bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute Stress-Induced Facilitation of the Hypothalamic-Pituitary-Adrenal Axis: Evidence for the Roles of Stressor Duration and Serotonin
Authors: Cassano Jr. William J. , D’mello Anil P.
Published: April 2003

Stress-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis stimulates the release of both facilitatory and inhibitory components. We proposed that the transient removal of the inhibitory component, corticosterone, during a stressor would leave the HPA axis in a state of hyper-responsiveness (facilitated state). Consistent with this expectation, we have previously observed that aminoglutethimide (AG)-induced removal of corticosterone during an immobilization stressor resulted in the hypersecretion of both ACTH and corticosterone to a subsequent stressor. In the present study we determined the effect of stressor duration on the magnitude of facilitation. AG plus a 10-min immobilization (IMM10) stress on day 1 resulted in facilitation of the HPA axis. This was reflected in higher ACTH and corticosterone responses to an injection stress on day 2 as compared to appropriate control rats. AG plus a 60-min immobilization (IMM60) stress on day 1 resulted in significantly greater facilitation as compared to the AG+IMM10 pretreatment. It is apparent that facilitation of the HPA axis is dependent on the duration of stress. Stress can alter plasma corticosterone-binding globulin levels and AG administration can cause accumulation of the corticosterone biosynthetic precursor, adrenal cholesterol. In order to rule out these peripheral reasons for the hypersecretion of ACTH and corticosterone in our paradigm, we measured the plasma free fraction of corticosterone and adrenal mitochondrial cholesterol levels on day 2 after different pretreatments on day 1. AG+IMM60 pretreatment caused a significant increase in the plasma free fraction of corticosterone. Hypersecretion of ACTH and corticosterone in this group, despite an enhanced feedback signal, suggests central loci for the origin of facilitation. Also, AG treatment on day 1 did not result in accumulation of free or esterified adrenal cholesterol levels on day 2, and therefore cannot account for the hypersecretion of corticosterone. In our final study we attempted to determine if serotonin released during the first stressor is partially responsible for stress-induced facilitation of the HPA axis. We administered 8-hydroxy-2-(di-n-propylamino)tetralin (DPAT), a 5HT1A agonist, either alone or in conjunction with stress and examined the effects of these pretreatments on the magnitude of facilitation. Interestingly, DPAT administered in lieu of stress produced facilitation similar in magnitude to that produced by IMM10. DPAT adminsitered in conjunction with IMM10 augmented stress-induced facilitation. Our results suggest that stress-induced facilitation of the HPA axis is associated with the release of serotonin during stress.
Melatonin Receptor Subtype MT2 (Mel 1b) and Not mt1 (Mel 1a) Is Associated with Melatonin-Induced Enhancement of Cell-Mediated and Humoral Immunity
Authors: Drazen Deborah L. , Nelson Randy J.
Published: April 2003

Individuals of many vertebrate species undergo seasonal changes in immune function in addition to marked seasonal changes in reproductive, metabolic, and other physiological processes. Despite growing evidence that photoperiod mediates seasonal changes in immunity, little is known regarding the neuroendocrine mechanisms underlying these changes. Enhanced immune function in short days is correlated with increased duration of nightly melatonin secretion, and recent studies indicate that melatonin can act directly on immune cells to enhance immune function. It remains unknown, however, which melatonin receptor subtype mediates immune enhancement by melatonin. The present study examined the contribution of specific melatonin receptor subtypes, mt1 (Mel 1a) and MT2 (Mel 1b), in mediating melatonin-induced enhancement of cell-mediated and humoral immune function in mice. Melatonin enhanced both splenocyte proliferation and anti-keyhole limpet hemocyanin (KLH) IgG concentrations in both wild-type (WT) and mice lacking a functional gene for melatonin receptor mt1 (mt1 –/–), suggesting that the mt1 receptor does not mediate these responses. In addition, luzindole, an MT2 receptor antagonist, attenuated melatonin-induced enhancement of splenocyte proliferation in both WT and mt1 –/– mice. Taken together, these results suggest that receptor subtype mt1 is not necessary for mediating melatonin-induced enhancement of immune function and provide the first evidence for a specific melatonin receptor subtype, MT2, that may be involved in melatonin-induced immune enhancement.
Plasma Orexin Concentrations in Patients on Hemodialysis
Authors: Sugimoto Taro , Nagake Yoshio , Sugimoto Shigeru , Akagi Shigeru , Ichikawa Haruo , Nakamura Yoshio , Ogawa Norio , Makino Hirofumi
Published: April 2003

Background: Orexins A and B are neuropeptides that regulate feeding behavior and are localized exclusively in neurons within and around the lateral hypothalamic area. Intracerebroventricular injection of orexin A stimulates food consumption in rats. Plasma concentrations of orexins may reflect nutritional states and may have clinical significance in patients on hemodialysis. In this study, we investigated the relationship between plasma orexin concentrations and nutritional states in patients on hemodialysis. Method: We measured plasma orexin concentrations in patients on hemodialysis (HD group, n = 67), patients with IgA nephropathy (n = 10), patients with diabetes mellitus (n = 11) and healthy controls (n = 10). We examined the relationships between plasma orexin concentrations and nutritional indices. Results: Plasma orexin A concentrations were significantly higher in the HD group than in the control group and showed a significant correlation with serum creatinine. In all subjects, there was a positive correlation between the plasma orexin A concentration and the serum creatinine concentration, but there were no correlations between these concentrations in each group. In the HD group, plasma orexin A concentrations had a significant positive correlation with the serum albumin concentration and percent creatinine generation rate (%CGR). Multiple regression analysis demonstrated that %CGR was the only independent factor associated with plasma orexin A concentrations. Conclusion: Plasma orexin A concentrations are increased in patients on hemodialysis. It is possible that the kidney plays a major role in the clearance of orexins. The plasma orexin A concentration is significantly correlated with %CGR, and it may be able to be used as a clinical marker of the nutritional state in patients on hemodialysis.
Urinary Retinol-Binding Protein as a Prognostic Marker in Glomerulopathies
Authors: Mastroianni Kirsztajn Gianna , Nishida Sonia K. , Silva Marcelo S. , Ajzen Horacio , Moura Luiz A. , Pereira Aparecido B.
Published: April 2003

Tubulointerstitial involvement seems to have a decisive influence on the progression of glomerular diseases. We have prospectively evaluated the levels of urinary retinol-binding protein (urRBP), a marker of proximal tubular dysfunction, in patients with different glomerulopathies (GPs) and correlated these levels with disease progression. By studying 238 patients with GPs, we found that urRBP tend to be lower in minimal change disease, glomerular hematuria and poststreptococcal glomerulonephritis as compared to focal segmental glomerulosclerosis, membranous nephropathy and membranoproliferative glomerulonephritis. By following 149 patients for up to 10 years, we have concluded that high levels of urRBP can identify patients who will progress with loss of renal function (defined as doubling of serum creatinine level) and that a urRBP level >1 mg/l was an efficient and independent indicator of poor prognosis as shown by multivariate analysis. This prediction was possible at a time when serum creatinine and creatinine clearance were still in the normal range. Our data suggest that this laboratory test adds important clinical information to the follow-up of GPs.
Vitamin Intervention for Stroke Prevention (VISP) Trial: Rationale and Design
Authors: Spence J. David , Howard Virginia J. , Chambless Lloyd E. , Malinow M. Rene , Pettigrew L. Creed , Stampfer Meir , Toole James F.
Published: April 2003

Elevated plasma levels of homocyst(e)ine [H(e)] are surprisingly common and strongly associated with endothelial dysfunction and a marked increase in vascular risk. Treatment with a combination of folic acid, pyridoxine (vitamin B6) and cobalamin (vitamin B12) reduces plasma H(e) levels in most cases, restores endothelial function, and regresses carotid plaque, but there is no evidence that such treatment will reduce clinical events. The Vitamin Intervention for Stroke Prevention (VISP) study is a double-masked, randomized, multicenter clinical trial designed to determine if, in addition to best medical/surgical management, high-dose folic acid, vitamin B6, and vitamin B12 supplements will reduce recurrent stroke compared to lower doses of these vitamins. Patients at least 35 years old with a nondisabling ischemic stroke within 120 days, and screening plasma H(e) > the 25th percentile of benchmark population data are eligible. Secondary endpoints are myocardial infarction or fatal coronary heart disease. This paper describes the design and rationale of the study.
Stroke Recovery Profile and the Modified Rankin Assessment
Authors: Lai Sue-Min , Duncan Pamela W.
Published: April 2003

Background and Purpose: The purpose of this study was to examine the relationship between the Modified Rankin Scale (MRS) and poststroke recovery in neurological deficits, activities of daily living (ADL), higher level of physical and social functioning and the patients’ preference for health state. Methods: Four hundred and fifty-nine participants in the Kansas City Stroke Study were prospectively assessed for measures of MRS, NIH Stroke Scale (NIHSS), Barthel ADL, SF-36 physical functioning, SF-36 social functioning, and Time Trade-Off (TTO). ANOVA and Bonferroni multiple comparisons were used to examine any differences in 3-month scores of NIHSS, Barthel ADL, SF-36 physical functioning, SF-36 social functioning and TTO between levels of the MRS. In addition, SF-36 physical functioning, SF-36 social functioning and TTO were characterized in patients who demonstrated improvement in global MRS outcome and also achieved a Barthel Index (BI) ≧95 at 3 months after stroke. Results: Two hundred and eighty patients (62%) shifted at least one grade in MRS from baseline to 3 months after stroke. Only 67 or 194 patients were considered to have a favorable outcome using MRS 0/1 or MRS 0/1/2, respectively, as criteria. Mean 3-month NIHSS and Barthel ADL scores were not significantly different between Rankin 0/1 and 2, but they were significantly different among Rankin 3, 4 and 5 (all p < 0.05). Mean 3-month scores of physical functioning and SF-36 social functioning were significantly different among Rankin 0/1, 2, 3 and 4 (all pairwise p < 0.05). Proportions of patients who achieved NIHSS ≤1 or BI ≧95 decreased as MRS grades worsened. In patients who showed improvement in MRS global outcome and also achieved BI ≧95, mean scores on TTO were similar. Conclusions: Definition of favorable outcomes should include transition in the Modified Rankin score rather than MRS dichotomized as 0/1 or 0/1/2 because patients with transition in MRS scores have improvement in ADL, increased higher level of functioning and higher utility for health state.
External Auditory Canal Measurements: Localization of the Isthmus
Authors: Ahmad Ijaz , Lee W.C. , Binnington J.D.
Published: April 2003

Objective: Foreign bodies are commonly impacted in the external auditory meatus (EAM), and removal is sometimes difficult due to the tortuous anatomy. A foreign body is more likely to be stuck at the narrowest point of the EAM. This study was designed to determine the location and cross-sectional shape of the narrowest point of the EAM, i.e., the isthmus, by using silicone casting material in human cadaver ears. Materials and Methods: Twelve impressions were taken from 8 adults. All abnormal ears were excluded from the study. The measurements of the impressions were done by using a micrometer (Vernier caliper), calibrated to 0.1 mm. Results: The narrowest point of the EAM, i.e., the isthmus, was located at the junction of the medial two thirds (mean 17.9 mm) to the lateral one third (mean 9.8 mm) of the canal. The mean canal length was 27.7 (range 20–34.8) mm. The isthmus corresponds to the bony and cartilaginous junction, which is traditionally thought to be narrowed by the canal angulation. This narrowing was 5.7 (range 3–7) mm wide in the anteroposterior plane, but 8.2 mm (range 6.5–10) mm wide in the vertical plane. The cross-section of this area was either an inverted pear or oval shape. Conclusions: The isthmus is a bony-cartilaginous junction, and the narrowest point of the EAM is situated at the junction of the outer one third of the inner two thirds of the canal length. This is mainly an anteroposterior narrowing and is oval or inverted pear shaped. Foreign bodies impacted at this point could be removed by use of aural hook, using the potential space at the superior portion of the isthmus.
HPA Axis Dysfunction in Major Depression: Relationship to 5-HT1A Receptor Activity
Authors: Pitchot William , Herrera Claudine , Ansseau Marc
Published: April 2003

Major depression is associated with a dysfunction of the serotonergic activity and the hypothalamic-pituitary- adrenal (HPA) axis. Moreover, a reciprocal relationship between the serotonergic and HPA axis systems has been hypothesized. The purpose of the present study was to assess the relationship between sensitivity of 5-HT1A receptors as measured by hormonal (ACTH, cortisol and PRL) and temperature responses to flesinoxan and HPA axis activity as measured by the dexamethasone suppression test. The sample included 21 inpatients with major depression. Dexamethasone nonsuppressors exhibited lower ACTH responses to flesinoxan as compared with dexamethasone suppressors. The results showed that a dysfunction in 5-HT1A receptor activity could be due to a hypersecretion of cortisol.
Analysis of the Metabolism of Haloperidol and Its Neurotoxic Pyridinium Metabolite in Patients with Drug-Induced Parkinsonism
Authors: Iwahashi K. , Anemo K. , Nakamura K. , Fukunishi I. , Igarashi K.
Published: April 2003

The blood levels of the neurotrophic drug haloperidol (HP) and its pyridinium metabolite, HPP+, have been analyzed by liquid chromatography/electrospray ionization-mass spectrometry in 10 schizophrenic patients treated with HP, without carbamazepine (HP, oral daily dose of 0.3–0.5 mg/kg body weight for more than 1 year, females, aged 41 ± 8.5 years). There was a significant difference (t-test, d.f. = 8, p (t₀ = 7.2) <0.005) in the blood HPP+ level between the 5 patients with (18.5 ± 6.4 ng/ml) and the 5 without (6.3 ± 2.4 ng/ml) severe side effects such as drug-induced parkinsonism (Extrapyramidal Symptom Rating Scale (ESRS) parkinsonism severity scores 2.8 ± 1.5 and 1.8 ± 1.1, respectively). Moreover, it is suggested that vitamin E may be effective for drug-induced parkinsonism through a change in the blood HPP+ level. It is necessary to investigate the HPP+ metabolism in psychiatric patients to avoid severe side effects such as drug-induced parkinsonism and cardiac functional disorders.
Clinical Features and Treatment Response of Patients with Major Depression and Silent Cerebral Infarction
Authors: Yamashita H. , Fujikawa T. , Yanai I. , Morinobu S. , Yamawaki S.
Published: April 2003

Previously, we reported a relationship between silent cerebral infarction (SCI), as detected by magnetic resonance imaging (MRI), and late onset major depression. In the present study, we clarify the clinical features of the depressive phase of patients with major depression and SCI, and their response to antidepressant pharmacotherapy. Using clinical charts, we retrospectively examined patients with depression, who were first admitted for antidepressant pharmacotherapy. All patients were classified according to the MRI findings and the age on admission (older or younger than 50 years) into either the young SCI(–) group (n = 23), the elderly SCI(–) group (n = 27) or the elderly SCI(+) group (n = 20).The characteristics of the clinical features were evaluated at the time of admission, after 2 weeks of treatment and at the time of discharge using the Hamilton rating scale for depression (HAMD). These data were compared between each patient group. No differences in the clinical features, as evaluated by HAMD, were observed between the three groups at the time of admission. However, the mean length of treatment was significantly longer and the treatment response, as evaluated by the total HAMD score, was significantly worse in the elderly SCI(+) group than in the other two groups, when examined after 2 weeks of treatment and at the time of discharge. The elderly SCI(+) group demonstrated higher scores in feelings of guilt, suicide, retardation and hypochondriasis than the young SCI(–) group and the elderly SCI(–) group after two weeks of treatment, and higher scores in early insomnia, late insomnia, somatic anxiety and hypochondriasis at the time of discharge. Our findings suggest that while the presence of SCI does not affect the clinical features observed at the time of admission, it does affect the treatment response to antidepressant pharmacotherapy.
Serum Leptin and Cholesterol Values in Suicide Attempters
Authors: Atmaca Murad , Kuloglu Murat , Tezcan Ertan , Ustundag Bilal , Gecici Omer , Firidin Burak
Published: April 2003

The growing number of studies examining the relationship between suicide and lipid metabolism are based upon studies suggesting that cholesterol-lowering procedures may incease the risk of death due to suicide or impulsive-aggressive behavior. Leptin seems to be strongly associated with lipid metabolism. In the present study, serum total cholesterol and leptin levels were compared in 24 suicide attempters and 24 healthy controls. The patients with suicide attempts had significantly lower serum cholesterol and leptin levels than controls. There was a positive correlation between cholesterol and leptin levels in both groups. Our results suggest that suicide attempts seem to be associated with decreased serum cholesterol and leptin levels.
Effects of Caffeine on Topographic Quantitative EEG
Authors: Siepmann Martin , Kirch Wilhelm
Published: April 2003

Despite the widespread use of caffeine as a central nervous stimulant, the central pharmacodynamic properties of the drug have not yet been conclusively evaluated in humans. The present study was undertaken to assess the acute effects of caffeine on measures of topographical quantitative electroencephalogram (EEG) in normal subjects. Ten healthy male volunteers (mean age ± SD 25 ± 4 years) received placebo and 200 mg of caffeine as powder with oral water solution (caffeine amount = 2 cups of coffee) under randomized, double-blind crossover conditions on two different occasions. Before administration and 30 min afterwards, a 17-channel quantitative EEG was recorded during relaxation with eyes open and closed (15 min each). Caffeine caused a significant reduction of total EEG power at fronto-parieto-occipital and central electrode positions of both hemispheres when the subjects kept their eyes open. Absolute power of the slow and fast alpha and slow beta activities was diminished in various regions of the brain (p < 0.05). The effect was more pronounced with the subjects keeping their eyes open than with eyes closed. It can be concluded that quantitative EEG is a sensitive method to assess the effects of psychostimulants on the human brain. Therefore, in pharmaco-EEG studies, environmental factors such as caffeine have to be excluded.
Xeloda® in the Treatment of Metastatic Breast Cancer
Authors: Blum Joanne L.
Published: April 2003

There are few treatment options available for patients with metastatic breast cancer who have failed anthracycline- and paclitaxel-based chemotherapy. Xeloda® (capecitabine) is a novel selectively tumoractivatedTM fluoropyrimidine carbamate producing clinically active levels of 5-fluorouracil (5-FU) at the tumor site. Xeloda is active in breast cancer and is administered orally. It is the only registered treatment for patients in whom anthracycline and taxoid treatment has failed. In a phase II trial of 163 paclitaxel-refractory patients with metastatic breast cancer, the overall response rate with Xeloda was 20%, with three complete responses, and the median survival was 12.8 months. A total of 20% of patients experienced a Clinical Benefit Response (a composite assessment of clinical benefit). Furthermore, Xeloda was well tolerated; the most common treatment-related adverse events were hand-foot syndrome, diarrhea, nausea, vomiting, and fatigue. Two additional studies of Xeloda in patients with metastatic breast cancer have also been completed. In the first study, patients with anthracycline-resistant metastatic breast cancer received either Xeloda or paclitaxel; the response rates were 36 and 26%, respectively. In the second study, women aged ≧55 years received first-line treatment with either Xeloda or cyclophosphamide/methotrexate/5-FU. The response rates were 25 and 16%, respectively. These studies show that Xeloda is an active agent in the treatment of metastatic breast cancer with the additional advantage of oral administration.
A Case of Quiescent Choroidal Melanoma: Early Echographic Signs of Reactivation
Authors: Mancini A. , Colangelo L. , Lapi G. , Lobefalo L. , Ciancaglini M. , Mastropasqua L. , Gallenga P.E.
Published: April 2003

A medium-sized choroidal melanoma was studied during a 5-year phase of remission. The tumour presented signs of reactivation with changes in the echographic features without a significant increase in size. The echographic signals in the reactivation phase and the echographic evolution after treatment are described.
Retinoic Acid Increases in the Retina of the Chick with Form Deprivation Myopia
Authors: Seko Yuko , Shimizu Masato , Tokoro Takashi
Published: April 2003

We previously reported that expression of retinoic acid receptor β increases in the sclera of the 2-week-old chick with form deprivation myopia (FDM) and that all-trans-retinoic acid (t-RA) influences proliferation and differentiation of scleral cells. The purpose of this study was to quantify t-RA in the retina of the chick with FDM and to investigate the role of t-RA in FDM in the chick. FDM was induced in 2-day-old chicks by placement of a translucent plastic goggle over one eye, with the contralateral eye used as a control. After 5 days, the chicks were sacrificed. t-RA was extracted from neural retina and served for high-performance liquid chromatography analysis. 3H-t-RA was used for normalization. Pieces of the retinae from 5 eyes served as one sample. As a result, t-RA was 0.960 ± 0.086 ng/eye (0.387 ± 0.056 ng/mg protein) in the myopic retina and 0.864 ± 0.108 ng/eye (0.319 ± 0.043 ng/mg protein) in the control retina. The concentration of t-RA (ng/mg protein) in the myopic retina was significantly higher than that in the control (p < 0.05, n = 7). These results demonstrate that t-RA increases in the retina within 5 days after visual deprivation. This finding suggests that t-RA may play a role in the metabolic changes in FDM.
20-Hz Flicker Stimulus Can Isolate the Cone Function in Rat Retina
Authors: Goto Yoshinobu , Yasuda Tetsujiro , Tobimatsu Shozo , Kato Motohiro
Published: April 2003

Cone electroretinograms (ERGs) are typically isolated in humans by flicker stimuli against rod-desensitizing adapting fields. To investigate the manner in which adapting-field luminance affects the cone ERGs, we recorded ERGs in normal albino Sprague-Dawley rats with flicker stimuli presented against adapting fields that ranged in luminance from –∞ to 1.75 log cd/m2. A flicker rate of 20 Hz was used to isolate the cone ERGs under all adaptation conditions. We found the amplitudes of cone ERGs to increase with increasing adapting-field luminance. These response characteristics are similar to human ERGs using 30-Hz flicker stimuli, which suggests that flicker stimuli are a useful technique to isolate the cone function in rats.
Serotonin-2A Receptor mRNA Expression in Rat Retinal Pigment Epithelial Cells
Authors: Nash Mark , Flanigan Thomas , Leslie Ron , Osborne Neville
Published: April 2003

Previous studies have shown that rat retinal pigment epithelial (RPE) cells in culture express 5-HT2-type serotonin receptors coupled to phospholipase C activity. The presented data confirm this observation where it is shown that serotonin induced increases in radioactive inositol phosphates accumulation in RPE cells pretreated with tritiated inositol. This increase was significantly (p < 0.01) attenuated by 1 µM spiperone, ketanserin, mesulergine and metergoline while the same concentration of spiroxatrine or yohimbine had no effect, suggesting the involvement of 5-HT2A receptors. Using reverse transcriptase-polymerase chain reaction the presence of 5-HT2A receptor mRNA was demonstrated in total RNA isolated from rat RPE cell cultures. Amplification of a 5-HT2A receptor mRNA-derived product was additionally confirmed by Southern blot analysis. The combined data demonstrates the existence of functional 5-HT2A receptors in rat RPE cells.
In vitro Testing of Antioxidants and Biochemical End-Points in Bovine Retinal Tissue
Authors: Chida M. , Suzuki K. , Nakanishi-Ueda T. , Ueda T. , Yasuhara H. , Koide R. , Armstrong D.
Published: April 2003

Lipid peroxidation in aliquots of bovine retina (without rod outer segments, ROS), purified ROS and retinal pigment epithelium (RPE) was initiated with 5 mM ferric iron and 80 mM ADP. After 30 min of oxidation at 37°C, the concentration of thiobarbituric-acid-reacting substances (TBARS) which approximates lipid hydroperoxide (LHP), increased in the ROS from 2.0 ± 3.6 to 90.2 ± 34.5 nmol malondialdehyde (MDA)/mg protein and in the RPE from 0.54 ± 0.2 to 51.5 ± 15.8 nmol MDA/mg protein. Sixteen lipid and aqueous antioxidants (AOX) from natural or synthetic sources, including five flavonoids, were evaluated for their ability to inhibit the oxidative reaction. Palm-oil-derived vitamin E showed significant protection in retina, ROS and RPE (64, 68 and 74%), respectively. Of the flavonoids tested, good protection in the retina was found at 10–5M for epigallocatechin gallate (50%) and at 50 ng/ml for pycnogenol (61%) and catechin (52%). When catechin and palm oil vitamin E, catechin and coenzyme Q10 or coenzyme Q10 and pycnogenol were combined, the individual effect was enhanced. TBARS as an indirect measure of LHP level and hemoglobin-methylene blue determination for direct LHP were used as alternative end-point determinations of lipid peroxidation. These measure different aspects of AOX reactions. The results demonstrate the usefulness of an in vitro model system that can rapidly and accurately determine the capacity of a single AOX against lipid peroxidation or be used to show synergistic efficacy.
Effect of Insulin-Like Growth Factors 1 and 2, and Glucose on the Migration and Proliferation of Bovine Retinal Pigment Epithelial Cellsin vitro
Authors: Spraul Christoph W. , Kaven Corinna , Amann Josef , Lang Gerhard K. , Lang Gabriele E.
Published: April 2003

Background: The retinal pigment epithelium (RPE) has been implicated in the development of diabetic retinopathy and it has been suggested that insulin-like growth factors (IGF) and glucose may be among those factors which are responsible for the RPE changes in diabetics. The purpose of this study was to investigate the effect of IGF-1, IGF-2, and glucose on the migration and proliferation of bovine RPE cells in vitro. Methods: Primary cultures of bovine RPE cells were established from freshly enucleated eyes and passages 5–8 were used for these experiments. RPE cell migration was studied in confluent RPE cultures grown in multiwell plates. After inhibition of proliferation with mitomycin C (10 µg/ml) and partial denudation of the RPE in each well, the cells were incubated with IGF-1 (10 ng/ml), IGF-2 (10 ng/ml) or glucose (10 mM). Migration was measured as the number of cells that had entered the denuded area after 20 h. RPE cell proliferation was determined by [3H]-thymidine incorporation after incubation with IGF-1, IGF-2, and glucose for 24 h. Statistical analysis was performed with the paired Student’s t test. Results: Exposure of RPE cells to IGF-1, IGF-2, and glucose resulted in a significantly higher RPE cell migration as compared to the control medium (p < 0.008) with 21, 20, 17, and 9 cells/raster field, respectively. Additionally, IGF-1 (p = 0.004) and IGF-2 (p = 0.008) but not glucose caused a statistically significant stimulation of DNA synthesis with 761, 747, and 593 ccpm, respectively, as compared to the negative control (352 ccpm). Conclusion: This study indicates that IGF-1 and IGF-2 influence RPE cell migration and proliferation. This is further evidence that these factors are among those which have to be kept in mind when trying to modulate the development of diabetic eye diseases.
Effect of Particle Size of Polymeric Nanospheres on Intravitreal Kinetics
Authors: Sakurai Eiji , Ozeki Hironori , Kunou Noriyuki , Ogura Yuichiro
Published: April 2003

In this study, we injected nanospheres containing a fluorescein derivative into the vitreous cavity of pigmented rabbit eyes and evaluated their intraocular kinetics as drug carriers in vivo. Polystyrene nanospheres (2 µm, 200 nm and 50 nm in diameter) containing a fluorescein derivative were used in this study. A suspension of each particle was prepared by diluting with distilled water at a concentration of 10 µg/ml equivalent to sodium fluorescein. The suspension of nanospheres was injected once into the vitreous cavity of unilateral eyes of pigmented rabbits. A sodium fluorescein solution of the same concentration was injected once into the vitreous cavity of the other eye as the control. The intraocular kinetics of nanospheres was evaluated by measuring vitreous fluorescence using a scanning fluorophotometer. To investigate elimination pathways of nanospheres in detail, serial cross-sections of the eyes were examined with a fluorescence microscope. The fluorescence derived from nanospheres was observed in the vitreous cavity for over 1 month (2 µm: t1/2 = 5.4 ± 0.8 days, 200 nm: t1/2 = 8.6 ± 0.7 days, 50 nm: t1/2 = 10.1 ± 1.8 days), whereas that in the control eyes completely disappeared within 3 days (t1/2 = 7.8 ± 0.7 h). The elimination half-life from the vitreous cavity correlated well with the particle diameter (r = –0.997, p = 0.007). Histological studies using a fluorescence microscope revealed that nanospheres with a diameter of 2 µm were seen in the vitreous cavity and trabecular meshwork, while nanospheres with a diameter of smaller than 200 nm were also observed in the retina as well as these tissues. Our findings indicated that nanospheres may be beneficial as a drug carrier to the retina, vitreous and trabecular meshwork.
Primary Squamous Cell Carcinoma of the Prostate: A Rare Clinicopathological Entity
Authors: Nabi G. , Ansari M.S. , Singh Iqbal , Sharma M.C. , Dogra P.N.
Published: April 2003

Primary squamous cell carcinoma of the prostate is an uncommon clinicopathological entity. It differs from more common adenocarcinomas in its cell of origin, biological behavior, therapeutic response to the usual hormonal manipulation and prognosis. The review shows that squamous cell carcinoma is biologically more aggressive than adenocarcinoma. Despite the agreement on its uniqueness, a controversy exists on the exact histopathogenesis, diagnostic criteria and modality of treatment. We report on 2 patients with primary squamous cell carcinoma of the prostate. One patient presented with lower urinary tract symptoms with a hard nodular prostate on digital rectal examination, and the other with acute urinary retention on normal digital rectal examination. The evaluation revealed metastasis in the pelvic and right femur in both cases. Palliative transurethral resection of the prostate with chemotherapy (Adriamycin based) was given in both the cases. However, both the patients died at 4 and 5 months of follow-up, respectively.
Characterisation of the human and mouse orthologues of the Drosophila ariadne gene
Authors: Tan N.G.S. , Ardley H.C. , Rose S.A. , Leek J.P. , Markham A.F. , Robinson P.A.
Published: April 2003

The specificity of the ubiquitin degradation system is regulated through interaction between individual ubiquitin-conjugating enzymes (E2s) and multiple ubiquitin-protein ligases (E3s). Here we describe the characterisation of a novel gene (ARIH1) that encodes the human homologue of Drosophila ariadne which interacts with the E2s, UbcH7 and UbcH8 and represents a component of an E3 complex. Three PACs (189N19, 142P17 and 179H7) were isolated that contain this gene. Using these PACs as probes, we mapped ARIH1 to human chromosome 15q24 by fluorescence in situ hybridisation (FISH). Sequencing of the ARIH1 PACs showed that the gene has 13 introns. In addition, we isolated two PACs (345D8 and 571P19) containing the mouse orthologue (Arih1) of ARIH1. The intron-exon structure of Arih1 was identical to ARIH1 and the proteins demonstrated a 98% identity at the amino acid level. Furthermore, comparison of Drosophila ariadne with ARIH1 indicates an identity at the amino acid level of 70% and introns at 3/7 identical sites. The high degree of homology demonstrated by the mouse and human orthologues of Drosophila ariadne indicates an important, conserved biological function, consistent with a putative role in ubiquitylation.
Generalized progressive retinal atrophy of Sloughi dogs is due to an 8-bp insertion in exon 21 of the PDE6B gene
Authors: Dekomien G. , Runte M. , Gödde R. , Epplen J.T.
Published: April 2003

We investigated the gene encoding the β subunit of cGMP phosphodiesterase (PDE6B) as a candidate for generalized progressive retinal atrophy (gPRA), an autosomal recessively transmitted eye disease in dogs. The PDE6B gene was isolated from a genomic library. Single-strand conformation polymorphism analysis revealed eight intronic variations in different subsets of the 14 dog breeds investigated. In addition, we identified an 8-bp insertion after codon 816 in certain Sloughi dogs. Analysis of PRA-affected and obligatory carrier Sloughis showed that this mutation cosegregates with disease status in a large pedigree. All other exchanges identified were not located in functionally relevant parts of the gene (e.g., in the splice signal consensus sites). In most dog breeds (Labrador retriever, Tibetan mastiff, dachshund, Tibetan terrier, miniature poodle, Australian cattle dog, cocker spaniel, collie, Saarloos wolfhound, Chesapeake Bay retriever, and Yorkshire terrier), PDE6B was excluded as a candidate gene for gPRA because heterozygous allele constellations were detected in diseased animals. Therefore, the PDE6B sequence variations did not segregate together with the mutation(s) causing gPRA. Direct and indirect DNA tests concerning gPRA can be offered now for a variety of different dog breeds.
Peg1/Mest locates distal to the currently defined imprinting region on mouse proximal chromosome 6 and identifies a new imprinting region affecting growth
Authors: Beechey C.V.
Published: April 2003

Mice with maternal duplication for proximal chromosome 6 (Chr 6) die in utero before 11.5 dpc, an effect that can be attributed to genomic imprinting. Previous studies have defined the region of Chr 6 responsible as lying proximal to the T6Ad translocation breakpoint in G-band 6B3. Evidence presented here with a new Chr 6 translocation T77H has substantially reduced the size of the imprinting region, locating it between G-band 6A3.2 and the centromere. The paternally expressed imprinted gene Mest had been mapped within the original imprinting region and was therefore a candidate for the early embryonic lethality. FISH has shown that Mest locates distal to T77H and therefore outside the redefined imprinting region. This evidence confirms that Mest is not a candidate for the early embryonic lethality found with two maternal copies of proximal Chr 6. Furthermore mice with maternal duplication for Ch 6 distal to T77H (MatDp.dist6) were found to be growth retarded at birth, the weight reduction remaining similar until adulthood. It can be concluded that the growth retardation is established in utero and is maintained at a similar level from birth to adulthood. Therefore Mest locates in a new imprinting region, distal to G-band 6A3.2 which affects growth. A targeted mutation of Mest has been reported that exhibits growth retardation, reduced postnatal survival and abnormal maternal behaviour. Here the phenotype of MatDp.dist6 mice is compared to that of Mest-deficient mutant mice. Unlike the latter, MatDp.dist6 mice have good survival rates and females have normal maternal behaviour. Possible reasons for these differences are discussed.
TSPY variants in six loci on the human Y chromosome
Authors: Dechend F. , Williams G. , Skawran B. , Schubert S. , Krawczak M. , Tyler-Smith C. , Schmidtke J.
Published: April 2003

We have studied the structure, organization, and evolution of the human TSPY gene family by mapping three sequence variants identified through RT-PCR analysis onto genomic clones derived from two different YAC contigs. TSPY gene family members occur in at least six locations on the human Y chromosome, and each cluster contains a unique combination of variants. Our data further suggest that an 18-bp tandem duplication found in TSPY exon 1 originated from an unequal sister chromatid exchange between two tandemly arranged TSPY clusters.
Gonadal development and birth weight in X*X and X*Y females of the wood lemming, Myopus schisticolor
Authors: Fredga K. , Setterfield L. , Mittwoch U.
Published: April 2003

A quantitative histological analysis of ovaries from 8- to 10-day-old wood lemmings revealed significant differences between females with X*Y and X*X sex chromosome constitutions. The ovarian volume of X*Y females was on average 57% of X*X, and the number of oocytes was less than half in X*Y compared to X*X. However, the frequency of growing oocytes in relation to the total number was 6.5% for X*Y compared to 3.0% for X*X. Oogenesis in X*Y wood lemmings resembles in many respects that of mice heterozygous for certain translocations and with tertiary trisomy (Ts31H), and those with X0 monosomy. The fertility in X*Y wood lemmings is not reduced. On the contrary, X*Y females have a higher reproductive fitness than X*X and XX. This is discussed in relation to the present findings. The body weight at birth was 8% higher in X*Y than in X*X.
Clustering of FGFR2 gene mutations inpatients with Pfeiffer and Crouzon syndromes (FGFR2-associated craniosynostoses)
Authors: Kress W. , Collmann H. , Büsse M. , Halliger-Keller B. , Mueller C.R.
Published: April 2003

A cohort of 36 unrelated German patients with craniosynostosis syndromes of the Crouzon and Pfeiffer type were analyzed for FGFR mutations. Mutations in FGFR2 were identified in 25 Crouzon and 5 Pfeiffer syndrome patients, whereas no sequence alterations were found in the remaining patients, even after screening of the relevant parts of FGFR1, FGFR3, and TWIST. Mutations in FGFR2 clustered at two critical cysteine residues, 278 and 342, which were involved in 18 of 30 cases (60%). These two mutational hot spots, therefore, are prime targets for an efficient mutation-screening strategy. The spectrum of mutations overlapped the two syndromes and thus reflected the phenotypic similarities observed in both patient groups. In 21 families, the origin of the mutation could be traced by analyzing parents and relatives. Eleven mutations arose de novo, indicating a high mutation rate for FGFR2. In the 10 familial cases, the clinical presentation varied considerably within the pedigree, but both syndromes “bred true,” i.e., a Pfeiffer syndrome phenotype was never observed in a Crouzon syndrome family and vice versa.
SRY protein is expressed in ovotestis and streak gonads from human sex-reversal
Authors: Salas-Cortés L. , Jaubert F. , Nihoul-Feketé C. , Brauner R. , Rosemblatt M. , Fellous M.
Published: April 2003

In mammals, a master gene located on the Y chromosome, the testis-determining gene SRY, controls sex determination. SRY protein is expressed in the genital ridge before testis determination, and in the testis it is expressed in Sertoli and germ cells. Completely sex-reversed patients are classified as either 46,XX males or 46,XY females. SRY mutations have been described in only 15% of patients with 46,XY complete or partial gonadal dysgenesis. However, although incomplete or partial sex-reversal affects 46,XX true hermaphrodites, 46,XY gonadal dysgenesis, and 46,XX/46,XY mosaicism, only 15% of the 46,XX true hermaphrodites analyzed have the SRY gene. Here, we demonstrate that the SRY protein is expressed in the tubules of streak gonads and rete testis, indicating that the SRY protein is normally expressed early during testis determination. Based on these results, we propose that some factors downstream from SRY may be mutated in these 46,XY sex-reversal patients. We have also analyzed SRY protein expression in the ovotestis from 46,XX true hermaphrodites and 46,XX/46,XY mosaicism, demonstrating SRY protein expression in both testicular and ovarian portions in these patients. This suggests that the SRY protein does not inhibit ovary development. These results confirm that other factors are needed for complete testis development, in particular, those downstream of the SRY protein.
Do the constraints of human speciation cause expression of the same set of genes in brain, testis, and placenta?
Authors: Wilda M. , Bächner D. , Zechner U. , Kehrer-Sawatzki H. , Vogel W. , Hameister H.
Published: April 2003

Evolution appears to be especially rapid during speciation, and the genes involved in speciation should be evident in species such as humans that have recently speciated or are presently in the process of speciation. Haldane’s rule is that when one sex is sterile or inviable in interspecific F1 hybrids, it is usually the heterogametic sex. For mammals, this implicates genes on the X chromosome as those particularly responsible for speciation. A preponderance of sex- and reproduction-related genes on the X chromosome has been shown repeatedly, but also mental retardation genes are more frequent on the X chromosome. We argue that brain, testis, and placenta are those organs most responsible for human speciation. Furthermore, the high degree of complexity of the vertebrate genome demands coordinate evolution of new characters. This coordination is best attained when the same set of genes is redeployed for these new characters in the brain, testis, and placenta.
Chromosome assignment of four plexin A genes (Plxna1, Plxna2, Plxna3, Plxna4) in mouse, rat, Syrian hamster and Chinese hamster
Authors: Kuroiwa A. , Suto F. , Fujisawa H. , Matsuda Y.
Published: April 2003

We determined chromosome locations of four plexin A subfamily genes, Plxna1, Plxna2, Plxna3 and Plxna4, in four rodent species, mouse, rat, Syrian hamster and Chinese hamster, by fluorescence in situ hybridization. Plxna1, Plxna2, Plxna3 and Plxna4 were localized to Chr 6E2, 1H6, XB-C1 and 6B1 in mouse, Chr 4q34.1, 13q26→q27, Xq37.1→q37.2 and 4q21.3→q22 in rat, Chr 8qb1.1→qb1.3, 11qb8, Xpb8 and 5qb3.3 in Syrian hamster, and Chr 8q1.2, 5q3.7, Xp2.7 and 1q2.2→q2.3 in Chinese hamster, respectively. All the mouse and rat plexin A genes were localized to chromosome regions where conserved homology has been identified among human, mouse and rat.
Cloning, organisation, chromosomal localization and expression analysis of the mouse Prkag1 gene
Authors: Shamsadin R. , Jantsan K. , Adham I. , Engel W.
Published: April 2003

The mammalian 5′-AMP-activated protein kinase (AMPK) is a heterotrimeric protein consisting of α-, β- and γ-subunits. The α-subunit is the catalytic subunit. The non-catalytic subunits AMPK-β and AMPK-γ form, together with the catalytic AMPK-α, the active kinase complex in mammals and its homologue in yeast. The gene for AMPK-γ-1 has been designated recently as PRKAG1. We have isolated mouse Prkag1 cDNA from testis (1623 nt) coding for 330 aa and we have shown its ubiquitous expression as a 1.8-kb transcript. A comparison between mouse, rat and human PRKAG1 cDNA and protein sequences shows that the gene is highly conserved among these species with a homology of 96% at the protein level. Southern blot analysis indicates that there is more than one gene for PRKAG in the mouse genome. Prkag1 contains 12 exons with short introns. Analysis of 50 interspecific backcross mice mapped the mouse gene to the distal region of chromosome 15.
Analysis of DEXI/Dexi refines the organization of the mouse 7C and human 15q11→q13 imprinting clusters
Authors: Kelly M. , Edgar A.J. , Wevrick R.
Published: April 2003

Identification of imprinted genes in the Prader-Willi/Angelman syndrome deletion region is complicated by the presence of large flanking repeats. While inactive copies of DEXI are located within the repeats, we have now localized the active DEXI gene to 15q11→q13 outside the PWS/AS deletion and Dexi to mouse chromosome 16, suggesting complex evolution of this genomic region in both species.
Conserved chromosome segments in Hylobates hoolock revealed by human and H. leucogenys paint probes
Authors: Nie W. , Rens W. , Wang J. , Yang F.
Published: April 2003

A complete comparative chromosome map of the white-browed gibbon (Hylobates hoolock, 2n = 38), white-cheeked gibbon (Hylobates leucogenys, 2n = 52), and human has been established by hybridising H. leucogenys chromosome-specific paints and human 24-colour paints onto H. hoolock metaphase chromosomes. In the 18 H. hoolock autosomes, we identified 62 conserved segments that showed DNA homology to regions of the 25 H. leucogenys autosomes. Numerous interchromosomal rearrangements differentiate the karyotypes of H. leucogenys and H. hoolock. Only H. hoolock chromosome 10 showed homology to one entire autosome of H. leucogenys. The hybridisation of human 24-colour paints not only confirmed most of the chromosome correspondences between human and H. hoolock established previously but also helped to correct five erroneous assignments and revealed three new segments. Our results demonstrate that the karyotypes of the extant gibbons have arisen mainly through extensive translocation events and that the karyotype of H. hoolock more closely resembles the ancestral karyotype of Hylobates, rather than the karyotype of H. leucogenys.