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J Medrano

Publications and source records attributed to J Medrano.

At least 37 records · Page 2Linked to original sources
PubMed1998

Detection of P-glycoprotein in frozen and paraffin-embedded gastric adenocarcinoma tissues using a panel of monoclonal antibodies.

AIMS: Most chemotherapeutic regimens used against gastric carcinoma include anthracyclines whose effectiveness can be impaired by the presence of P-glycoprotein. In order to obtain a reliable pattern of P-glycoprotein expression in these tumours an immunohistochemical study using a panel of anti-P-glycoprotein antibodies was performed in frozen and paraffinized tissues. METHODS AND RESULTS: Frozen and paraffinized samples from 25 gastric carcinomas were immunohistochemically analysed using a panel of four anti-P-glycoprotein monoclonal antibodies including C219, MRK16, JSB-1 and C494. Semiquantitative analysis indicated that moderate or high P-glycoprotein levels were detected in 40% to 76% of gastric adenocarcinomas, depending on the anti-P-glycoprotein antibody used. The antibody C494 was the most sensitive in detecting P-glycoprotein in both frozen and paraffinized gastric carcinoma samples. Moreover, C494 showed a pattern of staining exclusively associated with the plasma membrane, in contrast to the cytoplasmic with reinforcement of plasma membrane pattern displayed by the other three antibodies. Significant differences in P-glycoprotein levels were obtained when C494 and MRK16 were used in frozen tissues. Finally, detection of P-glycoprotein in frozen samples did not improve when compared to paraffinized ones. CONCLUSIONS: It appears that P-glycoprotein is frequently expressed in gastric adenocarcinomas, and the use of C494 complemented by JSB-1 is recommended for reliable detection of P-glycoprotein in this neoplasm.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Failure to detect early recurrence of gastric cancer.

Early gastric cancer recurrence is sometimes difficult to diagnose even by protocols using imaging techniques and tumor markers. We report a gastric cancer recurrence diagnosed by the appearance of a Sister Mary Joseph's nodule that illustrates the lack of sensitivity of these methods. We also discuss the protocol we currently follow for these patients.

Anastomosis, Roux-en-Y↗
PubMed1998

Canine pancreatic responses to intracolonic perfused nutrients.

To study the effect intracolonic perfusion of nutrients has on exocrine pancreatic secretion, six dogs were prepared with gastric, duodenal, and cecal cannulas using a modified Thomas technique. In our study protocol, we collected pancreatic juice by selective ductal cannulation after having applied several types of intracolonic stimulation: perfusion of sodium chloride, tryptophan, rice starch + glucose, or sodium oleate. All these solutions were applied together with a background dose of intravenous secretin. Our results showed a significant increase in the volume of pancreatic juice and bicarbonate output after intracolonic perfusion of sodium oleate. Other perfusions did not change these parameters. Protein output did not change in any of the cases. It seems that the ascending colon plays a regulating role in pancreatic secretion; in some conditions the colon could increase exocrine pancreatic function.

Animals↗
PubMed1997

omega-Conotoxins block neurotransmission in the rat vas deferens by binding to different presynaptic sites on the N-type Ca2+ channel.

Electrically-induced twitch responses of the prostatic segment of vas deferens (0.1 Hz, 65 V, 1 ms) are mainly due to the transient presynaptic release of ATP, which acts postsynaptically on non-adrenergic receptors to contract smooth muscle cells. These responses were fully blocked by nanomolar concentrations of the omega-conotoxins GVIA, MVIIA, and MVIIC, most likely by inhibiting Ca2+ entry through presynaptic N-type Ca2+ channels controlling the release of ATP. Repeated washout of the toxins allowed the recovery of contractions, except for omega-conotoxin GVIA, whose inhibitory effects remained unchanged for at least 60 min. In addition, micromolar concentrations of omega-conotoxin MVIIC were unable to protect against the irreversible inhibition of twitch contractions induced by nanomolar concentrations of omega-conotoxin GVIA. At low extracellular Ca2+ concentrations (1.5 mM), 20 nM of omega-conotoxin GVIA or MVIIA inhibited completely the twitch contractions in about 10 min. In 5 mM Ca2+ the blockade of twitch contractions after 10 min was 70% for both toxins. In 1.5 mM Ca2+ omega-conotoxin MVIIC (1 microM) inhibited completely the twitch contraction after 10 min. In 5 mM Ca2+ blockade developed very slowly and was very poor after 30 min, omega-conotoxin MVIIC depressed the response by only 20%. These results are compatible with the idea that the three omega-conotoxins block the purinergic neurotransmission of the vas deferens by acting on presynaptic N-type voltage-dependent Ca2+ channels. However, omega-conotoxin MVIIC seems to bind to sites different from those recognised by omega-conotoxin GVIA and MVIIA, which are markedly differentiated by their Ca2+ requirements for binding to their receptors.

Animals↗
PubMed1997

[Pulmonary artery aneurysm and thrombosis caused by vasculitis in Behçet's disease].

Behcet's disease in a 27-year-old male is described. The patient presented fever, dyspnea and hemoptysis. A chest X-ray revealed right hilar enlargement. Exploratory thoracotomy revealed a pulsating mass in the superior lobar artery consistent with aneurysm. Pulmonary biopsy confirmed necrotizing vasculitis of the tissue consistent with Behcet's disease. Pulmonary arteriography showed and aneurysmatic enlargement of the bifurcation between the mid and righ inferior lobar arteries, with thrombosis of the upper right and lower left lobar arteries. Resolution of symptoms was achieved through treatment with corticoids and azathioprine.

Adult↗
PubMed1997

Pancreatic enzyme secretion in response to test meals differing in the quality of dietary fat (olive and sunflowerseed oils) in human subjects.

The aim of the present study was to investigate in human subjects whether or not the ingestion of two liquid meals that differed only in their fatty acid composition (due to the addition of olive oil (group O) or sunflowerseed oil (group S) as the source of dietary fat) would lead to differences in the pancreatic enzyme activities secreted into the duodenum. The experiments were performed in eighteen cholecystectomized subjects who, during the 30 d period immediately before surgery, modified their habitual diets in such a way that their fat composition would reflect, as far as possible, that of the experimental meals. Lipase (EC 3.1.1.3), colipase, amylase (EC 3.2.1.1), chymotrypsin (EC 3.4.21.1) and trypsin (EC 3.4.21.4) activities were measured in duodenal contents aspirated before and after the ingestion of the test meals. The plasma levels of secretin and cholecystokinin (CCK) were also examined. Duodenal enzyme activities were similar in resting conditions. No significant differences were revealed in postprandial enzyme activities, except for lipase activity, which was higher in group O, probably in relation to the greater plasma CCK concentrations observed in this group. In the absence of enzyme output data, we should not exclude the possibility that the type of dietary fat will affect human pancreatic enzyme secretion to a greater extent than is evident from the present study, for instance through a flow-mediated effect, as we previously observed in dogs.

Amylases↗
PubMed1997

[Current status and clinical experience in the treatment of tracheobronchial stenoses with self-expanding metallic stents].

The development of symptomatic stenosis in the bronchial tree can lead to high risk asphyxia. The implantation of metallic prostheses (stents) can provide palliative resolution of stenosis and alleviate the acute symptoms of these patients. We assess the efficacy of expandable metallic stents for treating various types of tracheobronchial stenosis. Sixteen Wallstent type expandable metallic prostheses were implanted in 16 patients with tracheobronchial stenosis (12 malignant and 4 benign) in the interventional radiology unit under fluoroscopic and endoscopic guidance. The prostheses were placed correctly and no complications were observed, such that symptoms improved immediately. Three patients with post-intubation stenosis required additional treatment with laser therapy during follow-up examinations. All the patients with malignancies died from the underlying disease, but with open airways and no tracheal symptoms. Metallic prostheses are a valid alternative for palliative treatment of malignant tracheobronchial stenosis.

Adult↗
PubMed1995

Follow-up of patients resected for gastric cancer.

In this study we used a cost-outcome analysis to evaluate our follow-up protocol for patients who had been resected for gastric cancer. We designed a descriptive cross-sectional trial through consecutive sampling of patients who had undergone resection of gastric carcinoma and were followed in our outpatient department during 1991. Serological (CEA) and or imaging procedures were pathologic at least two months prior to the onset of symptoms in 33% of recurrences. No significant correlation was found between serum CEA levels and CEA tumor tissue staining in patients who recurred. Only 17% of patients who relapsed underwent further treatment (surgery and chemotherapy) with no improvement found in terms of survival. The overall cost per year has been estimated at US$ 6118. Our results show that serological levels of CEA and available imaging techniques for routine follow-up provide little advantage in diagnosing gastric cancer recurrence over clinical surveillance alone.

Adenocarcinoma↗
PubMed1995

[The long-term clinical and imaging follow-up of inferior vena cava filters. A cross-sectional study].

We carried out a cross-sectional study to assess morphological findings and incidence of complications in 77 inferior vena cava filters (IVC) implanted in 75 patients between April 1990 and January 1994. Follow-up ranged from 3 to 61 months (mean, 38.5 months) and was carried out by telephone interview, clinical examination, X-rays of the ilium/vena cavum and, in some cases, by Doppler sonogram and computed tomography. Findings revealed IVC thrombosis in 38% of patients, edema in the lower extremities in 63.4%, angling > 15 degrees in 8 patients, defective opening in 4, fibrosis of the vena cava with stenosis in 2 and perforation of the IVC in 3. Although our study shows that the incidence of IVC thrombosis after implantation of filters is higher than suspected, its clinical importance is slight.

Adult↗
PubMed1994

[Self-expandable metal prostheses. A new alternative palliative therapy of malignant stenotic lesions of the esophagus].

The treatment of malignant esophageal stenoses is a serious problem which may have a surgical solution at diagnosis in only a selected number of cases. Chemotherapy and radiotherapy are the main palliative treatments; surgery has a high morbidity and mortality rate. The insertion of esophageal prostheses could be an alternative palliative treatment. From January 1991 to November 1993, 41 autoexpandable metallic prostheses (12 Wallstent type, 19 Strecker type and 1 Rosch-Uchida type) have been implanted in 30 patients with esophageal cancer one with lung cancer and two with radiation induced esophagitis. Technical success resulted in 28 patients; an initial failure requiring a new prosthesis insertion occurred in 5 patients. Technical aspects and results are analyzed.

Adenocarcinoma↗
PubMed1993

Gastric carcinoma: study of the most eminent prognostic factors.

In order to analyse some prognostic factors in relation to gastric cancer, 218 patients were included in a prospective protocol at 'Hospital General de Elche' (Spain) with a follow-up of 100%. Survival curves were calculated using Kaplan-Meier analysis and compared using the log-rank test. The number of patients who underwent resection was 122 (63.5%). In 70 cases (36.5%) the resection was not possible. The postoperative mortality was 4.9%. In the survival of patients with gastric cancer we find the following prognostic factors are significant: age, tumour site, macroscopic type, depth of gastric wall affection, presence of lymph nodes, staging, resectability and surgical intention (curative vs palliative).

Adult↗
PubMed1990

[Metabolic disorders in the gastrectomized patient].

The present study attempts on one hand to study the metabolic disorders which may present themselves in the gastrectomized patient, such as the malabsorption of fat, vitamin B12, folic acid and iron as well as the possible correlation between steatorrhea and the presence of exocrine pancreatic insufficiency. For this purpose a group of 71 patients have been studied who have undergone a subtotal gastrectomy (70.42%) or total (29.58%) in the General Surgery Services of Elche. The results obtained show the presence of ferropenic or megaloblastic anemia in 61.97% of the group, serious steatorrhea in only 3 patients (4.22%) and calciumphosphorous metabolism alterations appeared in 21.13%. With this we conclude that anemia is the most frequent ferropenic alteration in the gastrectomy patient; steatorrhea does not seem to be produced exclusively by the presence of exocrine pancreatic insufficiency and bone alterations in the gastrectomized patient appear in an insidious manner, being more a question of biochemical alterations than actual clinical lesions.

Adult↗
PubMed1989

[Hernial strangulation of Meckel's diverticulum: Littre's hernia. Apropos of 4 cases].

Hernial strangulation of Meckel's diverticulum (Littre's hernia) is a rare anatomoclinical form. It represents 10% of all complications of Meckel's diverticulum (8.8% of our cases), and complications like hemorrhage, perforation and diverticulitis are fairly frequent. Four cases of Littre's hernia are presented: two males and two females, with an average age of 67 years (range 50-83 years), representing 0.08% of all the inguinal-crural hernias operated in the department. The clinical manifestations were those of intestinal obstruction because a mixed type Littre's hernia was involved, with compromise of the diverticulum and its intestinal loop. Preoperative diagnosis is unlikely in strangulation without disturbances in the intestinal transit and, in fact, is even less likely if it is accompanied by obstruction. The diagnosis is thus almost always intraoperative. The correct treatment is surgery after restoring the patient's hemodynamic equilibrium. Simple and/or loop diverticulectomy via herniotomy, herniolaparotomy or laparotomy are debated. We think that this disorder can generally be resolved using the inguinal approach, as in any strangled hernia, with the technical option of using a larger, more comfortable and safer approach in cases of important obesity and/or deterioration of the loop (necrosis, perforation). In elderly patients with uncomplicated Littre's hernia and Meckel's diverticulum, abstention from diverticular exeresis may be justifiable. Of the four patients, the first two died from cardiogenic shock and pulmonary embolism, respectively; the last two evolved well (except for a wound abscess).

Aged↗