Overexpression of VEGF-A induces neovascularization and increased vascular leakage in rabbit eye after intravitreal adenoviral gene transfer

Aims: The aim of this study was to determine dose–response effects of vascular endothelial growth factor A as delivered using an adenoviral vector on vascular growth and pathological changes in the rabbit eye. Moreover, we wanted to develop a large animal model for angioproliferative diseases in the eye. Methods: Seventeen New Zealand White rabbits were injected with adenoviral vascular endothelial growth factor‐A (AdVEGF‐A) intravitreally with different doses (10⁹–10¹¹ vp). Controls were injected with an empty virus (AdCMV). Some animals had a combination of AdVEGF‐A and AdsKDR (a soluble form of the VEGF receptor‐2). Animals were killed 6 days after the gene transfer. On the basis of these results, 14 rabbits were injected intravitreally with AdVEGF‐A or adenoviral LacZ (AdLacZ) with 10¹⁰ vp in a volume of 0.1 mL. Animals were killed 3, 6, 14 and 28 days after the gene transfer, eyes were removed and analysed histologically. Results: In enzyme‐linked immunosorbent assay (ELISA) analysis, human VEGF‐A was present in vitreous humour in all VEGF‐A transduced eyes. The amount of VEGF‐A showed a dose‐dependent increase with the AdVEGF‐A dose and was the highest 6 days after the gene transfer. Histologic analyses revealed an increased capillary area and density in the AdVEGF‐A eyes when compared with the AdLacZ eyes (P < 0.05). In the AdVEGF‐A/AdsKDR eyes the average capillary area was not increased compared with AdLacZ eyes. Conclusion: This model could be useful for large animal studies regarding the pathogenesis of neoangiogenesis and for the development of new therapeutic strategies for angioproliferative diseases of the eye. Our results establish the key role of VEGF‐A in the induction of neovascularization and pathological changes in the rabbit eye.     

Heparan sulphate and HB-GAM (heparin-binding growth-associated molecule) in the development of the thalamocortical pathway of rat brain

Extracellular matrix (ECM) molecules, such as laminin, tenascin, chondroitin sulphate proteoglycans and heparan sulphate proteoglycans have been suggested to have 'signpost' and directing roles in the formation of axonal projections in cortical development. We show here that the expression of the neurite outgrowth-promoting protein heparin-binding growth-associated molecule (HB-GAM) and N-syndecan, a transmembrane heparan sulphate proteoglycan previously isolated as a receptor for HB-GAM, is spatiotemporally associated with the developing thalamocortical pathway in the rat brain. Using in situ hybridization, thalamic neurons were shown to express mRNA for N-syndecan, and in vitro, thalamic neurons grew more neurites on HB-GAM than on laminin. The HB-GAM-induced neurite outgrowth in thalamic neurons was inhibited by heparitinase, heparin, soluble N-syndecan and by an excess of soluble HB-GAM in the culture medium. In a pathway assay, thalamic neurons selectively preferred attaching and growing neurites on matrices containing HB-GAM than on those containing fibronectin or laminin alone, suggesting that HB-GAM may modulate the effect of other ECM proteins. On an unfixed brain slice preparation, thalamic neurons repeatedly showed a typical neurite outgrowth and attachment pattern resembling the expression pattern of HB-GAM. On the brain slices, the neurite outgrowth was significantly inhibited by heparitinase, heparin and soluble HB-GAM, thus displaying features of neurite outgrowth on matrix-bound HB-GAM. Our results suggest that HB-GAM is important for the neurite outgrowth of thalamic neurons and it may function as an ECM-bound guidance cue for thalamic neurons that possess HB-GAM-binding heparan sulphates on their cell membrane.     

Regulation of ventricular atrial natriuretic peptide release in hypertrophied rat myocardium. Effects of exercise

Left ventricular hypertrophy is characterized by stimulation of ventricular synthesis of atrial natriuretic peptide (ANP). This study was designed to test the hypothesis that the increased ventricular ANP levels participate in the release of ANP into the circulation. Swimming was used as a physiologic model to induce ANP release from the heart, and atrial and ventricular levels of immunoreactive ANP (IR-ANP) and ANP messenger RNA (mRNA) were measured simultaneously in the spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats at rest and after swimming. IR-ANP concentration in the left ventricle of 1-year-old SHR with severe left ventricular hypertrophy was increased in association with the augmentation of ANP mRNA levels, whereas right ventricular levels of ANP were reduced in SHR compared with normotensive controls. A 30-minute exercise in hypertensive and in normotensive rats resulted in marked increases in mean arterial pressure, heart rate, plasma catecholamine levels, blood lactate levels, and plasma IR-ANP concentration. The increased ANP secretion was associated with a decrease in left (34-39%) and right (24%) ventricular concentration of IR-ANP; transmurally, this depletion of ventricular IR-ANP was greatest (28%) in the endocardial layer of the left ventricle of SHR. No significant differences were noted in total atrial and left or right auricular IR-ANP concentration between SHR and WKY rats or between the resting and swimming rats. When studied in vitro with an isolated, perfused heart preparation, the hypertrophic ventricular tissue after atrialectomy secreted more ANP into the perfusate than did control hearts; in SHR, ventricles contributed 28% of the total ANP release to perfusate, and in normotensive control rats, ventricles contributed 8%. These studies show that stimulated release of ANP is associated with depletion of endocardial left ventricular stores. The amount of ANP released in vitro and in vivo correlated with the degree of hypertrophy of the ventricle. Finally, the phorbol ester, known to increase ANP secretion from intact perfused hearts, had only a limited effect on ANP release after atrialectomy, suggesting that the secretion of ANP from ventricular cells may be mainly of the constitutive type.     

Outbreak of poliomyelitis in Finland in 1984. Description of nine cases with persisting paralysis

Finland has been free of poliomyelitis since 1964 following a high coverage regular immunization programme using the Salk-type trivalent inactivated poliovirus vaccine. In late 1984 an outbreak of poliomyelitis with widespread circulation of poliovirus type 3 throughout the country was found. A thorough surveillance revealed 9 sporadic cases with acute persisting paralysis, all shown to be caused by poliovirus type 3. The preceding 20-year period free from poliomyelitis contributed to some diagnostic problems.     

Pleuropulmonary involvement during bromocriptine treatment

The use of bromocriptine in the treatment of Parkinson's disease is increasing. More than 20 cases of suggested drug-induced pleuropulmonary disorders during bromocriptine therapy have been reported. We describe four male parkinsonian patients taking bromocriptine in whom pleuropulmonary abnormalities were discovered in a pulmonary hospital during a one-year period. In only one case were the roentgenographic changes reversible after withdrawal of the drug. Pleural fluid from two patients was analyzed and showed lymphocyte-predominant chronic inflammatory changes. Raised erythrocyte sedimentation rate (ESR) and C-reactive protein values decreased after cessation of bromocriptine. Lung function studies demonstrated volume restriction with normal or high CO transfer coefficient. The frequency of pleuropulmonary changes during bromocriptine therapy may be greater than assumed, and such patients may initially present with nonrespiratory symptoms. Follow-up of patients during bromocriptine treatment by ESR, C-reactive protein, and chest roentgenogram is recommended.     

Electron spin resonance (ESR) probe for interventional MRI instrument localization.

This article presents a miniaturized electron spin resonance (ESR) probe for deducing the position of a surgical instrument on an MR image. The ESR probe constructed was small enough to fit inside a 14-G biopsy needle sheath, and position information of the sheath could be acquired using a simple gradient sequence. The position accuracy was estimated from needle trajectories as inferred from the needle artifact, the actual physical trajectory, and measured coordinates. The probe was able to track the tip of a biopsy needle quickly (10 samples/sec) and precisely with accuracy better than +/-2 mm. J. Magn. Reson. Imaging 1999;10:216-219.     

A national series of 244 sinonasal cancers in Finland in 1990–2004

Sinonasal cancer is still a somewhat controversial entity because most series are single-center studies. The aim of this study was to give more accurate and generalisable information about treatment of the neck and prognosis of sinonasal cancer. Retrospective, population-based, multicentre study. Altogether 244 patients diagnosed in 1990–2004 were evaluated. The 3- and 5-year disease-specific survival (DSS) rates after treatment with curative intent were 68 and 57%, respectively. Regional status at the time of the diagnosis (P < 0.001, log rank) and local recurrence (P = 0.02, log rank) during the follow-up had a statistically significant effect on DSS. Initially 13% of the patients were diagnosed with neck metastasis. The proportion of regional recurrences during the follow-up was 9%, but it did not have a statistically significant impact on DSS (P = 0.68, log rank). Histopathology had no statistically significant impact on survival in this material of 244 patients. In conclusion, routine elective neck treatment of all sinonasal cancer patients is not recommended, but the importance of the treatment of the primary location is emphasised.     

B cell helper T cells and type 1 diabetes

Type 1 diabetes is an autoimmune disease typically starting in childhood that culminates in the destruction of insulin-producing beta cells in the pancreas. Although type 1 diabetes is considered to be a primarily T cell–mediated disease, B cells clearly participate in the autoimmune process, as autoantibodies recognizing pancreatic islet antigen commonly appear in circulation before the onset of the disease. T cells providing helper functions to B cells have recently been shown to be involved in the pathogenesis of a wide range of antibody-associated immune disorders. These T cells include CXCR5-positive follicular T helper (Tfh) cells, and a recently described closely related CXCR5-negative subset coined peripheral T helper (Tph) cells. Here, we review the current state of knowledge on different B cell helper T cell subsets, focusing on their potential involvement in the development of type 1 diabetes.