State-dependent changes in hippocampal grey matter in depression

Reduced hippocampal volume has been reported in depression and may be involved in the aetiology of depressive symptoms and vulnerability to depressive relapse. Neuroplasticity following antidepressant drug treatment in the hippocampus has been demonstrated in animal models but adaptive changes after such treatment have not been shown in humans. In this study, we determined whether grey matter loss in the hippocampus in depression (1) is present in medication-free depressed (2) changes in response to antidepressant treatment and (3) is present as a stable trait in medication-free remitted patients. Sixty-four medication-free unipolar depressed patients: 39 currently depressed and 25 in remission, and 66 healthy controls (HC) underwent structural magnetic resonance imaging in a cross-sectional and longitudinal design. Thirty-two currently depressed participants were then treated with the antidepressant citalopram for 8 weeks. Adherence to treatment was evaluated by measuring plasma citalopram concentration. We measured regional variation in grey matter concentration by using voxel-based morphometry-Diffeomorphic Anatomical Registration Through Exponentiated Lie algebra. Patients with current depression had bilaterally reduced grey matter in the hippocampus compared with HC and untreated patients in stable remission with the latter groups not differing. An increase in grey matter was observed in the hippocampus following treatment with citalopram in currently depressed patients. Grey matter reduction in the hippocampus appears specific to the depressed state and is a potential biomarker for a depressive episode.

Staphylococcal colonization in atopic dermatitis and the effect of topical mupirocin therapy

Forty-nine patients with atopic dermatitis entered a double blind placebo controlled cross-over study of mupirocin, a new topical antistaphylococcal antibiotic. Forty-five patients were evaluable. Quantitative bacteriological assessment before treatment showed that heavy colonization of the skin with Staphylococcus aureus was present in nearly all patients even in the absence of overt infection. However, the bacterial count was significantly reduced by 2 weeks' treatment with topical mupirocin, but not by the placebo. Moreover, a significant reduction of clinical severity was also observed after treatment with mupirocin, which was maintained over the following 4 weeks, although recolonization occurred during this period, with bacterial counts rising to pre-treatment levels. Despite recolonization, clinical deterioration was not observed during the trial period. No serious side-effects were observed. Phage typing showed that 50% of patients carried more than one bacterial phage type. Recolonization in eight patients (17%) was with a 'new' strain that had not previously been isolated.

Diabetes-induced vascular dysfunction in the retina: role of endothelins

AIMS/HYPOTHESIS

Vasoactive factors like endothelins, by virtue of the microvascular regulation as well as by other effects, possibly play important parts in the pathogenesis of diabetic retinal microangiopathy. We investigated retinal vascular dysfunction in streptozotocin-induced diabetes and its relation with endothelins in short- and long-term diabetes.

METHODS

Diabetic rats with or without an endothelin receptor antagonist (bosentan) treatment were investigated after 1 month and 6 months of follow-up. Retinal blood flow was measured and compared with age- and sex-matched non-diabetic control animals. Retinal tissues were analysed for endothelin-1, endothelin-3, endothelin A and endothelin B mRNA. Distribution of endothelin-1 and endothelin-3 was investigated by immunocytochemistry and that for endothelin receptors by ligand binding and autoradiography.

RESULTS

Diabetic animals showed hyperglycaemia, glycosuria, elevated glycated haemoglobin values and reduced body weight gain. Retinal blood flow showed an increased resistivity index, an indicator of vasoconstriction, after 1 month of diabetes which was prevented by treatment with bosentan. This functional change in diabetes was eliminated after 6 months of follow-up. The retina from the diabetic animals showed increased mRNA expression for endothelin-1, endothelin-3 and endothelin A after one month. In addition, endothelin B mRNA expression was increased after 6 months. Furthermore, endothelin-1 and endothelin-3 immunoreactivity and endothelin receptor concentrations were increased in the retina of diabetic rats.

CONCLUSION/INTERPRETATION

The results from this study indicate that the endothelin system is of importance in mediating retinal changes in diabetes although mechanisms of the endothelin system alteration as well as their effects might vary depending on the duration of diabetes. [Diabetologia (1999) 42: 1228-1234]

Segmentation of carotid artery in ultrasound images: method development and evaluation technique

Segmentation of carotid artery lumen in two-dimensional and three-dimensional ultrasonography is an important step in computerized evaluation of arterial disease severity and in finding vulnerable atherosclerotic plaques susceptible to rupture causing stroke. Because of the complexity of anatomical structures, noise as well as the requirement of accurate segmentation, interactions are necessary between observers and the computer segmentation process. In this paper a segmentation process is described based on the deformable model method with only one seed point to guide the initialization of the deformable model for each lumen cross section. With one seed, the initial contour of the deformable model is generated using the entropy map of the original image and mathematical morphology operations. The deformable model is driven to fit the lumen contour by an internal force and an external force that are calculated, respectively, with geometrical properties of deformed contour and with the image gray level features. The evaluation methodology using distance-based and area-based metrics is introduced in this paper. A contour probability distribution (CPD) method for calculating distance-based metrics is introduced. The CPD is obtained by generating contours of the lumen using a set of possible seed locations. The mean contour can be compared to a manual outlined contour to provide accuracy metrics. The variance computed from the CPD can provide metrics of local and global variability. These metrics provide a complete performance evaluation of an interactive segmentation algorithm and a means for comparing different algorithm settings.

Safety and efficacy of recombinant alpha(1)-antitrypsin therapy in cystic fibrosis

Neutrophil elastase (NE) is thought to be the most important protease which damages the cystic fibrosis (CF) lung. Attempts have been made to suppress this activity using the plasma-derived inhibitor, alpha(1)-antitrypsin (AAT). In this pilot study, the safety and efficacy of inhaled recombinant human AAT (rAAT) as a treatment for CF were investigated. Thirty-nine patients participated in a prospective, double-blinded, randomized, placebo-controlled phase II trial to examine the effect of rAAT (500, 250, and 125 mg) on sputum NE activity. Sputum myeloperoxidase (MPO), interleukin-8, tumor necrosis factor receptors, sputum and plasma NE/AAT complexes, and safety parameters were also measured. Subjects were randomized to receive nebulized treatment once a day for 4 weeks, followed by 2-4 weeks with no study treatment, and then a 2-week rechallenge phase. Trends toward a reduction in NE activity were observed in patients treated with 500 mg and 250 mg of rAAT compared to placebo. Sputum NE/AAT complex and MPO levels were lower on rAAT compared to placebo. No major adverse events and, in particular, no allergic reactions to rAAT were observed. Although significant differences between rAAT and placebo for sputum NE activity were not observed, some improvements were found for secondary efficacy variables. This study demonstrated that nebulized rAAT is safe and well-tolerated, but has a limited effect on NE activity and other markers of inflammation.

Pneumatic sequential compression reduces the risk of deep vein thrombosis in stroke patients

OBJECTIVE

To determine if pneumatic sequential compression devices (SCDs) combined with subcutaneous heparin and antiembolic hose reduce the risk of deep vein thrombosis (DVT) and pulmonary embolism (PE) in stroke patients.

BACKGROUND

DVTs and PEs are serious complications among hospitalized stroke patients. Subcutaneous heparin and SCDs have both been used to prevent DVT. It is not known if SCDs combined with subcutaneous heparin can improve the protection afforded by heparin alone.

METHODS

The study group was comprised of nonhemorrhagic stroke patients admitted to the neurology service from October 1988 through June 1996. From October 1988 through April 1991 (233 patients), and during February 1993 (16 patients), patients received 5,000 U subcutaneous heparin twice daily and antiembolic hose. From June 1991 through January 1993 and from March 1993 through June 1996 (432 patients) all nonambulatory stroke patients had SCDs applied to both legs in addition to subcutaneous heparin and antiembolic hose.

RESULTS

Twenty-three of 249 patients (9.2%; 21 of 233 and two of 16 patients) treated with heparin alone developed DVT and six patients (2.4%) developed PE (six of 233 and zero of 16). Half the PE cases (three of six) were fatal and all PEs were in patients with DVT. Eighty-three of the 249 patients were nonambulatory. Twenty-two of the 23 DVTs and all the PEs developed in nonambulatory patients. Only one DVT (0.23%) and no PEs occurred among the 432 patients (148 nonambulatory) treated with SCDs as well as heparin. The addition of SCDs resulted in more than a 40-fold reduction in the risk of DVT.

CONCLUSIONS

Nonambulatory stroke patients have an increased risk for DVT and PE. Adding SCDs to treatment with subcutaneous heparin and antiembolic hose reduced the risks of DVTs and PEs. SCDs should be considered for adjunctive DVT prophylaxis in nonambulatory stroke patients.

Future therapies for cystic fibrosis

We are currently witnessing transformative change for people with cystic fibrosis with the introduction of small molecule, mutation-specific drugs capable of restoring function of the defective protein, cystic fibrosis transmembrane conductance regulator (CFTR). However, despite being a single gene disorder, there are multiple cystic fibrosis-causing genetic variants; mutation-specific drugs are not suitable for all genetic variants and also do not correct all the multisystem clinical manifestations of the disease. For many, there will remain a need for improved treatments. Those patients with gene variants responsive to CFTR modulators may have found these therapies to be transformational; research is now focusing on safely reducing the burden of symptom-directed treatment. However, modulators are not available in all parts of the globe, an issue which is further widening existing health inequalities. For patients who are not suitable for- or do not have access to- modulator drugs, alternative approaches are progressing through the trials pipeline. There will be challenges encountered in design and implementation of these trials, for which the established global CF infrastructure is a major advantage. Here, the Cystic Fibrosis National Research Strategy Group of the UK NIHR Respiratory Translational Research Collaboration looks to the future of cystic fibrosis therapies and consider priorities for future research and development.

Interaction between a history of depression and rumination on neural response to emotional faces

BACKGROUND

Both past depressive episodes and the personality trait of depressive rumination are strong risk factors for future depression. Depression is associated with abnormal emotional processing, which may be a neurobiological marker for vulnerability to depression. A consistent picture has yet to emerge as to how a history of depression and the tendency to ruminate influence emotional processing. The aim of this study was to investigate the relationship between rumination, past depression and neural responses when processing face emotions.

METHOD

The Ruminative Responses Scale (RRS) was completed by 30 remitted depressives and 37 controls who underwent functional magnetic resonance imaging (fMRI) scanning while viewing happy, sad, fearful and neutral faces.

RESULTS

The remitted depressives showed overall reductions in neural responses to negative emotions relative to the controls. However, in the remitted depressives, but not the controls, RRS scores were correlated with increased neural responses to negative emotions and decreased responses to happiness in limbic regions.

CONCLUSIONS

Automatic emotion processing biases and rumination seem to be correlated to aspects of vulnerability to depression. However, remission from depression may be maintained by a general suppression of limbic responsiveness to negative emotion.

Evaluation of voxel-based registration of 3-D power Doppler ultrasound and 3-D magnetic resonance angiographic images of carotid arteries

Spatial registration and fusion of ultrasound (US) images with other modalities may aid clinical interpretation. We implemented and evaluated on patient data an automated retrospective registration of magnetic resonance angiography (MRA) carotid bifurcation images with 3-D power Doppler ultrasound (PD US) and indirectly with 3-D B-mode US. Volumes were initially thresholded to reduce the uncorrelated noise signals. The registration algorithm subsequently maximized the mutual information measure between the PD US and 3-D MRA via iterative simplex search to find best "rigid body" transformation. We rated the performance of the algorithm visually on (n = 5) clinical MRA and 3-D PD US datasets. We also evaluated quantitatively the effect of thresholding, initial misalignment of the paired volumes and the reproducibility registration. We investigated the effect of image artefacts by simulation experiments. Preregistration misalignments of up to 5 mm in the transaxial plane, up to 10 mm along the axis of the carotids and up to 40 degrees resulted in 107 of 110 successful registrations, with translational and rotational errors of 0.32 mm +/- 0.3 mm and 1.6 +/- 2.1 degrees. The algorithm was not affected by missing arterial segments of up to 8 mm in length. The average registration time was 4 min. We conclude that the algorithm could be applied to 3-D US PD and MRA data for automated multimodality registration of carotid vessels without the use of fiducials.

A novel follicle culture system markedly increases follicle volume, cell number and oestradiol secretion

This study reports a novel, simple method for culture of mouse follicles which results in follicles with cell numbers similar toin vivofully grown follicles. Using this method, follicles (180–240 μm in diameter) were cultured in a 100 μl inverted drop of medium without oil and compared with culture in upright drops with and without a mineral oil overlay. Follicles, isolated from C57BL/6 × CBA/ca crossbred and MF1 inbred mice, were cultured individually at 37 °C in 96-well round-bottomed suspension cell tissue culture plates for 6 days. Follicles grown in the inverted drop culture system reached a markedly higher final diameter (means±s.e.m.; 471 ± 6.0 μm) as compared with the upright with oil (363 ± 2.7 μm) and without oil (358 ± 4.0) systems. There was no significant effect of mouse strain on follicle diameter. Follicular secretion of oestradiol and lactate into the medium was measured on days 2, 4 and 6 of culture. Secretion of oestradiol per follicle on day 6 was 2.49 ± 0.45 ng in the inverted and 0.90 ± 0.17 ng in the upright without oil system (P< 0.001). Follicular secretion of lactate on a per unit of follicle volume basis remained constant in the inverted system over days 2, 4 and 6 and was less (P< 0.001) than secretion in both the upright with and without oil systems. Follicle cell proliferation was markedly increased in the inverted as compared with the upright with oil system; the increases in cell numbers were significant on day 3 (P< 0.01) and on all subsequent days (P< 0.001). These results are discussed in relation to the supply of oxygen to the follicle in culture.

Nitric oxide, iNOS, and inflammation in cystic fibrosis

Nitric oxide (NO) is produced from three isoforms of nitric oxide synthase (NOS), neuronal (nNOS), endothelial (eNOS) and inducible (iNOS). Cystic fibrosis (CF) patients have an increased bacterial load in the airways which stimulates iNOS and therefore NO production. Upregulation of iNOS in normal epithelial cells protects the lung from damage, but in CF cells, iNOS is not upregulated and NO production is reduced. Reduced iNOS expression is associated with neutrophil sequestration in the lung, thus increasing the potential damage from neutrophil proteases and reactive oxygen species. In contrast, high concentrations of NO may augment the inflammatory process in acute lung injury from sepsis. Meng et al. have shown that cystic fibrosis epithelial cells, when stimulated by a cytokine mix and co-cultured with activated neutrophils, have reduced iNOS expression compared to normal epithelial cells. Although iNOS expression may not accurately reflect activity and NO production may arise from elsewhere, this study suggests that reduced iNOS expression may play a part in the pathophysiological processes in cystic fibrosis.

"Impact? What impact?" Epidemiological research findings in the public domain: a case study from north-east England

This paper reflects on the dissemination of potentially controversial research evidence about industrial air pollution and health in north-east England. It draws on a participant observation study of the local impact of a four-year epidemiological research programme in Teesside. The difficulties in and obstacles to disseminating research findings are explored. It may thus be described as a study of the impact of a study. We look at institutional resistance (including from the funders of the research) to any evidence indicating adverse health effects from industrial pollution. We also look at the failure of researchers to surmount such resistance and to communicate effectively with those who lived in the vicinity of the major industrial operations. This leads us to consider how conflicting notions of accountability coloured dissemination strategies as well as researchers' judgements. We offer a critique of fashionable and unduly consensual notions of a 'user community', in a context where different 'user communities' had incompatible expectations about the purpose of a piece of research and the significance of the data to emerge from it. The study also highlights the difficulties of disseminating research findings when the topic has the potential to affect economic interests.

Dose-related suppression of serum luteinizing hormone in women by a potent new gonadotropin-releasing hormone antagonist (Ganirelix) administered by intranasal spray

OBJECTIVE

To determine if the GnRH antagonist (GnRH-a) Ganirelix (Syntex Research, Palo Alto, CA), administered by intranasal (IN) spray to normal women, is absorbed into the systemic circulation and suppresses LH secretion.

DESIGN

A single center, open label, nonrandomized, dose-escalation study.

SETTING

Academic research environment.

PATIENT(S)

Normal female volunteers ages 23 to 43 years.

INTERVENTION(S)

Ganirelix was administered as a single dose by IN spray. The administered doses and the number of women receiving each of them were 0.1 mg (n = 1), 0.3 mg (n = 1), 1 mg (n = 2), 3 mg (n = 5), and 6 mg (n = 5). Blood samples were collected from -15 minutes to 24 hours after dosing.

MAIN OUTCOME MEASURE(S)

Serum concentrations of Ganirelix and LH.

RESULT(S)

Ganirelix was absorbed rapidly. The mean time to maximal serum levels in the 3- and 6-mg groups was 0.67 and 0.53 hour, respectively. Mean serum LH levels were suppressed by > or = 35% relative to baseline from 2 to 12 hours after dosing in both groups. The mean maximal percent decrease in serum LH was -62% (at 8 hours after dosing) and -74% (at 6 hours after dosing) in the 3- and 6-mg groups, respectively.

CONCLUSION(S)

Single dose IN administration of 3 or 6 mg of Ganirelix suppressed serum LH levels in women, further enhancing the potential clinical utility of this potent GnRH-a. This is the first clinical report of a GnRH-a reducing the secretion of a pituitary gonadotropin when administered by an IN delivery system. Based on the duration and extent of LH suppression observed in this study, Ganirelix, administered by twice daily IN spray, may be effective for the treatment of gonadal hormone-dependent disorders in women.

Three-dimensional ultrasound imaging of the vasculature

With conventional ultrasonography, the diagnostician must view a series of two-dimensional images in order to form a mental impression of the three-dimensional anatomy, an efficient and time consuming practice prone to operator variability, which may cause variable or even incorrect diagnoses. Also, a conventional two-dimensional ultrasound image represents a thin slice of the patients anatomy at a single location and orientation, which is difficult to reproduce at a later time. These factors make conventional ultrasonography non-optimal for prospective or follow-up studies. Our efforts have focused on overcoming these deficiencies by developing three-dimensional ultrasound imaging techniques that are capable of acquiring B-mode, colour Doppler and power Doppler images of the vasculature, by using a conventional ultrasound system to acquire a series of two-dimensional images and then mathematically reconstructing them into a single three-dimensional image, which may then be viewed interactively on an inexpensive desktop computer. We report here on two approaches: (1) free-hand scanning, in which a magnetic positioning device is attached to the ultrasound transducer to record the position and orientation of each two-dimensional image needed for the three-dimensional image reconstruction; and (2) mechanical scanning, in which a motor-driven assembly is used to translate the transducer linearly across the neck, yielding a set of uniformly-spaced parallel two-dimensional images.

Serial rapid naming skills in children with reading disabilities

This study compared the performance of children with reading disability (RD) and normal reading achievement (NRA) on tasks of serial rapid naming, verbal fluency, letter-based word retrieval, and articulatory speed. The groups, composed of children at two discrete age levels, one younger and one older, were matched for age, gender, and neighborhood school. Analyses of the on-line measurement of the children's serial rapid naming indicated that the children with RD had significantly larger reaction times and production durations than their NRA peers despite similar levels of accuracy. They also performed significantly worse on the categorical verbal fluency task, the letter-based word retrieval task, and the test of articulatory speed. The findings suggest that both access and post-access processes, such as oral-motor inefficiency that extends the duration of word production, may be implicated in the slower serial rapid naming that has typified many samples of children with RD.

A technique for magnetic resonance imaging of the temporomandibular joint

T1-weighted Magnetic Resonance Imaging (MRI) of 72 temporomandibular joints (TMJs) of symptomatic patients and normal subjects was performed after they had been clinically classified. The images were then interpreted by two radiologists, blinded to the clinical classification. The technique of imaging used a head coil for bilateral imaging, allowing a 3-position study in under 1 h. Correlation between MRI and clinical classification at the level of normal vs abnormal was achieved in 61/72 joints, giving a sensitivity of 79% and a specificity of 91% for MRI relative to the clinical assessment. True coronal images were of no added value. The addition of supplemental gradient-echo images was helpful in 12/15 joints. Osseous condylar abnormalities were present in 15 joints, all of which had otherwise identifiable disc abnormalities. Diminished condylar translation was a useful indirect sign of non-reducing disc displacement. We conclude that MRI is a very useful and reliable technique in TMJ imaging. The technique described is applicable to any MR unit, without the need for dedicated coils.

Effect of cystic fibrosis exacerbations on neutrophil function

In cystic fibrosis (CF), inflammation is caused by persistent bacterial infection from Pseudomonas aeruginosa and Burkholderia cenocepacia in the lung and is characterised by the persistent infiltration of massive numbers of neutrophils which leads to lung injury. The aim of this present study was to investigate the effects of CF exacerbations on the reactivity of peripheral blood neutrophils compared to data from a normal healthy control population. Peripheral blood neutrophils were isolated from control subjects and CF patients before and after an exacerbation of their lung disease. Isolated neutrophils were stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP) and phorbol 12-myristate 13-acetate (PMA) and the rate of superoxide generation and elastase activity measured and compared with neutrophils from healthy age-matched controls. Neutrophils from CF patients spontaneously generated higher levels of superoxide after resolution of the exacerbation compared to control neutrophils. The stimulated generation of superoxide from control neutrophils was not significantly different from neutrophils isolated from CF patients either before or after resolution of the CF exacerbation. Neutrophils from CF patients spontaneously released more elastase than control neutrophils but released less elastase than control neutrophils in response to fMLP. The stimulated release of elastase from neutrophils was not significantly different before compared to after resolution of the exacerbation. Neutrophils from CF patients displayed a different pattern of response than those from control subjects; however, CF exacerbations did not appear to modulate neutrophil function.

Somatosensory projections to the superior colliculus of the anaesthetized cat

1. Experiments in anaesthetized cats have shown that the superior colliculus receives deep afferent input from the forelimb and hindlimb, but not from the large superficial neck muscles. 2. Neuronal activity in the superior colliculus is readily elicited by electrical stimulation of C2 and C3 cutaneous nerves. A significant proportion of neurones so activated have multiple receptive fields and some with no identifiable receptive fields in regions innervated by C2 and C3 nerves have receptive fields elsewhere on the body surface. Many collicular neurones activated by C2 and C3 stimulation had no identifiable receptive fields. 3. Natural stimuli to the limbs, hitherto believed to activate only cutaneous receptors, are sufficient to activate deep receptors which contribute to the neuronal responses in the superior colliculus elicited by the natural stimulus. These same natural stimuli set up transmitted vibration adequate to excite receptors some distance from the applied stimulus. 4. No evidence was found for a rigorous somatotopy in the superior colliculus. The great majority of neurones received trigeminal input which is widely distributed throughout the superior colliculus. 5. Tactile stimuli to the face are most effective in eliciting unit activity in the superior colliculus and many neurones activated by these stimuli were shown to be tectospinal neurones. In particular, the specialized receptors of the face, including the glabrous skin of the snout (the planum nasale) and the vibrissae, are major sources of input to collicular neurones including tectospinal neurones. 6. It is suggested that a major role of the superior colliculus is in the organization of head movements associated with the use of the specialized receptor organs of the face in exploratory behaviours. The superior colliculus may also be involved in the organization of aversion movements of the head.

Chronic lung disease in common variable immune deficiency (CVID): A pathophysiological role for microbial and non-B cell immune factors

One of the most common and most severe forms of primary antibody deficiency encountered in the clinical setting is a heterogeneous group of syndromes termed common variable immune deficiency (CVID). This disorder is characterized by reduced immunoglobulin production and increased susceptibility to infection, particularly of the respiratory tract. Infection and subsequent immunological/inflammatory processes may contribute to the development of pulmonary complications such as bronchiectasis and interstitial lung disease. Immunoglobulin replacement and/or antibiotic therapy, to prevent infection, are routinely prescribed treatments. However, chronic lung disease, the major cause of morbidity and mortality in this patient cohort, may still progress. This clinical progression suggests that pathogens recalcitrant to currently prescribed treatments and other immunological defects may be contributing to the development of pulmonary disease. This review describes the potential role of microbiological and non-B cell immunological factors, including T-cells, neutrophils, complement, toll like receptors, and antimicrobial peptides, in the pathogenicity of chronic lung disease in patients with CVID.

Endothelins, their receptors, and retinal vascular dysfunction in galactose-fed rats

PURPOSE

Endothelins are potent vasoactive factors that have been implicated in the pathogenesis of several vascular disorders. This study was conducted to determine the role that endothelins play in the development of retinal microangiopathy under hyperhexosemic conditions induced by galactose feeding.

METHODS

Retinal blood flow was determined using Doppler sonography in galactose fed rats with or without an endothelin receptor antagonist (Bosentan) treatment and were compared to control rats after 1 and 6 months of follow-up. Levels of endothelin-1, endothelin-3, (ET-1, ET3) and receptors endothelin A, endothelin B, (ET(A), ET(B)) mRNA expression were determined by semiquantitative RT-PCR. Immunohistochemical distribution of ET-1 and ET-3, ligand binding, and autoradiography to determine ET receptor distribution were carried out.

RESULTS

Retinal vasoconstriction measured by an increase in resistivity index (RI) was present in 1 month galactose feeding compared to controls, which was prevented by Bosentan treatment. After 6 months of follow up all animal groups exhibited higher RI compared to their 1 month counterpart, although they were not different from each other. Compared to the controls, after 1 month levels of mRNA for ET-1, ET-3, and ET(A) were increased in galactose-fed rats, whereas ET(B) mRNA production remained similar to controls. After 6 months, all four genes exhibited increased levels compared to the controls, and no effect of Bosentan treatment on gene expression was evident. Increased immunoreactivity of ET-1 and ET-3 was determined, as well as increased ET receptor concentration was further present in the retina of galactose-fed animals.

CONCLUSION

The data suggests that endothelin production is increased under hyperhexosemic conditions and that the endothelins play an important role in regulating the hemodynamics of retinal blood flow.

College students with dyslexia: persistent linguistic deficits and foreign language learning

The first of these two studies compared college students with dyslexia enrolled in modified Latin and Spanish classes and non-dyslexic students enrolled in regular foreign language classes on measures of foreign language aptitude, word decoding, spelling, phonological awareness and word repetition. The groups did not differ on age or grade point average. Analyses indicated that students with dyslexia performed significantly poorer on the foreign language aptitude measures as well as on both phonological tasks, reading and spelling. In the second study, students with learning disabilities who were enrolled in a modified Latin class were not significantly different from their peers in a regular Latin class on grade point average or on performance on a proficiency examination at the end of the second semester. The data suggest that while phonological processing deficits persist into adulthood, students with dyslexia are able to acquire appropriate skills and information to successfully complete the University's foreign language requirement in classes modified to meet their needs.