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E Estrada

Publications and source records attributed to E Estrada.

15 recordsLinked to original sources
PubMed1992

TIMP-2 reduces proteolytic opening of blood-brain barrier by type IV collagenase.

Intracerebral hemorrhage occurs in tumors, stroke and head trauma. Proteolysis of the extracellular matrix around cerebral capillaries by naturally occurring mammalian 72-kDa type IV collagenase may initiate this pathologic event. To investigate this hypothesis adult rats underwent intracerebral injection of type IV collagenase purified from human melanoma cells. Histologically, at 4 h there was perivascular cellular infiltration with hemorrhage, and by 24 h there was infarction with necrosis, edema and hemorrhage. Ultrastructurally, the basal lamina of endothelial cells was disrupted at 2 h. Brain uptake of [14C]dextran and [3H]sucrose increased after intracerebral injection of type IV collagenase compared to controls (P less than 0.0001). Tissue inhibitor of metalloproteinase-2 (TIMP-2) reduced the tracer uptake (P less than 0.02). Metalloproteinase inhibitors reduce extracellular matrix proteolysis and protect the blood-brain barrier.

Analysis of Variance↗
PubMed1992

Arginine vasopressin V1-antagonist and atrial natriuretic peptide reduce hemorrhagic brain edema in rats.

BACKGROUND AND PURPOSE: Injection of arginine vasopressin into the cerebral ventricles in animals with brain injury increased brain water, whereas injection of atrial natriuretic peptide reduced water content. Therefore, to determine the role of endogenous arginine vasopressin in brain edema, we attempted to inhibit edema from a hemorrhagic lesion with an arginine vasopressin V1 receptor antagonist or atrial natriuretic peptide. METHODS: Adult Sprague-Dawley rats with hemorrhages induced by 0.4 IU bacterial collagenase were treated with 75 ng (n = 9) or 8 micrograms (n = 9) of the vasopressin V1 receptor antagonist d(CH2)5Tyr(Me)Arg, 3.2 micrograms (n = 4) atrial natriuretic peptide injected intracerebrally, or 5 micrograms/kg per hour (n = 7) atrial natriuretic peptide intraperitoneally. They were compared with control groups injected with 0.4 IU collagenase only. Brain water and electrolytes were measured 24 hours later. Brain uptake of [14C]sucrose was measured 30 minutes after lesions were induced by 0.4 IU collagenase alone (n = 5) or after collagenase injection and 50 micrograms/kg per hour (n = 5) atrial natriuretic peptide injected intravenously. RESULTS: The arginine vasopressin V1 receptor antagonist and atrial natriuretic peptide significantly (p < 0.05) reduced water and sodium contents in the posterior edematous regions. Brain uptake of [14C]sucrose was significantly reduced by intravenous atrial natriuretic peptide. CONCLUSIONS: Antagonists to arginine vasopressin V1 receptors and atrial natriuretic peptide both significantly reduce hemorrhagic brain edema, and atrial natriuretic peptide appears to protect the blood-brain barrier.

Angiotensin Receptor Antagonists↗
PubMed1992

Normal and elevated 3 alpha-androstanediol glucuronide concentrations in women with various causes of hirsutism and its correlation with degree of hirsutism and androgen levels.

We investigated peripheral androgen metabolic activity in 54 hirsute females (HF) by evaluating the serum 3 alpha-androstanediol glucuronide (3AG) concentration, hirsutism score (HS), and etiology of hirsutism. Based on basal and ACTH-stimulated steroid profiles (1 h post-Cortrosyn, 0.25 mg, i.v. bolus), the causes of hirsutism were determined to be increased adrenal androgen production (greater than 2 SD above normal mean), increased ovarian testosterone (T) production (greater than 2 SD above normal mean basal T of ovarian source only), or idiopathic cause (normal steroid profile). Serum 3AG levels in each group of HF were significantly higher (P less than 0.01-0.001) than those in normal females [normal: 2.9 +/- 0.94 nmol/L (n = 28); HF: increased adrenal androgen production of undefined cause, 7.7 +/- 7.5 nmol/L (n = 14); 21-hydroxylase deficiency, 7.6 +/- 7.4 nmol/L (n = 5); increased ovarian T production 5.5 +/- 3.5 nmol/L (n = 18); idiopathic cause, 5.8 +/- 4.8 nmol/L (n = 17)]. However, normal 3AG levels (less than 5.2 nmol/L) were present in 50-67% of HF in each group. Collectively, 3AG levels in HF correlated significantly (P less than 0.01) with dehydroepiandrosterone (DHEA; r = 0.41) and DHEA sulfate (DS; r = 0.44), while the correlation with androstenedione (r = 0.15) or T (r = 0.19) was not significant. Serum 3AG and adrenal androgen levels decreased in all subjects after dexamethasone treatment (0.5-1 mg at hour of sleep; 2 mg/day for 3-5 days). The correlation between 3AG and HS was significant (r = 0.6-0.74; P less than 0.01-0.001) only in HF with increased adrenal androgen secretion and idiopathic cause, and was not significant (r = 0.42) in HF with increased ovarian T secretion. There was no significant correlation between androgen levels and HS. We conclude that the serum 3AG level was not consistently elevated in HF and did not differ significantly between the various causes. Significant correlations between 3AG and DHEA/DS levels, and the simultaneous decrease in 3AG and adrenal androgens after dexamethasone administration in HF suggest that adrenal androgens contribute significantly to 3AG production. The significant correlation between 3AG and HS in HF with increased adrenal androgen secretion and idiopathic cause indirectly suggests an adrenal androgen contribution to both 3AG production and hirsutism in these HF. The insignificant correlation between 3AG and HS in HF with increased ovarian T secretion may result from a confounding effect of ovarian T on hirsutism.

Adolescent↗
PubMed1991

Phase II trial of ifosfamide in recurrent and metastatic head and neck cancer.

Thirty-six patients with recurrent carcinoma of the head and neck and no prior exposure to chemotherapy were treated with Ifosfamide. This drug was administered, concomitantly with Mesna, as a 24-hr infusion at a dose of 5-6.25 g/m2 every 3 weeks. Objective activity in 32 evaluable patients was 28% (9/32, 95% C.I. 17%-39%); 40% of patients had leukocyte values less than 2000 mm3 and 6% platelets less than 50,000 mm3. Nonhematologic toxicity consisted mainly of nausea/vomiting (66% greater than or equal to grade 2) and alopecia (80% greater than or equal to grade 2). The activity encountered warrants further studies with this drug in head and neck cancer.

Adult↗
PubMed1990

Autoradiographic patterns of brain interstitial fluid flow after collagenase-induced haemorrhage in rat.

Cerebral oedema accompanies intracerebral haemorrhage. We induced intracranial bleeding by the intracerebral injection of bacterial collagenase. There was oedema observed both at the haematoma site in the caudate/putamen and bilaterally in the hippocampal regions. To determine the role of vasogenic oedema spread from the site of injury, we studied by autoradiography the distribution of extracellular markers injected along with the collagenase. Both 14C-dextran (m.w. 70,000) and 14C-sucrose (m.w. 341) spread away from the injection site into both hippocampal regions in a similar pattern, suggesting bulk flow. Vasogenic oedema secondary to a haemorrhagic lesion in the caudate/putamen is an important cause of the oedema observed in both hippocampal regions in our model.

Animals↗
PubMed1990

Vasopressin-induced brain edema is mediated by the V1 receptor.

Arginine vasopressin-containing nerve fibers release AVP at extrahypothalamic sites where the hormone appears to regulate brain water. To determine its role in brain edema, we intracerebrally infused AVP, thus bypassing the blood-brain barrier. Thirteen adult cats had 2 mU (5 ng) of AVP infused into the caudate nucleus in 4 microliters CSF: 2 microliters at the start of the experiment and 2 microliters at 2 hr of a 4-hr experiment. Thirteen controls had similar microinfusions into the caudate nucleus of 4 microliters artificial CSF alone. A third group of nine animals had 2 mU AVP infused along with 50 ng of the V1 receptor antagonist (Manning compound). A fourth group of 10 animals had AVP infused along with 50 ng of a V1/V2 receptor antagonist (SK&F 101926). After 4 hr the brains were removed, and water content was measured in anterior, middle, and posterior areas in gray and white matter. We found that animals given AVP had a statistically significant increase in water content in both the gray (F = 7.1, p = 0.0002) and white matter (F = 9.4, p = 0.0001) compared with controls. Both the V1 and the V1/V2 antagonists blocked the increase in water content. We conclude that the V1 AVP receptor is important in water regulation.

Animals↗
PubMed1988

The effect of arginine vasopressin and V1 receptor antagonist on brain water in cat.

Arginine vasopressin (AVP) is important in brain water regulation. To better understand the effect of AVP released by extrahypothalamic fibers in brain, we microinfused AVP into intact brain and studied its effect on brain water and electrolytes. Adult cats had 5 ng of AVP infused into the caudate nuclei. Four h after infusion the brains were removed for measurement of water and electrolyte contents. Animals infused with AVP were compared to controls infused with saline. AVP increased water content significantly in gray and white matter sites, while electrolyte content was unchanged. Another group of animals had intracerebral infusions with 5 ng of AVP and 50 ng of a V1 receptor antagonist, (d(CH2)5Tyr-(Me)AVP). The antagonist blocked the increase in water, suggesting a V1 receptor mediated the action.

Animals↗
PubMed1988

Selective effect of mannitol-induced hyperosmolality on brain interstitial fluid and water content in white matter.

We studied the effect of mannitol-induced hyperosmolality on brain interstitial fluid (ISF) by autoradiography. Adult cats underwent intracerebral infusion of the extracellular marker, 14C-sucrose. Nine animals were given 2g/kg of mannitol intravenously, and another nine animals without mannitol were controls. Plasma and cerebrospinal fluid (CSF) osmolalities were measured. After 2 hr the brains were removed for determination of water and electrolyte content and for preparation of the autoradiograms. Diffusion coefficients were calculated for intracerebral transport with equations for radial diffusion. We found that mannitol increased the plasma osmolality but did not affect that of the CSF. Water and potassium contents were significantly lower in the white matter of mannitol-treated animals than in controls. Diffusion was reduced in the direction of gray matter into the white matter. We conclude that lower doses of mannitol control CSF pressure by selectively removing water from white matter, reducing the CSF volume, and affecting molecular transport at the gray/white interface.

Animals↗
PubMed1985

Survival and enumeration of the fecal indicators Bifidobacterium adolescentis and Escherichia coli in a tropical rain forest watershed.

The density of Bifidobacterium spp., fecal coliforms, Escherichia coli, and total anaerobic bacteria, acridine orange direct counts, percentages of total bacterial community activity and respiration, and 12 physical and chemical parameters were measured simultaneously at six sites for 12 months in the Mameyes River rain forest watershed, Puerto Rico. The densities of all bacteria were higher than those reported for uncontaminated temperate rivers, even though other water quality parameters would indicate that all uncontaminated sites were oligotrophic. The highest densities for all indicator bacteria were at the site receiving sewage effluent; however, the highest elevation site in the watershed had the next highest densities. Correlations between bacterial densities, nitrates, temperature, phosphates, and total phosphorus indicated that all viable counts were related to nutrient levels, regardless of the site sampled. In situ diffusion chamber studies at two different sites indicated that E. coli could survive, remain physiologically active, and regrow at rates that were dependent on nutrient levels of the ambient waters. Bifidobacterium adolescentis did not survive at either site but did show different rates of decline and physiological activity at the two sites. Bifidobacteria show promise as a better indicator of recent fecal contamination in tropical freshwaters than E. coli or fecal coliforms; however, the YN-6 medium did not prove to be effective for enumeration of bifidobacteria. The coliform maximum contaminant levels for assessing water usability for drinking and recreation appear to be unworkable in tropical freshwaters.

Bacteria, Anaerobic↗
PubMed1978

[Uptake of tryptophan and tyrosine in some cases of manic depressive psychosis and schizophrenia (author's transl)].

The uptake of tryptophan and tyrosine by the brain has been studied in 6 manic-depressive patients and in 8 schizophrenics. In an attempt to saturate the blood-brain transport mechanisms, this uptake has been evaluated by measuring the arteriovenous differences (arterial plasma-internal jugular plasma) of these two amino acids before and after perfusion with L-dopa and L-5-HTP. Considering a positive difference as an uptake and a negative one as an outflow, results show (1) in melancholia an uptake of tryptophan and an outflow of tyrosine; (2) in mania an uptake of tyrosine and an outflow of tryptophan, and (3) in schizophrenia an outflow of tryptophan accompanied with either an uptake or an outflow of tyrosine. In addition, the kinetics of tryptophan binding to plasma proteins and the ratio of tryptophan/tyrosine uptake are different in manic-depressive illness and in schizophrenia. These results support the view that a disturbance in the blood-brain transport mechanisms of tryptophan and tyrosine could be involved in the physiopathology of manic-depressive illness and schizophrenia.

Bipolar Disorder↗
PubMed1976

[Coffee hulls and pulp. XII. Effect of storage of coffee pulp on its nutritive value for calves].

Coffee pulp, dehydrated and stored for 7, 13 and 17 months or ensiled for 4, 10 and 14 months, was studied in calves with a rapid growing rate. Storage of dehydrated coffee pulp did not affect its chemical composition, but ensiling reduced crude fiber and increased its nitrogen free extract content after 10 and 14 months. Three growth trials were carried out with Holstein calves averaging 95 kg in the first and second trials, and 130 kg in the third. Eighteen calves were used in the first trial and 24 in each of the other two. In each trial the animals were divided into three equal groups and randomly assigned to one of the following treatments: control, which contained 48% cottonseed hulls, and the other two, with 30% dehydrated coffee pulp or 30% ensiled coffee pulp. Basically, the difference between trials consisted in the time of storage or ensiling of coffee pulp. In all trials, weight gains of calves fed coffee pulp (1.00, 0.90 and 0.98 kg/day, and 1.06, 0.94 and 1.08 kg/day, respectively) were significantly lower (P less than 0.05) than the weight gains induced by the control ration (1.21, 1.08 and 1.19 kg/day). Feed intake was also lower, but feed conversion ratio was higher for those rations containing coffee pulp. Calf performance was better with ensiled than with deydrated coffee pulp, particularly in the third trial, where the differences in weight gains were significantly higher (P less than 0.05). It is concluded that storage time does not change nutritive value of coffee pulp; and the ensiling is an adequate process for storing pulp during coffee harvesting, and, possibly also, for improving its nutritive value.

Animal Feed↗
PubMedDate not supplied

Combination chemotherapy with cisplatin and 5-fluorouracil 5-day infusion in the therapy of advanced gastric cancer: a phase II trial.

Fifty-six patients with measurable or evaluable advanced gastric cancer were treated with cisplatin, 100 mg/m2 in continuous infusion of 24 hours, and 5-fluorouracil, 1000 mg/m2/day (by continuous 5-day infusion) every 4 weeks. Three patients were found ineligible for the study. A response rate of 41% (22/53) was obtained (95% confidence interval: 28%-54%), with a median duration of remission of 10.2 months and an overall median survival time of 10.6 months. Leukopenia and thrombocytopenia were mild. Nausea and vomiting were common, and 23.5% of the patients had grade 3 stomatitis. Peripheral neuropathy and renal insufficiency increased with the number of cycles, representing the cumulative dose-limiting toxicity. This study indicates that the combination of cisplatin plus 5-fluorouracil is synergistic or at least has additive antitumor activity. We think that this association of 2 drugs should be considered for further phase III clinical trials.

Adult↗
PubMedDate not supplied

[Ewing's sarcoma].

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Child, Preschool↗