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Biomedical subjects

S Morales

Publications and source records attributed to S Morales.

At least 37 records · Page 2Linked to original sources
PubMed2000

Additive satiety-delaying effects of capsaicin-induced visceral deafferentation and NMDA receptor blockade suggest separate pathways.

Both ablation of visceral afferents and blockade of NMDA receptor-mediated glutamatergic transmission by MK-801 result in overconsumption of sucrose solution and other food, apparently by interrupting visceral signals and thus delaying satiation. If these two manipulations act on the same pathway, namely, the propagation of vagal afferent signals to NTS neurons, their effects would be expected to be non-additive. To test this hypothesis, two groups of rats - one with prior systemic capsaicin (n=11) and one with vehicle treatment (n=10) - were trained to drink 15% sucrose solution after 15 h food deprivation every 3-4 days, and then injected with MK-801 (100 microg/kg, i.p.) or saline. Both capsaicin and MK-801 produced the expected significant (P<.001) increase in 30 and 60 min sucrose intake if compared to their respective controls. Administration of MK-801 to capsaicin-treated rats further increased 60 min sucrose intake significantly (P<.001) in a fully additive fashion. These results suggest that the two treatments do not impinge on the same neural pathway to delay satiation. MK-801 may interfere with signals from capsaicin-resistant vagal afferents, or alternatively may act on other areas in the brain or periphery.

Animals↗
PubMed2000

Clinical Impact of 18F-FDG-PET in the Suspicion of Recurrent Ovarian Carcinoma Based on Elevated Tumor Marker Serum Levels.

Purpose: To retrospectively evaluate the contribution of 18F-fluorodeoxy-glucose-positron emission tomography (FDG-PET) to the diagnosis and clinical management of patients who were suspected of recurrent ovarian carcinoma, based on elevated tumor markers levels with normal or equivocal computed tomography (CT) or nuclear magnetic resonance (NMR).Procedures: 20 patients with these characteristics underwent FDG-PET. PET findings were confirmed in 14, in 7 by surgery, and in the other 7 by clinical course.Results: Recurrence was confirmed in 12 patients, all with FDG-PET positive. In other 2, recurrence was rule out and in 1, FDG-PET was negative. FDG-PET accuracy was 93% with 4 surgeries avoided and guided other 6.Conclusions: FDG-PET is an useful technique for detecting recurrent ovarian carcinoma suspected by elevated tumor markers levels and normal or equivocal results in the morphologic imaging techniques and has an important clinical impact on the management of these patients.

Journal Article↗
PubMed2000

Capsaicin-treated rats permanently overingest low- but not high-concentration sucrose solutions.

The effect of capsaicin-induced chemical ablation of visceral afferents on 1-h liquid sucrose consumption was investigated in food-deprived rats. We first show that although 10% sucrose is permanently overconsumed by capsaicin-treated (CAPs) compared with vehicle-treated (VEHs) control rats, 40% sucrose is only overconsumed during the first but not subsequent 1-h exposures. Furthermore, one group of CAPs lost the overconsumption response at 20% when exposed to progressively increasing sucrose concentrations of 10-40%, and another group recovered the overconsumption response at 10% when exposed to a series of decreasing concentrations. Control rats ingested relatively constant volumes of sucrose over the range of 10, 15, and 20%, resulting in significantly different energy intakes. In contrast, CAPs generally showed a concentration-dependent decrease in volume intake, resulting in relatively constant energy intake. These results suggest that capsaicin-sensitive visceral afferents, likely from gastric distension and other preabsorptive sensors, provide major control over volume ingested. In the absence of these signals, rats initially overconsume, but rapidly learn to use other signals from capsaicin-resistant preabsorptive or postabsorptive sites, to control future intake. This redundant satiety system appears to be sensitive to the osmotic value or caloric content of the unfamiliar food, but only if this is above a threshold of about 15% sucrose.

Animals↗
PubMed2000

[Role of the positron emission tomography (PET) in suspected tumor recurrence when there is increased serum tumor markers].

PURPOSE: Evaluate the usefulness of Positron Emission Tomography with 18F-Fluorodeoxyglucose (FDG-PET) to detect lesions when tumor recurrences are suspected due to the progressive increase of tumor markers and the study of their extension with negative or non-conclusive morphostructural diagnostic techniques. MATERIAL AND METHODS: Whole body FDG-PET was per-formed in 72 patients with different cancer diseases, 23 of whom had breast, 18 colorectal, 15 thyroid, 6 lung, 3 ovarian cancer and 7 had other types of cancers. Tumoral recurrence was suspected in all of the cases due to the progressive marker increase and negative or non-conclusive conventional studies. RESULTS: FDG-PET detected lesions in 85% patients, 33% of which were confirmed by the end of the study. In 40% of all cases, therapeutics measures were applied, 14% of which consisted in surgery with intention to cure. Sensitivity, specificity and accuracy were 96.4%, 75.6% and 93.9% respectively. CONCLUSIONS: Whole body FDG-PET is an accurate procedure in diagnosis of recurrent tumoral disease in patients with rising tumoral marker levels and with negative conventional morphostructural extension studies, and can make it possible to change the therapeutic approach in some cases.

Biomarkers, Tumor↗
PubMed1999

Double-blind, randomized, placebo-controlled clinical trials with non-prescription medications for the treatment of obesity.

OBJECTIVE: Phenylpropanolamine (PPA) and benzocaine are non-prescription medications approved for treating obesity. The dose of PPA for weight loss is 75 mg/day. PPA has the same chemical similarity to pseudoephedrine that amphetamine has to methamphetamine. Because benzocaine causes weight loss by altering taste and PPA by central appetite suppression, they may induce additional weight loss when combined. These studies explore the safety and efficacy of low-dose PPA, pseudoephedrine, and PPA with benzocaine in causing weight loss. RESEARCH METHODS AND PROCEDURES: Study 1 compared PPA 12.5 mg tid with 25 mg tid and placebo in a 6-week trial in 108 obese subjects. Study 2 compared pseudoephedrine 120 mg/day and a placebo in a 12-week trial with 72 obese subjects. Study 3 compared 4 groups of 20 obese subjects using PPA 75 mg/day, benzocaine gum 96 mg/day, PPA with benzocaine gum, and a placebo over 12 weeks. RESULTS: Both doses of PPA gave twice the weight loss of placebo, but the difference did not reach statistical significance. Pseudoephedrine was no different than placebo in inducing weight loss. The PPA with benzocaine group had more adverse events than the benzocaine group (p = 0.03), the placebo group (p = 0.03), or the PPA group (p = 0.09) without additional weight loss. DISCUSSION: We conclude that further studies with low-dose PPA for weight loss are indicated, that pseudoephedrine is not effective for weight loss, and that adding benzocaine to phenylpropanolamine increases adverse effects without increasing weight loss.

Adolescent↗
PubMed1998

Anticachectic efficacy of megestrol acetate at different doses and versus placebo in patients with neoplastic cachexia.

Anorexia and cachexia are present in the majority of patients with advanced-stage cancer. Several agents have been tested for their ability to reverse weight loss in these patients. Megestrol acetate has been demonstrated to improve appetite and weight, independent of tumor response, when used in the treatment of metastatic breast cancer. Several trials have studied the ability of megestrol acetate to stimulate weight gain in patients with non-hormone-sensitive tumors. One hundred fifty patients with a weight lost of more than 5% in the 3 previous months were randomized between double-blind megestrol acetate 160 mg daily (LMA), megestrol acetate 480 mg daily (HMA), or placebo (P). Weight, mid-arm circumference, triceps skinfold thickness (TST), performance status (Karnofsky index), and a quality-of-life status by seven linear analogic self-assessment scales were assessed before the start of treatment and at 4, 8, and 12 weeks thereafter. One hundred seven patients were assessable at 4 weeks, 79 at 8 weeks, and 64 at 12 weeks. Sixty-eight percent of patients treated with HMA increased their weights during their permanence on study, versus 37% and 38% of patients treated with P or LMA (p < 0.03). The mean weight gain after 12 weeks of treatment with HMA was 5.41 kg. A significant increase on TST was observed in the HMA group versus the LMA and P groups. There was no gain in performance status or quality of life in any group of treatment. The toxicity registered was mild. There were no thromboembolic events. This trial supports the efficacy of megestrol acetate at 480 mg/day in the treatment of cancer-related cachexia and anorexia, with mild toxicity. However, performance status and quality of life were not influenced by this treatment.

Aged↗
PubMed1997

Structural and functional analysis of the 5'-flanking region of the human insulin-like growth factor binding protein (IGFBP)-4 gene.

More than 3 kb of the human (h)IGFBP-4 gene 5'-flanking region was sequenced and assessed for promoter activity. The hIGFBP-4 promoter resides within a CpG island and demonstrates strong basal activity in human osteoblast-like osteosarcoma and COS-7 monkey kidney cells. Transient transfection of cells with hIGFBP-4 promoter-linked deletion constructs demonstrated that multiple cooperating cis-acting elements within 836 bp of the 5'-flanking region contributed to overall promoter strength.

Animals↗
PubMed1997

Enterotoxin and cytotoxin production by Salmonella enteritidis strains isolated from gastroenteritis outbreaks.

Seventy-six Salmonella enteritidis, three Salmonella virchow and one Salmonella bradenrup strains were screened for enterotoxigenicity by using the Chinese hamster ovary (CHO), Y1 adrenal, Vero and HeLa cell tests. All the strains gave positive reactions for enterotoxin production, except one, and the relative sensitivity to the toxin exhibited by the different cell lines was evaluated. An enterotoxic activity has been identified in sonicated extracts of Salm. enteritidis. This enterotoxin was purified on Agarose A-5m (Bio-Rad) and Superose 12 HR 10/30 column. The enterotoxic activity was eluted from the Superose column in the first peak. Like Vibrio cholerae toxin CT and Escherichia coli enterotoxin LT, it was blocked by GM1 ganglioside, but at a higher concentration. In addition, a cytotoxic factor has been partially identified. The procedure for isolating the cytotoxin included ammonium sulphate precipitation, size-exclusion chromatography and anion exchange chromatography. This cytotoxin factor caused inhibition of protein synthesis in cultured cells, as determined by flow cytometry and [3H]-leucine incorporation. Flow cytometry analysis also showed an activation of CHO cells when exposed to this cytotoxic factor resulting in a state of active growth. Cytotoxic activity was not blocked by gangliosides.

Animals↗
PubMed1994

Matrix vesicles produced by osteoblast-like cells in culture become significantly enriched in proteoglycan-degrading metalloproteinases after addition of beta-glycerophosphate and ascorbic acid.

Matrix vesicles, media vesicles, and plasma membranes from three well-characterized, osteoblast-like cells (ROS 17/2.8, MG-63, and MC-3T3-E1) were evaluated for their content of enzymes capable of processing the extracellular matrix. Matrix vesicles were enriched in alkaline phosphatase specific activity over the plasma membrane and contained fully active neutral, but not acid, metalloproteinases capable of digesting proteoglycans, potential inhibitors of matrix calcification. Matrix vesicle enrichment in neutral metalloproteinase varied with the cell line, whereas collagenase, lysozyme, hyaluronidase, and tissue inhibitor of metalloproteinases (TIMP) were not found in any of the membrane fractions examined. MC-3T3-E1 cells were cultured for 32 days in the presence of ascorbic acid (100 micrograms/ml), beta-glycerophosphate (5 mM), or a combination of the two, to assess changes in matrix vesicle enzymes during calcification. Ascorbate or beta-glycerophosphate alone had no effect, but in combination produced significant increases in both active and total neutral metalloproteinase in matrix vesicles and plasma membranes, with the change seen in matrix vesicles being the most dramatic. This correlated with an increase in the formation of von Kossa-positive nodules. The results of the present study indicate that osteoblast-like cells produce matrix vesicles enriched in proteoglycan-degrading metalloproteinases. In addition, the observation that matrix vesicles contain significantly increased metalloproteinases under conditions favorable for mineralization in vitro lends support to the hypothesis that matrix vesicles play an important role in extracellular matrix processing and calcification in bone.

3T3 Cells↗
PubMed1992

[Bladder neoplasm in a patient with panarteritis nodosa treated with cyclophosphamide].

Cyclophosphamide is used both in the treatment of malignant and non-malignant diseases. Urinary neoplasms secondary to its use have been described. We discuss the case of a patient with panarteritis nodosa treated with cyclophosphamide during 63 months, with a total dose of 210 grams, and that showed a bladder neoplasm 8 years after beginning of the treatment. In patients receiving a total dose of cyclophosphamide over 85 grams, a follow-up of ten years minimum should be performed aimed to the early detection of secondary neoplasms.

Adrenal Cortex Hormones↗
PubMed1992

Meningeal fibrosarcoma: a case report and review of the literature.

Meningeal Fibrosarcoma (MF) accounts only for 0.5% of the brain tumors. Since the clinical manifestations and radiologic findings are non-specific, the diagnosis can only be achieved by pathological examination of surgically removed specimens. MF are tumors that behave locally very aggressively and respond poorly to treatment, with reported median survivals ranging from 6 to 15 months. We report a new case of MF describing the peculiar onset as a slow growing mass in scalp with bone destruction and without neurological clinical findings.

Adult↗
PubMed1991

Amelioration of lapine osteoarthritis by treatment with glycosaminoglycan-peptide association complex (Rumalon).

The chondroprotective potential of glycosaminoglycan-peptide association complex (GP-C) was examined in the medial meniscectomy model of lapine osteoarthritis (OA). Prophylactic treatment with increasing doses of intramuscular GP-C (0.05-0.5 ml/kg) caused a significant reduction in OA lesion area and histologic scores, and the effect on disease activity appeared to be dose related. The DNA and uronic acid contents of OA tissue were unaffected by prophylactic treatment with GP-C. However, levels of hydroxyproline in OA cartilage increased to near control levels with prophylactic treatment. Cartilage levels of active and total metalloproteinases that digest proteoglycans were elevated in rabbits with OA; prophylactic treatment with low-dose GP-C (0.05 ml/kg) produced a significant reduction in active, but not total, enzyme. Cartilage levels of tissue inhibitor of metalloproteinases in animals with OA were comparable with control levels, but rose with increasing doses of GP-C. We also investigated GP-C as a therapeutic treatment in animals that had already developed OA lesions. Carbon black retention and histologic score returned to near-normal after therapeutic treatment with GP-C. Uronic acid and hydroxyproline levels were decreased in OA cartilage. Therapeutic treatment with GP-C had no statistically significant effect on uronic acid levels, but was associated with increased hydroxyproline content in the cartilage. The changes in metalloproteinase and metalloproteinase inhibitor were similar to those found in the studies of prophylactic treatment. The findings in this animal model may help explain some of the beneficial effects of GP-C in human OA.

Animals↗
PubMed1990

Addison's disease secondary to prostatic carcinoma. A case report.

Adrenal cortical insufficiency secondary to destruction of the cortex by a metastatic tumor is a rare condition. Addison's disease is usually caused by an autoimmune process or by a tuberculous infection. We report a case of adrenal insufficiency as the first clinical manifestation of a metastatic prostate carcinoma that occurred simultaneously with an active pulmonary infection by M. tuberculosis.

Addison Disease↗