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Biomedical subjects

A C Pinto

Publications and source records attributed to A C Pinto.

At least 37 records · Page 2Linked to original sources
PubMed1999

Can amyotrophic lateral sclerosis patients with respiratory insufficiency exercise?

The authors have shown in a recent paper that survival with amyotrophic lateral sclerosis (ALS) can be increased by the use of non-invasive methods of assisted ventilation (Bipap). However, the progression of muscle weakness was not affected and the quality of life was not positively enhanced. In ALS, reduced physical activity may partially be secondary to alveolar hypoventilation syndrome. This leads to deconditioning of ALS/motor neuron disease (ALS/MND) patients. The authors decided to investigate the possibility of reducing motor decline by exercising these patients to the anaerobic threshold, but simultaneously compensating the respiratory insufficiency with the Bipap STD. We conducted a controlled single blind study, exercising eight consecutive ALS/MND patients and used a control group of 12 ALS/MND patients. The patients were all evaluated during a 1 year period. Respiratory function tests (RFT) were performed at entry and then at 6 month intervals. Barthel, Functional Independent Mobility scale (FIM) and Spinal and Bulbar Norris scores were recorded every 3 months. There was a significant difference between the two groups with respect to FIM scores (P<0.03), but not Barthel scores (P<0.8). A slower clinical course (Spinal Norris score P<0.02) and a significant difference in the slope of the RFT (P<0.008) were observed in the treated group, suggesting that exercise may be beneficial in ALS patients once Bipap is used to control peripheral and muscle oxygenation.

Adult↗
PubMed1999

Antioestrogenic effect of trans-dehydrocrotonin, a nor-clerodane diterpene from Croton cajucara Benth. in rats.

This study examined trans-dehydrocrotonin (t-DCTN), a nor-clerodane diterpene isolated from the Brazilian medicinal plant Croton cajucara Benth., for a possible antioestrogenic activity using immature rats as a model system for bioassay of oestrogen, and for an antiimplantation effect in regularly cycling rats of proven fertility. In the antioestrogen test, t-DCTN (25 and 50 mg/kg) effectively prevented oestrogen-induced increases of uterine wet weights. In addition, the vaginal openings provoked by oestrogen were completely prevented by t-DCTN. However, blastocyst-implantation was only insignificantly affected in t-DCTN pretreated animals. These results suggest that t-DCTN may be an antioestrogen and warrants further studies with regard to its mechanism of action.

Animals↗
PubMed1999

Investigation of genotoxic activity of trans-dehydrocrotonin, a clerodane diterpene from Croton cajucara.

The genotoxic action of three doses of trans-dehydrocrotonin (t-DCTN), an active ingredient obtained from the bark extracts of an Amazon native plant, Croton cajucara, were examined in Swiss mouse bone marrow cells in vivo, submitted to acute intraperitoneal treatment, by micronucleus (MN) and chromosomal aberration (CA) tests. The statistical tests (Anova and Tukey) made to compare the results obtained in each of the three doses of t-DCTN with the negative-control group showed that the frequencies of MN and mitotic index were equal to the negative-control and that the frequencies of CA were lower than that observed in the negative-control. Therefore, based on our results it can be said that t-DCTN is not genotoxic nor cytotoxic to mouse bone marrow cells, submitted to acute intraperitoneal treatment in vivo. Teratogenesis Carcinog. Mutagen. 19:377-384, 1999.

Animals↗
PubMed1999

IGF-I levels rise and GH responses to GHRH decrease during long-term prednisone treatment in man.

Glucocorticoid excess is associated with a blunted GH response to GHRH. IGF-I levels in hypercortisolism are controversial and have been reported as low, normal or high. The aim of this study was to evaluate longitudinally time-dependent changes in the GH response to GHRH, IGF-I, IGFBP-3 and albumin values in patients during corticotherapy. Six patients received GHRH before and after one week and one month of prednisone administration (20-60 mg/d, orally). IGF-I, IGFBP-3 and albumin were determined in each test, at time 0. Ten normal controls were also evaluated in one occasion. There were no differences in basal GH values, GH response to GHRH, IGF-I and IGFBP-3 levels between controls and patients before starting corticotherapy. Albumin (g/l; mean+/-SE) values were lower in patients before treatment (31+/-4) than in controls (43+/-1). After one week of prednisone administration there was a significant decrease in peak GH (microg/l) levels (before: 18.8+/-7.4; 1 week: 5.0+/-1.3), which was maintained after one month (8.1+/-3.5). IGF-I (microg/l) levels increased significantly, from 145+/-23 to 205+/-52 after one week of therapy, reaching levels of 262+/-32 after one month. IGFBP-3 (mg/l) values did not increase significantly (before: 2.1+/-0.2; 1 week: 2.5+/-0.3; 1 month: 2.8+/-0.2). Albumin levels showed a significant rise both after one week (36+/-4) and one month (42+/-3) of corticotherapy. In summary, we observed a marked decrease in the GH response to GHRH after one week and one month of prednisone administration associated with an increase in circulating IGF-I and albumin values. The physiological implications of these findings are still uncertain. It is possible that glucocorticoids increase hepatic IGF-I and albumin synthesis, although other mechanisms may have a role.

Adult↗
PubMed1999

Acute dexamethasone administration enhances GH responsiveness to GH releasing peptide-6 (GHRP-6) in man.

OBJECTIVE: Acute administration of glucocorticoids stimulates GH secretion probably by a decrease in hypothalamic somatostatin release. GHRP-6 is a synthetic hexapeptide that increases GH secretion by a mechanism of action not yet fully known, but apparently not by inhibition of hypothalamic somatostatin release. The aim of this study was to evaluate the effect of acute dexamethasone administration on GH responsiveness to GHRP-6 in man. DESIGN: One group of subjects received iv GHRP-6 (1 microg/kg), GH-releasing hormone (GHRH; 100 microg), GHRH plus GHRP-6 or saline 3.5 h after oral acute dexamethasone administration (4 mg; at 0600 h). A second study group was treated with GHRP-6, GHRH or GHRP-6 plus GHRH after placebo ingestion, following the same protocol. PATIENTS: Sixteen normal subjects (mean age: 29 +/- 3.3 years), with normal BMI (22.4 +/- 2.0 kg/m2), were studied. Eight subjects received dexamethasone and the other eight were treated with placebo. MEASUREMENTS: Serum GH was measured by a two site monoclonal antibody immunofluorometric assay. RESULTS: In the placebo-treated subjects, mean peak GH (mU/l; mean +/- SE) and AUC (mU.min/l) values after GHRP-6 administration (peak: 43.8 +/- 9.0; AUC: 2262.0 +/- 459. 2) did not differ from those observed after GHRH injection (peak: 49. 8 +/- 12.0; AUC: 2903.4 +/- 872.6). The association of the two peptides markedly increased GH levels (peak: 172.4 +/- 34.2; AUC: 10393.0 +/- 1894.8) compared with the isolated administration of GHRP-6 or GHRH. In the subjects who received dexamethasone 3.5 h before saline injection, GH baseline values were significantly higher than those observed after 90 min of sampling (12.4 +/- 9.4 vs. 4.6 +/- 2.0). Mean GH peak and AUC values after GHRP-6 (peak: 78.8 +/- 11.0; AUC: 4114.6 +/- 588.2) and after GHRH administration (peak: 46.8 +/- 16.0; AUC: 3006.8 +/- 1010.0) did not differ significantly in the dexamethasone-treated subjects. In this study group, the administration of the two peptides together caused a significant increase in both peak (119.2 +/- 16.0) and AUC values (7377.0 +/- 937.2) compared with the response obtained after each peptide alone. When the two groups were compared, a significant increase in GH responsiveness to GHRP-6 was observed after dexamethasone administration compared with placebo. No differences in GH response to GHRH, or to the administration of the two peptides together, were seen between the two groups. CONCLUSIONS: Oral dexamethasone, at a dose of 4 mg, enhances GH releasing peptide-6-induced GH release when administered 3.5 h earlier. These results suggest that dexamethasone and GHRP-6 could act at different sites of GH releasing mechanisms. Further studies are necessary to elucidate these findings.

Adult↗
PubMed1999

Anti-tumour activity of two 19-nor-clerodane diterpenes, trans-dehydrocrotonin and trans-crotonin, from Croton cajucara.

The effects of two nor-diterpenes, trans-dehydrocrotonin (DCTN) and trans-crotonin (CTN) from Croton cajucara (Euphorbiaceae), on the survival of mice bearing Sarcoma 180 and Ehrlich carcinoma ascitic tumours, on the proliferation of cultured Ehrlich cells and TNF alpha activity were determined. When the mice were treated with 80 and 120 mg/kg of DCTN or 38 mg/kg of 5-FU a significant anti-tumour activity was obtained (%T/C of 128-140). The cytotoxicity against Ehrlich carcinoma was 16 microM for DCTN and CTN whereas the flavonoid quercetin was cytotoxic at 44 microM in 48 h cell culture. No apoptosis was seen on in vitro electrophoresis of DNA extracted from the tumour cells treated with DCTN and CTN. A significant TNF alpha activity was detected in Ehrlich tumour-bearing mice treated with DCTN suggesting an enhanced immune function.

Animals↗
PubMed1997

A bioactive seco-rosane diterpenoid from Vellozia candida.

Bioassay-directed fractionation of the bioactive alcoholic extracts of Vellozia candida yielded a new 6,7-seco-rosane diterpenoid, candidalactone (1), which showed moderate toxicity toward DNA repair-deficient mutants of Saccharomyces cerevisiae. Another new but inactive rosane diterpenoid, candidenodiol (3), was also obtained.

Antimutagenic Agents↗
PubMed1997

Hypoglycemic effect of trans-dehydrocrotonin, a nor-clerodane diterpene from Croton cajucara.

trans-Dehydrocrotonin (t-DCTN), a 19-nor-clerodane diterpene isolated from the bark of Croton cajucara Benth. (Euphorbiaceae) demonstrated a significant hypoglycemic activity in alloxan-induced diabetic rats but not in normal rats, at oral doses of 25 and 50 mg/kg body weight. The drug also effectively lowered the blood sugar levels in glucose fed normal rats. The hypoglycemic effect of t-DCTN was almost comparable to that produced by glibenclamide (2 mg/kg), a clinically useful drug. The results indicate the antihyperglycemic potential of t-DCTN.

Animals↗
PubMed1997

The use of carbon dioxide laser in pit and fissure caries prevention: clinical evaluation.

In this 4-year follow-up in vivo controlled study, 112 human permanent first molars from children between 6 and 11 years old were used to investigate the viability of the carbon dioxide (CO2) laser in promoting caries-free occlusal surfaces in permanent molars as an isolated form of treatment or associated with conventional fissure sealants. The findings suggest that occlusal caries prevention only by means of CO2 laser irradiation is not effective; that the utilization of photoactivated sealants, as well as its association with CO2 laser, applied over the occlusal fissures, are effective means of preventing occlusal caries, and that the application of CO2 laser over occlusal fissures prior to the application of a photoactivated fissure sealant improves the retention of the sealant.

Carbon Dioxide↗
PubMed1997

Effect of low-dose oral and intravenous dexamethasone administration on growth hormone secretion in children.

Acute dexamethasone administration (2 mg/m2 i.v. and 4 mg orally) increases growth hormone (GH) release in children. We evaluated the effect of a low intravenous dose (1 mg/m2) of dexamethasone on GH secretion in 8 short normal children and in 6 GH-deficient children. There was a significant GH increase at 120, 150 and 180 min in short normal children (maximal value: 18.9 +/- 2.1 micrograms/l; mean +/- EP), compared to placebo administration. In contrast, no significant GH elevation was seen in GH-deficient children (1.3 +/- 0.4 micrograms/l). There was no difference in the GH response after intravenous dexamethasone and oral clonidine in these same 8 short normal children and 6 GH-deficient children. Although no significant GH release was observed after dexamethasone or clonidine in GH deficiency, an increase in GH after GH-releasing hormone was seen (6.1 +/- 1.9 micrograms/l). There was a significant GH increase (18.5 +/- 3.3 micrograms/l) after low-dose (2-mg) oral dexamethasone administration in another 8 short normal children, which was similar to values after intravenous injection. No side effects were noted after intravenous or oral dexamethasone. In conclusion, low-dose intravenous or oral dexamethasone administration causes a marked GH release in short normal children, probably mediated by hypothalamic structures.

Administration, Oral↗
PubMed1996

A prolactin-secreting tumor in a patient with Klinefelter's syndrome: a case report.

We report the case of a patient with Klinefelter's syndrome who developed a prolactin (PRL)-secreting tumor. The patient developed headaches, visual alterations and also symptoms of hypogonadism despite appropriate testosterone (T) replacement therapy. The diagnosis of hyperprolactinemia was then suspected. The laboratory findings confirmed the hypothesis, showing high levels of serum PRL. The patient was initially treated with oral bromocriptine, and afterwards with the injectable form. There was a marked decrease in PRL levels and in tumor size. Although some neoplasms, like breast carcinoma and germ cell tumors, are known to occur more frequently in patients with Klinefelter's syndrome, an association with PRL-secreting tumor has not been reported yet. In conclusion, symptoms of hypogonadism in patients with Klinefelter's syndrome receiving appropriate T replacement therapy can suggest the presence of hyperprolactinemia.

Adenoma↗
PubMed1996

Investigation of anti-inflammatory and antinociceptive activities of trans-dehydrocrotonin, a 19-nor-clerodane diterpene from Croton cajucara. Part 1.

The anti-inflammatory and antinociceptive effects of trans-dehydrocrotonin, isolated from the bark of Croton cajucara (Euphorbiaceae), were investigated using several animal models. The trans-dehydrocrotonin produced a significant inhibition of carrageenin-induced paw edema and cotton pellet granuloma in rats. It also inhibited the writhings in mice induced by acetic acid, but did not show a significant effect in the hot-plate test in mice. The LD50 of t-DCTN was 555.0 mg/kg (p.o.) for mice.

Analgesics↗
PubMed1996

Growth hormone axis in cushing's syndrome.

All levels of the growth hormone (GH), GH binding protein (GHBP), insulin-like growth factor (IGF) and IGF binding protein (IGFBP) axis are influenced by chronic hypercortisolism. Thus, there is a blunted response to GHRH alone or together with other stimuli associated with a marked suppression of endogenous GH secretion but accompanied by normal GHBP, normal to low IGF-1 and GHBPs 1 and 3 with the correspondent 41.5 and 38.5-kD molecular forms of the latter presenting values similar to normal. These findings may suggest enhanced GH sensitivity with normal or increased IGF-1 bioavailability to the correspondent tissue receptors. In conclusion, the glucocorticoid (GC)-induced target tissue resistance can neither be attributed to the suppression of the GH axis nor to changes in circulating GHBPs 1 and 3. However, it may be related either to the described 12-to-20-kD inhibitor(s) which antagonizes postbinding IGF-1 bioactivity (gene expression) and/or by the downmodulation of activator protein-1 (Fos/Jun) activity by the GC-GC receptor complex.

Carrier Proteins↗
PubMed1995

Respiratory assistance with a non-invasive ventilator (Bipap) in MND/ALS patients: survival rates in a controlled trial.

Noninvasive ventilatory assistance, in ALS patients, with the bilevel intermittent positive air pressure (Bipap) was studied, in a prospective and controlled trial, by the authors. Twenty ALS bulbar patients, fulfilling El Escorial criteria for probable or definite disease, were selected. For the follow-up all patients were submitted to evaluation with the Norris scale, modified Barthel score and an analog scale of life satisfaction, every 3 months. All patients were also submitted to respiratory functional testing (RFT). Ten of these patients were treated with palliative management (group I), the remaining ten patients received Bipap support (group II). Clinical evolution curves and clinical parameters were not statistically different in both groups, except for the percentage of actual predicted value of vital capacity (p < 0.03), showing a more advanced disease in group II patients. Analog scale of life satisfaction showed improvement in the group II, even after the beginning of respiratory insufficiency, though without significance probably due to the small sample size (p < 0.1). Since 6 patients in group II are still alive survival rates were compared with log rank test considering cumulative survivals with Kaplan-Meier estimates. Total survival and survival from diurnal abnormalities in gas exchange (survival 1) were significantly longer for group II (p < 0.006 and p < 0.0004, respectively). In spite of the small number of patients, preliminary results strongly support the importance of BIPAP in ALS patients, though further studies must go on in order to optimize the best time for introducing Bipap.

Aged↗
PubMed1994

Norcucurbitacin gentiobiosides from Fevillea trilobata.

The new norcucurbitacin glycosides, andirobicin A gentiobioside [2], and andirobicin C gentiobioside [1], and the known fevicordin F gentiobioside [3], were isolated from the aqueous MeOH fraction of a liquid-liquid partition of the MeOH extract of the seeds of Fevillea trilobata. Their structures were determined by nmr and ms techniques.

Carbohydrate Conformation↗
PubMed1994

[Ultrasonographic diagnosis of the pathology of the rotator cuff and subacromial bursa: criteria].

Shoulder soft tissues echographic evaluation depends on the availability of well established echographic diagnostic criteria, which hasn't been fully accepted until nowadays, as results in that field have been controversial. The main purpose of the present study has been to determine the echographic criteria of the most frequent shoulder periarticular soft tissue pathology. A prospective study has been carried out, comparing the right to the left shoulder of 37 normals in order to determine the normal characteristics and limits of the selected echographic parameters (echogenicity, echostructure, dimensions in terms of width, rhythm of movement and rotator cuff competence ratio). Afterwards, the relative role of these variables in the identification of three different nosological groups determined through suitable gold standard diagnostic methods (36 suprasinatus tears, 20 supraspinatus tendinitis and 22 subacromial bursitis) has been determined. Lastly, the discriminant power of some echographic parameters association was tested, thus suggesting the echographic criteria to be selected. Results support the following criteria: 1) supraspinatus tears: cuff competence ratio less than 1, the difference value between the affected and the sound tendon thickness less than -1,8 mm associated with asymmetries of one of the remaining parameters (echogenicity, echostructure or rhythm); 2) supraspinatus tendinitis: the difference between the affected and the sound tendon thickness bigger than 1 mm associated with asymmetries of one of the remaining parameters (echogenicity, echostructure or rhythm); cuff competence ratio equal or above 1;3) subacromial bursitis: the difference between the affected and the sound bursa thickness bigger than 1 mm associated with asymmetries of one of the following parametres: echogenicity, echostruture or rhythm.

Acromioclavicular Joint↗
PubMed1993

New norcucurbitacin and heptanorcucurbitacin glucosides from Fevillea trilobata.

From the MeOH extract of the seeds of Fevillea trilobata (Cucurbitaceae) were isolated fevicordin A glucoside [1], cayaponoside B [2], cayaponoside D [3], a new norcucurbitacin glucoside, and a new heptanorcucurbitacin glucoside. The structure of the new norcucurbitacin glucoside, andirobicin A glucoside, was established as 29-nor-1,2,3,4,5,10-dehydro-25-methoxy-2-O-beta-D-glucopyranosyl- 3,16 alpha,20R,22 xi-tetrahydroxy-11-oxocucurbit-23-ene [4], and that of the novel heptanorcucurbitacin glucoside, andirobicin B glucoside, as 22,23,24,25,26,27,29-heptanor-1,2,3,4,5,10-dehydro-2-O-beta-D-g luc opyranosyl-3,16 alpha-dihydroxycucurbita-11,20-dione [5].

Antineoplastic Agents, Phytogenic↗