bluuebunny/crossref_metadata_2025 huggingface dataset:
The corticotrophin‐releasing hormone test in preterm infants
Authors: Bolt Roel J. , Van Weissenbruch Mirjam M. , Cranendonk Anneke , Lafeber Harry N. , Delemarre‐van de Waal Henriette A.
Published: March 2003

objective

The developing hypothalamic–pituitary–adrenal axis (HPAA) may be immature and not yet fully functional in preterm infants. This may result in an inappropriate adrenal response to stress. Little is known about the pituitary–adrenal response to corticotrophin‐releasing hormone (CRH) stimulation during the early neonatal period in preterm infants born before 32 weeks of gestation. Therefore, in a first study we investigated the pituitary–adrenal response to 1 µg/kg CRH i.v. in 13 preterm infants born ≤ 32 weeks of gestation. In addition, in a randomized placebo‐controlled study we compared the pituitary–adrenal response of 1 µg/kg CRH to placebo and stimulation with 2 µg/kg CRH.

results

In the first study, the level of ACTH increased from 6·9 ± 2·1 to 11·6 ± 5·1 pmol/l (P < 0·01) and cortisol increased from 350 ± 115 to 582 ± 201 nmol/l (P < 0·05). Thirty‐eight percent of the studied infants showed a maximal level of ACTH < 9 pmol/l, and 15% showed a maximal level of cortisol < 360 nmol/l. In the randomized study, infants in the 1 µg/kg and in the 2 µg/kg CRH group, but not in the placebo group, showed a significant increase in cortisol and ACTH after stimulation (P < 0·01). Stimulated levels of ACTH and cortisol were significantly higher in the 2 µg/kg group compared with the placebo and the 1 µg/kg group. No differences were found for plasma ACTH and cortisol levels in the 1 µg/kg group compared with the placebo group. Basal levels of cortisol and ACTH obtained from the first and from the randomized study correlated significantly (n = 29; r = 0·42, P < 0·03). In addition, in infants stimulated with 1 µg/kg CRH a lower cortisol response correlated with a longer stay in hospital (n = 13; r = –0·57, P < 0·05).

conclusions

 In this study we show that a 1 µg/kg CRH stimulation test in preterm infants results more often in an inappropriate adrenal response while stimulation with 2 µg/kg CRH gives rise to an appropriate response in all studied infants. Furthermore, stimulation with 2 µg/kg CRH results in higher levels of ACTH and cortisol compared to placebo and 1 µg/kg CRH. We conclude that in preterm infants the ability of the pituitary to respond adequately to CRH stimulation depends on the dose of CRH used and may also be dependent on the maturity of the pituitary–adrenal axis.
Electroencephalographic effects and serum concentrations after intranasal and intravenous administration of diazepam to healthy volunteers
Authors: Lindhardt Karsten , Gizurarson Sveinbjörn , Stefánsson Sigurjón B. , Òlafsson David R. , Bechgaard Erik
Published: March 2003

Aims  To evaluate the electroencephalographic (EEG) effects, blood concentrations, vehicle irritation and dose‐effect relationships for diazepam administered nasally.

Methods  The study had a cross‐over design with eight healthy volunteers (one drop out). It consisted of four legs with four different administrations: intranasal (i.n.) placebo, 4 mg diazepam i.n., 7 mg diazepam i.n. and 5 mg intravenous (i.v.) diazepam. Polyethylene glycol 300 (PEG300) was used as a vehicle in the nasal formulations to solubilize a clinically relevant dose of diazepam. Changes in N100, P200 and P300 brain event‐related potentials (ERP) elicited by auditory stimulation and electroencephalographic β‐activity were used to assess effects on neurological activity.

Results  The mean [95% confidence intervals] differences between before and after drug administration values of P300‐N100 amplitude differences were −0.9 [−6.5, 4.7], −6.4 [−10.1, −2,7], −8.6 [−11.4, −5.8] and −9.6 [−12.1, −7.1] for placebo, 4 mg i.n., 7 mg i.n. and 5 mg i.v. diazepam, respectively, indicating statistically significant drug induced effects. The bioavailabilities of 4 and 7 mg i.n. formulations, were found to be similar, 45% [32, 58] and 42% [22, 62], respectively.

Conclusion  The present study indicates that it is possible to deliver a clinically effective nasal dose of diazepam for the acute treatment of epilepsy, using PEG300 as a solubilizer.
Cervicogenic Headache: Evaluation of the Original Diagnostic Criteria
Authors: Antonaci F , Ghirmai S , Bono G , Sandrini G , Nappi G
Published: March 2003

A variety of headaches are frequently associated with the occurrence of neck pain. The purpose of this paper was to describe the adherence to diagnostic criteria of a series of patients enrolled on the basis of two clinical criteria: (1) unilateral headache without side-shift, and (2) pain starting in the neck and spreading to the fronto-ocular area. One hundred and thirty-two patients (36 male and 96 female) entered the study. Sixty-two patients were assigned to Group A (patients fulfilling criteria 1 and 2), 40 to Group B (criterion 2 only) and 12 to Group C (criterion 1, only). Eighteen subjects were excluded because X-rays of the neck were not available. Patients were evaluated regardless of whether or not they fell into one or more of the following diagnostic categories: cervicogenic headache (CEH), migraine without aura (M) and headache associated with disorders of the neck (HN) (IHS definitions). Fulfilment of the diagnostic criteria for CEH was found to be particularly frequent in Group A. A higher frequency of CEH diagnosis was found when two criteria were used (Group A) than in Group B ( P = 0.001); in the former group a higher mean number of diagnostic criteria for CEH were also present ( P = 0.001). Group A patients more frequently presented pain episodes of varying duration or fluctuating, continuous pain and moderate, non-excruciating, non-throbbing pain than Group B patients ( P = 0.04 and P = 0.08, respectively). In Group C patients, the frequency of these two criteria was relatively low (17%) especially of the first mentioned variable. The presence of at least five of the seven ‘pooled’ CEH criteria (present in ≥ 50% of the patients) might be deemed a reliable cut-off point, allowing the headache to be diagnosed as ‘probable’ CEH. If patients fulfilling M or HN criteria in addition to the CEH criteria are added to the ‘pure’ CEH group a total of 74% of Group A patients may have a CEH picture. The temporal pattern of pain and the quality of pain in Group A showed good sensitivity and specificity (≥ 75) when compared with Group B; therefore, the chances of diagnosing a definite CEH are significantly more frequent in patients presenting with unilateral pain that also begins as a neck pain. Head/neck trauma and radiological abnormalities in the cervical spine were not significantly associated with CEH, M or HN diagnoses. An improvement of the current diagnostic IHS criteria might make it possible to avoid the existing, partial overlap of CEH with HN and M. Extensive use should be made of the GON, and other, blockades in the routine work-up of CEH, both in the differential diagnosis and in the mixed forms (CEH + M, and CEH + HN), in order to improve the efficiency of the current diagnostic system.
Evaluation of the Dutch Version of the Migraine Quality of Life Instrument (Msqol) and Its Application in Headache Coping
Authors: Passchier J , Mourik JC , McKenna SP , van den Berg M , Erdman RAM
Published: March 2003

The Dutch version of the MSQOL was evaluated psychometrically and applied in a convenience sample of 90 migraine patients from the Dutch Society of Headache Patients. Internal consistency and test-retest reliability of the Dutch MSQOL were good (>0.90) and comparable with those of the original English version. The measure also had good validity, with its scores associated as expected with headache intensity, psychological well-being and level of patient functioning. Respondents who employ more passive methods of coping with their headaches, such as ‘worrying’, ‘retreating’ and ‘resting’, had worse quality of life. ‘Worrying’ was particularly associated with diminished quality of life, suggesting that cognitive interventions might be of benefit to migraineurs who use this method of coping.
Role of Factor Xiii Val 34 Leu Polymorphism in Patients with Migraine
Authors: Iniesta JA , Corral J , González-Conejero R , Ortuño A Díaz , Navarro ML Martínez , Vicente V
Published: March 2003

At present, it is contradictory to determine if the combination of certain prothrombotic polymorphisms and migraine increases the risk to develop ischaemic cerebrovascular disease. Recently, the common Val34Leu polymorphism of the A-chain factor XIII gene, associated with variations in factor XIII activity, has been suggested to play a significant role in the development of arterial and venous thrombotic disorders. We analysed the prevalence of this polymorphism in 17 patients with coexisting ischaemic cerebrovascular disease and migraine (5 with aura, and 12 without aura), 89 patients with migraine (43 with aura, and 46 without aura), 116 patients with ischaemic cerebrovascular disease, and 467 healthy Caucasian controls from the South of Spain. Genomic PCR amplification, using a mutated oligonucleotide, and allele-specific restriction assays were used for genotyping. The factor XIII Leu 34 variant was present in 47.1; 40.5; 34.9; and 35.1% of patients with coexisting ischaemic cerebrovascular disease and migraine, ischaemic cerebrovascular disease, migraine, and control subjects, respectively. These data suggest that the factor XIII Leu 34 allele does not play a protective role against these disorders in our population.
Use of an α‐glucosidase inhibitor to maintain glucose homoeostasis during postprandial exercise in intensively treated Type 1 diabetic subjects
Authors: Rabasa‐Lhoret R. , Burelle Y. , Ducros F. , Bourque J. , Lavoie C. , Massicotte D. , Péronnet F. , Chiasson J.‐L.
Published: March 2003

Aim  We evaluated the effects of an α‐glucosidase inhibitor, acarbose, on glucose homoeostasis during postprandial exercise in Type 1 diabetic subjects.

Methods  Seven Type 1 diabetic subjects with good glycaemic control on ultralente‐regular insulin were randomized in a single blind cross‐over study to acarbose 100 mg or placebo taken with a mixed meal (600 kcal, 75 g carbohydrates), followed 90 min later by 30 min of exercise at 50% maximum aerobic capacity. Glucose turnover was measured by tracer (d‐[6,6,2H2]glucose) methodology, and intestinal glucose absorption was quantified using carbohydrate polymers labelled with [13C]glucose.

Results  Acarbose resulted in a significant decrease in the postprandial glycaemic rise (mean ± SEM 2.9 ± 0.6 vs. 5.0 ± 0.7 mmol/l; P < 0.005) and in the glycaemic nadir during exercise (− 0.8 ± 0.6 vs. 0.9 ± 1.3 mmol/l below baseline; P < 0.05). Total glucose appearance increased similarly under the two treatments during the postprandial (27.0 vs. 27.9 µmol per kg per min) and exercise (33.9 vs. 33.5 µmol per kg per min) periods. Mean glucose absorption was significantly delayed by acarbose (7.8 vs. 10.2 µmol per kg per min; P < 0.02), but was compensated by the lack of postprandial suppression of hepatic glucose production (106% of basal hepatic glucose production vs. 81%; P < 0.006). Episodes of hypoglycaemia were no different (three vs. six).

Conclusion  These results indicate that, in Type 1 diabetic subjects, acarbose results in a better glycaemic profile during postprandial exercise and suggest that it could lead to a lower risk of exercise‐induced hypoglycaemia due to delayed glucose absorption and less suppression of hepatic glucose production.

Diabet. Med. 18, 739–744 (2001)
Assessment of cross‐reactivity between Japanese cedar (Cryptomeria japonica) pollen and tomato fruit extracts by RAST inhibition and immunoblot inhibition
Authors: Kondo Y. , Tokuda R. , Urisu A. , Matsuda T.
Published: March 2003

Background An association between pollinosis and sensitivity to fruits and vegetables has been reported. Although Japanese cedar (Cryptomeria japonica) pollinosis is one of the most widespread diseases in Japan, there have been no reports demonstrating cross‐reactivity between Japanese cedar pollen and other plant food.

Objective The aim of this study was to demonstrate cross‐reactivity between Japanese cedar pollen and tomato fruit (Lycopersicon esculentum) using RAST inhibition and immunoblot inhibition.

Methods The RAST and immunoblot inhibition were performed using sera from patients with oral allergy syndrome (OAS) after ingesting fresh tomatoes. We identified some proteins that took part in cross‐reactive IgE by the determination of N‐terminal amino acid sequences and a homology search through the SWISS‐PROT database.

Results In the RAST inhibition, the bindings of IgE from the sera from four out of five (4/5) subjects to Japanese cedar pollen discs were inhibited by more than 50% by preincubation of the serum with tomato fruit extracts. Likewise, the IgE bindings to tomato fruit discs were inhibited more than 50% by Japanese cedar pollen extracts in 3/5 sera. In immunoblot inhibition, IgE binding activities of some protein bands on both membranes were decreased by heterologous inhibitors. However, the combinations of these protein bands involved in cross‐reactivity were different between patients.

Conclusion We have demonstrated cross‐reactivity between Japanese cedar pollen and tomato fruit using RAST inhibition and immunoblot inhibition.
Quiescence, cell viability, apoptosis and necrosis of smooth muscle cells using different growth inhibitors
Authors: Pelisek J. , Armeanu S. , Nikol S.
Published: March 2003

Smooth muscle cells and endothelial cells play an important role in cardiovascular diseases and may therefore be a potential target for gene therapy. Most in vitro experiments are performed using proliferating cell cultures. Nevertheless, non‐dividing cells would represent more realistic in vivo conditions for gene therapy. Therefore, a simple method to achieve physiologically quiescence in cell cultures is needed for experiments. Growth to confluence is sufficient for endothelial cells to reach quiescence, in contrast to smooth muscle cells. Alternative techniques were investigated to achieve quiescence for smooth muscle cells. N‐acetyl‐cysteine, heparin, aphidicolin and serum‐free medium are known inhibitors of smooth muscle cell proliferation and were tested for cell viability, necrosis and apoptosis. The inhibition status was evaluated counting cells in a cell counter. Toxicity, necrosis and apoptosis were determined using FACS analysis. Then, smooth muscle cells and endothelial cells were transfected with plasmid containing the β‐galactosidase gene using liposomes. Analysis of gene expression in transfected cells included a quantitative β‐galactosidase assay and X‐gal staining. Growth inhibition was achieved with all agents tested. Using N‐acetyl‐cysteine, only slightly reduced growth rates were observed. Aphidicolin stopped cell growth almost immediately, but demonstrated enhanced toxicity. The amount of apoptotic and necrotic cells was lowest using heparin in the presence of foetal calf serum. Transfection experiments using stationary cultures of smooth muscle cells using heparin or aphidicolin demonstrated 5–10‐fold lower transfection rates compared to transfected proliferating cell cultures serving as controls. Transfection experiments using stationary cultures of endothelial cells using growth inhibition through confluence demonstrated 40‐fold lower transfection rates than transfected proliferating cell cultures. Transfer efficiency was much lower in endothelial cells compared to smooth muscle cells. In conclusion, quiescent cells simulate more realistically the in vivo situation and may therefore represent a better model for future in vivo experiments based on in vitro findings.
Basilar artery thrombosis
Authors: Richardson Philip G
Published: March 2003

Basilar artery thrombosis is an infrequent but important neurological emergency requiring early diagnosis and treatment. Of particular relevance to emergency medicine is the recognition and consideration of the unusual signs that may be present in an often previously well patient. It is therefore crucial to expedite investigations, confirm the diagnosis and commence life‐saving treatment through the early involvement of a number of disciplines including neurology, radiology and intensive care. This paper confirms the use of magnetic resonance imaging and angiography as the preferred investigative mode and microcatheter directed intra‐arterial thrombolysis as the treatment strategy of choice.
THE PROMOTION OF HEALTH CAREERS TO HIGH SCHOOL STUDENTS IN THE NEW ENGLAND HEALTH AREA: THE VIEWS OF HIGH SCHOOL CAREERS ADVISERS
Authors: Alexander Christian , Fraser John
Published: March 2003

One way to impact positively on the shortage of health professionals in rural areas is to effectively promote health careers to rural high school students. Rural high school careers advisers play a pivotal role in this. In order to assess how rural health careers advisers working in the north‐west of New South Wales currently promote health careers to their students, the New England Area Rural Training Unit carried out a survey of the area’s high school careers advisers. Of the 47 high school careers advisers, 38 returned completed questionnaires, yielding a response rate of 81%. While only about one‐third of careers advisers use visits by undergraduate students enrolled in tertiary health courses (42%), visits by locally practising health professionals (39%) and/or health careers site visits (27%), all careers advisers consider such promotional activities to be most effective. Improved exposure to such effective health career promotional activities for the area’s high school, increasing collaboration between careers advisers and health professionals, as well as renewed efforts to identify and to foster interested students prior to Year 10, should lead to an increasing number of rural high school students enrolling in tertiary health courses.
A synthesis of the life history and ecology of juvenile Pacific herring in Prince William Sound, Alaska
Authors: Norcross Brenda L. , Brown Evelyn D. , Foy Robert J. , Frandsen Michele , Gay Shelton M. , Kline Thomas C. , Mason Doran M. , Patrick E. Vincent , Paul A. J. , Stokesbury Kevin D. E.
Published: March 2003

Physical and biological variables affecting juvenile Pacific herring (Clupea pallasi) in Prince William Sound (PWS) from 1995 to 1998 were investigated as part of a multifaceted study of recruitment, the Sound Ecosystem Assessment (SEA) program. Though more herring larvae were retained in eastern PWS bays, ages‐0 and ‐1 herring used bays throughout PWS as nursery areas. Water transported into PWS from the Gulf of Alaska (GOA) contributed oceanic prey species to neritic habitats. Consequently, variations in local food availability resulted in different diets and growth rates of herring among bays. Summer food availability and possible interspecific competition for food in nursery areas affected the autumn nutritional status and juvenile whole body energy content (WBEC), which differed among bays. The WBEC of age‐0 herring in autumn was related to over‐winter survival. The limited amount of food consumption in winter was not sufficient to meet metabolic needs. The smallest age‐0 fish were most at risk of starvation in winter. Autumn WBEC of herring and winter water temperature were used to model over‐winter mortality of age‐0 herring. Differences in feeding and energetics among nursery areas indicated that habitat quality and age‐0 survival were varied among areas and years. These conditions were measured by temperature, zooplankton abundance, size of juvenile herring, diet energy, energy source (GOA vs. neritic zooplankton), WBEC, and within‐bay competition.
Up‐Regulation of Inducible Nitric Oxide Synthase and Nitric Oxide in Helicobacter pylori‐Infected Human Gastric Epithelial Cells: Possible Role of Interferon‐γ in Polarized Nitric Oxide Secretion
Authors: Kim Jung Mogg , Kim Joo Sung , Jung Hyun Chae , Song In Sung , Kim Chung Yong
Published: March 2003

Background. Nitric oxide (NO) generated by nitric oxide synthase (NOS) is known to be an important modulator of the mucosal inflammatory response. In this study, we questioned whether Helicobacter pylori infection could up‐regulate the epithelial cell inducible NOS (iNOS) gene expression and whether NO production could show polarity that can be regulated by immune mediators.

Materials and Methods. Human gastric epithelial cell lines were infected with H. pylori, and the iNOS mRNA expression was assessed by quantitative RT‐PCR. NO production was assayed by determining nitrite/nitrate levels in culture supernatants. To determine the polarity of NO secretion by the H. pylori‐infected epithelial cells, Caco‐2 cells were cultured as polarized monolayers in transwell chambers, and NO production was measured.

Results. iNOS mRNA levels were significantly up‐regulated in the cells infected with H. pylori, and expression of iNOS protein was confirmed by Western blot analysis. Increased NO production in the gastric epithelial cells was seen as early as 18 hours postinfection, and reached maximal levels by 24 hours postinfection. The specific MAP kinase inhibitors decreased H. pylori‐induced iNOS and NO up‐regulation. After H. pylori infection of polarized epithelial cells, NO was released predominantly into the apical compartment, and IL‐8 was released predominantly into basolateral compartment. The addition of IFN‐γ to H. pylori‐infected polarized epithelial cells showed a synergistically higher apical and basolateral NO release.

Conclusion. These results suggest that apical NO production mediated by MAP kinase in H. pylori‐infected gastric epithelial cells may influence the bacteria and basolateral production of NO and IL‐8 may play a role in the tissue inflammation.
Effect of ruminal dosing of mechanical stimulating brush on rumination time, ruminal passage rate and rumen fermentation status in Holstein steers fed a concentrate diet
Authors: HORIGUCHI Ken‐ichi , TAKAHASHI Toshiyoshi
Published: March 2003

This experiment was conducted to determine the effect of ruminal dosing of a mechanical stimulating brush on rumination time, ruminal passage rate and rumen fermentation status in steers fed a concentrate diet at maintenance level. Animals were dosed three Rumen Faibu (RF) per head through the rumen fistulae (RF treatment) and not dosed (control) in a change‐over design. The organic cell wall content of the concentrate diet was 12.7% of dry matter. Daily time spent on rumination was very short in both treatments with 24 min in RF treatment and 15 min in control. The turnover rate of ruminal fluid in RF treatment was higher than that in control. There were no differences in ruminal pH and total volatile fatty acid concentration between RF treatment and control. Acetic and butyric acid concentrations were not different between the treatments. Propionic acid concentration tended to be higher in the animals on RF treatment than in control animals. The RF dosing in Holstein steers fed a low fiber diet did not affect the rumination time, but increased rumen digesta passage rate and ruminal propionic acid production.
Numbers of nitrate‐reducing bacteria in the rumen as estimated by competitive polymerase chain reaction
Authors: ASANUMA Narito , IWAMOTO Miwa , KAWATO Masaru , HINO Tsuneo
Published: March 2003

Cell numbers of known species of nitrate‐ and nitrite‐reducing bacteria, Selenomonas ruminantium, Veillonella parvula and Wollinella succinogenes, in the rumen of goats (25–30 kg) were estimated by competitive polymerase chain reaction (PCR). The number of S. ruminantium was the largest of the three species examined, and tended to be greater in goats fed a high‐concentrate diet (5.6 × 107 cells/mL rumen fluid) than in goats fed a high‐roughage diet (1.3 × 107 cells/mL). The number of V. parvula tended to be greater when goats were fed a high‐roughage diet (6.7 × 103/mL) than when fed a high‐concentrate diet (3.2 × 103/mL). The number of W. succinogenes was below the detectable level (< 1.0 × 102/mL) when a high‐concentrate diet was fed, but was significantly increased by feeding a high‐roughage diet (1.6 × 103/mL). Addition of potassium nitrate (6 g/day) to the high‐concentrate diet tended to increase V. parvula, and significantly increased W. succinogenes, indicating that these two bacteria can be increased by feeding a diet containing nitrate.
Immunolocalization of sex steroid receptors in the epididymis and ductus deferens of immature and mature Japanese Quail, Coturnix Japonica
Authors: NISHIZAWA Hanako , OKAMOTO Toshikazu , YOSHIMURA Yukinori
Published: March 2003

The goal of this study was to determine whether in the Japanese quail the male genital tract contains receptors for progesterone, androgen and estrogen (PR, AR and ER, respectively), which have significant roles in reproductive functions, and whether their localization changes during sexual maturation. The epididymis and ductus deferens (middle and ampulla regions) of immature (approximately 30‐day‐old) and mature male Japanese quail were collected and frozen sections of them were immunostained for PR, AR and ER. The immunoreaction products for AR and PR were found in the nuclei of epithelial cells in the efferent ductules, epididymal duct, and the middle and ampulla regions of the ductus deferens of mature and immature birds. In the mature birds, the epithelial cells of the efferent ductules, epididymal duct, and the middle and ampulla regions of the ductus deferens were positive for ER, although some of the cells in the ductus deferens were negative. The epithelial cells of the ductules in the epididymis stained positive for ER, but the immunoreactions were negligible in the ductus deferens of immature birds. These results suggest that the epididymis and ductus deferens in quail possesses PR, AR and ER receptors. Each receptor is expressed before sexual maturation, although enhancement of ER expression may occur during maturation.
Comparative study of milk compositions of cattle, sheep and goats in Nigeria
Authors: MALAU‐ADULI Aduli Enoch Othniel , ANLADE Yakubu Rade
Published: March 2003

Variations in the milk composition of Nigerian cattle, sheep and goats (Bunaji, Yankasa and Red Sokoto breeds, respectively), as well as residual phenotypic correlations between the milk constituents, were investigated. Results indicated that sheep and goats differed significantly (P < 0.05) from cattle in all constituents except protein percentage, which averaged 5.43%, 5.43% and 5.49%, respectively. Caprine milk contained the highest percentages of fat (5.80%), total solids (15.37%) and ash (0.77%), and bovine milk contained the least percentages of fat (0.68%) and lactose (1.84%). Overall, the milk compositions of sheep and goats were very similar as they were not statistically different from each other (P > 0.05). Residual phenotypic correlations between the milk constituents revealed highly significant (P < 0.01) and positive relationships between total solids and solids‐not‐fat (0.97 and 0.98 in cattle and sheep, respectively). All other correlations were positive in cattle (ranging from 0.12 to 0.77), except between protein and total solids (−0.44) and protein and solids‐not‐fat (−0.64). Multiple linear regression equations were fitted to predict the percentages of protein and fat. It was demonstrated that the protein percentage could be predicted from total solids and solids‐not‐fat with the highest accuracy of 94%, 86% and 82% in cattle, sheep and goats, respectively. On the other hand, the accuracy of prediction of fat percentage was very low in all the species (R2 = 0.01, 0.3 and 0.37 in cattle, sheep and goats, respectively).
Ammonia volatilization from Vertisols
Authors: Sigunga D. O. , Janssen B. H. , Oenema O.
Published: March 2003

Farmers want to minimize losses of nitrogen (N) by volatilization of ammonia when adding fertilizers and improve fertilizer recovery of N by plants. We aimed to quantify the losses of N through NH3 volatilization as affected by soil moisture content, type of fertilizer, and placement method in Vertisols in Kenya, and conducted three experiments for the purpose under controlled conditions in the laboratory. We found that NH3‐N losses were greatest at 80% water holding capacity, which we ascribed to the ready availability of water to dissolve the fertilizer at that water content. The soil's cation exchange capacity (CEC) did not influence volatilization, whereas the soil's pH indicated the potential of the soil to volatilize ammonia. Ammonia losses from the fertilizers were in the order urea > ammonium sulphate > ammonium nitrate applied. Incorporating fertilizer within the 0–5 cm soil layer more than halved NH3 volatilization but did not prevent it completely. These results indicate that soil pH, rather than CEC, is the main inherent characteristic influencing ammonia volatilization from Vertisols. Ammonium‐based fertilizers should be incorporated within the 0–5 cm soil layer, or preferably somewhat deeper, to avoid losses via NH3 volatilization, particularly in alkaline soils. Nitrate fertilizers are preferable to urea where the risks of NH3 volatilization are large, provided due consideration is given to denitrification risks.
Effects of elevated atmospheric CO2on root decomposition in a scrub oak ecosystem
Authors: Dilustro John J. , Day Frank P. , Drake Bert G.
Published: March 2003

The effects of elevated atmospheric CO2on fine root decomposition over a 828‐day period were investigated using open top chambers with both ambient and elevated (700 ppm) CO2treatments in an oak–palmetto scrub ecosystem at Kennedy Space Center, Florida. Carbon dioxide enrichment of the chambers began 15 May 1996. The experiment included roots grown in ambient and elevated carbon dioxide. Vertical litterbags installed in September 1996 in each elevated and ambient chamber incubated from December 1996 to December 1998 showed no significant treatment effect on fine root or rhizome mass loss. Initial fine root percentage mass loss varied from 10.3% to 13.5% after three months; 55.5% to 38.3% of original mass had been lost after 828 days. A period of nitrogen immobilization occurred in both fine roots and rhizomes in the elevated CO2incubation, which is a potential mechanism for nitrogen conservation for this system in an elevated CO2world.
Elevated atmospheric CO2 stimulates aboveground biomass in a fire‐regenerated scrub‐oak ecosystem
Authors: Dijkstra Paul , Hymus Graham , Colavito Debra , Vieglais David A. , Cundari Christina M. , Johnson David P. , Hungate Bruce A. , Hinkle C. ROSS , Drake Bert G.
Published: March 2003

The effect of elevated atmospheric CO2 concentration (Ca) on the aboveground biomass of three oak species, Quercus myrtifolia, Q. geminata, and Q. chapmanii, was estimated nondestructively using allometric relationships between stem diameter and aboveground biomass after four years of experimental treatment in a naturally fire‐regenerated scrub‐oak ecosystem. After burning a stand of scrub‐oak vegetation, re‐growing plants were exposed to either current ambient (379 µL L−1 CO2) or elevated (704 µL L−1 CO2) Ca in 16 open‐top chambers over a four‐year period, and measurements of stem diameter were carried out annually on all oak shoots within each chamber. Elevated Ca significantly increased aboveground biomass, expressed either per unit ground area or per shoot; elevated Ca had no effect on shoot density. The relative effect of elevated Ca on aboveground biomass increased each year of the study from 44% (May 96–Jan 97), to 55% (Jan 97–Jan 98), 66% (Jan 98–Jan 99), and 75% (Jan 99–Jan 00). The effect of elevated Ca was species specific: elevated Ca significantly increased aboveground biomass of the dominant species, Q. myrtifolia, and tended to increase aboveground biomass of Q. chapmanii, but had no effect on aboveground biomass of the subdominant, Q. geminata. These results show that rising atmospheric CO2 has the potential to stimulate aboveground biomass production in ecosystems dominated by woody species, and that species‐specific growth responses could, in the long term, alter the composition of the scrub‐oak community.
Nitrogen‐15 budget in model ecosystems of white clover and perennial ryegrass exposed for four years at elevated atmospheric pCO2
Authors: Hartwig Ueli A. , Lüscher Andreas , Nösberger Josef , Van Kessel Chris
Published: March 2003

Although there are many indications that N cycling in grassland ecosystems changes under elevated atmospheric CO2 partial pressure (pCO2), most information has been obtained in short‐term studies. Thus, N budgets were established for four years under ambient and 60 Pa pCO2 at two levels of N fertilization in two contrasting model ecosystems: Trifolium repens L. (white clover) and Lolium perenne L. (perennial ryegrass) were planted in soil in boxes in the Swiss FACE experiment. While T. repens showed an 80% increase in harvested biomass with no change in biomass allocation under elevated atmospheric pCO2 compared to ambient conditions, L. perenne showed an increase only in the biomass of the roots. During the four years of the experiment, the systems gained N both from N retained in the soil and from stubble/stolon and roots left after the final harvest; in total between 11 and 86 gN m−2. Nitrogen retention in the soil was between 4 and 64 g m2. The L. perenne system gained the most N and retained the most N in the soil at high N fertilization and elevated atmospheric pCO2. The input of new C and N into the soil correlated well in the L. perenne systems but not in the T. repens systems. Elevated atmospheric pCO2 led neither to an increase in N retention in the soil nor did it reduce the loss of N from the soil. In the L. perenne systems, N fertilization played the main role in both the retention of N and the sequestration of C, while in the T. repens systems symbiotic N2 fixation may have controlled N retention in the soil.
Stemwood volume increment changes in European forests due to climate change—a simulation study with the EFISCEN model
Authors: Nabuurs Gert‐Jan , Pussinen Ari , Karjalainen Timo , Erhard Markus , Kramer Koen
Published: March 2003

This paper presents the results of a modelling study of future net annual increment changes in stemwood of European forests owing to climate change. Seven process‐based growth models were applied to 14 representative forest sites across Europe under one climate change scenario. The chosen scenario was the HadCM2 run, based on emission scenario IS92a, and resulted in an increase in mean temperature of 2.5 °C between 1990 and 2050, and an increase in annual precipitation of 5–15%. The information from those runs was incorporated in a transient way in a large‐scale forest resource scenario model, EFISCEN (European forest information scenario). European scale forest resource projections were made for 28 countries covering 131.7 million ha of forest under two management scenarios for the period until 2050.

The results showed that net annual increments in stemwood of European forests under climate change will further increase with an additional 0.9 m3 ha−1 y−1in 2030 compared to the ongoing increase under a current climate scenario, i.e. an extra 18% increase. After 2030 the extra increment increase is reduced to 0.79 m3 ha−1 y−1in 2050. Under climate change, absolute net annual increments will increase from the present 4.95, on average for Europe, to 5.93 m3 ha−1 y−1in 2025. After 2025, increments in all scenarios start to decline owing to ageing of the forest and the high growing stocks being reached.

The results of the present study are surrounded by large uncertainties. These uncertainties are caused by unknown emissions in the future, unknown extent of climate change, uncertainty in process‐based models, uncertainty in inventory data, and uncertainty in inventory projection. Although the results are thus not conclusive, climate change may lead to extra felling opportunities in European forests of 87 million m3y−1. Because Europe's forests are intensively managed already, management may adapt to climate change relatively easily. However, this study also indicates that climate change may lead to a faster build‐up of growing stocks. That may create a less stable forest resource in terms of risks to storm damage.
Identification of activity‐regulated proteins in the postsynaptic density fraction
Authors: Satoh Keiko , Takeuchi Masakazu , Oda Yoshiya , Deguchi‐Tawarada Maki , Sakamoto Yoshimasa , Matsubara Kaho , Nagasu Takeshi , Takai Yoshimi
Published: March 2003

Background: The postsynaptic density (PSD) at synapses is a specialized submembranous structure where neurotransmitter receptors are linked to cytoskeleton and signalling molecules. Activity‐dependent dynamic change in the components of the PSD is a mechanism of synaptic plasticity. Identification of the PSD proteins and examination of their modulations dependent on synaptic activity will be valuable for an understanding of the molecular basis of learning and memory.

Result: We attempted here to identify proteins in the PSD fraction by two‐dimensional (2D) gel electrophoresis and mass spectrometry. About 1.7 × 103 protein spots were detected on 2D gels. A total of 90 spots were identified, containing 47 different protein species. In addition to previously identified PSD proteins such as PSD‐95/SAP90, several new proteins were identified in the PSD fraction. They included stomatin‐like protein 2 and NIPSNAP1. We also examined activity‐dependent modulations of PSD proteins by 2D gel electrophoresis. The spot concentration of G protein β subunit 5 and NIPSNAP1 increased 2 h after kainate treatment that caused generalized seizures.

Conclusion: These results indicate that the combination of 2D gel electrophoresis and mass spectrometry is an excellent tool for the identification of activity‐regulated PSD proteins.
Heroin use in New South Wales, Australia, 1996–2000: 5 year monitoring of trends in price, purity, availability and use from the Illicit Drug Reporting System (IDRS)
Authors: Darke Shane , Topp Ibby , Kaye Harlene , Hall Wayne
Published: March 2003

Aims

To document trends in the price, purity, availability and use of heroin in New South Wales detected by the Illicit Drug Reporting System (IDRS) between 1996 and 2000, and to demonstrate the utility of the IDRS in identifying such trends.

Design

The IDRS compares information derived from interviews with injecting drug users, key informants who work in the illicit drugs field, and key indicator data on illicit drug trends.

Setting

New South Wales, Australia.

Findings

The price of heroin approximately halved over this period, from a median of A$400 per gram in 1996 to A$220 per gram in 2000. While the price of heroin fell dramatically over the study period, the purity of police seizures of the drug was high across all years, ranging between 62% and 71%. In all years heroin was considered easy to obtain by both heroin users who purchased the drug, and by key informants from the law enforcement and health fields. Concurrent with the large fall in heroin prices, there appeared to have been an increase in the number of heroin users. Between 1997 and 1998 there was a sharp increase in the injecting use of cocaine by heroin users in NSW, a pattern that has persisted.

Conclusions

Regular and formal monitoring of illicit drug trends provides timely data in a systematic way to inform health and law enforcement policies towards current and emerging illicit drug problems.
Intracellular calcium and electrical restitution in mammalian cardiac cells
Authors: SZIGLIGETI  , BÁNYÁSZ  , MAGYAR  , SZIGETI  , PAPP  , VARRÓ  , NÁNÁSI
Published: March 2003

The role of calcium current and changes in intracellular calcium concentration ([Ca2+]i) in regulation of action potential duration (APD) during electrical restitution process was studied in mammalian ventricular preparations. Properly timed action potentials were recorded from multicellular preparations and isolated cardiomyocytes using conventional microelectrodes and EGTA‐containing patch pipettes. APD increased monotonically in canine and guinea pig ventricular preparations with increasing diastolic interval (DI), while in rabbit papillary muscles the restitution process was biphasic: APD first lengthened, then shortened as the DI increased. When the restitution process was studied in single cardiomyocytes using EGTA‐containing patch pipettes, the restitution pattern was similar in the three species studied. Similarly, no difference was observed in the recovery time constant of calcium current (ICa‐L) measured under these conditions in voltage clamped myocytes. Loading the myocytes with the [Ca2+]i‐chelator BAPTA‐AM had adverse effects in rabbit and canine cells. In rabbit myocytes steady‐state APD lengthened and the late shortening component of restitution was abolished in BAPTA‐loaded cells. In canine myocytes BAPTA‐load shortened steady‐state APD markedly, and during restitution, APD decreased with increasing DI. The late shortening component of restitution, observed in untreated rabbit preparations, was greatly reduced after nifedipine treatment, but remained preserved in the presence of 4‐aminopyridine or nicorandil. Beat to beat changes in APD, peak ICa‐L and [Ca2+]i, measured using the fluorescent dye, Fura‐2, were monitored in rabbit ventricular myocytes after a 1‐min period of rest. In these cells, the shortening of APD was accompanied by a gradual reduction of the peak ICa‐L and elevation of diastolic [Ca2+]i during the initial eight post‐rest action potentials. It is concluded that elevation of [Ca2+]i shortens, while reduction of [Ca2+]i lengthens APD in rabbit, but not in canine ventricular myocytes. These differences may probably be related to different distributions of [Ca2+]i‐dependent ion currents and/or to differences in calcium handling between the two species.
Endothelin‐induced contractions in placental arteries is mediated by both ETA‐ and ETB‐receptors
Authors: SAND A. E. , ÖSTLUND E. , ANDERSSON E. , FRIED G.
Published: March 2003

We have examined the contractile response to the vasoconstrictor endothelin‐1 (ET‐1) in uteroplacental arteries from normal pregnant women in the presence and absence of specific ET‐receptor antagonists and agonists, and the vasodilator nitric oxide. Segments of placental arteries (n = 97) obtained from 37 placentas immediately after delivery were mounted in organ baths superfused with Krebs‐Ringer solution at 37 °C. The tension was recorded isometrically and registered on a polygraph. We found that the placental artery segments responded to ET with a dose‐dependent vasoconstriction. Half‐maximal response was obtained at 2.6 × 10−8 M. At 10−7 M, the contractile response was 52% of the maximum KCl‐response. The ET‐1 induced contraction at 10−7 M was inhibited by 74% after addition of the ETA ‐antagonist BQ‐123 (10−6 M), and by 58% by the ETB ‐antagonist BQ‐788 (10−6 M). Both BQ‐123 and BQ‐788 almost completely abolished the response to ET (10−7 M). The selective ETB ‐agonist IRL‐1620 also elicited vasoconstriction in the placental artery with a half maximal response at 8 × 10−7 M. On a molar basis at 10−7 M, the contraction by IRL‐1620 as compared to ET was 30‐fold lower. The contractile response of IRL‐1620 (10−6 M) was inhibited by 99% by BQ‐788 (10−6 M). After pre‐contraction of the placental arteries with ET‐1 (10−7 M), the vessels relaxed in response to the nitric oxide donor, nitroglycerin (10−6 M). The present results show that ET‐1 contracts placental arteries through both ETA‐ and ETB‐receptor activation. Nitric oxide (10−6 M) was able to relax more than half of the initial ET‐1 contraction, indicating that nitric oxide may be an important vasodilator in the placenta.
Bradykinin causes contraction in rat uterus through the same signal pathway as oxytocin
Authors: WASSDAL  , NICOLAYSEN  , IVERSEN
Published: March 2003

The signal pathway for bradykinin‐induced contraction of the uterine smooth muscle was investigated by comparing the effect of blocking agents on bradykinin and oxytocin induced contractions of the isolated rat uterus in organ bath. The phospholipase C inhibitor U‐73122 abolished the effect of both bradykinin and oxytocin. Inhibition of non‐voltage‐dependent Ca2+ influx by SK & F 96365 reduced the contraction induced by both agonists to about 20% of control. The tissues failed to contract when they were exposed to bradykinin or oxytocin in Ca2+‐free Krebs–Henseleit buffer with 2 mM EDTA. Both bradykinin and oxytocin induced further contraction when the tissues were partially depolarized and partially contracted by 30 mM KCl. These observations suggest that bradykinin, like oxytocin, activates phospholipase C which generates IP3 with a subsequent release of Ca2+ from intracellular stores followed by store‐operated Ca2+ influx. Thus, membrane potential independent steps appear to be important in bradykinin‐induced contraction in the rat uterus.
Integrity and metabolism of human ileal mucosa in vitro in the Ussing chamber
Authors: SÖDERHOLM  , HEDMAN  , ARTURSSON  , FRANZE´N  , LARSSON  , PANTZAR  , PERMERT  , OLAISON
Published: March 2003

The Ussing chamber is increasingly being used for in vitro studies of human intestinal mucosa, but little attention has been paid to the viability of specimens over time. Ninety‐one mucosal specimens from the ileum in 19 patients operated on for colonic cancer were studied in regard to intestinal barrier function, metabolism, electrophysiology and histology during 360 min of incubation in Ussing chambers. Steady‐state permeability to 51Cr‐EDTA was maintained for 120 min. Mucosal ATP and lactate levels were stable for 180 min and transmucosal glucose flux for 240 min. Lactate dehydrogenase leakage was limited within 120 min. Transepithelial potential difference was 9.0 ± 3.0 mV at the start, and declined slowly throughout 360 min. Light microscopy revealed epithelial lifting from the basal lamina at 90 min. Transmission electron microscopy demonstrated preserved ultrastructure for 120 min. Specimens with a transepithelial potential difference below 6 mV at the start were associated with increased 51Cr‐EDTA permeability and lactate dehydrogenase leakage and more pronounced light microscopy changes. All studied parameters pointed to preserved viability if experiments were kept within a period of 90 min after equilibration. The few specimens with early viability derangement were identified by a transepithelial potential difference below 6 mV at the start. The Ussing chamber provides a tool for in vitro studies of human intestinal epithelium, including permeability. To minimize viability problems, experiments should be limited in time and monitored by measurements of transepithelial potential difference.