bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of light on the settlement of the salmon louse, Lepeophtheirus salmonis, on Atlantic salmon, Salmo salar L.
Authors: Browman H I , Boxaspen K , Kuhn P
Published: December 2004

The salmon louse, Lepeophtheirus salmonis, is an ectoparasitic copepod that infests both wild and farmed salmonid fish. Salmon lice are a major disease problem in the farming of Atlantic salmon, Salmo salar L., and the possibility of salmon lice playing a role in the decline of wild anadromous stocks has also been raised. Lepeophtheirus salmonis can detect a range of stimuli (pressure/moving water, chemicals and light) in the external environment. However, the response thresholds to various stimuli, and the spatial and temporal scales over which they operate in the context of host location, are largely unknown. In this context, we attempted to determine whether salmon lice copepodids settle onto hosts more effectively, or at different locations on the fish's body, under different qualities of light. Lice settlement trials were conducted under three lighting conditions; L1: unpolarized under ultraviolet A (UVA)‐through visible; L2: unpolarized without UVA (control); L3: 100% linearly polarized without UVA. A dark control was also conducted. No statistically significant difference in lice settlement was found. While changes in light intensity are involved in host detection at spatial scales on the order of metres, the results presented here suggest that it is not the primary sensory modality underlying host location at smaller spatial scales (cm to mm).
A new analytical model for whole‐leaf potential electron transport rate
Authors: BUCKLEY T. N. , FARQUHAR G. D.
Published: December 2004

A new analytical model for the response of whole‐leaf potential electron transport rate (J) to light is presented. The model treats incident irradiance at the upper and lower leaf surfaces independently, describes transdermal profiles of light absorption and electron transport capacity explicitly, and calculates J by integrating the minimum of light‐ and capacity‐limited rates among paradermal chlorophyll layers. The capacity profile is assumed to be a weighted average of two opposed exponential profiles, each of which corresponds to the profile of light‐limited rate when only one surface is illuminated; the weights may take on any values, provided they sum to unity, so the model can describe leaves with a wide range of ‘preferred’ illumination regimes. By treating irradiance at either surface independently and assuming the capacity profile is fixed on short time scales, the model predicts observed effects of leaf inversion on light‐response curves and their apparent convexity. By assuming the capacity profile can adapt on developmental time scales, the model can predict the observed dependence of inversion effects on the growth lighting regime. It is suggested that the new model, which is mathematically compact and formally similar to the standard non‐rectangular hyperbola model for J, be used in place of the standard model in studies in which the effects of leaf angle or diffuse light fraction on gas exchange are of interest.
Utilization of inorganic carbon in the edible cyanobacterium Ge‐Xian‐Mi (Nostoc) and its role in alleviating photo‐inhibition
Authors: QIU B. S. , LIU J. Y.
Published: December 2004

The present work investigated the inorganic carbon (Ci) uptake, fluorescence quenching and photo‐inhibition of the edible cyanobacterium Ge‐Xian‐Mi (Nostoc) to obtain an insight into the role of CO2 concentrating mechanism (CCM) operation in alleviating photo‐inhibition. Ge‐Xian‐Mi used HCO3– in addition to CO2 for its photosynthesis and oxygen evolution was greater than the theoretical rates of CO2 production derived from uncatalysed dehydration of HCO3–. Multiple transporters for CO2 and HCO3– operated in air‐grown Ge‐Xian‐Mi. Na+‐dependent HCO3– transport was the primary mode of active Ci uptake and contributed 53–62% of net photosynthetic activity at 250 µmol L−1 KHCO3 and pH 8.0. However, the CO2‐uptake systems and Na+‐independent HCO3– transport played minor roles in Ge‐Xian‐Mi and supported, respectively, 39 and 8% of net photosynthetic activity. The steady‐state fluorescence decreased and the photochemical quenching increased in response to the transport‐mediated accumulation of intracellular Ci. Inorganic carbon transport was a major factor in facilitating quenching during the initial stage and the initial rate of fluorescence quenching in the presence of iodoacetamide, an inhibitor of CO2 fixation, was 88% of control. Both the initial rate and extent of fluorescence quenching increased with increasing external dissolved inorganic carbon (DIC) and saturated at higher than 200 µmol L−1 HCO3–. The operation of the CCM in Ge‐Xian‐Mi served as a means of diminishing photodynamic damage by dissipating excess light energy and higher external DIC in the range of 100–10000 µmol L−1 KHCO3 was associated with more severe photo‐inhibition under strong irradiance.
Over‐expression of the water and salt stress‐regulated Asr1 gene confers an increased salt tolerance
Authors: KALIFA Y. , PERLSON E. , GILAD A. , KONRAD Z. , SCOLNIK P. A. , BAR‐ZVI D.
Published: December 2004

ASR1 is a plant‐specific, highly charged, low molecular weight polypeptide. Purified ASR1 was shown to posses sequence specific Zn2+‐dependent DNA binding activity (Kalifa et al. Biochemical Journal 381, 373–378, 2004). Steady‐state levels of tomato Asr1 mRNA and protein are transiently increased following exposure of plants to polyethylene glycol, NaCl or abscisic acid. The biological role of ASR1 could not be deduced from sequence analyses or sequence homologies. Tobacco plants over‐expressing tomato ASR1 have a decreased rate of water loss and improved salt tolerance. Upon exposure to salt, ASR1‐over‐expressing plants accumulate less Na+ and proline than wild‐type plants, and also results in increased steady‐state levels of other gene products under non‐stressed plant growth conditions. Therefore, ASR1 is probably involved in the regulation of water‐ or salt‐stress‐modulated gene expression.
Cell Cycle Stage Analysis of Rabbit Foetal Fibroblasts and Cumulus Cells
Authors: Liu CT , Yu KC , Ju JC
Published: December 2004

Contents

Synchronization of the cell cycle stages in G0/G1 phase is one of the key factors determining the success of nuclear transplantation. Serum deprivation, contact inhibition and chemical inhibitors are widely used methods for this purpose. In this study, cell cycle stages of foetal fibroblasts and cumulus cells were determined using flow cytometry [fluorescence‐activated cell scan (FACS)]. Foetal fibroblasts (in vitro cultured for 72–120 h) and fresh cumulus cells were analysed in Experiment 1. Fifty to 55% proliferating fibroblasts remained in G0/G1 phase compared with 78% in confluent culture (p < 0.05). In contrast to foetal fibroblasts, fresh cumulus cells maintained 90% of the population in the G0/G1 stage. When serum was retrieved from the proliferating fibroblasts from day 1 to day 5 (Experiment 2), proportions of G0/G1 cells increased from the initial ratio of 53 to 87% at day 4 of starvation, which was significantly higher than the non‐starved proliferating cells (p < 0.05). In Experiment 3, fibroblasts were treated with aphidicolin (0.1 μg/ml, 6 h), demicolcine (0.5 μg/ml, 10 h), or a combination of these two chemicals to synchronize the cell cycle stages. Surprisingly, no differences or significantly lower in the proportions of G0/G1 phase cells were detected (25–50%) compared with the uncontrolled growing cells (53%). These results suggested that fresh cumulus cells rest their cell cycle in G0/G1 stage. Serum deprivation became effective in the first 24 h and reached the highest proportions during days 4–5 after deprivation. Chemical synchronization of the cell cycle stage of rabbit foetal fibroblasts to G0/G1 phase appeared less effective compared to serum deprivation.
Timing of Early Foetal Loss for Single and Twin Pregnancies in Dairy Cattle
Authors: López‐Gatius F , Santolaria P , Yániz JL , Garbayo JM , Hunter RHF
Published: December 2004

Contents

The incidence of early foetal loss is increasing under intensive management systems for dairy cattle. The aims of the present study were to determine whether there is any peak period of pregnancy loss during the early foetal period and to evaluate possible differences between single and twin pregnancies. The study population consisted of 1442 pregnant cattle from a single herd. Pregnancy was diagnosed by transrectal ultrasonography between 36 and 42 days after insemination, and then weekly until day 90 of gestation or until pregnancy loss. A total of 1310 cows (90.8%) bore single embryos and 132 (9.2%) carried twins. Pregnancy loss was registered in 139 (9.6%) cows before day 90 of pregnancy: 101 (7.7%) in single and 38 (28.8%) in twin pregnancies. The average time of pregnancy loss for all animals was 58.4  ± 12.6 days and ranged from 45 to 90 days. Seventy‐five per cent of the pregnancy losses were registered between 45 and 60 days of gestation. The average time of pregnancy loss for cows with singletons was 52.1 ± 4.1 days and ranged from 45 to 61 days and that for those with twins was 75.1 ± 12.4 days and ranged from 46 to 90 days. Seventy‐five per cent of the twin pregnancy losses were registered between 68 and 90 days of gestation. Our data show that the foetal loss in singleton pregnancies occurs earlier than in twin pregnancies. Assessment of normal development of gestation on days 60 and 90 after insemination is suggested.
Reduction of Twin Pregnancy in the Mare by Transvaginal Ultrasound‐Guided Aspiration
Authors: Mari G , Iacono E , Merlo B , Castagnetti C
Published: December 2004

Contents

Diagnosis and management of twin pregnancies in the mare are an ongoing challenge in equine reproduction. Early detection of twin and manual crush of one vesicle are the main steps in the management of twins. Few studies were carried out about the use of transvaginal ultrasound‐guided aspiration (TUGA) for reduction of twins in the mare. In this study, the efficiency of TUGA for management of twin pregnancies was investigated. Reduction of unicornuate twins between 16 and 25 days of gestation gave a success rate of 70.0% (14 viable foals/20 twin pregnancies); when reduction was performed after day 40 of gestation, all mares (one unicornuate; three bicornuate) lost both. For those cases in which the window for early crush of a twin vesicle has been missed, TUGA can be successfully used to reduce twin pregnancy between 16 and 25 days of gestation.
Use of Powdered Egg Yolk vs Fresh Egg Yolk for the Cryopreservation of Ovine Semen
Authors: Marco‐Jiménez F , Puchades S , Mocé E , Viudes‐de‐Cartro MP , Vicente JS , Rodriguez M
Published: December 2004

Contents

Egg yolk is a common additive to sperm cryopreservation diluents. Because of its animal origin, however, it also represents a potential risk of microbiological contamination in the diluent. This potential contamination can be avoided by using powdered egg yolk, instead of fresh egg yolk, as it is pasteurized. This study was conducted to determine ram sperm cryosurvival was affected by the type of egg yolk used (powdered egg yolk or fresh egg yolk) and by yolk concentration (10, 15 or 20%) in the diluent. Microbiological analyses were also performed to quantify the microbiological contamination in the diluents containing the two types of egg yolk. Sperm cryosurvival was determined by motility and morphology analyses after thawing. Motility parameters were assessed using a computer‐assisted sperm analysis (CASA) system, and the percentage of sperm with a normal apical ridge was evaluated using a differential interference contrast microscope. No significant differences were observed between diluents in the percentage of sperm with normal apical ridge. However, higher percentages of total motile cells were observed for samples containing powdered egg yolk (69%) compared to samples containing fresh egg yolk (60%). However, sperm in diluents containing fresh egg yolk, exhibited higher values for average‐path velocity, straight‐line velocity and beat cross frequency and lower values for amplitude of lateral head displacement (p < 0.05), compared to cells in diluents containing powdered egg yolk. Microbiological contamination was similar (<200 CFU/ml) in both diluents, and no bacterial growth was observed in either, when antibiotics were added. Therefore, powdered egg yolk can be effective used in diluents for the freezing of ram semen. However, the in vivo fertility of sperm frozen in diluents containing powdered egg yolk should be tested, as some motility parameters were different for sperm treated with powdered egg yolk compared to fresh egg yolk.
Cell Proliferation in the Atretic Follicles of Buffalo and Cattle Ovary
Authors: Feranil JB , Isobe N , Nakao T
Published: December 2004

Contents

The present study was carried out to describe the proliferative activity of granulosa and theca cells in healthy antral and atretic follicles of Philippine buffaloes (BU) and Holstein–Friesian (HF) cows. Paraffin sections of ovary were immunostained with mouse monoclonal antibody to proliferating cell nuclear antigen (PCNA). Then the follicles were classified into healthy and various stages of atretic follicles. The granulosa layer of healthy follicles had a significantly higher frequency of PCNA‐positive cells than the early and advanced atretic follicles in both breeds. In the theca interna, significantly reduced populations of the PCNA‐positive cells were found in both breeds as atresia progressed. Moreover, HF had significantly higher PCNA‐positive cells in the theca interna of healthy, early atretic and advanced atretic follicles than BU. A reduction of PCNA‐positive cells during atresia was also noted in the theca externa in both animals although differences were not significant. The results of the present work suggest that the proliferative activity of granulosa and theca cells decreases in association with follicular atresia in the BU similar to HF. Furthermore, a significantly deficient cell proliferative activity of theca interna was found in BU compared with HF.
Long‐term outcome of vertically acquired and post‐transfusion hepatitis C infection in children
Authors: RERKSUPPAPHOL SANGUANSAK , HARDIKAR WINITA , DORE GREGORY J
Published: December 2004

Background and Aim: To determine the natural history of perinatally acquired hepatitis C virus (HCV) infection, clinical and laboratory outcomes among 31 children with HCV infection were retrospectively reviewed. Fifteen children had acquired HCV by blood transfusion (BT) prior to 6 months of age and 16 had vertically acquired (VT) HCV.

Methods: Demographic data, clinical symptoms and signs, liver biochemistry, HCV antibody, HCV‐RNA and liver histology were evaluated.

Results: Mean age at last visit was 13.0 years (range 9.0–16.8 years) in the BT group and 8.6 years (range 0.5–18.1 years) in the VT group. There were no abnormal clinical findings of chronic liver disease in either group. Estimated HCV‐RNA clearance rate was 19%, with no significant difference between the groups. In HCV‐RNA‐negative children (n = 6), two lost anti‐HCV antibody and two developed indeterminate anti‐HCV antibody results, while all HCV‐RNA‐positive children (n = 25) remained both anti‐HCV antibody positive and HCV‐RNA positive throughout follow up. The alanine aminotransferase level was significantly higher in the VT group than in the BT group during the first 5 years of life. Liver biopsy, which was carried out in four children, revealed mild to moderate fibrosis and/or necroinflammatory activity, but no cirrhosis.

Conclusions: Outcomes among children with HCV acquired in infancy demonstrate asymptomatic and slowly progressive disease, at least for the initial decade of infection. Mode of acquisition appears to have a limited impact on outcomes, with similar viral clearance and anti‐HCV antibody seroreversion rates in vertical and transfusion acquired infection.
Intralesional steroid injection in benign esophageal strictures resistant to bougie dilation
Authors: ALTINTAS ENGIN , KACAR SABITE , TUNC BILGE , SEZGIN ORHAN , PARLAK ERKAN , ALTIPARMAK EMIN , SARITAS ULKU , SAHIN BURHAN
Published: December 2004

Objective:  Some benign esophageal strictures are highly resistant to bougie dilation. The aim of this study was to determine whether intralesional steroid injection had additional benefit to Savary‐Gilliard's bougie dilation therapy (SGBD).

Methods:  Twenty‐one patients were treated with a bougie dilator. The patients were randomized into  control  and  study  groups.  There  were  11  patients  in  the  control  group  (7  males,  4  females; mean age 45.09 ± 24.64 years) and 10 patients in the study group (4 males, 6 females; mean age 49.40 ± 16.49 years). The patients in the control group underwent only SGBD, but patients in the study group received an additional intralesional steroid injection (8 mg triamcinolone acetate into each quadrant). The number of dilations was divided by the follow‐up period (in months) to determine the periodic dilatation index.

Results:  There was no difference in age, sex, etiology, localization and recurrence of lesions, treatment outcome, complications and the number of dilations between the study and control groups. In the study group, the mean periodic dilatation index was 0.712 (range 0.097–2.75) and 0.289 (range 0–1) before and after injections, respectively (P = 0.03). Additionally, the mean number of dilations was 5.3 (range 2–11) and 1.6 (range 0–5) before and after injections, respectively (P = 0.03). The mean symptom‐free interval was 24 ± 12.75 months in the study group and 5.18 ± 5.06 months in the control group (P < 0.001). The total periodic dilatation index was 0.193 ± 0.123 in the study group, while it was 0.597 ± 0.583 in the control group (P < 0.05).

Conclusions:  It can be concluded that intralesional steroid injections increase efficacy of bougie dilation and decrease the requirement for repetition of bougie dilatation.
Analysis of eight different methods for the detection of Helicobacter pylori infection in patients with dyspepsia
Authors: KULLAVANIJAYA PINIT , THONG‐NGAM DUANGPORN , HANVIVATVONG ORRAWADEE , NUNTHAPISUD PONGPUN , TANGKIJVANICH PISIT , SUWANAGOOL PONGSAPEERA
Published: December 2004

Background:  The present study was designed to compare the accuracy of eight different methods for the detection of Helicobacter pylori (H. pylori) infection in patients with dyspepsia. These tests included culture, histology, rapid urease test (CLO test), serology, saliva IgA, gastric juice IgA, and two in‐house methods, namely in‐house urease test and Gram stain.

Methods:  H. pylori infection was diagnosed prospectively in 200 untreated patients who underwent upper gastrointestinal endoscopy at King Chulalongkorn Memorial Hospital, Bangkok, Thailand, between July 1999 and August 2001. The gold standard for H. pylori infection was based on a positive culture or both a positive histological examination and CLO test.

Results:  The culture provided a sensitivity of 55.9% whereas saliva IgA and gastric juice IgA had a sensitivity of 26.8% and 22.2%, respectively. In contrast, the other tests provided satisfactory sensitivities ranging between 89.3% and 100% (Gram stain 89.3%, histology 93.5%, serology 96.8%, CLO test 99.0%, in‐house urease test 100%). The specificities of the tests ranged between 75% and 100% (culture 100%, CLO test 91.9%, histology 90.4%, in‐house urease test 88.9%, Gram stain 93.5% serology 96.8%, gastric juice IgA 91.7% and saliva IgA 75%).

Conclusions:  Majority of invasive and non‐invasive tests in this study were accurate for the diagnosis of H. pylori infection. However, the secretory IgA‐based techniques in saliva and gastric juice seem to be inappropriate for determining H. pylori status in our populations due to their low sensitivities.
Immunohistochemical analysis of short‐segment Barrett's esophagus
Authors: ISHIZUKA IZUMI , ANDOH AKIRA , KOYAMA SHIGEKI , MORITANI SUZUKO , KUSHIMA RYOJI , HATTORI TAKANORI , FUJIYAMA YOSHIHIDE
Published: December 2004

Background and Aims:  The majority of dysplasias and adenocarcinomas in Barrett's esophagus are closely associated with the specialized columnar epithelium. In this study, we performed an immunohistochemical analysis of columnar metaplasia presenting in short‐segment Barrett's esophagus (SSBE).

Patients and Methods:  The endoscopic biopsy specimens obtained from 91 patients were analyzed. Ten were cases of long‐segment Barrett's esophagus (LSBE) and 81 had SSBE. Expression of MUC2, MUC5AC, Con A and CD10 was evaluated using immunohistochemical staining.

Results:  All samples from LSBE (n = 9) were histologically diagnosed as specialized columnar epithelium. The 81 SSBE samples were divided into gastric fundic‐type (n = 26), junctional‐type (n = 16) and specialized columnar epithelium (n = 39). In the specialized columnar epithelium of SSBE, there was a predominance of goblet cell‐type metaplasia proposed by Watanabe et al. which is characterized by MUC2‐positive pyloric epithelium (66.7%). The total percentage of non‐goblet cell‐type and goblet cell‐type was 76.9%. In contrast, 80% of LSBE revealed the large intestinal‐type or the large and small intestinal‐type. The long oval and villous pit by magnifying endoscope suggests the presence of the specialized columnar epithelium, but the phenotypic classification of Watanabe's criteria was not associated with the endoscopic pit pattern.

Conclusion:  Intestinal metaplasia in Barrett's esophagus changes immunohistochemically with progress of the disease.
Clinical trial to compare efficacy and side‐effects of injection of posterior sub‐Tenon triamcinolone versus orbital floor methylprednisolone in the management of posterior uveitis
Authors: Ferrante Paolo , Ramsey Andrew , Bunce Catey , Lightman Susan
Published: December 2004

Aim: To compare the efficacy and side‐effects of posterior sub‐Tenon injection of triamcinolone acetonide (Kenalog) with orbital floor injection of methylpredisolone acetate (Depomedrone) in the management of posterior uveitis.

Methods: Non‐randomized comparative prospective clinical study. Sixty‐four eyes from 60 consecutive patients with non‐infectious posterior uveitis requiring treatment were allocated on an alternate 1:1 basis to receive either orbital floor methylprednisolone or sub‐Tenon triamcinolone using standard procedures and assessed at 6 and 12 weeks.

Results: After five eyes of five patients who had received the same treatment bilaterally were excluded from the statistical analysis, 14 out of 29 eyes treated with orbital floor methylprednisolone and 10 out of the 30 eyes given sub‐Tenon triamcinolone improved at 6 weeks. There was no statistically significant difference in the improvement rate between the two groups. However, two patients given triamcinolone had prolonged upper lid ptosis, which required surgery, and another two developed markedly raised intraocular pressure, neither of which occurred in the methylprednisolone‐treated group.

Conclusions: Although the two drugs and routes compared were of similar efficacy, lid ptosis occurred in the triamcinolone‐treated but not the methylprednisolone group. This should be borne in mind when choosing the preferred route of delivery of periocular corticosteroid in the treatment of posterior uveitis.
Intravitreal triamcinolone for diabetic macular oedema in Chinese patients: six‐month prospective longitudinal pilot study
Authors: Lam Dennis SC , Chan Carmen KM , Tang Emily WH , Li Kenneth KW , Fan Dorothy SP , Chan Wai‐Man
Published: December 2004

Aim: To evaluate the safety and efficacy of intravitreal triamcinolone (IVTA) in Chinese patients with diabetic clinical significant macular oedema (CSMO).

Methods: Eighteen eyes of 17 consecutive patients with CSMO were prospectively recruited and treated with a 4 mg injection of IVTA. Best‐corrected visual acuity (BCVA) on the ETDRS chart and central macular thickness (CMT) on optical coherence tomography were measured at baseline weeks 1, 2, 3, and months 1, 2, 3, 4, 5 and 6. Side‐effects were monitored.

Results: All patients completed 6 months of follow up. The mean baseline BCVA and CMT were 1.20 ± 0.31 logMAR units and 552 ± 179 µm, respectively. Improvements in CMT and BCVA were observed as early as at 1 and 2 weeks, respectively (P < 0.05). Mean BCVA peaked at 2 months (0.97 ± 0.38 logMAR units) while mean CMT was maximally reduced at 3 months (326 ± 145 µm). Improvements in BCVA and CMT were less afterwards but still statistically significant at 6 months; the final mean BCVA and CMT were 0.99 ± 0.36 logMAR units and 427 ± 145 µm, respectively. A total of 5/18 (28%) eyes developed a transient increase in intraocular pressure. Cataract progression was noted in 2/12 (17%) of the phakic eyes.

Conclusions: Intravitreal triamcinolone appeared generally safe and effective in Chinese patients with CSMO. Although the improvements in BCVA and CMT were transient, there were residual benefits at 6 months. Due to the transient nature of IVTA, re‐treatment seems necessary but the optimal timing and dosage will require further investigations.
Comparison of the Tono‐Pen and Goldmann tonometer for measuring intraocular pressure in patients with glaucoma
Authors: Horowitz Gregory S , Byles Julie , Lee John , D’Este Catherine
Published: December 2004

Aim: To estimate agreement between measurement of intraocular pressure (IOP) by the Tono‐Pen and by the Goldmann tonometer. The hypothesis tested was that the mean difference in measurements would be <–2 mmHg.

Methods: A prospective, single‐centre, comparison study was carried out. The Tono‐Pen was compared to the Goldmann tonometer in 138 patients systematically selected from two glaucoma clinics and among selected patients known to have high pressures (n = 22). For both groups the investigators were masked to the value of the Goldmann readings, the instruments were used in random order, and duplicated readings were taken with both tonometers.

Results: In the systematically selected group, for right eyes, the mean difference in measurement between the Tono‐Pen and Goldmann tonometer was –0.41 mmHg (SD: 2.59). The 95% limits of agreement were –5.5 to 4.7 mmHg, and the intraclass correlation coefficient (ICC) was 0.90. Results for left eyes were very similar. For patients with high pressures (≥25 mmHg), the mean difference between instruments (Tono‐Pen reading minus Goldmann reading): was –4.2 mmHg (P = 0.0004), SD: 4.6, 95% limits of agreement: –13.2 to 4.8 mmHg and ICC = 0.76. Combining the analysis for both groups, the Tono‐Pen significantly underestimated the IOP when the pressure was >20 mmHg.

Conclusions: The Tono‐Pen cannot replace the Goldmann tonometer in the sense that it will give the same readings of IOP. The accuracy of the Tono‐Pen is increased, if at least two measurements are taken per eye and then averaged.
Glaucoma treatment in Australia: changing patterns of therapy 1994–2003
Authors: Walland Mark J
Published: December 2004

Aim: To document the change in pattern of glaucoma treatment in Australia over the decade 1994–2003.

Methods: Observational study: retrospective data audit.

Results: The total number of prescriptions for glaucoma items has increased in this time period from 1.9 million to 3.3 million, with a cost increase to the Pharmaceutical Benefits Scheme (PBS) of in excess of $50m. The largest increase has been in the class of prostaglandin analogues, which now comprise 49% of all glaucoma topical therapy prescriptions. Rates of laser trabeculoplasty and trabeculectomy surgery have fallen by 60% and 58%, respectively. Rates for secondary procedures such as repeat trabeculectomy, drainage implant devices and cycloablation have remained stable, although with some variation between Australian states.

Conclusions: The introduction of multiple new medications has resulted in a decline in the amount of glaucoma surgery and laser trabeculoplasty performed. There has been an associated increase in the total number of glaucoma prescription items dispensed, and a large increase in the cost to the PBS of this change. Outcome measures of the benefit of these changes are lacking.
Clinical Case Notes
Authors: Garrott Helen M , Walland Mark J , O'Day Justin
Published: December 2004

Cataracts are well known to be associated with myotonic dystrophy. Less well known are the phenomena of recurrent posterior capsule opacification and capsulorhexis contracture post cataract surgery. Two cases are described herein of postoperative capsular complications requiring multiple capsulotomies in patients with myotonic dystrophy. It is proposed that a common aetiology may underlie both posterior capsule opacification and capsulorhexis contracture in myotonic dystrophy cases.
Sexually dimorphic effects of hippocampal cholinergic deafferentation in rats
Authors: Jonasson Zachariah , Cahill Jonathan F. X. , Tobey Rachel E. , Baxter Mark G.
Published: December 2004

To determine whether the basal forebrain‐hippocampal cholinergic system supports sexually dimorphic functionality, male and female Long‐Evans rats were given either selective medial septum/vertical limb of the diagonal band (MS/VDB) cholinergic lesions using the neurotoxin 192 IgG‐saporin or a control surgery and then postoperatively tested in a set of standard spatial learning tasks in the Morris water maze. Lesions were highly specific and effective as confirmed by both choline acetyltransferase/parvalbumin immunostaining and acetylcholinesterase histochemistry. Female controls performed worse than male controls in place learning and MS/VDB lesions failed to impair spatial learning in male rats, both consistent with previous findings. In female rats, MS/VDB cholinergic lesions facilitated spatial reference learning. A subsequent test of learning strategy in the water maze revealed a female bias for a response, relative to a spatial, strategy; MS/VDB cholinergic lesions enhanced the use of a spatial strategy in both sexes, but only significantly so in males. Together, these results indicate a sexually dimorphic function associated with MS/VDB‐hippocampal cholinergic inputs. In female rats, these neurons appear to support sex‐specific spatial learning processes.
Autonomous activity of CaMKII is only transiently increased following the induction of long‐term potentiation in the rat hippocampus
Authors: Lengyel I. , Voss K. , Cammarota M. , Bradshaw K. , Brent V. , Murphy K. P. S. J. , Giese K. P. , Rostas J. A. P. , Bliss T. V. P.
Published: December 2004

A major role has been postulated for a maintained increase in the autonomous activity of CaMKII in the expression of long‐term potentiation (LTP). However, attempts to inhibit the expression of LTP with CaMKII inhibitors have yielded inconsistent results. Here we compare the changes in CaMKII autonomous activity and phosphorylation at Thr286 of αCaMKII in rat hippocampal slices using chemical or tetanic stimulation to produce either LTP or short‐term potentiation (STP). Tetanus‐induced LTP in area CA1 requires CaMKII activation and Thr286 phosphorylation of αCaMKII, but we did not observe an increase in autonomous activity. Next we induced LTP by 10 min exposure to 25 mm tetraethyl‐ammonium (TEA) or 5 min exposure to 41 mm potassium (K) after pretreatment with calyculin A. Exposure to K alone produced STP. These protocols allowed us to monitor temporal changes in autonomous activity during and after exposure to the potentiating chemical stimulus. In chemically induced LTP, autonomous activity was maximally increased within 30 s whereas this increase was significantly delayed in STP. However, in both LTP and STP the two‐fold increase in autonomous activity measured immediately after stimulation was short‐lived, returning to baseline within 2–5 min after re‐exposure to normal ACSF. In LTP, but not in STP, the phosphorylation of αCaMKII at Thr286 persisted for at least 60 min after stimulation. These results confirm that LTP is associated with a maintained increase in autophosphorylation at Thr286 but indicate that a persistent increase in the autonomous activity οf CaMKII is not required for the expression of LTP.
Impaired formation of the inner retina in an AChE knockout mouse results in degeneration of all photoreceptors
Authors: Bytyqi Afrim H. , Lockridge Oksana , Duysen Ellen , Wang Yuxia , Wolfrum Uwe , Layer Paul G.
Published: December 2004

Blinding diseases can be assigned predominantly to genetic defects of the photoreceptor/pigmented epithelium complex. As an alternative, we show here for an acetylcholinesterase (AChE) knockout mouse that photoreceptor degeneration follows an impaired development of the inner retina. During the first 15 postnatal days of the AChE–/– retina, three major calretinin sublaminae of the inner plexiform layer (IPL) are disturbed. Thereby, processes of amacrine and ganglion cells diffusely criss‐cross throughout the IPL. In contrast, parvalbumin cells present a nonlaminar IPL pattern in the wild‐type, but in the AChE–/– mouse their processes become structured within two ‘novel’ sublaminae. During this early period, photoreceptors become arranged regularly and at a normal rate in the AChE–/– retina. However, during the following 75 days, first their outer segments, and then the entire photoreceptor layer completely degenerate by apoptosis. Eventually, cells of the inner retina also undergo apoptosis. As butyrylcholinesterase (BChE) is present at a normal level in the AChE–/– mouse, the observed effects must be solely due to the missing AChE. These are the first in vivo findings to show a decisive role for AChE in the formation of the inner retinal network, which, when absent, ultimately results in photoreceptor degeneration.
Dissociation between short‐term increased graft survival and long‐term functional improvements in Parkinsonian rats overexpressing glial cell line‐derived neurotrophic factor
Authors: Georgievska Biljana , Carlsson Thomas , Lacar Benjamin , Winkler Christian , Kirik Deniz
Published: December 2004

The present study was designed to analyse whether continuous overexpression of glial cell line‐derived neurotrophic factor (GDNF) in the striatum by a recombinant lentiviral vector can provide improved cell survival and additional long‐term functional benefits after transplantation of fetal ventral mesencephalic cells in Parkinsonian rats. A four‐site intrastriatal 6‐hydroxydopamine lesion resulted in an 80–90% depletion of nigral dopamine cells and striatal fiber innervation, leading to stable motor impairments. Histological analysis performed at 4 weeks after grafting into the GDNF‐overexpressing striatum revealed a twofold increase in the number of surviving tyrosine hydroxylase (TH)‐positive cells, as compared with grafts placed in control (green fluorescent protein‐overexpressing) animals. However, in animals that were allowed to survive for 6 months, the numbers of surviving TH‐positive cells in the grafts were equal in both groups, suggesting that the cells initially protected at 4 weeks failed to survive despite the continued presence of GDNF. Although cell survival was similar in both grafted groups, the TH‐positive fiber innervation density was lower in the GDNF‐treated grafted animals (30% of normal) compared with animals with control grafts (55% of normal). The vesicular monoamine transporter‐2‐positive fiber density in the striatum, by contrast, was equal in both groups, suggesting that long‐term GDNF overexpression induced a selective down‐regulation of TH in the grafted dopamine neurons. Behavioral analysis in the long‐term grafted animals showed that the control grafted animals improved their performance in spontaneous motor behaviors to approximately 50% of normal, whereas the GDNF treatment did not provide any additional recovery.
Galectin‐1 in regenerating motoneurons
Authors: McGraw J. , McPhail L. T. , Oschipok L. W. , Horie H. , Poirier F. , Steeves J. D. , Ramer M. S. , Tetzlaff W.
Published: December 2004

The exogenous application of recombinant galectin‐1 has recently been shown to promote the rate of peripheral nerve regeneration. Endogenous neuronal galectin‐1 expression has recently been demonstrated to increase after axotomy. Here we demonstrate a significant increase in the endogenous neuronal expression of galectin‐1 mRNA in facial motoneurons after either a nerve resection or crush injury in mice. This increase in galectin‐1 expression was due in part to the loss of target‐derived factor(s) as indicated by both the return of galectin‐1 expression to control levels following target re‐innervation and the increase in galectin‐1 expression after blockade of axonal transport by an interneuronal colchicine injection. Furthermore, interneuronal injections of glial‐derived neurotrophic factor into the uninjured nerve also increased galectin‐1 mRNA expression within facial motoneurons suggesting that positive signals may also be involved in the regulation of galectin‐1 expression. Galectin‐1 null mutant mice showed an attenuated rate of functional recovery of whisking movement after a facial nerve crush.
Primary pupils’ recall of interactive storybooks on CD‐ROM: inconsiderate interactive features and forgetting
Authors: Trushell John , Maitland Amanda
Published: December 2004

The use of interactive storybooks in the primary classroom has the potential to facilitate pupils’ reading, in small groups or individually. However, critics have expressed concern at the exposure of pupils to interactive storybooks. In particular, concern has been expressed that the interactive animations and sound effects in such storybooks may adversely affect pupils’ responses to the written text. These small scale studies examined whether story recall of small groups of pupils, respectively in Year 5 and Year 4, was affected by the provision of cued animations and sound effects. Consideration of the outcomes of both studies indicates that access to cued animations and sound effects did have adverse effects on pupils’ story recall.
Competency, capability, complexity and computers: exploring a new model for conceptualising end‐user computer education
Authors: Phelps Renata , Hase Stewart , Ellis Allan
Published: December 2004

Notions  of  competency  have  dominated  the  computer  education  literature, and have underpinned Competency‐Based Training (CBT) in information technology at all levels of education and training. The emergence of counter‐narratives underpinned by the capability movement, have as yet had minimal impact on practice in computer education. New discourses in educational theory and practice which are founded on non‐linear approaches to learning and teaching provide added impetus to engage in the competency/capability debate, and re‐examine our approaches to computer education. This paper explores complexity theories and demonstrates how complexity's pedagogical implications can lead to new models for understanding computer learning and teaching. A new model for conceptualising end‐user computer education is presented that was derived from a three‐year action research initiative with pre‐service teachers.
THE CREATED CO‐CREATOR: WHAT IT IS AND IS NOT
Authors: Peterson Gregory R.
Published: December 2004

AbstractIn this article I briefly assesses Philip Hefner's concept of the created co‐creator by considering both what it does and does not claim. Looking at issues of reductionism, biological selfishness, biology and freedom, and environmental ethics, I point out strengths and weaknesses in Hefner's conception of the created co‐creator.
Biochemical and kinetic characterization of BACE1: investigation into the putative species‐specificity for β‐ and β′‐cleavage sites by human and murine BACE1
Authors: Yang Hsiu‐Chiung , Chai Xiyun , Mosior Marian , Kohn Wayne , Boggs Leonard N. , Erickson Jon A. , McClure Don B. , Yeh Wu‐Kuang , Zhang Lianshen , Gonzalez‐DeWhitt Patricia , Mayer John P. , Martin Jose Alfredo , Hu Jingdan , Chen Shu‐hui , Bueno Ana Belen , Little Sheila P. , McCarthy James R. , May Patrick C.
Published: December 2004

β‐amyloid peptides (Aβ) are produced by a sequential cleavage of amyloid precursor protein (APP) by β‐ and γ‐secretases. The lack of Aβ production in beta‐APP cleaving enzyme (BACE1)–/– mice suggests that BACE1 is the principal β‐secretase in mammalian neurons. Transfection of human APP and BACE1 into neurons derived from wild‐type and BACE1–/– mice supports cleavage of APP at the canonical β‐secretase site. However, these studies also revealed an alternative BACE1 cleavage site in APP, designated as β′, resulting in Aβ peptides starting at Glu11. The apparent inability of human BACE1 to make this β′‐cleavage in murine APP, and vice versa, led to the hypothesis that this alternative cleavage was species‐specific. In contrast, the results from human BACE1 transgenic mice demonstrated that the human BACE1 is able to cleave the endogenous murine APP at the β′‐cleavage site. To address this discrepancy, we designed fluorescent resonance energy transfer peptide substrates containing the β‐ and β′‐cleavage sites within human and murine APP to compare: (i) the enzymatic efficiency; (ii) binding kinetics of a BACE1 active site inhibitor LY2039911; and (iii) the pharmacological profiles for human and murine recombinant BACE1. Both BACE1 orthologs were able to cleave APP at the β‐ and β′‐sites, although with different efficiencies. Moreover, the inhibitory potency of LY2039911 toward recombinant human and native BACE1 from mouse or guinea pig was indistinguishable. In summary, we have demonstrated, for the first time, that recombinant BACE1 can recognize and cleave APP peptide substrates at the postulated β′‐cleavage site. It does not appear to be a significant species specificity to this cleavage.
S100B protein is released by in vitro trauma and reduces delayed neuronal injury
Authors: Willoughby Karen A. , Kleindienst Andrea , Müller Christian , Chen Tao , Muir Judith K. , Ellis Earl F.
Published: December 2004

S100B protein in brain is produced primarily by astrocytes, has been used as a marker for brain injury and has also been shown to be neurotrophic and neuroprotective. Using a well characterized in vitro model of brain cell trauma, we examined the potential role of exogenous S100B in preventing delayed neuronal injury. Neuronal plus glial cultures were grown on a deformable Silastic membrane and then subjected to strain (stretch) injury produced by a 50 ms displacement of the membrane. We have previously shown that this injury causes an immediate, but transient, nuclear uptake of the fluorescent dye propidium iodide by astrocytes and a 24–48 h delayed uptake by neurons. Strain injury caused immediate release of S100‐beta with further release by 24 and 48 h. Adding 10 or 100 nm S100B to injured cultures at 15 s, 6 h or 24 h after injury reduced delayed neuronal injury measured at 48 h. Exogenous S100B was present in the cultures through 48 h. These studies directly demonstrate the release and neuroprotective role of S100B after traumatic injury and that, unlike most receptor antagonists used for the treatment of trauma, S100B is neuroprotective when given at later, more therapeutically relevant time points.
Developmental regulation of tissue transglutaminase in the mouse forebrain
Authors: Bailey Craig D. C. , Johnson Gail V. W.
Published: December 2004

Tissue transglutaminase (tTG) is a multifunctional enzyme that catalyzes both transamidation and GTPase reactions. In cell culture models tTG‐mediated transamidation positively regulates many processes that occurin vivoduring the mammalian brain growth spurt (BGS), including neuronal differentiation, neurite outgrowth, synaptogenesis and cell death mechanisms. However, little is known about the levels of tTG expression and transglutaminase (TG) activity during mammalian brain development. In this study, C57BL/6 mouse forebrains were collected at embryonic day (E) 12, E14, E17, postnatal day (P) 0, P7 and P56 and analyzed for tTG expression and TG activity. RT–PCR analysis demonstrated that tTG mRNA content increases during mouse forebrain development, whereas immunoblot analysis demonstrated that tTG protein content decreases during this time. TG activity was low in prenatal mouse forebrain but increased fivefold to peak at P0, which corresponds with the beginning of the mouse BGS. Further analysis demonstrated that the lack of temporal correlation between tTG protein content and TG activity is the result of an endogenous inhibitor of tTG that is present in prenatal but not postnatal mouse forebrain. These results demonstrate for the first time that tTG enzymatic activity in the mammalian forebrain is developmentally regulated by post‐translational mechanisms.
Clindamycin is neuroprotective in experimental Streptococcus pneumoniae meningitis compared with ceftriaxone
Authors: Böttcher Tobias , Ren Hao , Goiny Michel , Gerber Joachim , Lykkesfeldt Jens , Kuhnt Ulrich , Lotz Miriam , Bunkowski Stephanie , Werner Carola , Schau Ingmar , Spreer Annette , Christen Stephan , Nau Roland
Published: December 2004

In animal models of Streptococcus pneumoniae meningitis, rifampin is neuroprotective in comparison to ceftriaxone. So far it is not clear whether this can be generalized for other protein synthesis‐inhibiting antimicrobial agents. We examined the effects of the bactericidal protein synthesis‐inhibiting clindamycin (n = 12) on the release of proinflammatory bacterial components, the formation of neurotoxic compounds and neuronal injury compared with the standard therapy with ceftriaxone (n = 12) in a rabbit model of pneumococcal meningitis. Analysis of the CSF and histological evaluation were combined with microdialysis from the hippocampal formation and the neocortex. Compared with ceftriaxone, clindamycin reduced the release of lipoteichoic acids from the bacteria (p = 0.004) into the CSF and the CSF leucocyte count (p = 0.011). This led to lower extracellular concentrations of hydroxyl radicals (p = 0.034) and glutamate (p = 0.016) in the hippocampal formation and a subsequent reduction of extracellular glycerol levels (p = 0.018) and neuronal apoptosis in the dentate gyrus (p = 0.008). The present data document beneficial effects of clindamycin compared with ceftriaxone on various parameters linked with the pathophysiology of pneumococcal meningitis and development of neuronal injury. This study suggests neuroprotection to be a group effect of bactericidal protein synthesis‐inhibiting antimicrobial agents compared with the standard therapy with β‐lactam antibiotics in meningitis.
Identification of Tbr‐1/CASK complex target genes in neurons
Authors: Wang Ting‐Fang , Ding Chia‐Nung , Wang Guey‐Shin , Luo Shih‐Chi , Lin Yi‐Ling , Ruan Youlin , Hevner Robert , Rubenstein John L. R. , Hsueh Yi‐Ping
Published: December 2004

Tbr‐1, a neuron‐specific T‐box transcription factor, plays a critical role in brain development. Here, we performed a computational search using the non‐palindromic T‐box binding sequence, namely the non‐palindromic T‐element, to determine the putative downstream target genes of Tbr‐1. More than 20 identified genes containing the non‐palindromic T‐element in the 5′ regulatory region were found expressed in brain. Luciferase reporter assays using cultured hippocampal neurons showed that overexpression of Tbr‐1 and CASK‐enhanced promoter activities of some of these putative target genes, including NMDAR subunit 2b (NR2b), glycine transporter, interleukin 7 receptor (IL‐7R) and OX‐2. Among these genes, NR2b promoter responded strongest to overexpression of Tbr‐1 and CASK. Deletion of the non‐palindromic T‐elements from NR2b promoter impaired the induction by Tbr‐1 and CASK. We also examined expression of these target genes in Tbr‐1 knockout mice, it was found that NR2b expression was consistently downregulated. Similarly, both RNA and protein expression levels of NMDAR subunit 1 (NR1), which also contains the non‐palindromic T‐elements in its 5′ regulatory region, were reduced in Tbr‐1 knockout mice. We suggest that Tbr‐1/CASK protein complex regulates expression of these downstream target genes and thus modulates neuronal activity and function.