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G Robles-Díaz

Publications and source records attributed to G Robles-Díaz.

At least 19 recordsLinked to original sources
PubMed1995

Androgen receptor in the rat pancreas: genetic expression and steroid regulation.

Androgens influence the incidence and prevalence of pancreatic cancer in humans and animal models. To our knowledge there has been molecular demonstration of the presence of neither the androgen receptor (AR) nor transcripts of the AR gene. Reverse-transcription polymerase chain reaction (RT-PCR)-Southern blotting was employed for molecular detection and measurement of the androgen receptor messenger ribonucleic acid (AR mRNA) in pancreas. Total RNA obtained from pancreas, prostate, seminal vesicles, and testes of neonatal and adult male and female rats, as well as castrated males substituted with testosterone cyclopentylate, was analyzed by Northern blot technique. Positive hybridization to AR cDNA was obtained in all tissues assayed but not in the pancreas. However, a clear AR 32P cDNA hybridization signal was obtained in pancreatic tissues after cDNA synthesis using RT-PCR-Southern blotting. The levels of the AR transcripts obtained by RT-PCR in the various pancreatic samples were as follows: adult females and neonatal animals > castrated adult males > adult males > castrated adult males substituted with testosterone. These results indicated that the pancreatic tissue possessed transcriptional activity of the AR gene, although to a lesser extent than the typical androgen responsive tissues (prostate and seminal vesicles). In conclusion, transcriptional activity of the AR gene in the pancreas seemed to be modulated by the androgenic milieu in the tissue similar to that reported for the classical androgen-responsive organs.

Androgens↗
PubMed1991

Testosterone biotransformation by the isolated perfused canine pancreas.

There is strong evidence indicating that the pancreas is under the influence of sex steroid hormones, and that it may even participate in their biosynthesis and metabolism. In the present study, [3H]testosterone was perfused into the isolated canine pancreas, and measured in the effluent with several of its metabolites (5 alpha-dihydrotestosterone, androstenedione, and estradiol). Results show that testosterone is readily transformed by the canine pancreas. The main product found in the effluent is androstenedione. The testis and spleen were also perfused with [3H]testosterone and used as controls. In both cases, this hormone appeared mostly unchanged in the effluent as compared to the pancreatic perfusion (p less than 0.0001). From our data, we conclude that the canine pancreas has the capacity to transform sex steroid hormones, and could be considered an extragonadal site of sex steroid biosynthesis.

Androstenedione↗
PubMed1991

Serum testosterone:dihydrotestosterone ratio and CA 19-9 in the diagnosis of pancreatic cancer.

The testosterone:dihydrotestosterone ratio (T:DHT) and the antigenic marker CA 19-9 were studied in the serum of 21 male patients with pancreatic cancer and 62 controls with other gastrointestinal malignancies or benign pancreatobiliary disease. Specificity of the T:DHT ratio was 98%, significantly better than the specificity of CA 19-9 at both a 37 U/ml cutoff level (61%) and at 100 U/ml (79%). Sensitivity of the T:DHT ratio was 67%, and that of CA 19-9, 71% and 90% at the upper and lower cutoff levels, respectively. False-negative results of the T:DHT ratio were found predominantly in cases of advanced pancreatic cancer, whereas all four stage I patients had an abnormal (less than 5) T:DHT ratio. These results suggest that the T:DHT ratio is a useful marker for pancreatic cancer in males. It can be used alone or in combination with CA 19-9, and should be further evaluated in the differential diagnosis of patients with the early stages of this disease.

Adult↗
PubMed1990

Chronic pancreatitis in Mexico City.

The incidence, etiology, clinical characteristics, and long-term outcome of patients with chronic pancreatitis (CP) studied at the Instituto Nacional de la Nutrición in a 12-year period were retrospectively analyzed. One hundred fifty cases were identified, with an overall incidence of 4.4 per 1,000 hospital admissions and of 5.4 per 1,000 in the last 6 years. In 68% of the cases, CP was secondary to alcoholism, in 29% it was idiopathic, and in the rest it was secondary to other causes. Overall, 74% of patients had pancreatic calcifications at time diagnosis was established, and 21% were asymptomatic regarding pain. Patients with idiopathic CP had an earlier age of onset than did patients with alcoholic CP, and in addition the former developed symptoms of diabetes or pancreatic exocrine insufficiency less frequently than alcoholic patients did (p less than 0.05). The sex ratio was different in both groups, with a marked male predominance in alcoholic CP and an equal distribution in the idiopathic group. A 30% actuarial mortality was found in the first 10 years after the onset of the disease, which remained the same at 20 years with a tendency to better survival in nonalcoholic patients. Five patients developed pancreatic cancer throughout the study period.

Adult↗
PubMed1990

Pancreatic cancer and androgen metabolism: high androstenedione and low testosterone serum levels.

Serum androstenedione and testosterone levels were measured in 39 male patients with pancreatic cancer, and compared with the values obtained from 37 male patients with chronic pancreatitis or benign obstructive jaundice, and with those from 36 male patients with other gastrointestinal malignancies. Mean androstenedione values were significantly higher in the pancreatic cancer patients when compared to both control groups, and mean testosterone levels were significantly lower. The testosterone/androstenedione ratio was calculated and was also found to be significantly lower in the patients with pancreatic cancer. There was no difference in this ratio or in the androstenedione or testosterone levels when comparing both control groups. In two patients with stage I pancreatic cancer, serum androstenedione and testosterone levels were significantly altered, and returned to normal values after successful resection. These results confirm previous findings indicating that there is significant derangement in the androgen profile of patients with pancreatic cancer.

Aged↗
PubMed1990

Tuberculosis of the pancreas.

A 67-year-old woman was admitted to the hospital because of intermittent pain in the upper left quadrant of the abdomen. Ultrasound and computed tomography (CT) scan revealed a mass in the body of the pancreas, and angiography demonstrated encasement of the celiac trunk and splenic vein thrombosis. She was thought to have a pancreatic carcinoma and was surgically explored to obtain tissue for diagnosis. A hard and irregular tumor was found, and biopsies revealed granulomatous inflammation with caseous necrosis. The final diagnosis was tuberculosis, and treatment with rifampicin, isoniazid, and ethambutol was undertaken. One year later the patient is asymptomatic and new CT scan shows disappearance of the pancreatic mass.

Aged↗
PubMed1990

Association of pancreatic biotinidase activity and intestinal uptake of biotin and biocytin in hamster and rat.

Pancreatic biotinidase activity was higher in hamster than in rat; these results were reversed in plasma. Uptake was studied in everted intestinal rings. Saturation kinetics at 37 degrees C were observed for biotin in hamster and for biocytin in rat, with a Vmax of 1.83 and 1.05 nmol min-1 ml-1 and an apparent Kt of 25.14 and 40.7 microM, respectively. Biotin uptake by hamster intestine was reduced at 4 degrees C and when choline or potassium replaced sodium; it was inhibited by biocytin only at very high concentrations. Biocytin uptake in the rat was small compared to passive diffusion and was not influenced by sodium or temperature; it was not inhibited by biotin. We observed only passive diffusion of biotin in rat and of biocytin in hamster. Our results suggest that protein-bound biotin may be absorbed mainly in its free form in the hamster. In the rat, on the other hand, at least part of the dietary biotin may be absorbed lysine-bound, as biocytin.

Amidohydrolases↗
PubMed1987

Microcystic adenoma of the pancreas.

Three cases of pancreatic microcystic adenoma (PMA) are presented. These tumors comprise less than 1% of all pancreatic tumors in a large series, and exhibit a benign course, in contrast to mucinous cystadenomas, which have a definite malignant potential. The cases here presented are middle and advanced aged women who complained of epigastric discomfort and mild weight loss. Two of them also had a palpable epigastric mass and one of them diabetes mellitus. They were treated surgically with total excision of the tumor. During surgery and thereafter no evidence of spreading beyond the pancreas was found. CT scan shows a characteristic image of PMA, which may then be confirmed by a percutaneous biopsy. If the patient is asymptomatic or a poor surgical risk, it is reasonable to rely on this evidence and follow the patient rather than operate.

Adenoma↗
PubMed1985

Nutritional data and etiology of chronic pancreatitis in Mexico.

Alcoholism and malnutrition have been implicated commonly in the etiology of chronic pancreatitis (CP). The geographical distribution and clinical and nutritional features differ between the alcoholic and tropical forms of CP. This work presents the etiology and nutritional characteristics of CP in Mexico, a country in which both alcoholism and childhood malnutrition are common. Two well-defined groups of patients have been identified: an alcoholic group composed mainly of males with a mean age at clinical onset of 41 years and a high dietary intake of fat, protein, carbohydrates, and calories; and a nonalcoholic group with a female preponderance, a mean age at onset of 23 years, and a higher intake of protein than controls. We conclude that alcoholic chronic pancreatitis in Mexico is similar to that reported in other temperate countries. Although the nonalcoholic group resembles that observed in tropical countries in many ways, our patients are not malnourished, further questioning the role of childhood malnutrition in the pathogenesis of this type of chronic pancreatitis.

Adolescent↗
PubMedDate not supplied

[Dissolution of pancreatic calcifications with oral citrates in a woman with chronic idiopathic pancreatitis].

Pain control is one of the most important objectives in the medical treatment of patients with chronic calcifying pancreatitis (CCP). It is generally accepted that pain in CCP is secondary to the obstruction of the pancreatic duct by calcifications, protein plugs and stenotic areas. Experimental studies have shown that calculi and protein plugs are soluble in citrates. We report here the case of a young non alcoholic woman with idiopathic CCP who after a pancreatojejunostomy developed again pain and pancreatic calcifications which were dissolved with oral citrates. The case confirms previous observations and illustrates the potential use of citrates in subjects with CCP.

Abdominal Pain↗
PubMedDate not supplied

[Pancreatic phlegmon: a potentially fatal form of acute pancreatitis].

AIM: To report the clinical characteristics of a group of patients with pancreatic phlegmon (PF) seen at the Instituto Nacional de la Nutricion Salvador Zubiran, Mexico City. MATERIAL AND METHODS: We reviewed all the cases of acute pancreatitis hospitalized from January 1981 to December 1989. The diagnosis of pancreatic phlegmon was established when the CT scan showed a solid mass in the pancreas and peripancreatic region with more than 20 Hounsfield units without liquid collections or a fibrous capsule. We analyzed clinical, biochemical, and radiological data. RESULTS: Acute pancreatitis was diagnosed in 132 patients. In 14 a pancreatic phlegmon was observed (10.6%). Twelve were men; the mean age was 44.7 years. In six cases acute pancreatitis was secondary to alcohol abuse and in four to gallstones. Abdominal pain was present in all patients. Ten had leucocitosis and seven fever and/or jaundice. An abdominal mass was detected in three cases. The severity of pancreatitis was graded according to our institutional criteria as mild (0-2 signs) or severe (3-5 signs). In 10 patients AP was graded as mild: no mortality was observed in this group but three presented complications (two liquid collections and one an abscess). The four patients with severe pancreatitis presented complications and three died (one abscess, two multiorgan failure). Five patients were operated on. In three an abscess was drained. CONCLUSIONS: Pancreatic phlegmon is a potentially severe form of AP. All patients who died presented, in addition to PF, clinical criteria of severe pancreatitis.

Acute Disease↗
PubMedDate not supplied

[4 cases of annular pancreas at the Instituto Nacional de la Nutrición Salvador Zubirán].

Annular pancreas (AP) is a rare congenital anomaly due to malrotation of the pancreatic ventral yolk. Although it has been described in young and middle age adults it predominates in children. Its clinical picture is that of duodenal obstruction or acute pancreatitis episodes. In this paper we report four cases of AP that were seen at the Instituto Nacional de la Nutricion Salvador Zubiran in Mexico City. Three were females and three were less than twenty years old. In one case the diagnosis was established at birth and the operation done in another hospital. In another patient a diagnosis of pyloric hypertrophy was made and a pyloroplasty was performed. This young man was admitted in our hospital because of abdominal pain and hyperamylasemia. An eighty four year old woman was seen due to abdominal pain, nausea and vomit. In all cases the diagnosis of AP was carried out with radiological studies and confirmed by laparotomy. Surgical procedures consisted of duodenal-duodenal anastomosis in two, sphincteroplasty in one, and gastrojejunoanastomosis in the other. Two patients are asymptomatic, one died in the postoperative period, and one was lost for follow up. These four cases represent all the experience of our institute and correspond to one case in 36,735 admissions.

Abdominal Pain↗
PubMedDate not supplied

[Sphincteroplasty of the minor papilla in a female patient with pancreas divisum].

We report the case of a 30 year old woman with recurrent episodes of acute pancreatitis secondary to pancreas divisum. The diagnosis was established 18 years after the initiation of her symptomatology. She denied a family history of pancreatic disease and had no risk factors in her personal history. Diagnosis was confirmed by endoscopic retrograde cholangiopancreatography. She was surgically treated by means of a sphincteroplasty of the minor papillae with excellent results. After three years of follow-up, the patient remains asymptomatic.

Acute Disease↗