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Biomedical subjects

J Ramos

Publications and source records attributed to J Ramos.

At least 19 recordsLinked to original sources
PubMed1992

EEG activity during estral cycle in the rat.

EEG activity was recorded from right and left parietal cortex in adult female rats daily during 6 days. Immediately after EEG recording vaginal smears were taken and were microscopically analyzed to determine the estral stage. Absolute and relative powers and interhemispheric correlation of EEG activity were calculated and compared between estral stages. Interhemispheric correlation was significantly lower during diestrous as compared to proestrous and estrous. Absolute and relative powers did not show significant differences between estral stages. Absolute powers of alpha1, alpha2, beta1 and beta2 bands were significantly higher at the right parietal cortex. Comparisons of the same EEG records with estral stages randomly grouped showed no significant differences for any of the EEG parameters. EEG activity is a sensitive tool to study functional changes related to the estral cycle.

Animals↗
PubMed1992

The antrum exclusion technique in cholesteatoma surgery.

A new surgical technique for the treatment of cholesteatoma is reported. The technique involves auto-exclusion for exteriorization of the attic and tympanic box only. The resulting cavity is rather small. The technique allows visual post-operative control of the attic and tympanic membrane. There is no visual access to the mastoid cavity which, however, is the most unlikely site for occurrence of a residual cholesteatoma. The proposed technique was applied to 102 patients and both the anatomic and functional results obtained are reported.

Adolescent↗
PubMed1992

Changes in the waking EEG as a consequence of sleep and sleep deprivation.

Electroencephalographic (EEG) activity was monopolarly recorded during resting wakefulness in 10 volunteers under the following conditions: at night before going to sleep, at night before total sleep deprivation, in the morning after waking, in the morning after sleep deprivation and at night after having slept during the day. Absolute and relative power and inter- and intrahemispheric correlation were established. After diurnal and nocturnal sleep as compared to sleep deprivation, we obtained the following significant results: interhemispheric correlations were higher; intrahemispheric correlations were lower; absolute power of alpha 2, beta 1 and beta 2 was lower; and relative power of alpha 2 and beta 2 was lower. EEG changes as a consequence of sleep or lack of sleep are dependent on prior sleep and/or wakefulness and not on circadian phase. EEG activity during wakefulness is a sensitive parameter and a useful tool to assess the consequences of sleep on brain functional organization.

Adult↗
PubMed1992

Occipital encephalocele associated with a dermoid cyst.

The case of a neonate with a dermoid cyst originating within an occipital encephalocele is reported. The finding of the tumor was made during the routine repair of the meningoencephalocele. To our knowledge this is the first time that this association has been described.

Brain Neoplasms↗
PubMed1992

[Gammagraphic findings in hepatic focal nodular hyperplasia].

Two cases, of focal nodular hyperplasia (FNH) are presented which were detected by chance and in which the gammagraphic study was the only parameter which indicated the changes that occurred in the hyperplasia revealing a hypervascular mass, colloid capture and 99mTc-DISIDA retention in the later image. These liver masses are now seen more frequently given the wide use of echography and the gammagraphic studies could be useful in the orientation of their nature in a non aggressive manner.

Adult↗
PubMed1991

[Histochemical and immunohistochemical study of the lymphoid tissue of swine: lymphatic ganglia, spleen and thymus].

Immunohistological (S-100, cIg) and enzyme histochemical (ANAE/ANBE, beta-glu, ATPase, AcP) investigations were carried out to identify lymphocyte and reticular cell subpopulations "in situ", in pig lymphoid tissue (lymph node, spleen, and thymus) of a 6 months old group, and a 6-9 days old one. By means of immunohistological techniques, in the 6 month old pigs we could detect S-100 protein (PAP), chiefly in T-areas lymphocytes, but we also found some S-100 positive lymphocytes in spleen follicles. Also S-100 protein were detected at Follicular Dendritic Cells (FDC) in lymph node and spleen; and Reticular Fibroblastic Cells (RFC) only in the first one. Finally, S-100 were noted in Hassall corpuscles (thymus), nervous fibres, and endothelial cells too. Using PAP (IgG, IgM) and IPI (IgA) techniques we could detect lymphocyte cytoplasmatic surface immunoglobulins (cIg) in lymphocytes, lymphoblastoid and plasmacytoid cells in nearly all tissue compartments. By means of histochemical techniques we could identify T-area lymphocytes ANAE/ANBE and beta-glu positives (cytoplasmatic spots) and B-area lymphocytes ATPase positive; macrophages, and polymorphonuclear eosinophiles PHNE being ANAE/ANBE and beta-glu positives (diffuse cytoplasmic stain); and Hassall corpuscles ANAE/ANBE and AcP positives. Concerning to reticular cells, we found FDC and RFC in lymphoid follicles, and Interdigitating Reticular Cells (IDC) in lymphoid diffuse tissue, with enzyme activity (all the enzymes studied) in nearly all the cases. In piglets, the immunohistological and histochemical pattern was nearly the same.

Animals↗
PubMed1991

[Spectrum analysis of the variability of heart rate in athletes].

OBJECTIVES: Characterize power spectrum pattern of the heart rate variability and assessment of the relative contributions of sympathetic and parasympathetic cardiac nervous system control in athletes. STUDY DESIGN: Prospective study of athletes and sedentary healthy control group sex and age matched. SUBJECT AND METHODS: 8 athletes, 3 female and 5 male, swimming (4), canoeing (2) and cycling (2), aged 17.4 +/- 3.6 years, and 8 sedentary healthy controls. ECG signals were recorded after a period of 15 minutes in supine rest with controlled breathing at 15 cycles/min. Signal acquisition was done at 300 samples/sec. From 512 consecutive heart beats, we calculated the average, the standard deviation, the maximum and the minimum values and the rate between the longest and the shortest R-R interval (E/I). We also calculated, after computing the fast Fourier transform, the total spectrum power, the low frequency component (LF, from 0.01 to 0.15 Hz) and the high frequency component (HF, greater than 0.15 Hz) and its ratio (LF/HF). RESULTS: The average R-R interval was 921 +/- 154.2 msecs and 673.2 +/- 98 msecs, the standard deviation was 72.5 and 29.4 msecs and the ratio E/I 1.63 +/- 0.14 and 1.28 +/- 0.08, respectively for athletes and control group. Differences between groups were significant (p less than 0.01) for all parameters, with higher variability in the athletes. Both spectral bands (LF and HF) and higher power in athletes (LF = 0.54 +/- 0.23 and HF = 0.76 +/- 0.14) than in the control group (LF = 0.14 +/- 0.10 and HF = 0.18 +/- 0.15) (p less than 0.001). There were no significant differences for LF/HF ratio, or normalized LF (LF%) or normalized HF (HF%) between groups. CONCLUSIONS: The present results indicates higher power of both spectral bands (LF and HF) and higher amplitude of the respective peaks in athletes when compared with healthy sedentary, with a clear predominance of the HF band in the total spectral power density, which suggest that the higher heart rate variability observed in athletes reveals the predominance of parasympathetic activity, without reduction of the sympathetic tone.

Adolescent↗
PubMed1990

Regulation of potassium fluxes in Saccharomyces cerevisiae.

To investigate the regulation of K+ fluxes in Saccharomyces cerevisiae the dependence of K+ efflux and Rb+ influx on [K+]i, pHi, [Na+]i, membrane potential, cell volume, and turgor pressure were studied in cells with different K+ contents. By decreasing the cell volume with osmotic shocks and the cellular pH with butyric acid the following was found. (1) The K+ efflux induced by uncouplers decreases simultaneously with the decrease of the K+ content of the cell, but the process was insensitive to [K+]i, pHi, cell volume and turgor pressure. The internal presence of Na+ inhibited this K+ efflux. (2) The increase of the Vmax of Rb+ influx observed in low-K+ cells is due to the decrease of the pHi and probably mediated by the increase of the activity of the plasma membrane ATPase. The Vmax is independent of [K+]i, [Na+]i, cell volume and turgor pressure. (3) The decrease in the Km of Bt+ influx observed in low-K+ cells does not depend directly on [K+]i, pHi, cell volume or turgor pressure. If Na+ is present, [Na+]i might be directly involved in the regulation of the Km.

Carbonyl Cyanide m-Chlorophenyl Hydrazone↗
PubMed1990

[Extracorporeal biliary lithotripsy: results in 60 cases of single calculus].

The outcome of 60 cases of single biliary stone with a maximum diameter of 25 mm was evaluated. The patients were symptomatic, with functioning gallbladder, and were selected from a group of 180 to evaluate the effects of electrohydraulically generated shockwaves on a priori ideal cases for this procedure. In seven patients fragmentation was not achieved, probably because of the pigmentary character of the stone, that was later verified at cholecystectomy. In 20 out of the 53 in whom fragmentation was satisfactory (38%), fragments were not observed after 24 hours. 32 patients (54%) had a stone-free gallbladder 3 months afterwards; at six months, the number had increased to 40 (66%). This rate becomes 77% if only the cases with fragmentation are considered. In 29% of patients episodes of colicky biliary pain developed as complication. No case of pancreatitis or stuck in gallstone were observed. We conclude that shock waves appear as an excellent therapeutic alternative in single gallstones up to 25 mm in size.

Adult↗
PubMed1990

Priapism and Fabry disease: a case report.

A 10-year-old boy presented with priapism of 10 h duration which after unsuccessful conservative measures, was relieved by a saphenocorporeal shunt. A 4-year history of intermittent vague aching of fingers and toes accompanied by low-grade fever was reported. Fabry disease was confirmed by the lack alpha-galactosidase activity in serum and leucocytes. Other characteristic features of Fabry disease were not present. The condition was also diagnosed in his 14-year-old brother and suspected in his maternal grandfather who died at the age of 49 from renal failure of unknown aetiology.

Child↗
PubMed1990

Transcutaneous electrical nerve stimulation (TENS) for the treatment of primary dysmenorrhea: a randomized crossover comparison with placebo TENS and ibuprofen.

In a randomized four-way crossover study, 32 women with primary dysmenorrhea were treated with transcutaneous electrical nerve stimulation (TENS) for two cycles, placebo (sham) TENS for one cycle, or ibuprofen 400 mg four times a day for one cycle. The TENS setting used was 100 pulses per second with 100-microsecond pulse widths. The subjects were allowed to adjust the amplitude to a comfortable level. The pain rescue medication was ibuprofen 400 mg as needed, up to 1600 mg/day. Significantly more subjects who had TENS treatment did not require rescue medication or required less backup ibuprofen at 0-4, 4-8, and 8-12 hours after the onset of dysmenorrhea and starting treatment, as well as during the first 24 hours and for the duration of the menstrual flow, when compared with placebo TENS or ibuprofen-treated cycles (Tukey multiple comparison, P less than .01). Transcutaneous electrical nerve stimulation significantly delayed the need for ibuprofen by an average of 5.9 hours, compared with 0.7 hours when using ibuprofen alone (P less than .05, paired t test). Transcutaneous electrical nerve stimulation alone provided good to excellent subjective pain relief in 42.4% of subjects, compared with 3.2% with placebo TENS, and significantly reduced diarrhea, menstrual flow, clot formation, and fatigue compared with placebo TENS. Transcutaneous electrical nerve stimulation plus less ibuprofen provided pain relief equivalent to that obtained with ibuprofen alone (71 and 75% of the subjects, respectively). We conclude that TENS is a safe, effective, non-medication method for managing primary dysmenorrhea and that TENS plus ibuprofen was the best overall treatment, as indicated by pain relief.

Adult↗
PubMed1990

The supraoptic nucleus: a morphological and quantitative study in control and hypophysectomised rats.

Several quantitative and morphometric parameters were analysed in the pars principalis of the supraoptic nucleus (SON) of the hypothalamus in control and hypophysectomised rats at several postnatal ages. The cell number in the control group remained approximately constant from Day 1, when it was 5034 +/- 348 (mean +/- S.D.M.), until Day 90 when the number of cells was 5234 +/- 110. In the group that was hypophysectomised on Day 60, the number of neurons on Day 90 was 1366 +/- 131, which represents a loss of 74% of the neurons. Morphometric parameters on Day 90 indicated a significant difference in nuclear size, 52.1 +/- 6.7 microns 2 in controls and 57.3 +/- 6.8 microns 2 in the hypophysectomised group. Based on these results, it is concluded that there is no postnatal loss of neurons in the pars principalis of the SON in normal rats. As a consequence of the stress induced by hypophysectomy, the remaining cell population undergoes adaptive changes in the nuclear RNA synthesis machinery of neurohypophyseal hormone precursors in order to compensate for the reduction in the number of neurosecretory neurons.

Age Factors↗
PubMed1989

[Dysplastic nevus syndrome with familial melanoma (type D2)].

A 37 year-old woman presented with type D2 familial dysplastic nevus syndrome with melanoma. A melanoma was excised of her back and more than one hundred pigmented lesions, four of which presented histologic characteristics of dysplastic nevus were observed. Several relatives of her presented multiple nevi and a sister of her mother and a brother of the patient had been diagnosed of melanoma. It is well established that such kind of nevi are precursor for melanomas, particularly familial forms. The clinical identification of such lesions is very simple and facilitates the diagnosis and early treatment of melanoma.

Adult↗
PubMed1989

Regional distribution of glycoconjugates in normal, transitional and neoplastic human colonic mucosa. A histochemical study using lectins.

Regional distribution of glycoconjugates in normal and neoplastic colonic mucosa was studied by means of eight lectins: Dolichos biflorus (DBA), Glycine max (SBA), Triticum vulgare (WGA), Arachis hypogaea (PNA), Griffonia simplicifolia-I (GS-I), Canavalia ensiformis (Con A), Limax flavus (LFA), and Ulex europaeus-I (UEA-I). The lectin binding patterns were examined in 40 normal colonic mucosa (NM) (12 proximal (P) and 28 distal (D], 38 carcinomas (15 P and 23 D), and 31 transitional mucosa (TM) (9 P and 22 D). Sections of NM located 5 cm and 10 cm distant from the tumour and sections from the resection margins (more than 10 cm from the tumour) of the surgical specimens were also studied in 19 cases (6 P and 13 D). In NM, regional differences between the proximal and distal colon were detected with most lectins. DBA, SBA and LFA bound mainly to the goblet cell mucin of the distal colon, while GS-I and UEA-I labelling predominated in proximal colonic mucosa. The lectin reactivity in carcinomas was: DBA 26%, SBA 63%, PNA 95%, GS-I 66%, UEA-I 76%, WGA 100%, Con A 92% and LFA 42%. No regional differences were observed in the lectin patterns of proximal and distal colonic carcinomas nor was any relationship detected between lectin reactivities and Dukes stage, size or histological type of tumours. Transitional mucosa of both the proximal and distal colon showed an increase in PNA-binding and loss of DBA and SBA. LFA and UEA-I reactivity in proximal TM was similar to that observed in proximal NM. Distal TM showed a decrease in LFA labelling and the appearance of UEA-I reactivity in goblet cell mucin in 5 cases (23%). The reactivity of the other lectins was as with NM. The only change in normal mucosa distant from tumours was a focal increase in PNA reactivity in 4 cases. These findings suggest that carcinomas from different colonic regions have a more uniform distribution of carbohydrates than the respective NM.

Colon↗
PubMed1989

Effect of normal sleep and sleep deprivation on interhemispheric correlation during subsequent wakefulness in man.

EEG activity was recorded from the right and left central, temporal, parietal and occipital derivations in 10 volunteers under the following conditions: at night before going to sleep, at night before sleep deprivation, in the morning after waking, in the morning after sleep deprivation and in the morning 48 h after recovery. Interhemispheric correlation and relative power were calculated for EEG samples of 20.48 sec. In the morning after normal sleep interhemispheric correlations were higher in all derivations in comparison to presleep values, while in the morning after sleep deprivation, interhemispheric correlations were lower or similar to predeprivation values in all derivations except the temporal cortex. The relative power of beta was significantly lower after normal sleep and higher after sleep loss, while the relative power of low frequencies was higher in the morning after sleep and lower in the morning after deprivation.

Adult↗