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Biomedical subjects

A Villalobos

Publications and source records attributed to A Villalobos.

At least 19 recordsLinked to original sources
PubMed2000

[Chemotherapy in germinal and epithelial ovarian cancer].

Generically, ovarian cancer represents a group of tumors with diverse biological and clinical behavior. Thus, germinal cells ovarian tumors, in the vast majority of patients are successfully treated utilizing traditional based on cisplatin chemotherapy. Epithelial ovarian cancer, that accounts for 90% of these cases, although sensitive to chemotherapy has not shown satisfactory results. In the search better tumoral response in the treatment of epithelial ovarian cancer new drugs have surged that promise good results, including docetaxel, topotecan and gemcitabine, both as single agents, or in combination with other therapies utilizing monoclonal antibodies.

Carcinoma↗
PubMed1999

Polycystic ovarian syndrome: assessment with color Doppler angiography and three-dimensional ultrasonography.

We conducted a three-dimensional ultrasonographic evaluation of the size and structure of the ovaries of women who had clinical and biochemical findings suggestive of polycystic ovary syndrome. We carried out a comparative color Doppler frequency and color Doppler amplitude study of the vascular patterns of these ovaries. This study involved 65 women of reproductive age with polycystic ovary syndrome and 25 eumenorrheic women who were not taking hormonal contraceptives and who had a body mass index below 25 kg/m2. Compared to controls, women with polycystic ovary syndrome had larger ovaries and thicker stroma, increased impedance in the uterine arteries, increased stromal vascularity with decreased impedance that persisted throughout the menstrual cycle, and a lack of luteal conversion.

Adult↗
PubMed1998

First-trimester neck abnormalities: three-dimensional evaluation.

In order to study the first trimester ultrasonographic differences between nuchal translucency and hygroma colli, we rescanned 25 fetuses (13 with nuchal translucency and 12 with hygroma colli) using transvaginal and three-dimensional ultrasonography, after obtaining a fetal karyotype report. Our objective was to test the premise that the different physiopathologic mechanisms of both processes would be reflected in detectable sonographic differences. Our retrospective analysis showed that the most striking ultrasonographic difference was the presence of bullae as well as greater irregularity, extent, and amplitude of the membrane in cases of hygroma colli. Fetuses with simple nuchal translucency had a more homogeneous linear membrane. Although detailed analysis was impossible in 30% of cases, we found three-dimensional ultrasonography to be a useful technique for establishing the differences between these two entities.

Female↗
PubMed1998

[Frequency of cesarean section in at-term pregnancies with premature rupture of membranes].

The purpose of the present study was to evaluate cesarean section frequency in patients with premature rupture of membranes (PROM) at term, after active management, independent Bishop score. One hundred and four patients was to evaluate, and they was classified in four groups: group 1. nulliparous patients with favorable cervix, group 2. nulliparous patients with unfavorable cervix, group 3. previous delivery patients with unfavorable cervix, group 4. previous delivery patients with favorable cervix. Cesarean section percentage was: 15% in group 1, 24% in group 2, 17% in group 3, and 0% in group 4. Attempt should make to diminish cesarean section frequency, maybe with an expectant management in those patients with PROM at ther and unfavorable cervix.

Cesarean Section↗
PubMed1998

Anaplastic carcinoma of the fimbriated end of the fallopian tube as an incidental finding.

Carcinoma of the fallopian tube is an uncommon gynecologic tumor that is usually diagnosed in an advanced stage. The majority are tubal in origin, and rarely arise in the fimbriae. It appears that the latter may have a worse prognosis than the equivalent stage of tubal tumors that do not arise from fimbriae. We present a case of a 53-year-old white woman with FIGO stage 1 primary anaplastic carcinoma of the fimbriated end of the fallopian tube that was incidentally found in a specimen resected during a total abdominal hysterectomy with bilateral salpingo-oophorectomy. The patient underwent surgery because of findings of severe cervical dysplasia, atypia and dyskaryosis on a routine Papanicolau smear. Postoperative recovery was uneventful, and follow-up abdominal and pelvic CT scans showed no evidence of disease. However, because of the poor degree of differentiation, focal serosal infiltration and fimbrial end tube site of the carcinoma she was considered to have a high risk of recurrence. Thus, it was recommended that she undergo adjuvant chemotherapy with cyclophosphamide and carboplatin. Eighteen months after diagnosis, the patient is alive and well with no evidence of disease.

Adenocarcinoma↗
PubMed1995

5,7-dihydro-3-[2-[1-(phenylmethyl)-4-piperidinyl]ethyl]-6H- pyrrolo[3,2-f]-1,2-benzisoxazol-6-one: a potent and centrally-selective inhibitor of acetylcholinesterase with an improved margin of safety.

A series of N-benzylpiperidines (2a-d, 10) with novel isoxazole-containing tricycles has been prepared. This series has shown potent in vitro inhibition of the enzyme acetylcholinesterase (AChE), with IC50S = 0.33 - 3.6 nM. Compound 2a was the most potent inhibitor with an IC50 = 0.33 +/- 0.09 nM. Derivatives 2a-d and 10 displayed weak in vitro inhibition of butyrylcholinesterase (BuChE) with IC50S = 600 - 23,000 nM. The most selective compound was 2a with a BuChE/AChE ratio in excess of 4 orders of magnitude (> 10,000). Pyrrolobenzisoxazole 2a also displayed a favorable profile in vivo. In microdialysis experiments, 2a produced a 200% increase in extracellular levels of acetylcholine (ACh) at a dose of 0.4 mg/kg in freely moving, conscious rats. Peripheral side effects (salivation ED50 = 26 +/- 1.5 mg/kg) and acute lethality (LD50[1 h] = 42 mg/kg) were observed at > 60-fold higher doses. These data indicate that 2a is an AChE inhibitor with good central selectivity and a favorable margin of safety. Compound 2a, designated as CP-118,954, is currently in clinical development for the treatment of cognitive disorders.

Animals↗
PubMed1995

Defining topological similarities among ion transport proteins with anti-amiloride antibodies.

The structural features of amiloride binding sites on amiloride-sensitive transport proteins have received limited characterization. An antibody that recognizes limited regions of amiloride and can mimic, in binding specificity, certain amiloride-sensitive transport proteins was used as a model to elucidate potential amino acid residue relationships that might define putative amiloride contact sites. Analysis of the structure of this antibody has allowed us to identify sequence relationships among several Na+ selective transport proteins. A structure-based relational database was employed to re-examine sequence homologies among these ion transport proteins. A search of the protein sequence databank identified representative amino acid tracts among amiloride sensitive proteins involving planar residues that might be involved in interacting with amiloride. Computer models of sites within transmembrane domains of NHE1 and NHE2 isoforms of the Na+/H+ exchanger reflective of these planar tracts indicate that amiloride probably spans two helices for interaction with the Na+/H+ exchanger. Structural analysis of this monoclonal anti-amiloride antibody appears to mimic some of the salient features of amiloride binding sites on these proteins.

Amiloride↗
PubMed1994

Novel benzisoxazole derivatives as potent and selective inhibitors of acetylcholinesterase.

A series of N-benzylpiperidine benzisoxazoles has been developed as potent and selective inhibitors of the enzyme acetylcholinesterase (AChE). The benzisoxazole heterocycle was found to be an appropriate bioisosteric replacement for the benzoyl functionality present in the N-benzylpiperidine class of inhibitors. The title compounds were synthesized by alkylating 3-methyl-1,2-benzisoxazoles with an iodo piperidine derivatives as the key step. Benzisoxazoles 1b-j,o displayed potent inhibition of AChE in vitro with IC50's = 0.8-14 nM. Particularly interesting were N-acetyl and morpholino derivatives 1g (IC50 = 3 nM) and 1j (IC50 = 0.8 nM), respectively, which displayed outstanding selectivity for acetyl-over butyrylcholinesterase, in excess of 3 orders of magnitude. N-Acetyl 1g also displayed a favorable profile in vivo. This analog showed a dose-dependent elevation of total acetylcholine in mouse forebrain after oral administration with an ED50 = 2.4 mg/kg. In addition, 1g was able to reverse amnesia in a mouse passive avoidance model at doses of 3.2 and 5.6 mg/kg with an average reversal of 89.7%. Molecular dynamics simulations were used to study the possible binding modes of N-benzylpiperidine benzisoxazoles to AChE from Torpedo californica. Key structural insights were obtained regarding the potency of this class of inhibitors. Specifically, Asp-72, Trp-84, Trp-279, Phe-288, and Phe-330 are implicated in the binding of these inhibitors. The N-benzylpiperidine benzisoxazoles may be suitable compounds for the palliative treatment of Alzheimer's Disease.

Acetylcholine↗
PubMed1991

[Pulmonary function in the preterm and full-term newborn during the neonatal period: II. Pulmonary function].

The pulmonary function of 18 preterm neonates weighing less than 1500 g. and of 35 full-term newborn infants weighing more than 2500 g. at birth was measured during the neonatal period. The children were grouped according to their postnatal age (less than 24 h, 24 h- 7 days, and greater than 7 days). The inspiratory and expiratory flow was measured by means of a pneumotachograph and the esophageal pressure by means of a feeding tube filled with distilled water. Lung compliance (CL) was significantly lower in the preterm infants than in full-term infants for all postnatal age groups. However, with relation to body weight (CL/Kg) there were no significant differences. The expiratory lung resistance was higher than the inspiratory resistance in all groups. The work of breathing (Wr) was significantly lower in the preterm neonates than in term infants in all postnatal age groups. Nevertheless, as Wr refers to body weight, there were no significant differences.

Birth Weight↗
PubMed1989

[Pulmonary function in newborn infants with transitory tachypnea and pneumothorax].

The pulmonary function has been studied in 13 newborns with transient tachypnea (TT), matched for birth weight in 7 newborns with pneumothorax (NT) with higher birth weight than 2,500 g and the results were compared with 21 newborns healthy, matched for weight. The study was done in first 24 h after birth. Inspiratory and expiratory flow was measured by a pneumotachograph, esophageal pressure though a water-filled feeding tube. Lung compliance was lower in the newborns with respiratory distress, which results in less tidal volume, whereas the minute ventilation remains unchanged due higher significantly breathing rate. Lung resistance were higher in the newborns with Nt, although without significantly differences. Work of breathing was higher in the newborns with respiratory distress although without significantly differences.

Humans↗
PubMed1985

Successful administration of metoclopramide for the treatment of nausea in patients with advanced liver disease. A double-blind controlled trial.

A double-blind comparison of metoclopramide versus placebo was performed on 8 cirrhotic patients with nausea (8 cases) and heartburn (3 of the 8 cases) plus mild portal-systemic encephalopathy. As metoclopramide is a dopamine antagonist and dopamine-inadequate neurotransmission has been implicated in the pathogenesis of hepatic coma, this study was also designed to evaluate the effects of metoclopramide on mental state. The study included basal, placebo, metoclopramide, and final periods; each period lasted for 2 wk. Throughout the study patients received 3 g/day of neomycin and an 1800-cal diet containing 40 g/day of mixed protein. During the placebo and metoclopramide phases patients received either two 10-mg metoclopramide capsules t.i.d. or identical placebo capsules. During the study, biweekly liver function tests and portal-systemic encephalopathy parameters were evaluated. A self-evaluation for the presence of nausea and heartburn was also obtained. To monitor the dopamine-blockade effect of metoclopramide, serum prolactin levels were measured. Metoclopramide significantly suppressed the subjective signs of nausea (7 of 8 cases) and heartburn (all cases). Serum prolactin levels were 22 +/- 21 ng/ml, 30 +/- 31 ng/ml, 110 +/- 57 ng/ml (p less than 0.01), and 18.6 +/- 2 ng/ml during basal, placebo, metoclopramide, and final periods, respectively. In spite of these signs of dopamine blockade, no deterioration in mental state, asterixis, electroencephalograms, blood ammonia levels, or psychometric testings were observed. In addition, no extrapyramidal signs were noticeable during any period of the study. One patient presented transient somnolence at the end of the metoclopramide period. We conclude that dopamine blockade is not associated with the appearance of portal-systemic encephalopathy. Metoclopramide is a safe and effective treatment for nausea and heartburn in patients with advanced liver disease.

Chronic Disease↗
PubMed1982

Treatment of chronic portal--systemic encephalopathy with vegetable and animal protein diets. A controlled crossover study.

A controlled crossover clinical comparison of 40-g/day and 80-g/day vegetable protein diets vs a 40-g/day meat protein diet plus neomycin-milk of magnesia (as control therapy) was performed on 10 cirrhotic patients with mild chronic portal-systemic encephalopathy. The 40-g vegetable protein diet had a high fiber volume and contained low methionine and low aromatic amino acids. The 80-g vegetable protein diet was rich in branched-chain amino acids and fiber, with a similar content of sulfur-containing amino acids as compared to the 40-g meat protein diet. Serial semiquantitative assessments were done, including mental state, asterixis, number connection tests, electroencephalograms and blood ammonia levels. No patient developed deep coma while ingesting either vegetable protein diet or neomycin-milk of magnesia plus 40-g meat protein diet. A significant improvement in the number connection test times was observed during the 40-g vegetable protein diet (P less than 0.05) and during the 80-g vegetable protein diet (P less than 0.05) as compared to their previous 40-g meat protein--neomycin periods. In addition, during the period of 80-g vegetable protein diet, the patients showed a significant improvement in their electroencephalograms (P less than 0.05). The frequency of bowel movements significantly increased (P less than 0.05) during the 80-g vegetable protein diet period. During the 40-g vegetable protein diet, two cirrhotic--diabetic patients experienced hypoglycemia. Three patients complained of the voluminous 80-g vegetable protein diet. Patients with mild portal--systemic encephalopathy may be adequately controlled with vegetable protein diets as a single therapy.

Adult↗
PubMed1980

Chemoimmunotherapy for canine lymphosarcoma: a prospective evaluation of specific and nonspecific immunomodulation.

Fifty-six dogs were given chemoimmunotherapy for spontaneous lymphosarcoma. The dogs had been given identical combination chemotherapy (8 weeks) for induction of remission, and after achieving complete clinical remission, they were randomly assigned to one of three treatment groups to evaluate immunotherapy as a method ancillary to chemotherapy to maintain or extend the remission. For immunostimulation, one-third of the dogs were given chemically modified autochthonous tumor cell extract in Freund's complete adjuvant (FCA), one-third were given nonmodified tumor cell extract in FCA, and one-third were given FCA alone. A historical control population of dogs given the same chemotherapy was used for comparison. Of the 56 dogs, 50 (89.3%) achieved initial remission, but 18 of the latter relapsed clinically during the initial 8-week-chemotherapy regimen. The remaining 32 dogs (or 57.1% of the original 56 dogs) were subsequently given immunotherapy. Duration of remission and survival time were recorded. The median remission duration and survival time for all dogs given immunotherapy following cytoreductive chemotherapy were significantly longer than the historical control population given chemotherapy alone. However, there was no significant difference in remission duration or survival among the three immunotherapy groups.

Animals↗
PubMed1978

[Infantile brucellosis (author's transl)].

Some aspects concerning brucellosis are revised. This is a disease with a high incidental rate among the children's population in Salamanca and bordering provinces. The local prevailing epidemiologic conditions are reviewed, as well as the most outstanding clinical features, which are in children, according to the author's personal experience, less protean than in adult's illness.

Adolescent↗
PubMedDate not supplied

Acute pancreatitis secondary to ifosfamide.

Acute pancreatitis in cancer patients can be secondary to the malignant process itself. It is also a rare complication of antineoplastic agent administration. Ifosfamide is an effective drug in the treatment of several tumors and has known neurologic, renal, and hematologic toxicities. There is only one recent report in the literature of pancreatitis associated with ifosfamide. We report a case of a 65-year-old woman with small cell bronchogenic carcinoma without pancreatic metastases who developed acute pancreatitis after ifosfamide administration.

Acute Disease↗
PubMedDate not supplied

Association of differing dietary, metabolic, and clinical risk factors with macrovascular complications of diabetes: a prevalence study of 503 Mexican type II diabetic subjects. I.

Macrovascular and microvascular complications of diabetes may be associated with different environmental factors. To investigate this further, a prevalence study of 503 Mexican type II diabetic subjects was carried out while their patterns of nutrition were constrained by government food subsidies. Average daily dietary intakes were 1866 kcal; 46.5% as carbohydrate, 13.7 mmol cholesterol, 8.7 g fiber, and a polyunsaturated/saturated fat ratio of 0.98. With respect to macrovascular disease, 49.3% of patients had evidence of peripheral vascular disease, and 21.6% myocardial ischemia, 6.0% angina, 10.8% EKG evidence of ischemia, 4.8% EKG evidence of myocardial infarction. Only 1.2% (six patients) had a clear history of completed stroke, and all were hypertensive. Six patients had also undergone amputations for diabetic gangrene. Tabulation of the means of clinical characteristics according to presence or absence of myocardial ischemia showed that higher cholesterol, calorie, and fat intake, higher mean blood pressure, higher serum cholesterol, and serum triglyceride levels were found in those with myocardial ischemia. Patients with peripheral vascular disease were more commonly smokers. Stepwise logistic regression revealed significant positive associations between myocardial ischemia and dietary cholesterol, serum cholesterol, and mean blood pressure. In contrast, the presence of peripheral vascular disease was significantly related only to smoking and retinopathy. There were no associations between macrovascular complications and duration of diabetes in the multivariate analysis, and they occurred with equal frequency in men and women. Prospective studies of atherosclerosis in maturity-onset diabetes should assess and seek to modify dietary cholesterol, serum cholesterol, and hypertension.

Cholesterol↗
PubMedDate not supplied

Association of differing dietary, metabolic, and clinical risk factors with microvascular complications of diabetes: a prevalence study of 503 Mexican type II diabetic subjects. II.

The overall prevalences of microvascular complications and their association with dietary, clinical, and metabolic characteristics have been studied in 503 Mexican type II diabetic subjects. Average daily dietary intakes were 1866 kcal, 46.5% as carbohydrate, 13.7 mmol cholesterol, 8.7 g fiber, and a polyunsaturated/saturated fat ratio of 0.98. Prevalence rates of microvascular and metabolic complications were as follows: background retinopathy 12.3%, exudative retinopathy 24.2%, proliferative retinopathy 8.1% (1% blind, 4% able to read large print only), 9.1% of patients had cataract, 15.9% nephropathy, and 40.8% peripheral neuropathy. In addition, 3.6% had experienced transient lower motor neuron facial paralysis and 0.2% oculomotor paralysis. Patients with retinopathy had a longer mean duration of diabetes, were less obese at the time of examination, and had higher initial and mean blood pressures and higher mean fasting blood glucose levels when compared with those without retinopathy. Similar differences were observed between groups with and without nephropathy except that mean blood glucose levels were similar in the two groups. The presence of peripheral neuropathy was associated with longer duration of diabetes, less obesity, higher mean blood pressure and mean blood glucose levels, and lower hemoglobin concentration. Patients treated with diet alone had significantly lower prevalences of all three microvascular complications but they also had significantly shorter duration of diabetes and lower mean blood glucose levels. However, multivariate analyses on the subgroup of 360 patients who had repeated fasting blood glucose measurements for at least 5 yr demonstrated associations between retinopathy and duration of diabetes, mean blood pressure and mean blood glucose, and percent calories from carbohydrate.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗