Role of local amyloidosis of the fundus oculi tissues in the pathogenesis of senile maculopathy

Histological, histochemical, and electron microscopic studies of tissues of the fundus oculi in 111 eyes with senile maculopathy revealed amyloid in the nodules. Bruch's membrane, and between the basal membrane of retinal pigmented epithelium and the internal collagen layer of Bruch's membrane in the center of the fundus oculi. The detected amyloid incorporations are referred to senile amyloidosis and reliably differ from amyloid in generalized amyloidosis. Comparative analysis of morphologic changes in tissues of the macular and paramacular areas of the fundus oculi and of the incidence of amyloid incorporations in them permit us to propose that accumulation of local senile amyloid is conductive to development and aggravation of senile maculopathy. A relationship between the degree of pigmented epithelium degeneration and accumulation of amyloid in the fundus oculi was revealed. The authors put forward a hypothesis of the pathogenesis of some stages of senile maculopathy, in which the principal role in the formation and deposition of abnormal protein, amyloid, is played by degenerative cells of pigmented epithelium. It is followed by amyloid destruction of Bruch's membrane and accumulation of amyloid under it and the basal membrane of pigmented epithelium. this in its turn, promoting neovascularization and formation of fibrovascular membrane.     

Further evidence linking urolithiasis and blood coagulation: urinary prothrombin fragment 1 is present in stone matrix

The fact that organic material is always present and distributed throughout each renal calculus suggests that it may play a role in stone formation. The organic matrix of calcium oxalate (CaOx) crystals freshly generated in urine in vitro contains urinary prothrombin fragment 1 (UPTF1) as the principal protein. In this initial study, matrix was extracted from 12 renal calculi and evaluated for the presence of UPTF1 using Western blotting. UPTF1 was present in all eight stones whose principal component was CaOx, and in one of two stones which consisted mainly of calcium phosphate (CaP). UPTF1 was absent from the two struvite calculi examined. The relationship between CaP and UPTF1 was explored further. Matrix harvested from CaP crystals freshly generated in urine in vitro was also shown to contain UPTF1 as its principal component. Our inability to detect UPTF1 in one mixed CaOx/CaP stone may be related to our methods of matrix retrieval, while its absence from two struvite stones argues against it being present in the other stones merely as a consequence of passive inclusion. This absence may be related to the alkaline environment typical of struvite stone growth. The finding that UPTF1 is present in some renal stones provides the first direct evidence that links blood coagulation proteins with urolithiasis.     

Maturation of the blood-retina barrier in the developing pecten oculi of the chicken

The major interest in the development of the blood-brain barrier and its underlying induction mechanisms is given by the crucial role they play in the maturation of the central nervous system in general. Whilst it is believed that it is the microenvironment in the brain that destines the endothelial cells to become committed to barrier properties, the analysis of the multitude of factors probably responsible for this commitment is extremely difficult. Therefore, in a previous study, we inaugurated the pecten oculi of the avian eye as a relatively simple in vivo model of the blood-brain barrier [Gerhardt, S. et al, Cell Tissue Res., 285 (1996) 91-100]. In the present study, we demonstrate data on the development of the pecten which allow us to understand better the commitment of barrier properties in endothelial cells in an environment which is considerably less complex than that realized in the brain. The pecten is built up by mainly two cell types, the pigmented glial cells and the endothelial cells. The pigmented cells, which are believed to originate from the retinal pigment epithelium, lose their tight junctions in the microenvironment of the vitreous body, whereas the endothelial cells, which originate from the permeable choroidal vessels, gain tight junctions and other barrier properties in the microenvironment of the vitreous body. On embryonic day 7 (E7), tight and gap junctions between epithelial-like glial cells line the vitreal border of the developing pecten. By E16, these junctions disappear, and the endothelial cells gradually acquire barrier characteristics (continuous and P-face associated tight junctions, no extravasation of lanthanum nitrate, and the exclusive expression of the glucose transporter isoform 1 and the barrier specific antigen HT7 in their luminal and abluminal membranes). The results are discussed considering the switch from an epithelial (glial) to an endothelial barrier.     

Giant ureteral stone in a 4-year-old boy

A 4-year-old boy presented with sudden onset of fever, pyuria, and bacteriuria. Ultrasound revealed left hydronephrosis and hydroureter. A plain abdominal radiography and excretory urogram showed a giant ureteral stone measuring 9 cm causing ureteral obstruction. Underlying anatomic or metabolic abnormalities were not detected. Extraction of the stone resulted in complete disappearance of the hydronephrosis and hydroureter.     

Treatment of orbicularis oculi muscle hypertrophy in lower lid blepharoplasty

Curschmann's spirals have been observed for more than 100 yr in the sputum of patients affected by lung cancer, asthma, chronic bronchitis, or in asymptomatic smokers. However, to date, their clinical significance and pathogenesis have not been completely explained. Curschmann's spirals in the sputum of two populations were studied: 164 traffic policemen of Rome and 119 subjects living in a rural district near Perugia. Of these two groups, only the first were exposed daily to urban environmental pollutions. Spirals were detected in the sputum of 29 traffic policemen and in 3 subjects from the group not exposed daily to urban environmental pollutants. Between these two groups of subjects the difference was statistically significant (P < 0.001). Therefore, daily exposure to urban atmospheric pollution may play a role in the production of Curschmann's spirals. Our two groups were also divided into smokers and nonsmokers to evaluate if cigarette smoking could influence the presence of spirals in sputum. Our study confirms the association of spirals in the sputum of smokers but also indicates their presence in individuals who never smoked but were exposed to environmental pollutants. We also noticed that exposure to pollution and cigarette smoking may have a synergistic effect on the formation of spirals in the respiratory tract.     

Yellowhammers get fatter in the presence of a predator

According to predictions from theoretical models, body mass and the daily foraging pattern of small birds in winter should be sensitive to predation risk. With increased risk of predation birds are expected to lower their body mass and shift their foraging to the afternoons. I studied the effect of predator presence on daily mass gain in captive yellowhammers, Emberiza citrinella. The birds were tested in unisex pairs, one bird being dominant over the other. In the first treatment the amount of food was restricted, and the daily pattern of mass gain was recorded. The second treatment was identical to the first, but, in addition, a stuffed sparrowhawk, Accipiter nisus, was displayed to the birds in the morning. Contrary to predictions from some theoretical models and other studies, the birds gained weight on days when the hawk was shown. Furthermore, the increased foraging happened mainly in the first half of the day, which also contradicts predictions from models. These results could be explained as a response to interrupted foraging, decreasing the probability of the birds acquiring the critical evening body mass. Alternatively, the birds increased their body reserves in preparation to leave a dangerous situation. Both dominance classes showed a similar response. The results suggest that the effects of predators on foraging interruptions should be included in models of daily routines of reserve accumulation. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.