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Biomedical subjects

M Castillo

Publications and source records attributed to M Castillo.

At least 199 records · Page 11Linked to original sources
PubMed1991

Hypolipidemic activity of dipyridamole: effects on the main regulatory enzyme of cholesterogenesis.

The in vivo dipyridamole treatment for 16 days produced a significant decrease in chick plasma cholesterol, mainly due to the esterified form. This effect was especially patent in the VLDL + LDL fraction. Similar results were observed in triglyceride content. To our knowledge, this is the first report on this hypolipidemic effects of dipyridamole. Total and esterified cholesterol increased after the same treatment in chick liver, while brain cholesterol content was not affected. Hepatic 3-hydroxy-3- methylglutaryl-CoA reductase activity was drastically reduced, while other secondary regulatory enzymes such as mevalonate kinase, mevalonate 5-phosphate kinase and mevalonate 5-pyrophosphate decarboxylase did not change significantly. No significant differences were found in cholesterol and lipidic phosphorus from liver microsomes, so that the effect of dipyridamole on reductase activity cannot be due to modifications in cholesterol/lipidic phosphorus molar ratio. Neither of these enzyme activities was affected in vitro by dipyridamole.

Animals↗
PubMed1991

Immunological identification and distribution of parathyroid hormone-like protein polypeptides in normal and malignant tissues.

Monoclonal and polyclonal antibodies recognizing human parathyroid hormone-like protein (PTHLP) have been produced using a series of recombinant and synthetic PTHLP peptides. These antibodies have been used to develop a two-site immunometric enzyme immunoassay which detects PTHLP[1-87] and PTHLP[1-141] but not PTH. The immunoassay detected PTHLP in extracts of squamous carcinomas and normal tissues at concentrations from 7-515 ng PTHLP[1-87]/mg protein. Immunoblotting of the extract which showed the highest immunoreactivity, a squamous carcinoma of the lung from a patient with hypercalcemia, revealed a major band having an apparent mol wt of 26,500 and several other higher mol wt bands. Similar polypeptides were observed by immunoblotting cell extracts from a cell line, SCaBER, which secretes immunoreactive PTHLP into its medium and also from tumors in nude mice derived from this cell line. Chaotropic agents did not alter the immunoblotting pattern, and antibodies to three different epitopes of PTHLP recognized these bands, indicating PTHLP expression in the extracts. Immunohistochemical staining of normal human tissue with these antibodies revealed several PTHLP-containing tissues and confirmed the results of the immunoassay, suggesting a paracrine role for PTHLP. Staining was observed in several neoplastic tissues including squamous cell carcinomas, lung carcinoma, bladder carcinoma, osteogenic sarcoma, and adenocarcinoma of the colon.

Adenocarcinoma↗
PubMed1991

Effect of phenylpyruvate on mevalonate-activating enzymes from chick brain and liver.

Mevalonate-activating enzymes from chick brain and liver were stable when 105,000 x g supernatants were stored at -4 degrees C for 168 h. Mevalonate kinase and mevalonate 5-phosphate kinase retained their activities for 72 h at 4 degrees C while mevalonate 5-pyrophosphate decarboxylase activity significantly decreased after 24-48 h of storage at 4 degrees C. Direct addition of 2.5 mM phenylpyruvate to the reaction mixture produced a significant inhibition of decarboxylase activity in brain and liver. When enzyme preparations were preincubated with 2.5 mM phenylpyruvate for 20 min before the addition of substrate, an increased inhibition was observed. Mevalonate kinase and mevalonate 5-phosphate kinase from both tissues were not affected in the same conditions. The inhibition of brain and liver decarboxylase was progressive with increasing concentrations (2.5-10.0 mM) of phenylpyruvate. No significant difference was observed in the inhibition of decarboxylase after 10 or 20 min of preincubation.

Animals↗
PubMed1991

Magnetic resonance findings in a patient with internuclear ophthalmoplegia. Neuroradiological-clinical correlation.

A 49-year-old female presented with symptoms compatible with internuclear ophthalmoplegia. Magnetic resonance using T2-weighted images showed an eccentric area of high signal intensity in the mid pons corresponding to the right medial longitudinal fasciculus. Magnetic resonance is the method of choice when internuclear ophthalmoplegia is suspected. The findings should be differentiated from the normal central hyperintensity called the "pseudo MLF hyperintensity."

Female↗
PubMed1991

Peritonitis after cecal perforation. An experimental model to study the therapeutic role of antibiotics associated with allopurinol and catalase.

This work uses cecal perforation on the rat as a model of intra-abdominal sepsis. Under these conditions, various antibiotics were tested alone or in association with free radical scavengers, such as allopurinol and catalase. It can be concluded that the scavengers were not effective alone, but when combined with antibiotics they rendered good results in the majority of the groups when given postsepsis. Further studies are needed to determine the real role of agents like the free radical scavengers in infectious situations such as the one discussed here.

Allopurinol↗
PubMed1990

Sonographic anatomy of the caudate lobe veins.

Because of their small size, the caudate lobe veins (CLV) are not routinely imaged with ultrasonography. We recently examined 4 patients with elevated central venous pressure in whom the CLV were easily identifiable. To our knowledge this is the first report of sonographic visualization of these veins. We suggest that visualization of the CLV may not be as rare as previously presumed, and based on our experience, we will propose a nomenclature system for these veins.

Central Venous Pressure↗
PubMed1990

Effect of L-carnitine upon ammonia tolerance test in cirrhotic patients.

In a group of liver cirrhosis (LC) patients subjected to a rectal ammonium overload test, the effect of L-carnitine on ammoniemia and on the type A numerical connection and star clock psychomotor tests has been evaluated. On comparing 40 LC patients given L-carnitine with 40 control cirrhotics given a placebo, no significant differences were observed in ammonium levels after performing the overload test in both groups. However, on studying the patients with the greatest liver involvement, those given L-carnitine showed smaller elevations in ammoniemia and better responses to the psychometric tests than those receiving the placebo. The results obtained emphasize the need to continue testing the effect of L-carnitine using either similar tests or carrying out long-term evaluations to determine its protective effect in the appearance of hepatic encephalopathy, perhaps even including its evaluation in the treatment of established encephalopathy.

Aged↗
PubMed1990

Effects of clofibrate on the main regulatory enzymes of cholesterogenesis.

The in vivo effect of clofibrate on the main regulatory enzymes of cholesterogenesis has been comparatively studied for the first time in chick liver and brain. 3-Hydroxy-3-methylglutaryl-CoA reductase and mevalonate 5-pyrophosphate decarboxylase from chick liver were significantly inhibited by this hypocholesterolenic drug, while mevalonate kinase and mevalonate 5-phosphate kinase were not affected. No enzyme from chick brain was significantly inhibited by the in vivo treatment. However, both liver and brain reductase activity was inhibited in vitro by clofibrate, inhibition that was progressive with increasing concentrations (1.25-5.00 mM) of drug.

Animals↗
PubMed1990

Incidental magnetization transfer contrast in standard multislice imaging.

Radio frequency magnetic fields from 5 to 100 kHz off resonance reduce longitudinal magnetization of water in some tissues without affecting the magnetization of simple solutions (Wolff, S.D.; Balaban, R.S. Magnetization transfer contrast (MTC) and tissue water proton relaxation in vivo. Magn. Reson. Med. 10:135-144; 1989). We demonstrate that off resonant fields used in day to day multislice imaging have a significant effect. Extra slices reduced brain (gray and white matter) and muscle intensities 10%-20% relative to fat, water, and paramagnetic solutions, a larger effect than produced by slice overlap. Implications for image contrast and quantitation are discussed.

Body Water↗
PubMed1990

Intracranial ganglioglioma: MR, CT, and clinical findings in 18 patients.

Eighteen cases of pathologically proved intracranial gangliogliomas were reviewed to determine their MR, CT, and clinical characteristics. Seventeen patients were evaluated with contrast-enhanced CT and 14 were studied by MR imaging. Eight tumors were predominantly cystic; half of these demonstrated some contrast enhancement, and five contained calcifications. These cystic gangliogliomas were located, in order of decreasing frequency, in the cerebellum, temporal, frontal, and parietal lobes. Ten tumors were solid; eight of these showed contrast enhancement, and only one contained calcifications. Small cysts were present in one solid mass. Solid gangliogliomas occurred preferentially in the temporal lobes. On MR, the findings were nonspecific and reflected the CT findings. In one patient who received gadolinium-DTPA the lesion did not enhance. Clinically, all patients presented with nonfocal long-standing symptoms and all but three were alive an average of 18 months after the initial diagnosis. Pathologists are recognizing ganglioglioma with increasing frequency, and although its radiographic characteristics vary, it should be included in the differential diagnosis when the above-described findings are encountered.

Adolescent↗
PubMed1990

Influence of fatty acid composition of diet on cholesterol content of eel liver and muscle.

The influence of different diets on cholesterol content of liver and muscle of European eel (Anguilla anguilla) was studied for the first time. In control eel, cholesterol constituted near 7.5% of total lipids in liver and about 1% in muscle. Feeding herring meal-55% diet produced a drastic increase in hepatic cholesterol after a 30 d period. In muscle, cholesterol content also increased after any dietary treatment. Free cholesterol represented about 34% of total cholesterol in liver and about 50% in muscle. In both tissues, these percentages increased after any experimental condition assayed. The n-3/n-6 ratio in the fatty acid composition was manifestly low in herring meal-55% diet, mainly due to the minimal amount of total n-3 fatty acids. This fact may account for the increase in liver cholesterol, bearing in mind the hypocholesterolemic effect of the polyunsaturated n-3 fatty acids.

Animals↗
PubMed1990

Lamicel for induction of labor.

Lamicel is a synthetic osmotic cervical dilator currently used as a method of cervical dilation in first- and second-trimester pregnancy termination. It works by extracting fluid from the cervical tissue and softening the cervix. This study evaluated its effectiveness in nonelective medical induction of labor in high-risk patients. Forty inpatients who, for medical and obstetric reasons, required delivery within the next 24-48 hours were studied. Patients were evaluated to make certain that a 12- to 24-hour delay was safe for mother and child. The evening prior to the day of induction, a pelvic examination determined the Bishop score, and bacterial cultures were obtained from the endocervix. As many Lamicels as possible (usually one to three) were then placed in the endocervix without rupturing the membranes. The next morning the devices were removed, a repeat Bishop score obtained, amniotomy performed, internal monitors placed and oxytocin infusion initiated. Data were collected for preinsertion and postinsertion Bishop scores, induction-delivery times, duration of ruptured membranes, and cesarean and vaginal birth rates. Maternal and neonatal infectious morbidity was determined. A comparison group of patients with premature rupture of the membranes was selected. From data studied at our institution, patients were matched for parity and duration of labor (not significantly different from the Lamicel group). The study revealed that Lamicel can be an effective means of ripening the cervix for induction of labor.

Bacterial Infections↗
PubMed1990

[A comparative study of the oral and rectal ammonium overload test in liver cirrhosis].

The ammonium loading test has been realized in 66 patients, 8 of them without clinical or laboratory data of hepatic disease and 58 diagnosed of hepatic cirrhosis (HC). In 40 patients with HC and 8 patients without liver disease the ammonium was administered by rectum and in the remaining 18 patients with HC it was administrated orally. In each case, non stagnant venous blood was drawn at 0, 30, 45, 60 and 75 minutes after the administration of ammonium and plasmatic levels were measured. The results show that in patients with HC there are no significant differences between rectal and oral administration although the rectal way presented less secondary effects and is better tolerated. The test is discriminatory when comparing patients with HC and patients without liver disease as well as between patients with HC and portal hypertension and those without clinical signs of portal hypertension.

Acetates↗