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Biomedical subjects

G Ramos

Publications and source records attributed to G Ramos.

At least 55 records · Page 3Linked to original sources
PubMed1984

Preliminary study of hormone determinations during aminoglutethimide therapy for advanced breast cancer.

The aim of this study is to report on Aminoglutethimide-induced hormonal modifications in advanced breast cancer. Estradiol (E2), Testosterone (T), Dehydroepiandrosterone sulphate (DHEA(s] and Aldosterone (A) were determined before, and once every two weeks during treatment with Aminoglutethimide plus Hydrocortisone in 13 menopausal women with advanced breast cancer. The patients were selected either for their E2 and P4-receptor-positive in the original tumor or in metastases or by presenting objective clinical improvement to prior endocrine treatment. On the basis of the response to treatment the patients may be classified in two groups: 1) responders (n = 7) and 2) non-responders. No significant modifications of T concentrations were obtained in group 1 until after the first 8 months of treatment. One spontaneous menopausal patient with a T basal value of 0.80 ng/ml was evaluated during 12 months of treatment. From month 8, T diminished to values below 0.30 ng/ml, indicating a direct action of Aminoglutethimide, hydrocortisone or both drugs on ovarian steroidogenesis. The results obtained from the remaining hormonal parameters, evaluated in all the cases beginning from the second week of treatment, remained unchanged throughout the entire period of study. They were as follows: 1) E2 diminished with respect to basal values between 36 and 60%, thus confirming Aminoglutethimide inhibitory effect upon peripheral aromatization; 2) DHEA(s) diminished between 80 and 90%, indicating an adrenal inhibition due to the combined effect of both drugs, and 3) Aldosterone diminished to values between 80 and 110 pg/ml, these values being within the normal lower range.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Schwannoma of the intrathoracic vagus nerve].

Schwannomas, or neurilemomas, are tumors that originate in the sheaths covering peripheral nerve fibers. They are usually encapsulated, slow growing, and asymptomatic. Such tumors may appear in any nerve, although most are found in the extremities. Intrathoracic vagus schwannomas are very rare and only 72 cases have been reported. We present a new case in a 39-year-old man in whom chest film showed a well-defined, homogeneous mass measuring 3 cm in diameter located in the left para-aortic region. The presence of a smooth tumor on the vagus nerve and recurrent loop was confirmed by left lateral thoracotomy. After removal, the tumor was shown to be a vagal nerve schwannoma.

Adult↗
PubMedDate not supplied

Does alkalinization of 0.75% ropivacaine promote a lumbar peridural block of higher quality?

BACKGROUND AND OBJECTIVES: We did not find clinical studies of the alkalization of ropivacaine in the literature. The objectives of this study were: (1) to determine the quantity of sodium bicarbonate (NaHCO(3)), which alkalinizes 0.75% ropivacaine (with and without adrenaline); (2) to verify the physico-chemical alterations arising from this alkalization; and (3) to determine whether alkalinized ropivacaine produces a higher-quality epidural block measured via sensory-motor onset, block spread and anesthesia duration. METHODS: It was determined in the laboratory that 0.012 and 0.015 mEq of NaHCO(3), respectively, alkalinized 10 mL of the 0.75% ropivacaine solutions without and with adrenaline (1:200,000). In the second phase, the study was random and double-blind and involved 60 patients divided into 3 groups of 20 (G1, G2, and G3). Via epidural lumbar blocks, these groups received, respectively, 10 mL of 0.75% ropivacaine plus 0.5 mL of 0.9% NaCl (solution A), 10 mL of 0.75% ropivacaine plus 0.0012 mEq of NaHCO(3) (solution B), and 10 mL of 0.75% ropivacaine (with adrenaline) plus 0.015 mEq of NaHCO(3) (solution C). The pH, PCO(2) (partial CO(2) pressure), and the nonionized fractions of the 0.75% ropivacaine solutions were compared before and after the addition of 0.9% NaCl or NaHCO(3) or adrenaline plus NaHCO(3). The motor and sensory onsets, block spread, and the duration of the block were evaluated. RESULTS: The values of the pH, PCO(2), and nonionized fractions increased significantly in solutions B and C in relation to solution A. No differences among the groups were observed in relation to block spread and sensory-motor onset. The duration of the sensory blocks was significantly greater in the patients in groups G2 and G3. CONCLUSION: This study indicates that the quantity of NaHCO(3) needed to alkalize 10 mL of 0.75% ropivacaine at room temperature is 0.012 mEq. When the solution contains adrenaline 1:200,000 (mg.mL(-1)), up to 0.015 mEq of NaHCO(3) may be added. The alkalization of the 0.75% ropivacaine solution did not cause a reduction of sensory-motor onset, but did provide a significant increase in the duration of the epidural block with no significant differences between the solutions with and without adrenaline.

Adult↗
PubMedDate not supplied

Time-frequency analysis of the heart rate variability during the Valsalva manoeuvre.

We present an analysis of the heart rate variability during the Valsalva manoeuvre. The more frequently used time-frequency distributions were applied in order to analyse the dynamical behaviour of several spectral indexes during the manoeuvre. The influence of the branches of the autonomous system can be predicted following the evolution of the studied indexes. The exponential time-frequency distribution showed the best results in the graphical representation, as well as in the indexes calculation. The total power, the low-to-high frequency ratio and the fractal dimension were analysed throughout the different phases of the manoeuvre and a representative model of these parameters' evolution was proposed.

Adult↗
PubMedDate not supplied

[Sodium caseinate induces differentiation of 32D pluripotential hematopoietic cells].

AIM: To determine the role of sodium caseinate (CasNa) in the modulation of hemopoiesis. MATERIALS AND METHODS: 32D cells, a murine hemopoietic multipotential cell line dependent on interleukin-3 (IL-3) for proliferation and survival, were used. These cells were cultured with 0.5 ng/mL of IL-3, together with different concentrations of CasNa. We evaluated: proliferation (direct counting under the microscope and use of thymidine 3H), morphological differentiation (giemsa staining), cytochemistry (specific staining for monocytes and granulocytes), and function (presence of Fc receptors and reduction of nitro-blue tetrazolium). In addition, we determined cell viability through trypan blue exclusion and apoptosis using the TUNEL assay in situ. RESULTS: We showed that CasNa induced a decrease in cell proliferation, which is dose dependent, and is neither a result of a diminished cell viability, nor due to an increase in cell death through apoptosis. In addition, CasNa induces cell differentiation towards the monocytic lineage. CONCLUSIONS: CasNa has the capacity to differentiate 32D cells towards the monocytic lineage, and, importantly, has a potent differentiating activity on 32D cells being able to promote differentiation in a shorter time than the well known factors G-CSF and GM-CSF.

Apoptosis↗