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Biomedical subjects

J Zanelli

Publications and source records attributed to J Zanelli.

17 recordsLinked to original sources
PubMed2000

Conserved charges for gravity with locally anti-de sitter asymptotics

A new formula for the conserved charges in 3+1 gravity for spacetimes with local anti-de Sitter asymptotic geometry is proposed. It is shown that requiring the action to have an extremum for this class of asymptotia sets the boundary term that must be added to the Lagrangian as the Euler density with a fixed weight factor. The resulting action gives rise to the mass and angular momentum as Noether charges associated to the asymptotic Killing vectors without requiring specification of a reference background in order to have a convergent expression. A consequence of this definition is that any negative constant curvature spacetime has vanishing Noether charges. These results remain valid in the Lambda = 0 limit.

Journal Article↗
PubMed1994

Norms, reliability, and concurrent validity measures of the Portuguese version of the Depression Adjective Check Lists.

This study reports normative data of depressive mood in Brazil, using a Portuguese version of the Depression Adjective Check Lists (DACL; Lubin, 1981, in press). Participants (N = 1,063) were college students drawn from randomly selected courses in 10 Brazilian universities. Cross-cultural comparisons showed that this Brazilian sample had significantly higher depressive scores compared to Hispanic (p < .01), American (p < .01), and Israeli (p < .05) samples. The results also indicated that Brazilian females (p < .05) and young adults (p < .05) reported significantly more depressive mood than males and older adults, respectively. All reliability (internal consistency, split-half, and alternate form) and concurrent validity measures were found to be appropriate and compared well to other cross-cultural samples.

Adolescent↗
PubMed1991

Effect of unmodified eel calcitonin on gastric acid secretion and gastric ulcers in the rat.

A new peptide, eel calcitonin (eCT), synthesized to the sequence of calcitonin (CT) extracted from the ultimo branchial bodies of eels, is now on the market in some countries for clinical use in the treatment of Paget's disease of bone and in the prophylaxis or treatment of certain osteoporoses. We have now studied the effect of eCT on the inhibition of gastric acid secretion and protection against experimentally induced gastric ulcers in rats as other CTs have previously been shown to have such effects. EelCT shows a dose dependent inhibition of gastric acid secretion, both volume and concentration of acid - dose range 100-900 ng/Kg injected subcutaneously. Central administration is also effective at a dose of 100 ng/rat. There is no published evidence for a direct effect of CTs in the stomach and there is considerable speculation on possible mediating pathways. Somatostatin may be involved in the inhibitory effect of eCT on gastric acid secretion because when administered both centrally or peripherally eCT is ineffective in rats depleted of somatostatin by pretreatment with cysteamine. However, other mechanisms must also be involved as eCT has no preventive effect against gastric ulcers induced by ethanol but has a high index of protection against ulcers induced by cold restraint stress or indomethacin.

Animals↗
PubMed1987

Transient hypoparathyroidism induced by synthetic human parathyroid hormone-(1-34) treatment.

Daily injections of low doses of a synthetic fragment of human PTH [hPTH-(1-34) have increased iliac trabecular bone volume when used in the treatment of osteoporosis. In approximately 50 patients no major side-effects had occurred. However, during daily sc 100-micrograms injections of the peptide, one patient repeatedly developed parathyroid hypofunction which resolved each time treatment was stopped. Specific immunoglobulin G (IgG) antibodies binding [125I]hPTH-(1-34) were identified in the patient's serum, and positive immunohistochemical reactions were obtained when bovine parathyroid sections were exposed to the patient's IgG. After adsorption with PTH, the patient's IgG, free of anti-PTH antibodies, reacted with renal cell membranes, as demonstrated by indirect immunofluorescence and blocked renal PTH-dependent adenylate-cyclase activation in vitro. These results support the hypothesis that anti-PTH receptor as well as anti-PTH antibodies were generated during hPTH-(1-34) treatment, which led to the development of hypoparathyroidism when their titers were high.

Adenylyl Cyclases↗
PubMed1982

Risk factors for fractured neck of femur in the elderly.

During a 15-month period, 47 elderly female patients admitted to hospital with a fractured neck of femur were studied immediately prior to discharge, in comparison with 34 elderly female control patients undergoing elective surgery who had been admitted over the same period to the same orthopaedic wards. The principal differences between the two populations were that the fracture patients had a lower forearm trabecular bone density, with lower bodyweight (both lower muscle mass and lower fat content), increased body sway, worse eyesight and reduced mental acuity. The serum biochemistry of the two groups was almost indistinguishable except that the fracture patients tended to have slightly lower concentrations of proteins. There was no evidence to implicate dietary vitamin D deficiency, osteomalacia, oestrogen deficiency or alcoholism in the aetiology of the fracture, nor was there evidence to suggest alterations in endocrine function with respect to cacitonin or parathyroid hormone.

Aged↗