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Biomedical subjects

R Rodriguez

Publications and source records attributed to R Rodriguez.

At least 73 records · Page 4Linked to original sources
PubMed1988

Tuberculosis of the rectum in a patient with acquired immune deficiency syndrome. Report of a case.

Tuberculosis of the rectum is a rare disease. A patient with a miliary pattern of pulmonary tuberculosis had a rectal lesion which proved to be tuberculosis. The patient subsequently developed several opportunistic infections characteristic of acquired immune deficiency syndrome. The clinical, endoscopic, radiologic, and histologic findings of this treatable lesion are presented.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Efficacy and safety of cilazapril, a new angiotensin-converting enzyme inhibitor.

Cilazapril (CIL), a new angiotensin-converting enzyme inhibitor, was evaluated for 16 weeks in 29 patients with mild to moderate essential hypertension (diastolic pressure 95 mm Hg to 115 mm Hg). Twenty-four patients (83%) normalized their blood pressure (BP) (diastolic pressure less than 90 mm Hg), 11 with low-dose CIL, six with high-dose CIL, one with high-dose CIL plus low-dose thiazide, and six with high-dose CIL and high-dose thiazide. Three withdrew because of side effects (fatigue, bloating, and polyuria). Statistically significant reductions in sitting and standing systolic and diastolic pressures occurred at 8 and 16 weeks on CIL. There was no change in standing or sitting heart rate, white blood cell count, creatinine clearance, urine protein levels. This is the first long-term data on this new converting enzyme inhibitor in human beings.

Aldosterone↗
PubMed1988

Properties and ontogenic development of membrane-bound histidine decarboxylase from rat brain.

Histidine decarboxylase (HD) activity was determined in high-speed fractions (100,000 g for 60 min) obtained from whole rat brain homogenates. Twenty-eight percent of the HD activity was associated with membranes, and the remaining was soluble. Several properties of the soluble and membrane-bound HD were compared. No significant differences in the values of Km for histidine and pyridoxal 5'-phosphate were observed. The solubilization of membrane-bound HD with Triton X-100 resulted in an increase of 60% over the nonsolubilized activity with no changes in the Km for substrate and cofactor. The proportion of free pyridoxal 5'-phosphate-independent activity was identical in both fractions. The soluble and membrane-bound forms of the enzyme differ slightly in their pH-activity profiles, although both enzymes showed an optimum pH near 6.5. The HD activities present in soluble and membrane fractions were determined at different postnatal ages. The soluble activity increased until day 90, whereas the membrane-bound activity became stabilized from day 20.

Aging↗
PubMed1988

Stage IV breast cancer: clinical course and survival of patients with osseous versus extraosseous metastases at initial diagnosis. The GOCS (Grupo Oncológico Cooperativo del Sur) experience.

The medical records of 414 patients with metastatic breast carcinoma treated between 1978 and 1986 were reviewed and 44 women were identified as having stage IV disease when the primary breast lesion was detected. Of these 44 women, 25 had metastatic disease limited to the skeleton while 19 had extraosseous lesions only. The clinical features, response to therapy, and survival were analyzed and compared for both groups. The median survival of those patients with bone-only metastases was 52 months as compared with 13 months for those with extraskeletal lesions (p = 0.0025). The response rate to first-line systemic therapy was similar for both groups (47% for bone metastases and 44% for extraosseous metastases). The median duration of response was 14 months (range, 3-55 months) for patients with bone disease and 8 months (range, 4-43 months) for those with extraskeletal lesions. We conclude that patients with metastatic breast cancer confined to the skeleton at initial diagnosis tend to follow an indolent, chronic course with prolonged survival. Therefore the increase in response rate with aggressive chemotherapy should be balanced against its higher morbidity. Further studies are needed to confirm whether the better prognosis of these patients is determined by the anatomical confinement of the disease to the skeleton or merely reflects the influence of other prognostic factors.

Bone Neoplasms↗
PubMed1987

A structural comparison of type c lysozymes based on their hydropathic profiles.

Hydropathic profiles can be considered as an approach to the three-dimensional structure of a protein and so their use for comparison of homologous proteins is proposed, as they provide information on relative structural conservativeness. A simple approach was developed for comparison of hydropathic profiles and applied to 19 lysozymes c of known primary structure. Trees were constructed in order to discover which method yielded the best estimation of the phenotypic differences between the proteins considered, by means of the goodness-of-fit criterion. Iterative methods, such as the Fitch-and-Margoliash and the unweighted-pair-group methods, gave a better fit than did a non-iterative method. When the hydropathic approach is used for comparison of lysozymes c, the enzyme obtained from chachalaca egg-white is placed closer to those from pheasant-like birds than to those of ducks; this result agrees with the morphological resemblance of the chachalaca to pheasant-like birds. Pigeon egg-white and equine milk lysozymes differ greatly in sequence from other lysozymes c and their hydropathic analysis shows important differences with respect to the other homologous enzymes.

Amino Acid Sequence↗
PubMed1987

Total glossectomy.

Total glossectomy is a procedure based on sound oncologic principles, and its usefulness may not be fully appreciated. Given the dimensions of the tongue and the need to obtain a wide margin of resection, this procedure may be indicated in selected T3 lesions and recurrences after irradiation. The procedure offers excellent palliation of pain, and form and function may be preserved by rim mandibulectomy when indicated. New reconstructive techniques allow for speedier recovery. Aspiration need not be a complication of total glossectomy if care is taken to preserve the superior laryngeal nerve. Speech rehabilitation plays an important role in returning these patients to their normal environment. Overall 1 and 3 year disease-free survival rates have been encouraging.

Adolescent↗
PubMed1987

Reliability estimates for steady-state evoked potentials.

The steady-state evoked potentials are most efficiently recorded using Fourier analysis. The reliability of this evoked potential is best estimated using either Hotelling's T2 or phase coherence. Using these techniques, the response to 500 Hz tones presented at a rate of 40/sec can be reliably recognized on average down to intensities of below 15 dB SL in an awake subject. Sleep significantly decreases the amplitude of the response and significantly raises the threshold for recognizing the response by 11 dB.

Adult↗
PubMed1987

Effect of nimodipine on arachidonic acid metabolites after subarachnoid hemorrhage.

Arachidonic acid metabolites are under investigation as possible vasoactive agents involved in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage. Prostaglandins, as well as other vasoactive compounds, activate contractile proteins through utilization of extracellular bound Ca++ to the intracytoplasmic free fraction. Recently, calcium-antagonists, mainly Nimodipine, have been proposed for the prophylaxis and/or reversal of the ischemic damage caused by vasospasm. Nimodipine failed to reduce vasospasm incidence in a series of 30 patients admitted with diagnosis of subarachnoid hemorrhage from ruptured intracranial aneurysm. Nimodipine failed to reduce level of four arachidonate metabolites measured (prostaglandin D2, prostacyclin, thromboxane B2 and leukotriene C4) in lumbar and cisternal CSF. After subarachnoid hemorrhage there is a significant increase of CSF levels of arachidonate metabolites; in perianeurysmic cisterns level of prostaglandin D2, thromboxane B2 and leukotriene C4 are significantly higher than lumbar CSF levels. Moreover, cisternal CSF level of prostaglandin D2 and leukotriene C4 are significantly higher in patients with symptomatic vasospasm. Nimodipine did not significantly modify CFS level of arachidonate metabolites: this suggests that Nimodipine treatment, which definitely improves long-term results of patients for intracranial aneurysms, could exert its pharmacological action reducing Ca++ intake from the extracellular compartment and preventing a direct toxic effect of calcium, without a direct action against the release of vasoactive compounds.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Influence of the qualitative caloric composition of enteral diets on liver protein synthesis in normal and operated rats.

Protein synthesis L-(l-14C) leucine in liver was studied. Normal (n = 40) and operated (n = 40) Sprague-Dawley rats with an initial body weight of 161.18 +/- 12 g were divided into four groups (n = 10), respectively. Each group, subjected to the same conditions of temperature, light, noise and movement received a different commercial formula for human enteral nutrition and water for 8 days (normal rats) and six days (operated rats). All rats received the same caloric and protein intake per ml (l kcal; 6-7.10(-3) g protein), with no statistically significant differences among groups. The differences in diets were merely qualitative. The tolerance to all diets was similar, with rats attaining the expected weight. Losses of protein, alpha aminic nitrogen, total fat and non sterified fatty acid in faeces were negligible. In normal rats, different results in liver protein synthesis were obtained. No mass/synthesis rate correlation was found. Under these conditions it would appear that these results are due to the different diets used. In operated rats, a significantly different liver protein synthesis per gram of body weight was obtained, but not per gram of organ weight. These results suggest that the influence of the qualitative caloric intake, in the stress phase, is less than in the normal state.

Animals↗
PubMed1987

Phosphatidylinositol depletion in GH3 rat pituitary cells inhibits sustained responses to thyrotropin-releasing hormone. Reversal with myo-inositol.

TRH stimulation of rat pituitary (GH3) cells causes biphasic changes in cytoplasmic free Ca2+ concentration [( Ca2+]i) and PRL secretion. It has been proposed, based primarily on indirect evidence, that the first phase effects are mediated by inositol 1,4,5-trisphosphate, which releases Ca2+ from cellular stores, and the sustained effects are mediated by 1,2-diacylglycerol, which activates protein kinase C. To determine more directly if inositol lipid hydrolysis leading to protein kinase C activation is involved in the sustained effects of TRH, GH3 cells were depleted of phosphatidylinositol (PtdIns) by prestimulation and incubation in myo-inositol-free, Li(+)-containing medium. Cells depleted of PtdIns (to 53 +/- 3.2% of control) had unchanged PtdIns 4,5-bisphosphate content, and responded to TRH with a rapid elevation of inositol trisphosphate, and a first phase (or burst) elevation of [Ca2+]i and PRL secretion that was not different from that found in control cells. In contrast, in PtdIns-depleted cells, the prolonged generation of inositol phosphates, which are produced in equimolar amounts with 1,2-diacylglycerol, caused by TRH was virtually abolished, and the second phase (or sustained) elevation of [Ca2+]i and PRL secretion were inhibited by 50% and 40%, respectively. The inhibition of both sustained effects was reversed by adding 100 mM myo-inositol to the medium, which allowed for synthesis of PtdIns. Last, in cells in which protein kinase C was down-regulated by pretreatment with a phorbol ester, the sustained effects of TRH were inhibited also.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Fine needle thyroid aspiration: university hospital experience.

Fine needle thyroid aspiration (FNTA) as a diagnostic tool of thyroid disease was started at the University District Hospital (UDH) in 1983. FNTA was performed in 54 willing patients from December 1984 through December 1985. If no medical contraindications existed, thyroid surgery was recommended in order to assess diagnostic accuracy. Surgery was done in 34 (63%) patients; while not in 20:3 for medical reasons, 2 lost to follow-up, 3 refused, 7 had inappropriate FNTA, and 5 for unknown reasons. None had complications to FNTA. Cytology was classified as Class O: inadequate; Class 1: benign; Class 2: indeterminate; and Class 3: malignant. "Non-benign" cytology was obtained in 14 patients: 7 indeterminate (class 2) and 7 malignant (class 3). Four of these had carcinoma confirmed by surgery. Of the 19 with benign FNTA (class 1) only one has thyroid carcinoma. One patient had inadequate sample (Class O). The sensitivity was 80%, specificity 65%, and diagnostic accuracy 67%. All these statistical values are within the range reported in fifteen reviewed series. Thus, FNTA at UDH had a diagnostic value comparable to that described in the literature. It may be utilized as a safe, reliable tool complementary to clinical data in order to reduce the amount of unnecessary thyroid surgery, carry out earlier diagnoses of malignant nodules and increase the yield of carcinoma among those operated.

Adenocarcinoma↗
PubMed1986

Human auditory steady state responses: effects of intensity and frequency.

Human auditory steady state responses were recorded in 41 normal subjects and 22 patients with hearing loss. The effect of intensity on the responses at different tonal frequencies was assessed using the sweep technique. The amplitude of the responses increases and the phase delay decreases with increasing intensity. Both the amplitude and the phase delay are smaller for high frequency tone bursts. Notched noise decreases the amplitude of the response by a factor of two but does not affect the phase of the responses. Thresholds were estimated in waking subjects using two techniques: intensity sweeps analyzed by linear regressions, and fixed intensities analyzed by Hotelling's T2 test. Frequency-specific thresholds obtained with notched noise were less variable and more accurate with the fixed intensity technique. In patients with sensorineural hearing loss the amplitude increased more with increasing intensity above threshold than in patients with conductive hearing loss.

Adult↗
PubMed1985

Amino acid sequence around the cysteine residues of pigeon egg-white lysozyme: comparative study with other type c lysozymes.

The cysteine-containing tryptic peptides of pigeon egg-white lysozyme have been purified by reverse-phase chromatography and thin-layer chromatography and electrophoresis on cellulose plates. They contain the eight cysteine residues of the protein. The amino acid sequence of these peptides reveals the existence of 24 differences in comparison to the homologous regions in hen egg-white lysozyme, among the 53 sequenced residues. The sequence data are compared to the corresponding ones in other type c lysozymes. According to this study, the pigeon lysozyme exhibits ten substitutions not observed in any other type c lysozyme. Pigeon lysozyme is the most different type c lysozyme from birds, according to the data on primary structure.

Amino Acid Sequence↗