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Biomedical subjects

B Ricci

Publications and source records attributed to B Ricci.

At least 55 records · Page 3Linked to original sources
PubMed1988

Oxygen-induced retinopathy in newborn rats: effects of prolonged normobaric and hyperbaric oxygen supplementation.

An experimental study was conducted to verify the effects of prolonged normobaric and hyperbaric oxygen supplementation on retinal vessels in newborn animals. Nine litters of newborn Wistar rats were used in the following way. Two litters were used as controls. Two other litters received normobaric oxygen supplementation (FiO2 80%) for five days after birth. These rats were then removed and kept for five more days in room air. Retinopathy with marked peripheral retinal neovascularization was seen in these litters. Three other litters were exposed to the same treatment for ten days after birth, removed from oxygen, and kept for 15 more days in room air. Severe retinopathy with extraretinal proliferation and, in some cases, retinal detachment developed in these animals. Two other litters received hyperbaric (1.80 atm) oxygen supplementation (FiO2 80%) for ten days after birth and were then kept for 15 days in normobaric room air. These animals showed no evidence of peripheral retinopathy. It is possible that moderate hyperbarism exerts, in the newborn rat, a protective action against the toxic effects of oxygen supplementation on immature retinal vessels.

Animals↗
PubMed1987

Effects of hyperbaric, normobaric and hypobaric oxygen supplementation on retinal vessels in newborn rats: a preliminary study.

An experimental study was conducted on eight litters of newborn rats to evaluate the effects of supplemental oxygen administration on the retinal vasculature. The animals and their mothers were kept inside a pressure chamber and treated for the first 5 days of life. On the sixth day, they were removed and kept for five more days under room air and normobaric conditions. Three litters received continuous flow oxygen at 80% at a compression pressure of +81 kPa, one litter oxygen at 80% at a pressure of -39.5 kPa atms and three other litters received oxygen at 80% under normobaric conditions. The eighth litter was treated with room air oxygen at a compression pressure of +81 kPa. A severe retinopathy with marked retinal neovascularization was seen only in the newborn animals of the litters that received oxygen supplementation under normobaric or hypobaric conditions. Retinal vessels showed no pathological changes in the litters treated with hyperbaric normoxia or hyperoxia. It is possible to hypothesize that the prolonged period of oxygen supplementation failed to produce harmful effects on the retinal vasculature because the moderate hyperbarism caused mild retinal and choroidal vasoconstriction thus preventing excessive oxygen transport to the inner retina from the choroid during hyperoxia without inducing structural damage to the retinal tissue.

Animals↗
PubMed1981

Biomechanics of sit-up exercises.

Sit-up exercises performed by four male subjects revealed the presence of initial lumbar "hollowing" (lumbar curvature), or trunk hyperextension, or both prior to trunk flexion. Maximum muscular moment developed at the hip joint, which varied with sit-up exercise, was of moderate order of magnitude. Intraesophageal pressure, cardiopulmonary response, and metabolic response to a commonly used sit-up exercise (curl-up) reveals it to be a light exercise which stresses the muscles of the lower limbs as well as those of the trunk, especially the abdominal muscle group.

Abdominal Muscles↗
PubMed1979

GH secretion in open-angle glaucoma.

Open-angle glaucoma is frequently observed in patients with acromegaly suggesting that the somatotropic hormone might facilitate a condition of glaucoma. The open-angle glaucoma patients studied, displayed higher plasma human growth hormone (HGH) levels than control subjects 60 min (30.3 +/- 1.7 against 16.8 +/- 2.7 ng/ml; p less than 0.001) and 90 min (19.0 +/- 1.9 against 9.3 +/- 1.2 ng/ml; p less than 0.001) after intravenous administration of arginine (25 g in 30 min). The authors support the hypothesis that the increased plasma HGH level may interfere with the regulation of ocular pressure by modifying the flow of aqueous humor from the eyeball via changes in the sclero-corneal trabecular meshwork; these changes are also found in diabetic subjects. The interplay between HGH and changes of carbohydrate metabolism (frequently occurring in glaucomatous patients) may be at the root of the variations of intraocular pressure in open-angle glaucoma.

Arginine↗
PubMed1979

[Therapeutic efficacy of nicergoline in ophthalmology. Fluorescence retinographic study (author's transl)].

10-Methoxy-1,6-dimethyl-ergolin-8 beta-methanol-(5-bromonicotinate) (nicergoline, Sermion) administered intravenously (8 mg) in a group of 10 healthy subjects caused a reduction of the arm-retina circulation time and a reduction of the ocular tone. The therapeutic effectiveness in 37 patients with various eye diseases was tested by administering nicergoline p.o. at a dose of 30 mg/day for 30 days and 20 mg/day as maintenance dose for 60-120 days. Positive results, in various percentages, were observed in cases of arterial obstructions, venous thrombosis, diabetic retinopathies, senile macular degenerations, papilla ischaemic oedema, central serous chorioretinopathies. Nicergoline caused no subjective or objective undesired effects.

Adult↗
PubMed1976

[Secretion of GH and diabetic retinopathy].

Recently it has been studied a possible pathogenetic role of GH in diabetic angiopathy. The purpose of the present study was to verify whether the diabetic retinopathy is associated or not with a high plasma GH level. In an attempt to answer this question we did the dosage of plasma GH after a oral glucose load (110 g), Insulin (0,1 U/Kg) i.v., and arginin i.v. (25 g/30'). The plasma GH measurements were approximately the same as in normal patients. The Authors underline the importance of GH in pathophysiology of diabetic angiopathy and report all recent literature on this argument.

Adult↗
PubMed1975

[Simple glaucoma and diabetic disease].

Blood sugar, blood insulin and the insulinogenic index after oral glucose were studied in 41 subjects with simple glaucoma. Clinical diabetes was present in 9.76% and asymptomatic diabetes in 21.95%. It is suggested that a high incidence of diabetes may be expected in simple glaucoma, probably as expressions of a common genetic disorder.

Adult↗