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Biomedical subjects

J Aguiló

Publications and source records attributed to J Aguiló.

14 recordsLinked to original sources
PubMed2003

Minimally invasive silicon probe for electrical impedance measurements in small animals.

It is commonly accepted that electrical impedance provides relevant information about the physiological condition of living tissues. Currently, impedance measurements are performed with relatively large electrodes not suitable for studies in small animals due to their poor spatial resolution and to the damage that they cause to the tissue. A minimally invasive needle shaped probe for electrical impedance measurements of living tissues is presented in this paper. This micro-probe consists of four square platinum electrodes (300 microm x 300 microm) on a silicon substrate (9 mm x 0.6 mm x 0.5 mm) and has been fabricated by using standard Si microelectronic techniques. The electrodes are not equally spaced in order to optimise the signal strength and the spatial resolution. Characterisation data obtained indicate that these probes provide high spatial resolution (measurement radius <4 mm) with a useful wide frequency band going from 100 Hz to 100 kHz. A series of in vivo experiments in rat kidneys subjected to ischemia was performed to demonstrate the feasibility of the probes and the measurement system. The impedance modulus and phase were measured at 1 kHz since this frequency is sufficiently low to permit the study of the extracellular medium. The extracellular pH and K+ were also simultaneously measured by using commercial miniaturised Ion Selective Electrodes. The induced ischemia period (45 min) resulted in significant changes of all measured parameters (Delta/Z/ approximately 65%; DeltapH approximately 0.8; DeltaK+ approximately 30 mM).

Animals↗
PubMed2003

Multiparametric monitoring of ischemia-reperfusion in rat kidney: effect of ischemic preconditioning.

BACKGROUND: Microelectrode technology is a promising tool for monitoring kidney ischemia and the changes induced by its therapeutic management. Ischemic preconditioning, that is, brief ischemic periods before sustained ischemia, has been shown to protect several organs, including the kidney, from ischemia-reperfusion injury. We tested whether the effect of preconditioning could be appraised by real-time measurement of parameters representative of tissue hypoxia. METHODS: In a sample of pentobarbital-anesthetized and mechanically ventilated rats, we studied the effect of renal ischemic preconditioning (10-min ischemia and 10-min reflow interval) on subsequent ischemia-reperfusion (45 min and 60 min). Renal tissue electrical impedance, extracellular pH, and potassium concentration [K+] were measured continuously by implanted microelectrodes. RESULTS: Ischemia induced an early, rapid rise in extracellular potassium and impedance module, followed by a phase of slower increase, whereas pH decreased rapidly, reaching a plateau. Preconditioning treatment did not cause significant changes in interstitial pH and [K+] but increased ischemic tissue impedance. During reperfusion, the three variables recovered progressively; however, after a decline, electrical impedance showed a clear postischemic increase. This rise was suppressed by preconditioning. CONCLUSIONS: Real-time measurement of any of the three parameters showed capability for early detection of ischemia. In contrast with findings in myocardial tissue, preconditioning in the kidney did not increase potassium cell loss during ischemia or improve ischemic acidosis or tissue impedance. Electrical impedance increased for a second time during reperfusion, indicating the presence of a postischemic cellular edema; concealing this episode was the most noticeable effect of the preconditioning treatment.

Acidosis↗
PubMed2000

Effect of hydrocolloid dressings on healing by second intention after excision of pilonidal sinus.

OBJECTIVE: To assess the efficacy of hydrocolloid dressings in wound management after excision of pilonidal sinus. DESIGN: Prospective randomised trial. SETTING: District hospital, Spain. PATIENTS: 38 patients with chronic pilonidal sinus. INTERVENTIONS: Open excision with healing by second intention. Divided into three groups: conventional gauze dressing (control, n = 15), Comfeel (n = 12) and Varihesive (n = 11). MAIN OUTCOME MEASURES: Median healing time, infection rate, intolerance, pain, comfort, ease of management, leakage, and recurrence. RESULTS: Median healing time was 68 days (range 33-168) in the control group, compared with 65 days (range 40-137) in the two hydrocolloid groups combined. There were no differences between the hydrocolloid groups. There were no recurrences during the 74 months of follow-up. A third of the postoperative cultures in the control group grew pathogens compared with 1/23 of the patients treated with hydrocolloid dressings (p = 0.03). This was of no clinical relevance. 14/23 in the hydrocolloid group developed leaks. Pain was significantly less in the first four postoperative weeks among the patients in the hydrocolloid group than in the control group (p < 0.05). CONCLUSIONS: Hydrocolloid dressings lessen pain and increase comfort for patients after excision of pilonidal sinus, though time to healing is no shorten than when a conventional gauze dressing is used.

Adolescent↗
PubMed1998

Home treatment of deep vein thrombosis: a two-years experience of a single institution.

BACKGROUND AND OBJECTIVE: Low molecular weight heparin (LMWH) is known to be safe and effective for the initial treatment of patients with acute deep-vein thrombosis (DVT). Moreover, LMWH allows patients to be treated at home. However, only limited data are available on the feasibility of LMWH treatment at home in daily clinical practice. DESIGN AND METHODS: We evaluated the feasibility, efficacy and safety of home treatment of DVT in a consecutive series of outpatients using LMWH over a two year period. The two main reasons for exclusion were concomitant pulmonary embolism and a high hemorrhagic risk. Patients were treated with 95 IU/kg bid of nadroparin for a minimum of 7 days. The study design allowed patients to go home immediately after diagnosis or to be discharged after a short hospital stay. Anticoagulation with acenocoumarol was started 2 days before discontinuing nadroparin. RESULTS: From 1995 to 1997, 71 consecutive outpatients with DVT were treated with nadroparin. Ambulatory treatment was feasible in 39 patients (24 patients did not require admission and 15 patients were discharged in less than 48 hours). The remaining 32 patients were treated in hospital. The main causes for admission were the presence of serious comorbid conditions, the severity of symptoms in the involved leg and the inability to obtain a diagnosis. None of the patients had clinical recurrent venous thromboembolism during the initial treatment with nadroparin. One patient receiving nadroparin at home had a non-fatal major bleeding. None of the patients to whom the possibility of home therapy was offered wished to remain at hospital. However, only 26% of the home-treated patients injected the drug by themselves. INTERPRETATION AND CONCLUSIONS: Home therapy of DVT with LMWH bid at doses adjusted to patient's body weight is feasible, efficient and safe. Over 50% of outpatients with DVT can be treated at home, either entirely or after a short stay in hospital. Nevertheless, before using this therapeutic alternative as a standard of practice, an adequate assessment of embolic and hemorrhagic risks, and comorbid conditions, should be made.

Adult↗
PubMed1997

Video-laparoscopic staging of gastric cancer. A prospective multicenter comparison with noninvasive techniques.

BACKGROUND: The high proportion of gastric carcinomas present in an unresectable stage, together with the emergence of multimodal treatments, increases the usefulness of objective staging methods that avoid unnecessary laparotomies. METHODS: A prospective evaluation of the accuracy of laparoscopy in the staging of 71 patients with gastric adenocarcinoma is presented. Serosal infiltration, retroperitoneal fixation, metastasis to lymph nodes, peritoneal and liver metastasis, and ascites were determined in the staging workup. Sensitivity, specificity, and predictive values were calculated and compared with those obtained with ultrasonography (US) and computed tomography (CT). RESULTS: The diagnostic accuracy of laparoscopy in the determination of resectability was 98.6%. Consequently, over 40% of patients were spared unnecessary laparotomies. Laparoscopy yielded diagnostic indices superior to US and CT for all the tumoral attributes studied. Our technique permits accurate assessment and pathologic verification of liver and the peritoneal and retroperitoneal extent of tumor invasion in the majority of patients. CONCLUSIONS: Laparoscopy in gastric adenocarcinoma is a reliable technique that provides accurate assessment of resectability and stage, thus avoiding unnecessary laparotomies in patients in whom surgical palliation is not indicated. A stepwise diagnostic workup combining imaging and minimally invasive techniques is proposed.

Adenocarcinoma↗
PubMed1996

[Simultaneous pancreas-kidney transplantation. First cases in Chile].

We report two insulin dependent diabetic patients with a past history of 21 and 30 years complicated with retinopathy, neuropathy and nephropathy with arterial hypertension and kidney failure. Simultaneous pancreas-kidney transplantation was done 8 and 18 months after starting hemodialysis, performing a double intraperitoneal implant with pancreato-duodeno-vesical anastomosis and contralateral kidney grafting with uretero vesical anastomosis using antireflux techniques. In the second case, a second kidney transplant from the same donor was needed, due to a thrombosis of renal vein. There was one rejection episode in each case but renal or pancreatic function was not impaired. Other observed complications were metabolic acidosis and hyperkalemia due to urine loss of bicarbonate, moderate arterial hypertension and bacterial and fungal infections. There was a graft dysfunction due to the association of vancomycin and cyclosporin. In conclusion, in the two presented patients, simultaneous pancreas-kidney transplantations were successful and they remain free of insulin or dialytic therapy 4 and 9 months after the operation.

Adult↗
PubMed1996

[Renal transplantation in patients with neurogenic bladder].

BACKGROUND: Renal transplantation can be done in patients with neurogenic bladder and clean intermittent self catheterization maintains renal function AIM: To retrospective assess the results of renal transplantation in patients with neurogenic bladder. PATIENTS AND METHODS: The medical records of seven patients aged 10 to 22 years old (3 female) followed during 7 to 32 months were reviewed. All patients had urinary tract infection, prior to transplantation, were instructed on self catheterization and received tri-associated immunosuppression. RESULTS: Grafts came from alive related donors in 5 patients and from cadavers in two. Prior to transplantation, three patients were subjected to nephrectomy and three to bladder enlargement, leaving a pigtail catheter. After transplantation, one lymphocele was drained, one uretherostomy due to an impacted lithiasis and one nephrectomy plus vesical enlargement due to intravesical pressures over 40 cm H2O, were done. One uretheral stricture was treated with dilatation. Seven episodes of pyelonephritis, 19 urinary tract infections and 77 asymptomatic bacteriurias were documented. Serum creatinine at the end of follow up ranged from 0.7 to 2.1 mg/dl. There were 0.7 acute rejection episodes per patient and all grafts survived. CONCLUSIONS: Renal transplantation in patients with neurogenic bladder is feasible, performing a vesical enlargement. There is however a high frequency of infectious episodes.

Acute Disease↗
PubMed1996

[Diagnosis and therapeutic management of gastric lymphomas].

PURPOSE: The optimal management of primary gastric non-Hodgkin's lymphoma (PGL) remains controversial. The purpose of this paper is to describe the histopathology, clinical behavior and management of 15 patients with PGL. PATIENTS AND METHODS: All patients were diagnosed of PGL in our Center from January 1985 to September 1995. Resection specimens were reexamined and cases were reclassified according to the concept of MALT-derived lymphoma. Age, sex, symptoms, localization, stage, treatment, complications and response were reported. RESULTS: 9 patients had low-grade B-cell lymphoma of MALT type, 5 had high-grade B-cell lymphoma (one with evidence of low-grade lymphoma of MALT type) and 1 had centroblastic-centrocytic B-cell lymphoma. Seven cases were diagnosed by endoscopy biopsies, 8 through laparatomy specimens. Stage was I in 3 cases, II1 in 5, II2 in 5, III in 0 and IV in 2. 13 patients had undergone primary gastric resection: 10 received additional chemotherapy and 1 radiotherapy. The two cases with stage IV have died: one died after surgery and one relapsed immediately after chemotherapy. After a median follow-up of 40 months, 13 patients are alive: 11 in complete response and 2 in relapse. Minor surgical complications occurred in 12 patients and major complications in 6 patients. CONCLUSIONS: Gastric resection still plays an important role in the management of early-stage PGL. Chemotherapy can be an effective therapeutic procedure in unresected or surgical high-risk patients.

Adult↗
PubMed1994

Central venous brachial catheter (P.A.S. Port TM) and catheter scanning system (Cath-Finder TM).

To assess the effectiveness and safety of an implanted portal with a central venous brachial implanted catheter, P.A.S. Port TM(P-P), and the accuracy of its Cath Finder TM tracking system (C-F), (Pharmacia Deltec) vs. radiology, a phase II multicentric study was designed. The catheter was implanted in 53 oncologic patients treated with chemotherapy and the performance of the catheter was evaluated for 3 months. No problems arose during the implantation in 77% of the cases and in all cases radiologic location of the catheter tip coincided with the C-F. We can conclude that P-P is easy to implant and to maintain in the arm and that it is well tolerated by the patients. C-F is an accurate and reliable system for locating the catheter tip. The use of both systems is an attractive alternative to the standard ones.

Antineoplastic Agents↗
PubMed1992

[Size of breast cancer at the time of initial diagnosis].

BACKGROUND: To observe whether patients with breast cancer of an epithelial strain consult physician with a less advanced disease, the patients attended by the Valencian Interhospital Group were studied between January 1981 and December 1990. METHODS: The same diagnosis of disease spread (anamnesis, physical examination, blood analysis and imaging techniques of the thorax, bones and liver) was carried out in all cases. Surgical techniques and histopathologic criteria were homogenous throughout the study. The classification used was that of the International Union Against Cancer of 1987. Histopathologic correlations were studied. RESULTS: Seven hundred seventy-nine patients with a mean age of 57.3 years (range: 24-85) were studied. A statistically significant (S) progressive reduction in the size of the tumor was observed (p less than 0.003) with the percentage of stage II progressively increasing and stage IIIa (more advanced disease than stage II) parallelly diminishing (p less than 0.0019) (S). In patients over the age of 55 this diminution was not observed. To the contrary, more advanced stages (stage IIIb--locally advanced, and stage IV--metastatic disease) were presented than in younger women (p = 0.000) (S). There is a direct correlation between the size of the tumor, the degree of tumoral differentiation and lymphatic metastases. CONCLUSIONS: Patients under the age of 55 spontaneously and progressively consult the physician with a less advanced breast cancer. This is expected to have beneficial effects on survival. It is suggested that primary medicine may play a fundamental role in making women more aware of breast cancer, particularly those over 55 years of age regardless of early detection campaigns.

Adult↗
PubMedDate not supplied

Vascular anastomosis techniques in renal transplants.

In our series of 250 RT's 192 (76.8%) from living donors and 58 (23.27%) from cadaver donors, there were 207 (88.8%) kidneys with a single renal artery, 40 (16%) with a double artery and 3 (1.2%) with a triple artery. End to side anastomosis to common iliac vessels was the most frequently used technique for kidneys with a single renal artery (52%). Extracorporeal renal surgery was performed on 83.7% of kidneys with multiple arteries. There were 32 (12.8%) complications with 6 (2.4%) unsuccessful RT's due to technical reasons. The actuarial survival of patients and grafts after 5 years from live donors was 87% and 69% and from cadaver donors was 78% and 46%, respectively.

Adult↗