half saturation constant (Vm/Ks) in the plankton increased by over two orders of magnitude during the P‐limited (summer) period at the two ecotone sites, suggesting that plankton used the scarce phosphorus more efficiently. The specific uptake rate of plankton was significantly greater than that of periphyton at all sites, suggesting that the plankton were more efficient than periphyton at taking up phosphate.

5. Periphyton biomass, as well as absolute and percentage P uptake rate, was greater at the marsh site than at the ecotone sites, despite the lower P concentrations in the marsh. This was probably a result of rapid nutrient cycling, combined with high light availability in the marsh.
An acanthocephalan parasite mediates intraguild predation between invasive and native freshwater amphipods (Crustacea)
Authors: Macneil Calum , Fielding Nina J. , Dick Jaimie T. A. , Briffa Mark , Prenter John , Hatcher Melanie J. , Dunn Alison M.
Published: November 2003

1. The balance of predation between closely related invasive and native species can be an important determinant of the success or failure of biological invasions. In Irish freshwaters, the introduced amphipod Gammarus pulex has replaced the native G. duebeni celticus, possibly through differential mutual intraguild predation (IGP). Theoretically, parasitism could mediate such predation and hence the invasion outcome. However, this idea remains poorly studied.

2. In a field survey, we show that the acanthocephalan parasite Echinorynchus truttae is present in more G. pulex populations than G. d. celticus populations. In addition, within parasitised populations, E. truttae is more prevalent in the invader than in the native.

3. We show for the first time that an acanthocephalan parasite mediates predation between its intermediate macroinvertebrate hosts. In a field experiment, E. truttae parasitism of the invader lowered IGP upon the unparasitised native. In laboratory experiments, parasitism of G. pulex significantly reduced their predatory impact on recently moulted female G. d. celticus. Parasitism also appeared to cause reduction in predatory behaviour, such as attacks per contact on precopula guarded female natives.

4. We conclude that higher parasite prevalence in invaders as compared with natives, by mediation of interspecific interactions, could promote species coexistence, or at least slow species replacements, in this particular biological invasion.
The effect of prey morphology on the feeding behaviour and population growth of the predatory rotifer Asplanchna sieboldi: a case study using five species of Brachionus (Rotifera)
Authors: Nandini S. , Pérez‐Chávez Ricardo , Sarma S. S. S.
Published: November 2003

1. We investigated the numerical response, functional response and prey preference of Asplanchna sieboldi to five different prey brachionids. We also analysed the feeding behaviour of the predator in terms of encounters, attacks, capture and prey ingested per unit time.

2. The five prey species (Brachionus havanaensis, B. rubens, B. patulus, B. macracanthus and B. calyciflorus) differed in their body size and spine length.

3. The population growth rates of A. sieboldi ranged from 0.074 ± 0.03 to 0.431 ± 0.02 depending on prey type and density. There was a significant impact of the spine length rather than body size per se on the population growth rates of the predator.

4. The maximum number of prey consumed depended on both body size and spine length. In the functional response analyses, the plateau was reached at a prey density of 4–8 ind. mL−1.

5. There was a significant impact of prey density on the prey preference of the predator.
Biodiversity and distribution of water mites (Acari, Hydrachnidia) in spring habitats
Authors: Sabatino Antonio Di , Cicolani Bruno , Gerecke Reinhard
Published: November 2003

1. The distribution, species richness and ecology of spring‐dwelling water mites in Italy were investigated with the aim to better elucidate the role of spring habitats to sustain high levels of biodiversity and their contribution to freshwater biodiversity at a local and regional scale.

2. More than 300 springs in different geographic areas (Alps, Central and Southern Apennines, Sicily and Sardinia), were examined with a total of 163 water mite species recorded.

3. Species richness in each area ranged from 33 species on Sardinia to 77 on Sicily. The highest diversity was found in the Gran Sasso (Central Apennines). The proportion of crenobionts (species strictly bound to this type of habitat) exceeded 50% in almost all the areas investigated.

4. A diverse (up to 20 species per spring) and highly specialised mite fauna was observed in undisturbed rheocrenes and in natural springs of intermediate typology (rheohelocrenes and rheopsammocrenes). In springs subjected to human impacts (pasture, deforestation, alteration and transformation of spring sources) species richness declined and crenobionts were replaced by unspecialised crenoxenes.

5. The zoogeographic importance of spring habitats is confirmed by the presence of 18 endemic species and by members of genera with an interesting disjunct and relict distribution.

6. A comparison with other geographic areas suggests that springs contain a significant fraction of the total number of species found in freshwater habitats and may contribute almost one third of regional freshwater biodiversity. The presence of endemic crenobionts and rare taxa highlights the importance of these habitats in maintaining high levels of biodiversity as well as their contribution to a better understanding of biodiversity patterns in freshwaters.
Variation in fecundity and other reproductive traits in freshwater mussels
Authors: Haag Wendell R. , Leann Staton J.
Published: November 2003

1. Life histories of the highly diverse and endangered North American freshwater mussel fauna are poorly known. We investigated reproductive traits of eight riverine mussel species in Alabama and Mississippi, U.S.A.: Amblema plicata, Elliptio arca, Fusconaia cerina, Lampsilis ornata, Obliquaria reflexa, Pleurobema decisum, Quadrula asperata and Q. pustulosa, and compare our results with existing life history information for other species.

2. These eight species had reproductive traits characteristic of large, outcrossing populations: hermaphrodites were rare, we found no evidence of protandry, and sex ratios were even or slightly male‐biased.

3. Age at sexual maturity varied among species, ranging from <1 to 2 years for L. ornata to 3–9 years for Q. asperata. In all species, most mature females participated in reproduction and fertilisation success was high.

5. Fecundity was related positively to both length and age, but length was the best predictor. In six species, fecundity increased exponentially with increasing size; in two species the rate of increase in fecundity declined in larger animals. In four species, fecundity declined in older animals. These latter results indicate weak reproductive senescence; however, in all species, older individuals continued to produce large numbers of offspring. Mean annual fecundity differed widely among species ranging from 9647 to 325 709. Within‐species differences in fecundity were found among rivers and among populations within a river.

6. The wide variation in reproductive traits among species indicates the existence of widely divergent life history strategies in freshwater mussels.
Coexistence of cryptic rotifer species: ecological and genetic characterisation of Brachionus plicatilis
Authors: Ortells Raquel , Gómez Africa , Serra Manuel
Published: November 2003

1. The coexistence of five cryptic species of the rotifer species complex Brachionus plicatilis was investigated in four coastal Mediterranean ponds. Monthly sampling was undertaken for 15 months and species were characterised using allozyme electrophoresis.

2. We describe species‐diagnostic allozyme loci that can be used for rapid identification of these species.

3. The five species overlapped to some extent in their temporal use of the ponds, although some seasonal segregation was observed.

4. The match between temporal and spatial distribution and limnological conditions suggested ecological specialisation in some cases, although we found striking examples of extensive seasonal overlap.

5. Our results indicate that sympatry of cryptic rotifer species is largely because of seasonal ecological specialisation, which allows seasonal succession and partitioning of resources. The processes that might be involved in the long periods of overlapping seasonal distributions of species which are potentially competitors are discussed. This example illustrates that the ‘paradox of the plankton’ is more the rule than the exception.
Perturbation of fluid reabsorption in the efferent ducts of the rat by testosterone propionate, 17β‐oestradiol 3‐benzoate, flutamide and tamoxifen
Authors: HANSEN L. A. , CLULOW J. , JONES R. C.
Published: November 2003

The regulation by oestradiol and testosterone of fluid reabsorption in the efferent ducts of the rat was investigated by determining the effects of administering the hormones and their antagonists. Untreated rats were compared to animals treated for 7 days with testosterone propionate (1 mg d−1), oestradiol benzoate (400 μg d−1), flutamide (10 mg d−1) or tamoxifen (1 mg d−1). Two procedures were used to measure perturbation of transepithelial fluid fluxes in vivo. The first procedure used cannulation of the proximal epididymal duct and micropuncture of the rete testis to compare the rate at which fluid enters and leaves the efferent ducts. Oestradiol administration increased ( p < 0.001) the volume of fluid entering the epididymal duct from the efferent ducts (i.e. reduced reabsorption) while flutamide and tamoxifen decreased ( p < 0.05) the amount of fluid entering the epididymal duct (i.e. increased fluid reabsorption). Testosterone did not have a statistically significant effect, although it produced a small increase in fluid reabsorption. There was some perturbation of the concentration of electrolytes and the osmotic pressure of the fluid leaving the efferent ducts, but as these were not large, it is suggested that the treatments had little effect on the basic mechanisms of osmotic water transport via solute–solvent coupling. The second procedure used to test the effect of the steroids involved microperfusing individual efferent ducts, and the results were consistent with those of the first study. Oestradiol decreased fluid reabsorption by the efferent ducts ( p < 0.05), and testosterone ( p < 0.05, lowest perfusion rate only), flutamide ( p < 0.001) and tamoxifen ( p < 0.01) increased reabsorption. The similar responses to flutamide and testosterone administration suggest that flutamide acted as an androgenic agonist by elevating systemic and luminal androgen. It is concluded that fluid reabsorption in the efferent ducts is perturbed by oestrogens and androgens. Although their actions have not been completely resolved, it is proposed that they are involved in a chronic regulation, with androgens stimulating and oestrogens suppressing fluid reabsorption by the ducts.
Decreased steroidogenesis and cAMP production in vitro by Leydig cells isolated from rats made hypothyroid during adulthood
Authors: VALENTI S. , GUIDO R. , FAZZUOLI L. , BARRECA A. , GIUSTI M. , GIORDANO G.
Published: November 2003

The Leydig cell function of adult male rats made hypothyroid with 6‐propyl‐ 2‐thiouracil (6‐PT, 0.1% w/v in drinking water for 1 month) was studied and compared with that of age‐matched controls. After 6‐PT treatment, a slight, non‐significant decrease in serum testosterone was observed, but no changes in testis weight or number of Leydig cells were noted. The in vitro function of Leydig cells was therefore investigated during incubation for 3 h in the presence or absence of several stimuli: LH (30 mIU/mL), forskolin (FK 1 μM), isobutylmethylxanthine (IBMX, 100 μM), GnRH (100 nM) or FK 1 μM + IBMX 100 μM. Irrespective of the stimulus, cells from hypothyroid rats secreted less cyclic AMP, 17‐hydroxyprogesterone, androstenedione and testosterone. No differences in LH receptors were noted between the groups. Prolonged incubation with triiodothyronine (5–250 ng/mL) or thyroxine (5–250 ng/mL) for 3, 16, 24 or 48 h did not affect testosterone secretion in either group; however, administration of IGF‐I (8 ng/mL for 24 h) resulted in increased spontaneous and stimulated testosterone production in both groups. However, when hypothyroid animals were supplemented in vivo with thyroxine a full recovery of Leydig cell function in vitro was noted.

In conclusion: (1) Leydig cells from rats made hypothyroid during adulthood produce less testosterone in vitro, both spontaneously and in response to cAMP and non‐cAMP‐mediated stimuli; (2) this is due to a reduction in cAMP production and in the activity of the enzymes in the androgen biosynthetic pathway, and not to changes in LH receptors; (3) direct administration of thyroid hormones did not improve testosterone secretion in either group, while incubation with IGF‐I did.
CASA as an aid to selecting sperm suspensions for artificial insemination in Callithrix jacchus
Authors: MORRELL J. M.
Published: November 2003

The ability to use sperm motility parameters, obtained by computer‐assisted sperm motility analysis (CASA), as an aid to selecting sperm samples for artificial insemination (AI) would have considerable benefits for commercial organizations and for the captive breeding of endangered species. In this study the Hobson sperm tracker (HST) was validated for use with spermatozoa from Callithrix jacchus, the common marmoset, by comparing values for straight line velocity by CASA with those obtained by direct measurement of sperm tracks. Using the settings established during validation, ejaculated and epididymal spermatozoa were analysed with the HST. The range of values for velocity parameters were used to establish expected motility profiles for the two types of spermatozoa as follows: for epididymal spermatozoa (concentration 2.2–85.8 × 106 spermatozoa/mL) VCL 109.8–155.9, VSL 75.2–141.5, VAP 85.8–142.1, MAD 13.7–40.7, ALH 3.8–7.8, BCF 1.4–4.2, LIN 40.5–91.1% and STR 70.1–97.1%; for ejaculated spermatozoa (concentration 3.2–82.0 × 106 spermatozoa/mL) VCL 89.6–136.7, VSL 69.6–110.3, VAP 74.5–121.9, MAD 19.2–29.3, ALH 3.0–9.9, BCF 2.8–5.5., LIN 65.4–85.3% and STR 93.8–97.7%. Epididymal spermatozoa from males which were not sexually active had significantly lower values for VCL, VSL and VAP, while values for MAD were significantly higher than for spermatozoa from sexually active males ( p < 0.031). Sperm concentration affected motility parameters significantly. Although motility parameters differed according to the batch of medium used, the differences were not statistically significant. Epididymal sperm samples had significantly higher VCL, VSL and VAP but lower BCF and LIN than ejaculated sperm samples of the same concentration diluted in the same batch of medium, while MAD, ALH and STR were not different. Urine contamination significantly reduced VCL, VSL and VAP ( p < 0.008, < 0.016 and < 0.008, respectively, sample size = 7) whereas MAD, ALH, BCF, LIN and STR were not affected. Therefore CASA could be useful in screening ejaculates for use in AI to eliminate samples with unusual motility patterns.
Purification and characterization of hepatocyte growth factor (HGF) from human seminal plasma
Authors: DEPUYDT C. E. , ZALATA A. , FALMAGNE J.‐B. , BOSMANS E. , COMHAIRE F. H.
Published: November 2003

Naturally occurring forms of hepatocyte growth factor/scatter factor (HGF/SF) have been purified by heparin‐Sepharose chromatography, followed by cation exchange chromatography from a pool of human seminal plasma. Using an enzyme‐linked immunosorbant assay, MDCK scatter assay, and Western blot analysis, it was found that, after heparin‐Sepharose chromatography, human HGF/SF present in seminal plasma eluted in two different fractions, between 0.72 and 0.85 M NaCl (fraction I) and between 0.95 and 1.10 M NaCl (fraction II). Further purification of fraction I by cation exchange chromatography resulted again in two fractions which eluted at 0.2–0.4 and at 0.6–0.8 M NaCl. The fraction which eluted at 0.2–0.4 M NaCl consisted of two biologically less active heavy chains of the heterodimeric form of HGF/SF (107.1 U/ng immunoreactive HGF), with approximate molecular weights of 65 and 62 kDa under reducing conditions. The second fraction, which eluted at 0.6–0.8 M NaCl, revealed three bands with molecular weights of 87, 65 and 62 kDa, respectively. The 87 kDa form is thought to be a single chain precursor of HGF/SF devoid of biological activity.

After subjecting fraction II to cation exchange chromatography, only one major peak eluted between 0.9 and 1.0 M NaCl, and consisted of two biologically active heavy chains of the heterodimeric form of HGF/SF (708.3 U/ng immunoreactive HGF), with approximate molecular weights of 65 and 62 kDa under reducing conditions. Non‐reducing conditions for both fraction I and fraction II revealed only one band with a molecular weight of 68 kDa. The ratio of pro‐HGF/SF and less biologically active HGF/SF (fraction I) over mature heterodimeric HGF/SF (fraction II) was ≈1:3, in seminal plasma from sperm donors.

In seminal plasma, pro‐HGF/SF represents an 87 kDa glycoprotein which, apparently, is converted by limited proteolysis into several bands with molecular weights of 65 and 62 kDa. This is the first report showing the presence of pro‐HGF/SF and heterodimeric mature HGF/SF, as well as less biologically active forms of HGF/SF in human seminal plasma.
Effect of male occupational heat exposure on time to pregnancy
Authors: THONNEAU P. , DUCOT B. , BUJAN L. , MIEUSSET R. , SPIRA A.
Published: November 2003

The relationship between male occupational heat exposure and the time required to achieve a pregnancy [ TTP] was studied in a retrospective survey of 402 fertile couples. The TTP for the subgroups `exposure to heat' (median = 4.0 months; mean = 11.8; SD = 13.3) and `professional driver >3 h/day' (median = 4.5; mean = 14.4; SD = 28.5) was significantly longer (both p < 0.05) than for the controls (median = 2.8; mean = 7.8; SD = 13.3).

Bakers and welders showed comparable results: only 14% of the bakers' partners became pregnant within 3 months (cf. 55% of controls, p < 0.05) and only 29% became pregnant within 6 months (cf. 74% of controls, p < 0.02).

This study suggests that occupational exposure to heat is a `weak' risk factor for male subfertility.
Quality changes in frozen whole and gutted anchovies during storage at −18°C
Authors: Karaçam Hikmet , Boran Muhammet
Published: November 2003

Fresh samples of whole and gutted anchovies were blast frozen at −35°C and stored at −18°C. The quality of the samples was examined as organoleptic, microbiological and chemical changes during the storage period. Gutting had no significant effect on the quality of the final product. Sensory quality was good for up to 90 days of storage. No increase in microbial activity was detected, but some oxidative and hydrolytic deterioration of fats were observed. The final product was still edible after 180 days.
Water vapour sorption behaviour of original and defatted wheat gluten
Authors: De Jong Gerard I.W. , Van den Berg Cornelius , Kokelaar Anita J.
Published: November 2003

The water vapour sorption isotherms of original and defatted gluten samples, prepared from two wheat cultivars (Spring and Taurus) with good and poor baking performance, respectively, were investigated at 25 and 40°C. The GAB isotherm equation described the isotherms well up to a relative humidity of at least 84% at 25°C and up to 75% at 40°C. The GAB constants of Spring gluten indicated an increased number of adsorption sites and a decreased average interaction energy per binding site at increased defatting (petroleum ether, chloroform). This tendency was also observed for Taurus, however, here no significant differences were found between the solvents. When comparing both cultivars the isotherm analysis indicated less available active sites for water adsorption with a stronger interaction energy per site for Taurus gluten. This stronger interaction is in accord with the higher isosteric heat of adsorption (Clausius‐Clapeyron analysis) found at low relative humidities. These findings are related to bread baking performance.
Numerical method for prediction of final microbial load in inoculated cylindrical cans of tomato concentrate heated in a pilot plant
Authors: Rodríguez René D. Peralta , Martínez Antonio , Rodrigo Miguel , Safón José
Published: November 2003

A finite difference numerical method to predict temperatures and destruction of a thermally labile species in cylindrical cans of conduction heating food was applied to compute final microbial load in an inoculated 18°Brix canned tomato concentrate at pH = 4.5 processed under conditions simulating industrial practice. Predictions of product temperature and final microbial load in three can sizes compared well with experimental heat penetration data and estimation of surviving species of Bacillus coagulans ATC 8038 spores inoculated into the cans. The application of the model as an aid to establishing process schedules is illustrated for a can with a required IS14100= 11.44 min. The model predicts that a 29.5 min heating time at 105.6°C would provide an IS14100= 11.77 min.
The microbiology of mixed salad containing raw and cooked ingredients without dressing
Authors: Nguyen‐the Christophe , Halna‐du‐Frétay Boris , Abreu da Silva Alexandra
Published: November 2003

Growth of aerobic mesophilic bacteria in mixed salad without dressing, containing cooked sweet corn and raw endive, was similar to that of raw endive alone. At 9°C, sweet corn permitted the growth of the lactic acid bacterium Leuconostoc mesenteroides, whenever the bacterium was present on raw endive, whereas no growth of lactic acid bacteria was recorded on raw endive alone. Listeria monocytogenes, artificially inoculated in the samples, grew more in the mixed salad than in the raw endive alone, for products stored at 6°C and 9°C. Acidification of sweet corn to pH 5.0 was proposed to reduce the development of L. monocytogenes in the mixed salad to a level similar to that recorded in the raw endive alone. Acidification with citric acid reduced spoilage of sweet corn, whereas acetic acid caused necrosis on the leaves of raw endive.
Review: Modified Atmosphere Packaging and its effects on the microbiological quality and safety of produce
Authors: Phillips Carol A.
Published: November 2003

Modified Atmosphere Packaging and related technologies are increasingly used to extend shelf‐life of fresh produce. This paper reviews the effect of such technology on the spoilage microbiological flora and food‐borne pathogens which may be present in produce and also on the organoleptic properties of the product.
Scientific knowledge in medicine: a new clinical epistemology?
Authors: Marshall Tom
Published: November 2003

Technological developments in the field of communications have widened access to research evidence and, as a result, scientific epistemology is in the ascendancy in the area of medical knowledge. This has been the subject of vigorous debate within the medical profession itself, with many opposing the increasing weight given to research evidence at the expense of expert opinion. Medicine has a professional culture which identifies knowledge with particular individuals — a ‘person culture’. Much of the authority of physicians derives from the presumption that medical professionals have privileged access to medical knowledge. Scientific epistemology, on the other hand, identifies knowledge with a process of investigation. The esoteric knowledge to which expert individuals claim privileged access has no currency in this process. Because of this, the rise of scientific epistemology in medicine partially undermines the profession's authority. Access to scientific research evidence can be used to undermine the individual authority of professional experts. Illustrative examples are given of the nature of debate within a ‘person culture’ and of ways in which research evidence has been used to challenge the authority of physicians.
A Popperian perspective of the term ‘evidence‐based medicine’
Authors: Shahar Eyal
Published: November 2003

If the term ‘evidence‐based medicine’ conveys more than is conveyed by the word medicine, then there must be a way to distinguish between evidence‐based medicine and non‐evidence‐based medicine. In particular, there must be a logically acceptable way to classify medical decisions as justified or unjustified by scientific evidence. In this essay I examine the nature of medical theories, the nature of the evidence that is produced by empirical tests of medical theories, and the relation of medical decisions to both. I conclude that attempts to classify medical decisions as justified or unjustified by scientific evidence have no foundation in logic and that the term ‘evidence‐based medicine’ is logically indistinguishable from the term ‘medicine’. The use of the term ‘evidence‐based medicine’ calls for a new type of authoritarianism in medical practice.
Evidence‐based medicine, practice variations and clinical freedom
Authors: Hampton J. R.
Published: November 2003

Much of cardiovascular disease can be treated on the basis of the results of large clinical trials and can be considered ‘evidence‐based’. However, trial results are not infallible and it is important to recognize their limitations. Despite the evidence, widespread variation exists in medical practice between and within countries; the reasons may be cultural, or may indicate poor medical education. Purchasing authorities have to do the best they can with available evidence, and our full evidence base needs to include costs; in some instances we now have evidence of benefit from treatment that we almost certainly cannot afford. Evidence‐based medicine is a further — but possibly an acceptable — limitation to clinical freedom.