PubMed Health⌕ Search

Biomedical subjects

J Segarra

Publications and source records attributed to J Segarra.

At least 19 recordsLinked to original sources
PubMed2006

[Perineal prostatectomy].

There is a lack of prospective randomised trials comparing the efficacy of the different techniques for treating localised prostate cancer. Consequently, selecting one rather than the other appears very difficult. Even radical prostatectomy is controversial regarding its best approach--perineal, retropubic or laparoscopic. The perineal route was the first to be undertaken, and it was dropped out due to the need of performing obturator lymphadenectomy by a separate approach. Widespread use of prostate-specific antigen as a screening method has enabled to diagnose prostate cancer at its early stages, when the potential for lymphatic dissemination is low, which enables to obviate Lymphadenectomy in most patients. This was a promoting circumstance to use the perineal route in radical prostatectomies. In this article we discuss the perineal radical prostatectomy surgical technique, its indications, and its advantages and disadvantages as compared to other approaches.

Humans↗
PubMed2006

Nephron-sparing surgery for renal tumor: a choice of treatment in an allograft kidney.

The incidence of de novo malignancies is an accepted complication of organ transplantation. Renal cell carcinoma (RCC) was 4.6% of cancers occurring de novo in organ allograft recipients compared with 3% in the general population. Less than 10% of these renal cancers affected the renal allograft. Among patients developing a renal tumor in the kidney allograft, transplant nephrectomy reduced the quality of life. For these patients for whom preservation of renal function is a relevant clinical consideration, partial nephrectomy may be considered the choice for treatment. Fifteen cases have been reported regarding conservative surgery on kidney transplant tumors. Herein we have reported three cases of renal masses in well-functioning kidney transplants that were successfully treated with nephon-sparing surgery. Our experience demonstrated that in selected patients, nephron-sparing surgery on a renal allograft represents a feasible approach for tumor removal with preservation of graft function.

Adult↗
PubMed2004

[Living donor nephrectomy for kidney transplantation. Experience in the first two years].

OBJECTIVES: Laparoscopic surgery offers potential advantages in terms of diminishment of postoperative pain, shorter hospital stay, faster convalescence, and better cosmetic results. These advantages may increase kidney donation, making donation be accepted by more candidates. We report our first 2 years' experience with laparoscopic donor nephrectomy METHODS: Between March 2002 and February 2004 we performed 38 laparoscopic living donor nephrectomies for kidney transplantation. The technique of choice was the transperitoneal laparoscopic approach with four trocars, usually three of them from the start of the procedure--two 10-12 mm and one 5 mm--, and a 6.5 cm perumbilical midline incision for kidney retrieval at the end of the procedure. RESULTS: Receptor and donor survivals were 100%. Graft survival was 97.6%. There was not any case of delayed graft function. Donor: Mean operative time was 161 minutes (115-260). Mean estimated blood loss was 270 ml (100-1200). Three patients required blood transfusions, 2 units of packed red blood cells each. Mean hospital stay was 5.1 days (3-11). Mean warm ischemia time was 3.2 min. (2-10). Conversion to open surgery was necessary in four cases. Receptor: there have been three significant complications requiring surgical repair: one case of low arterial flow, one vesico ureteral leak, and one midurethra stenosis. Initial renal function: mean serum creatinine at one month was 147mmol/l, with a trend to improve to 126 mmol/l at one year, which is considered optimum. First postoperative day mean serum creatinine was 192mmol/l and the nadir was on second postoperative day with a value of 152mmol/l. CONCLUSIONS: We believe laparoscopic living donor nephrectomy is a real alternative to open surgery because it offers better recovery to the donor with the same capacity to preserve renal function in the receptor.

Humans↗
PubMed2001

Hasson's laparoscopic trocar in percutaneous bladder stone lithotripsy.

Bladder calculi are a common problem traditionally treated with open cystolithotomy or transurethral cystolithalopaxy. Percutaneous cystolithotomy via an Amplatz sheath is a recent approach that keeps urethral instrumentation to a minimum. We describe a percutaneous approach to bladder stones using a Hasson's trocar. With this approach, one or more watertight approaches to the bladder can be created, allowing any kind of endoscopic surgical material to be introduced, thus opening new possibilities in the design of percutaneous bladder surgery techniques.

Humans↗
PubMed1999

The effect of topical diltiazem on ocular hypertension induced by water loading in rabbits.

The aim of this work was to assess the effect of topical diltiazem on the ocular hypertension induced by water loading in rabbits. The effect of three different concentrations of diltiazem on the intraocular pressure rise produced by oral administration of tap water (60 ml/kg) was tested in groups of nine or ten rabbits each. When applied at the lowest concentration studied, topical diltiazem was found to enhance the intraocular pressure rise after water loading. In contrast, when applied at the highest concentration, diltiazem counteracted the ocular hypertension caused by water loading. Although diltiazem, and probably other calcium channel blockers, may be useful in the management of ocular hypertension, the data obtained suggest that these drugs may have complex actions on aqueous humor dynamics; therefore further studies in animal models for glaucoma should be carried out before their clinical evaluation in humans.

Animals↗
PubMed1999

Topical verapamil lowers outflow facility in the rabbit eye.

Results of studies examining the mechanism of the ocular hypotensive effect of topical calcium channel blockers are controversial. Whereas evidence obtained in perfused human eyes indicates that these drugs lower intraocular pressure by increasing the aqueous humor outflow, tonographic studies in rabbits have revealed that they reduce both the aqueous humor outflow and inflow. In order to clarify such a discrepancy, the aim of this study was to assess whether the effect of topical verapamil on the facility of aqueous humor outflow in the rabbit eye was dose-related. Total outflow facility was determined by two-level constant pressure perfusion in anesthetized rabbits. The effect of 5 different concentrations on aqueous humor outflow at 60 minutes postdrug was studied in groups of 10 rabbits each. Baseline outflow facility was also determined in a group of 15 rabbits. In order to check the reliability of the method for detecting drug-induced changes in aqueous outflow, the effect of pilocarpine was also tested. Topical verapamil was shown to lower outflow facility in the rabbit eye in a dose-related fashion. On the contrary, topical pilocarpine was found to significantly increase outflow facility. Our data indicate that topical verapamil reduces outflow facility in the rabbit eye.

Administration, Topical↗
PubMed1998

The effect of topical dihydroergocristine on the intraocular pressure in alpha-chymotrypsin-induced ocular hypertensive rabbits.

Having previously reported that topical dihydroergocristine dose-dependently reduces intraocular pressure in ocular normotensive rabbits with a maximum response and potency higher than those of timolol and pilocarpine, the aim of the present work was to assess the effect of this drug in alpha-chymotrypsin-induced ocular hypertensive rabbits. Intraocular pressure was measured with a pneumatonometer. The experiments examining the effects of dihydroergocristine on intraocular pressure were conducted in 10 albino rabbits in which ocular hypertension was induced by intracameral injection of alpha-chymotrypsin. Intraocular pressure responses to drug vehicle and 5 different doses of topical dihydroergocristine were studied in order to obtain a dose-response curve. Tonographies were also performed in ocular hypertensive rabbits 2 h after vehicle and dihydroergocristine instillation to ascertain the actions of this drug on aqueous humor dynamics. Topical dihydroergocristine was found to lower intraocular pressure in alpha-chymotrypsin-induced ocular hypertensive rabbits in a dose-related manner, with the ED50 of the concentration-response curve very similar to that previously obtained in ocular normotensive rabbits. Data from tonographic studies indicate that dihydroergocristine reduces intraocular pressure in this animal model for glaucoma by decreasing the aqueous humor inflow. Our findings suggest that topical dihydroergocristine may be useful in the treatment of ocular hypertension.

Administration, Topical↗
PubMed1998

The effect of topical diltiazem on the intraocular pressure in betamethasone-induced ocular hypertensive rabbits.

The effect of calcium channel blockers (CCBs) on intraocular pressure (IOP) remains still controversial, although some preliminary reports suggest that these drugs may be effective in the management of ocular hypertension and low-tension glaucoma. The aim of the present work was to assess the effect of topical diltiazem on IOP in an animal model for glaucoma, the betamethasone-induced ocular hypertension in rabbits. IOP was measured with a manometrically calibrated applanation pneumatonograph. Ocular hypertension was produced in 120 rabbits by weekly subconjunctival injection of a betamethasone suspension into the left eye. The experiments examining the ocular actions of diltiazem were carried out in two stages. In the first one, the ability of topical diltiazem to prevent the rise in IOP induced by betamethasone was studied. In a second phase, the effect of topical diltiazem on IOP in betamethasone-induced ocular hypertensive rabbits was assessed. Diltiazem was topically applied once daily for 5 days a week into the left eye. The effect of five different concentrations of diltiazem was evaluated to obtain dose-response curves. Topical diltiazem was found to prevent in a dose-related fashion the betamethasone-induced IOP rise as well as to reduce IOP in rabbits made ocular hypertensive by weekly subconjunctival injection of betamethasone. Unilateral topical administration did not produce a clear effect on IOP in the untreated eye. This is the first report describing the ocular hypotensive action CCBs in animal model for glaucoma. These findings are in agreement with preliminary evidence suggesting that CCBs may have a beneficial effect in human ocular hypertension.

Administration, Topical↗
PubMed1997

A long-lasting hypotensive effect of topical diltiazem on the intraocular pressure in conscious rabbits.

The effect of calcium channel blockers on intraocular pressure and aqueous humor dynamics remains still controversial, although preliminary evidence suggests that these drugs may be beneficial in the management of ocular hypertension and low-tension glaucoma. Having previously reported the ocular hypotensive effect of topical nifedipine and verapamil in albino rabbits, the original aim of the present work was to evaluate the effect of topical diltiazem on aqueous humor dynamics in this species. Intraocular pressure was measured with a manual applanation tonometer. The experiments examining the ocular actions of diltiazem were carried out in two stages. In the first one, short term effects of topical diltiazem on intraocular pressure were studied in groups of 13 albino rabbits receiving 8 different doses of the drug in order to obtain a dose-response curve. Tonographies were performed in 13 anaesthetized animals before and 90 min after drug instillation. In a second phase, the persistence of the effect of diltiazem on intraocular pressure was examined in 6 groups of 10 rabbits each receiving three different doses of the drug. Topical diltiazem was found to lower intraocular pressure in a dose-related fashion. The maximum response to diltiazem was greater and the ED50 lower than those previously reported for nifedipine and verapamil. In the tonographic study, diltiazem was shown to reduce the facility of aqueous humor outflow and inflow. Diltiazem exhibited a long lasting effect on intraocular pressure that was again dose-related. Depending on the dose administered, the calculated time necessary for the peak effect to be halved ranged from 0.6 to 7.0 days. Due to the intensity and the persistence of its intraocular pressure-lowering effect, diltiazem shows great potential for the treatment of glaucoma, since a daily or less frequent administration may be enough to control ocular hypertension.

Administration, Topical↗
PubMed1997

Betamethasone-induced ocular hypertension in rabbits.

The effect of subconjunctivally injected betamethasone on intraocular pressure (IOP) was studied in 85 albino New Zealand rabbits. IOP was measured with a Mentor Model 30 classic pneumatonograph that was manometrically calibrated to the rabbit eye. Ocular hypertension was induced by weekly subconjunctival injections of a betamethasone suspension into the left eye. In one experiment, 70 rabbits were given betamethasone for 4 weeks, while a second group of 10 rabbits received betamethasone for 11 weeks. The short-term effects of subconjunctival injections of betamethasone on IOP were also recorded in a third group of 5 rabbits. Weekly injections over 4 weeks resulted in an increase in IOP in the treated eye, which was prolonged to 11 weeks by repeated weekly injections. A sustained increase in IOP was observed in the treated eye for a period of 7 weeks. During the early hours after betamethasone injection, a transient decrease in IOP was registered in both eyes. The results show that weekly subconjunctival injections of betamethasone cause a predictable increase in IOP in the treated eye which may be suitable for testing the short- and long-term effects of antiglaucoma drugs. Evidence suggesting that endogenous glucocorticoids may play a role in the development of ocular hypertension in humans strengthens the potential value of this glaucoma model.

Animals↗
PubMed1996

A complex interaction between topical verapamil and timolol on intraocular pressure in conscious rabbits.

Calcium channel blockers have complex actions on aqueous humour dynamics that seem to depend on the route of drug administration. When applied topically, verapamil and nifedipine effectively lower intraocular pressure. However, these drugs also produce a slight reduction in aqueous humor outflow through the trabecular meshwork whereby they could modify the effect of other drugs on intraocular pressure. As calcium channel blockers could be effective in the management of ocular hypertension and low-tension glaucoma, the aim of the present work was to assess the interaction between verapamil and timolol when both drugs are topically applied to the eye of albino rabbits. Intraocular pressure was measured with a manual applanation tonometer. The effects of 5-6 different doses of each drug alone and the effects of five mixtures of both drugs at fixed concentration ratios (timolol: verapamil 4:1, 2:1, 1:1, 1:2 and 1:4) were evaluated. After measuring baseline intraocular pressure, one 50 microliters drop of the different solutions was instilled in the left eye. Measures of the intraocular pressure were repeated at intervals of 30 min until the maximal effect was reached. Each set of experiments was carried out in a group of 9-11 rabbits. Dose-response curves were fitted with a nonlinear regression microcomputer programme. The median effect plot was constructed as proposed by Chou and Talalay (1981, 1983, 1984). In order to analyse the nature of the interaction between both drugs, the observed effect was compared with the theoretically expected one and the combination indices, that relate the doses of verapamil and timolol present in the mixtures with the doses of both drugs separately which are equieffective with the combination, were calculated. The effects of verapamil and timolol followed the principle of the mass action law when administered alone. Nevertheless, no adequate dose-response relationship was obtained when the mixtures of both drugs were applied. In general, the observed effects were lower than the expected ones. Combination indices also indicate the presence of antagonism, except for the lowest concentrations of mixtures where verapamil predominates. In this case, combination indices suggest summation of effects or synergy. Both drugs seem to decrease intraocular pressure by reducing aqueous humor secretion through different mechanisms. However, due to the reduction of aqueous humor outflow caused by verapamil, the ocular hypotensive effect of timolol may be antagonized when high doses of verapamil are administered.

Administration, Topical↗
PubMed1995

Renal abscess due to Aspergillus fumigatus in a patient with the acquired immunodeficiency syndrome.

Disseminated aspergillosis is a systemic fungal infection that may occur in previously healthy or immunocompromised patients. The condition, although rare, is being recognized with increasing frequency in persons with the human immunodeficiency virus. Clinical genitourinary involvement is unusual. We present a case of renal abscess for Aspergillus fumigatus in a patient with acquired immunodeficiency syndrome who complained of flank pain and fever.

AIDS-Related Opportunistic Infections↗
PubMed1994

[Clinical course in patients with BPH operated for acute urine retention].

Between 1980 and 1990, 5,949 cases of Benign Prostate Hyperplasia (BPH) were detected at the Puigvert Foundation. One thousand of them were randomized for analysis, and it was found that in 347 the indication for surgery was acute urine retention (AUR). During the initial visit the symptoms, their duration, creatinine values, correlation between creatinine and: 1) patients over 70 years, 2) relationship to prostate size, 3) distention of the upper urinary tract, 4) vesical lithiasis, 5) urinary infection, 6) complications, and 7) mortality were analyzed. Discussion of results, comparing these to other series and trying to find evolution differences between these patients and those operated by elective surgery. In our series, we only found statistically significant differences when correlating the high values of creatinine with the prostate size and the upper urinary tract distension.

Acute Disease↗
PubMed1993

Evidence for a synergistic interaction between isoprenaline and timolol on intraocular pressure in conscious rabbits.

1. Interaction between topical isoprenaline and timolol on intraocular pressure was studied in conscious rabbits through changes of the dose-response curves. 2. Both drugs caused a dose-dependent fall of intraocular pressure mainly by reducing the aqueous humour formation. 3. When combined, timolol increased the response to submaximal concentrations of isoprenaline as well as EC50 (from 2.06 x 10(-3) M to 3.63 x 10(-3) M) and slope (from 1.21 to 1.89), but peak response to isoprenaline remained unchanged. 4. Discordance between experimental and theoretical additive curves as well as an interaction index smaller than 1 show that the interaction between both drugs is synergistic.

Animals↗
PubMed1993

The topical application of verapamil and nifedipine lowers intraocular pressure in conscious rabbits.

1. The time-course of the ocular effects of topical verapamil and nifedipine as well as the dose-response relationship, were studied in conscious, normotensive rabbits. 2. Both drugs caused a dose-dependent fall of intraocular pressure, which lasted 4 hr or more. 3. Log dose-response curves of both drugs show a similar peak response, but the potency of verapamil was greater that of nifedipine. 4. A fall in the intraocular pressure in the untreated eye was also observed. 5. Verapamil and nifedipine induced a reduction of the tonographic outflow facility in the treated eye.

Administration, Topical↗
PubMed1991

Cardiopulmonary exercise responses after single lung transplantation for severe obstructive lung disease.

The purpose of this study was to characterize cardiovascular and ventilatory responses to exercise in single lung transplantation (SLT) recipients with nonseptic, severe obstructive lung disease (SLT-OB). We also investigated whether the hyperinflated native lung in SLT-OB recipients could limit normal increases in tidal volume by mechanically constraining the transplanted lung, resulting in ventilation-perfusion imbalance in the lung graft. Data from six SLT-OB recipients (five women, one man) and six age-matched SLT recipients (two women, four men) with severe interstitial lung disease (SLT-IN) were compared. Resting arterial O2 and CO2 tensions were normal and comparable between the SLT groups. Spirometry results were reduced but comparable between SLT groups. Total lung capacity was significantly larger in patients with SLT-OB than in patients with SLT-IN. Diffusion capacity was not different between SLT groups when differences in alveolar volume were accounted for. Quantitative perfusion to the lung graft was comparable between the SLT groups, but quantitative ventilation was greater in patients with SLT-OB than in patients with SLT-IN. Maximum exercise capacity following SLT-OB was decreased, but was comparable to that of SLT-IN recipients. None of the SLT-OB recipients reached predicted maximum minute ventilation and only one experienced mild arterial O2 desaturation, suggesting peripheral muscle abnormalities from corticosteroid use and deconditioning as limiting factors rather than a ventilatory limitation. Tidal volumes at end exercise in the SLT-OB recipients were normal. Our quantitative lung scan and exercise testing data suggest that ventilation-perfusion imbalance and resulting gas exchange abnormalities from lung graft constraint and compression do not occur at rest or with exercise after SLT for obstructive lung disease.

Anaerobic Threshold↗