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Biomedical subjects

J Fuentes

Publications and source records attributed to J Fuentes.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Sclerosing hepatocarcinoma not associated with hypercalcemia].

The sclerosing hepatocellular carcinoma is an unusual subtype of hepatocellular carcinoma characterized by an intense fibrous stroma in which the tubular structures are embedded. Histological diagnosis is difficult, and misinterpretation as cholangiocarcinoma or metastatic adenocarcinomas may occur. It usually presents on non-cirrhotic livers. Metastases located outside of the liver are frequent as well as hypercalcemia and low levels of serum phosphate. We report a case of this rare histopathologic subtype of hepatocellular carcinoma in a 35-year-old woman, asymptomatic and with no previous history of chronic liver disease. It was detected by a routine gynaecological ultrasonography. An important increase of serum alpha-fetoprotein was noted. Extension studies showed bilateral lung metastases. Several palliative therapies were tried out, including epirrubicin, with partial response. Twenty months after the diagnosis the patient's situation is nearly terminal.

Adult↗
PubMed1996

Adenosine receptor blockade and hypoxia-tolerance in rainbow trout and Pacific hagfish. II. Effects on plasma catecholamines and erythrocytes

The purpose of this study was to examine the role of adenosine receptors (ARs) in (1) the regulation of catecholamine secretion and (2) the modulation of blood oxygen capacitance by catecholamines. To this end, we assessed the response of rainbow trout and Pacific hagfish treated with either an AR blocker, theophylline, or saline under hypoxic and normoxic conditions. Compared with the control hypoxic rainbow trout, AR blockade resulted in a smaller increase in haematocrit and haemoglobin (Hb) concentration of the blood, smaller red blood cell transmembrane pH differences and mean cellular [Hb] (MCHC), as well as a 16-fold higher plasma adrenaline concentration after only 10 min of acute hypoxic exposure. In hypoxic hagfish, AR blockade had no effect on the [Hb] of the blood, and there was no regulation of red blood cell pH or changes in MCHC. However, whereas plasma [adrenaline] did not change following exposure to a PwO2 of 1.33 kPa in the hypoxic sham group, the concentration increased 3.8-fold within 10 min in the theophylline-injected group. These results suggest that adenosine modulates the circulating level of catecholamines in both hypoxic rainbow trout and hypoxic Pacific hagfish.

Journal Article↗
PubMed1996

Post-feeding carbohydrate and ketone bodies metabolism in brain and liver of Atlantic salmon.

A study of several pathways of carbohydrate and ketone bodies metabolism was carried out in Atlantic salmon (Salmo salar) to assess the basal metabolism of the brain, and the possible existence of post-feeding changes in brain and liver metabolism. The main results obtained in brain of Atlantic salmon indicate a use of exogenous glucose as a main fuel source since important hexokinase activities were noticed, and brain glycogen levels were usually very low. Several post-feeding changes were observed in brain including an apparent decrease in glycolytic potential, as well as a decreased use of ketone bodies. In contrast, no major post-feeding changes were detected in liver metabolism. A role for ketone bodies as a metabolic fuel in brain of Atlantic salmon is supported by both the high levels of acetoacetate found in brain, and the presence of an active beta-hydroxybutyrate dehydrogenase.

Animals↗
PubMed1996

Kidney ATPase response in seawater-transferred rainbow trout (Oncorhynchus mykiss). Effect of salinity and fish size.

Two sizes of domesticated rainbow trout (Oncorhynchus mykiss, 40 +/- 0.67 and 180 +/- 3.9 g) were directly transferred to brackish water (9 ppt) and seawater (28 ppt). Kidney Na(+)-K(+)-ATPase and Mg(2+)-ATPase activities were measured in fresh water, and after long-term seawater adaptation (up to 21 days). Renal Na(+)-K(+)-ATPase activity increased after saltwater loading in small trout, while large trout displayed an unmodified ATPase activity. The smallest trout showed a low but progressive increase in renal Mg(2+)-ATPase activity after the transfer to both salinities. However, ATPase activity remained unchanged or significantly decreased in large trout after the transfer to seawater or brackish water, respectively.

Adaptation, Physiological↗
PubMed1995

Chemotherapy and radiotherapy in locally advanced cervical cancer.

Radiotherapy has been standard therapy for locally advanced squamous cell cervical cancer. Neoadjuvant chemotherapy is being studied to improve responses and survival. We report a phase II study in locally advanced squamous cell cervical cancer (FIGO stages III and IVA) using chemotherapy with bleomycin, methotrexate and cisplatin (BMP) followed by radical radiotherapy. Of the 35 patients, 31 in stage III and 4 in stage IVA, 3 complete responses (CR) and 22 partial responses (PR) were achieved after chemotherapy treatment. Thirty-one patients completed radiotherapy; 19 achieved CR and 4 PR. Five-year actuarial survival for the entire group was 45% (95% confidence interval, 37-53%) with a median survival of 56 months. Patients with CR had a significantly better survival: the 5-year actuarial survival was 74% (95% CI, 59-89%). Recurrence developed in 4 of 19 patients. The most frequent side-effects were nausea and vomiting. Myelosuppression and impaired renal function also occurred. There was no evidence of radiotherapy toxicity enhancement. The stage and Karnofsky index were significant prognostic factors. It is concluded that BMP chemotherapy in advanced cervical cancer is effective and, followed by radiotherapy, allows a good control of this tumor. The group of patients with complete response have a low rate of recurrences and a long survival chance.

Adult↗
PubMed1995

Endometrial cancer stages I and II. Analysis of survival and prognostic factors.

BACKGROUND: Endometrial cancer is the most frequent gynaecologic neoplasia in women. Stages I and II account for 75% of endometrial cancers. METHODS: Diagnostic features, treatment and outcome based on therapy with surgery and/or irradiation of 185 endometrial cancer patients in Stage I and II were analysed retrospectively. RESULTS: There were 148 patients (80%) in Stage I and 37 (20%) in Stage II. Twenty-nine patients (16%) relapsed and 18 have died of cancer. The 5 and 10 year specific actuarial survival was 89% and 81% respectively. The 5 and 10 years disease free survival was 82% and 78% respectively. In our analysis of prognostic factors we observed a significantly worse survival for postmenopausal and Stage II patients, high grade tumors (grade III) and greater myometrial penetration (outer 2/3). CONCLUSIONS: Endometrial cancer has a relatively good prognosis partly because of its early diagnosis. There is general consensus that surgery is the optimal treatment in Stages I and II. While it is well documented that complementary irradiation improves survival in Stage II, there is no general agreement regarding the value of complementary irradiation in Stage I. Further studies are needed to delimit Stage I patients who would benefit from complementary irradiation.

Adult↗
PubMed1995

Synthesis and analgesic activity of 2-amino-5-tert-butyl-2-oxazoline.

2-Amino-5-tert-butyl-2-oxazoline (ATBO, 2) was synthetized from 3,3-dimethyl-2-iodobutyl isocyanate via N-(3,3-dimethyl-2-iodobutyl) urea (1). The structures of compounds 1 and 2 are based on analytical and spectroscopic data. Compound 2 induced in rats and mice a peripheral antinociceptive effect through both spinal and supraspinal mechanisms. ATBO did not impair motor coordination or activity of the experimental animals.

Acetates↗
PubMed1995

[Primary gastric lymphoma in an HIV positive patient].

We report the case of a young male patient, VIH (+), who was admitted in our hospital with severe epigastric pain. Endoscopical and histological diagnosis was primary gastric non-Hodgkin lymphoma without Helicobacter pylori. The patient was treated with chemotherapy by CHOP scheme (6 cycles), with high clinical improvement and endoscopical and histological regression of the lesion. We comment some features of this peculiar association.

Adult↗
PubMed1995

HCO3(-)-ATPase and Ca2+ dependent ATPase activities in the gills of the rainbow trout after the transfer to brackishwater and seawater.

The effect of seawater and brackishwater exposure on gill HCO3(-)-ATPase and Ca2+ dependent ATPase activity in rainbow trout (Oncorhynchus mykiss) was investigated at different periods of time. HCO3(-)-ATPase activity decreased after the transfer to either brackishwater or seawater. Ca2+ dependent ATPase activity decreased during the initial period (1 to 4 days) in both salinities and recovered freshwater values from the 7th day onwards. No effect from fish size was detected in both parameters after saltwater transfer. The results are discussed in terms of salinity and long-term saltwater adaptation.

Adaptation, Physiological↗
PubMed1994

Direct transfer of rainbow trout to seawater induces several changes in kidney carbohydrate metabolism.

The levels of glycogen and glucose, and the activities of several key enzymes of glycogenolysis, glycolysis, gluconeogenesis and the pentose phosphate shunt were assessed in kidneys of rainbow trout (Oncorhynchus mykiss) of two sizes (80 and 140 g) after transfer to seawater (28 p.p.t.) during 7 days. The results indicated changes, mainly size-independent, in kidney carbohydrate metabolism during transfer of rainbow trout to seawater. An enhanced glycogenolysis and a concomitant increase in gluconeogenic enzyme activity were clearly observed in kidneys of both sizes of animals during transfer to seawater. Changes are suggested to be related to the known role of kidney as a glucose producer tissue thus satisfying, at least in part, the high energetic requirements of the osmoregulatory work performed by other tissues using glucose as fuel, such as the gills, during adaptation to seawater.

Adaptation, Physiological↗
PubMed1994

Physical deletion of the p53 gene in bladder cancer. Detection by fluorescence in situ hybridization.

To understand better the role of physical p53 deletion in bladder cancer, 106 formalin-fixed and 45 unfixed bladder tumors were examined using fluorescence in situ hybridization. Probes for centromere 17 and the p53 locus were hybridized simultaneously to interphase tumor cells to analyze p53 and chromosome 17 copy number on a cell by cell basis. 17p deletion was found in four of 43 pTa tumors, 18 of 43 pT1 tumors and 29 of 58 pT2-4 tumors (P = 0.0001). 17p deletion was also highly correlated with grade (P = 0.0001) and with p53 immunostaining (P = 0.0005). Chromosome 17 polysomy was associated with stage, grade, 17p deletions, and p53 immunostaining (P = 0.0001). The strong difference in centromere 17 copy number and 17p deletions between pTa and pT1 tumors supports a relevant biological distinction between pTa and pT1 tumors.

Alleles↗
PubMed1987

Modulation of pacemaker activity by IPSP and brief length perturbations in the crayfish stretch receptor.

We have studied the influences of brief stretches and releases and of inhibitory postsynaptic potentials (IPSPs) on pacemaker activity of the crayfish stretch receptor (RM1). Stimuli shift or reset the ongoing rhythm. Resettings were different if evaluated in interspike intervals containing perturbations, or in succeeding ones, and are referred to as early and late, respectively. Early resetting revealed that stretches and releases or IPSPs advance and delay, respectively, the next spike. With small stretches and releases or IPSPs, effects depend on the timing of the perturbation relative to the previous spike or phase, but above a characteristic mechanical perturbation amplitude the next spike fires at a fixed latency, invariant with the phase. Of particular interest was the finding that during late resetting the first successive intervals following stretches and releases or IPSPs were longer and shorter, respectively, than the period. This led, in approximately 50% of the cases, to a gradual recovery of the original pacemaker beat in the sense that spikes fire timed as if the early rhythm shift had not occurred. In conclusion, the recent firing history is essential in determining the RM1's response. The receptor's sensitivity is a complex nonlinear and periodic function of the pacemaker activity, and the response is due to interactions between pacemaker- and perturbation-induced transmembrane ionic currents. Although several alternative mechanisms may underly beat recovery, the results suggest that at least two coupled oscillators, one perturbable and the other not, provide a better explanation than a single oscillator. The physiological significance of resettings is unknown, but the early rhythm shift may synchronize RM1s in several segments when the animal's tail is moved, and conversely recovery would reduce synchrony, with obvious influences on shared postsynaptic neurons.

Animals↗