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Biomedical subjects

E Hernandez

Publications and source records attributed to E Hernandez.

At least 19 recordsLinked to original sources
PubMed1992

Poor prognosis associated with thrombocytosis in patients with cervical cancer.

The medical records of 113 patients treated with radiation therapy for invasive cervical cancer between 1975 and 1985 were retrospectively reviewed. Patients with thrombocytosis (platelet count greater than 400,000/microliters) were compared with those with normal platelet counts. Thrombocytosis was present at the initiation of therapy in 20 (17.7%) of the 113 patients. The 5-year cumulative survival rate for the 93 patients with normal platelet counts was 65%, whereas it was 25% for the 20 with thrombocytosis (P less than 0.0001, log-rank test). Using Cox's proportional hazards model, thrombocytosis continued to correlate strongly with poor survival even when adjusted for histologic type, patient age, and disease stage (P less than 0.001). Thrombocytosis is an independent indicator of poor prognosis in patients with cervical cancer.

Female↗
PubMed1992

Histopathologic results of retinal diode laser photocoagulation in rabbit eyes.

Diode laser photocoagulation was applied to rabbit retina simulating scatter treatment using an endolaser probe and in a manner simulating treatment of peripheral retinal breaks using a transscleral retinopexy probe. Clinically appearing mild, moderate, and severe burns were created by altering the burn duration in one eye and by altering the power setting in the fellow eye. Histopathologic results demonstrated the clinically evident dose-response effect with sparing of inner retinal cellular elements with mild burns and full-thickness retinal cell loss with severe burns. Bruch's membrane ruptures were seen in three of 42 endophotocoagulation severe spots placed with high power, but in none of the 42 severe spots placed with long burn duration. Thus, longer burn duration appeared to be a safer way to produce a severe burn than higher power. Burns characteristically bloomed during the several seconds following laser application by both modalities, possibly indicating a deep source of energy absorption. Scleral effects, seen only when high energy levels were used to treat atrophic areas, were mild.

Animals↗
PubMed1992

Histopathologic characteristics of diode laser-induced chorioretinal adhesions for experimental retinal detachment in rabbit eyes.

A retinal break and localized retinal detachment were induced in 10 rabbit eyes. The retinal break was treated within regions of detached retina using diode laser transscleral retinopexy (four eyes), diode laser indirect ophthalmoscopy (two eyes), or retinocryopexy (two eyes). Two eyes were left as untreated controls. The clinical and histopathologic effects were studied 1 day and 3 weeks after initial treatment. Suitable chorioretinal adhesions were induced with all treatment modalities. The extent of tissue effects was greater in cryopexy and smaller in laser treatment. The histopathologic characteristics of the lesions induced by diode laser indirect ophthalmoscopy were similar to those seen with transscleral diode treatment and were more focal than those seen with cryopexy. Transscleral and transpupillary diode laser photocoagulation were effective in inducing chorioretinal adhesions in detached retina in this experimental model in rabbits.

Animals↗
PubMed1992

Measurement of cellular proliferation within the vitreous during experimental proliferative vitreoretinopathy.

Cellular proliferation is an important component in the pathogenesis of complex retinal detachments caused by proliferative vitreoretinopathy (PVR). We used flow cytometry to measure the proliferation of cells recovered from the vitreous cavity in an experimental model of tractional retinal detachment induced by homologous fibroblast injection. Two distinct populations of cells were detected. One population comprised smaller, dense cells representing mostly leukocytes. A second population of larger cells contained not only the injected fibroblasts but also high concentrations of host-derived cells with significant proliferative activity, whose number increased for 3 days following injection. Flow cytometry was useful for analysis of the recovered cells for concentration, morphologic features and proliferation. This technique may be applicable in the identification of patients at high risk for the development of PVR.

Animals↗
PubMed1992

Tissue plasminogen activator thrombolysis during surgical evacuation of experimental subretinal hemorrhage.

To assess the role for intraoperative thrombolysis during surgical evacuation of massive subretinal hemorrhage, the authors studied the ability of tissue plasminogen activator (tPA) to facilitate removal of an experimental subretinal blood clot through a small drainage retinotomy. In rabbit eyes, a single subretinal injection of tissue plasminogen activator in concentrations of up to 250 micrograms/ml failed to produce significant (greater than 50%) clot dissolution during a 3-hour period. However, repetitive subretinal lavage and aspiration with tPA (50 micrograms/ml) resulted in progressive intraoperative clot dissolution in rabbits and allowed complete evacuation of blood through a small drainage retinotomy in 6 (100%) of 6 cat eyes. Repetitive vigorous subretinal irrigation with saline solution had no discernible effect on clot size in rabbit eyes. Histopathologic examination of cat eyes following tPA-assisted surgical evacuation of subretinal blood showed preservation of the outer retina in 2 eyes and severe atrophy of the outer retina in 4 eyes.

Animals↗
PubMed1992

[Models and strategies for the control of air pollution in large urban areas].

In the attempt to define the characteristics of a global approach to the problem of atmospheric pollution, the mathematical and statisticals tools currently available are presented which will allow the rationalization of both the study and the management of reduction policy. An example of a possible application of this approach is given, which presents the results obtained by modelling the data on "conventional" pollutants furnished by the experimental sampling station set up at the Istituto Superiore di Sanità (ISS) in Rome. Since the suggested approach may not do without an integrated management of date, a hypothesis for an information system is outlined as well.

Air Pollution↗
PubMed1991

Retinal toxicity of human tissue plasminogen activator in vitrectomized rabbit eyes.

The retinal toxicity of human tissue plasminogen activator in normal rabbit eyes has recently been reported. We now report the retinal toxicity of tissue plasminogen activator in three groups of vitrectomized rabbit eyes. Group 1 underwent gas compression of the vitreous followed by tissue plasminogen activator injection in doses of 25, 50, and 100 micrograms (all doses were administered in 100 microL of fluid). Group 2 underwent lensectomy and vitrectomy followed by tissue plasminogen activator injection of 100 micrograms. Group 3 underwent lensectomy, vitrectomy, and complete fluid/gas exchange prior to injections of 12.5 and 25 micrograms of tissue plasminogen activator. Control eyes received 100 microL of balanced salt solution. In group 1, no retinal toxic reactions were observed after administration of 25 or 50 micrograms of tissue plasminogen activator, but all eyes receiving 100 micrograms demonstrated retinal damage on ophthalmoscopy, electroretinography, and light microscopy. In group 2, no retinal toxic reactions were seen after administration of 100 micrograms of tissue plasminogen activator. In group 3, two of 11 eyes receiving 25 micrograms of tissue plasminogen activator demonstrated toxic retinal changes by ophthalmoscopy, electroretinography, and light microscopy. These results suggest that gas compression of the vitreous does not significantly alter the toxic changes seen caused by tissue plasminogen activator. While lensectomy and vitrectomy appears to widen the therapeutic window for tissue plasminogen activator, the margin of safety is reduced with the addition of a large gas bubble.

Animals↗
PubMed1991

Balloon valvuloplasty for mild mitral stenosis.

Of a total number of 288 patients with mitral stenosis treated by percutaneous balloon valvuloplasty, 21 patients had a basal mitral area equal to or greater than 1.5 cm2, as measured hemodynamically. The immediate hemodynamic results of this particular group of patients with mild mitral stenosis are described, as well as the clinical and echo doppler findings at follow-up (22 +/- 12 mo). Patients with mild mitral stenosis (group I) had more pliable valves (p less than 0.01), as assessed by echo, and higher incidence of sinus rhythm (p less than 0.02) than that observed in the remaining 267 patients (group II). After valvuloplasty the valve area increased in group I from 1.7 +/- 0.2 to 3.1 +/- 0.7 cm2 (p less than 0.0001). This mean final area was significantly different (p less than 0.0001) than that observed in group II (1.98 +/- 0.6 cm2). No patients with mild mitral stenosis developed progression of mitral regurgitation, and none had any other major complications. Most of them reached a grade I final functional status. At echo doppler follow-up studies we did not observe significant changes in the mean mitral gradient as compared with the immediate hemodynamic results. These findings suggest that early mitral balloon valvuloplasty could be an alternative in trying to favorably influence the natural course of the rheumatic mitral disease in selected patients.

Adult↗
PubMed1991

Succinylcholine-stimulated muscle tensions following botulinum injection in the domestic cat.

Succinylcholine (SCh) selectively stimulates, and can therefore selectively assay, the multiple innervated (MI) fiber system of the extraocular muscles. Since botulinum-A toxin has been observed to induce changes in eye position in humans, SCh was used to assess the effect of botulinum-A on the SCh-sensitive MI fibers of extraocular muscles. Intravenous SCh infusion (40 micrograms-1 kg-1 min-1 was performed in the anesthetized domestic cat. Thirty-eight infusions were performed in 19 normal controls, measuring the peak tensions generated in the four horizontal and four vertical rectus muscles. Succinylcholine-stimulated muscle tensions (SSMT) were then repeated in nine animals, 4 weeks and 10 weeks following injection of botulinum-A toxin into both medial rectus muscles. Mean peak SSMTs were unchanged at 4 and 10 weeks following botulinum injection when compared to controls. We propose that botulinum chemo-denervation has no acute or chronic effect on the MI SCh-sensitive muscle fibers of the medial recti of the domestic cat. This lack of effect on the postsynaptic MI fibers indirectly supports light and electron microscopic studies which show changes predominantly in the singly innervated (SI), rather than the MI fibers following botulinum injection. Mean peak SSMTs were also greater for medial and superior rectus muscles compared to lateral and inferior recti respectively, suggesting a greater number or proportion of MI fibers in medial and superior recti.

Animals↗
PubMed1991

False tendon rupture simulating chordal rupture after percutaneous mitral balloon dilation. A report of two cases.

We describe two cases of ruptured false tendons following percutaneous balloon dilation of the mitral valve in one case, and combined mitral and aortic balloon valvotomy in the other, using in both the retrograde approach. The echocardiographic characteristics of this previously unreported complication of the procedure are presented with special emphasis on the differentiation with true chordal rupture. No short or mid term adverse effects were noted following this complication.

Adult↗
PubMed1991

Tubular dysfunction in nephrotic syndrome: incidence and prognostic implications.

Although some cases of tubular dysfunction (TD) associated with nephrotic syndrome have been described, the incidence and the characteristics of this complication remain unknown. We investigated the presence of TD (renal glycosuria, aminoaciduria, metabolic acidosis with normal anion gap, hypouricaemia, and throughout hypophosphataemia) in 36 patients with nephrotic syndrome. Ten patients (group 1) showed glycosuria at some time during the course of their illness, ranging from 2.5 to 11.2 g/24 h. In addition, seven of them had metabolic acidosis with normal anion gap, five aminoaciduria, and two hypouricaemia. Membranous glomerulonephritis was the most frequent aetiology in group 1 patients (7 of 10). Proteinuria and serum creatinine (SCr) were significantly higher in group 1 patients than in the 26 remaining patients without TD (group 2): 10.2 +/- 3.7 versus 6.7 +/- 2.9 g/24 h (P less than 0.01) and 3.2 +/- 1.9 versus 1.6 +/- 0.9 mg/dl (P less than 0.05) respectively. The appearance of TD coincided with a clear worsening of renal function in most of group 1 patients. In addition, at the end of follow-up, SCr had increased from 3.2 +/- 1.9 to 5.6 +/- 3.3 mg/dl (P less than 0.05) in this group. In contrast, SCr did not show significant changes in group 2 (1.6 +/- 0.9 versus 2.1 +/- 2.2 mg/dl). In conclusion, a significant proportion (27.7%) of patients with nephrotic syndrome present TD data at some moment of their course; the appearance of this complication appears to be a sign of poor prognosis.

Adolescent↗
PubMed1991

Uterine papillary serous carcinoma: a review.

Uterine papillary serous carcinoma, a histologic subtype of endometrial cancer, is characterized by a propensity for deep myometrial invasion, upper abdominal spread, and poor prognosis. We reviewed its histologic and clinical characteristics and compared them to those of endometrial adenocarcinoma with papillary features.

Carcinoma, Papillary↗
PubMed1991

Tissue plasminogen activator treatment of experimental subretinal hemorrhage.

Previous investigators have suggested that subretinal blood damages the retina in part because of its solid fibrin meshwork. The role of fibrinolysis in facilitating the clearance of subretinal hemorrhage and preventing degeneration of the overlying retina was studied. Autologous whole blood (0.1 ml) was injected into the subretinal space of 20 rabbits. Twenty-four hours later, the animals were randomized to subretinal treatment with 2.5 micrograms of tissue plasminogen activator or a similar volume of physiologic saline. Mean subretinal hemorrhage thickness 3 days after treatment had decreased to 42% of pretreatment thickness in treated eyes and remained unchanged in control eyes (P less than 0.0005). By 7 days mean clot thickness was 9% in treated eyes and 60% in controls (P = 0.005). Light microscopy revealed severe progressive retinal degeneration in both groups. No histologic evidence of retinal toxicity was found in cat retina after subretinal injection of tissue plasminogen activator (50 micrograms/ml). Although treatment with tissue plasminogen activator accelerated the clearance of subretinal hemorrhage, it failed to prevent secondary retinal degeneration in this rabbit model.

Animals↗
PubMed1991

Cutaneous involvement by an ovarian serous tumor of low malignant potential.

The case presented is of a 67-year-old woman with multifocal ovarian serous tumor of low malignant potential with skin involvement. To our knowledge this is the first such case not preceded by abdominal surgery. The pathogenesis of her cutaneous lesions is discussed. We propose neoplastic transformation of cutaneous endosalpingosis as a possible explanation.

Adenocarcinoma↗
PubMed1991

Treatment of cervical carcinoma with ionizing irradiation using moving fields.

This study was designed to assess the effectiveness and risk of complications from radiotherapy delivered by the moving field technique as opposed to the more commonly used fixed field technique. Between 1975 and 1985, 131 patients were treated for cervical cancer with a combination of teletherapy and brachytherapy. For teletherapy, 4-MeV photons were used and delivered by moving field technique (120 degrees to 160 degrees arcs, or a 360 degrees rotation). Most patients received one intracavitary radium implant using Fletcher-Suit applicators and the Manchester technique. Twenty-two percent of the patients had stage I disease, 37% stage II, 25% stage III, 13% stage IV, and 2% were unstaged. The cumulative 5-year survival for all patients was 57%. The survival by stage was: stage I, 82%, stage II, 62%, stage III, 53%, and stage IV, 6%. Chronic complications developed in 10 (7.6%) patients. The survival and complication rate of patients treated for cervical cancer with radiation using moving fields compares favorably with that of patients treated with the conventional parallel opposed (AP-PA) fields or the four-field box technique. Further studies are necessary to definitively determine if the moving field technique offers advantages over other techniques.

Brachytherapy↗