Biomedical subjects

R Lopez

Publications and source records attributed to R Lopez.

At least 19 recordsLinked to original sources

PubMed2007

Multimedia article. Success of episioproctotomy for cloaca and rectovaginal fistula.

PURPOSE: Surgical repair of rectovaginal fistula with an advancement flap has had suboptimal results. The existing literature documenting episioproctotomy as a surgical option in females with rectovaginal fistula or cloaca is limited. This study was designed to examine our experience with episioproctotomy in this group. Additionally we were interested in risk factors, which might predict failure. METHODS: All females who had repair of a rectovaginal fistula or cloaca with episioproctotomy from 1998 to 2004 were studied. Data were collected from chart review and telephone contact. This included demographics, body mass index, tobacco use, Crohn's disease, previous surgery, and diverting stoma. RESULTS: Data were obtained from 42 females (mean age, 39.2 (range, 25-70) years). The mean follow-up was 37 (range, 2-84) months. Nine females had a cloaca and the rest had a rectovaginal fistula with an anterior sphincter defect. Eleven (all with anterior tissue) had recurrence of fistula. None with cloaca had recurrence. Eight of 11 recurrences occurred in females who had failed at least one previous repair. No variables that were studied significantly affected recurrence. Median (25th, 75th percentiles) postoperative Wexner incontinence scores for those with and without recurrence were 8 (7, 12) and 5 (2, 6) respectively. CONCLUSIONS: Episioproctotomy is a successful technique for repair of rectovaginal fistula and cloaca. Incontinence score postoperatively were acceptable. It should be considered a first line of surgical treatment in those with a fistula that includes compromise of the anterior sphincter complex.

Adult↗

PubMed2006

SPINE bioinformatics and data-management aspects of high-throughput structural biology.

SPINE (Structural Proteomics In Europe) was established in 2002 as an integrated research project to develop new methods and technologies for high-throughput structural biology. Development areas were broken down into workpackages and this article gives an overview of ongoing activity in the bioinformatics workpackage. Developments cover target selection, target registration, wet and dry laboratory data management and structure annotation as they pertain to high-throughput studies. Some individual projects and developments are discussed in detail, while those that are covered elsewhere in this issue are treated more briefly. In particular, this overview focuses on the infrastructure of the software that allows the experimentalist to move projects through different areas that are crucial to high-throughput studies, leading to the collation of large data sets which are managed and eventually archived and/or deposited.

Computational Biology↗

PubMed2006

[Preoperative and palliative embolization of renal cell carcinomas: follow-up of 49 patients].

PURPOSE: To evaluate the influence of preoperative and palliative embolization of renal cell carcinomas on survival, intra- and post-operative procedures, and symptom control for palliative and preoperative indications. MATERIALS AND METHODS: 56 patients who underwent renal cell carcinoma embolization from 1981 to 1999 were included in this retrospective study. RESULTS: 24 women and 32 men were included (mean age 59.4 years). Complete follow-up data was available for 49 patients. 42 patients underwent preoperative embolization at different tumor stages (pT1: 1 patient, pT2: 6, pT3 a: 4, pT3 b: 19, pT3 c: 2, pT4: 5). 14 patients underwent palliative embolization (T1: 0 patients, T2: 5, T3: 4, T4: 4). Indications for preoperative embolization were bleeding of the renal tumor in 6 cases -- non-recurrent bleeding reported, flank pain in 4 patients -- 3 of 4 patients had no further symptoms, recurrent tumor embolization in 1 patient, and 2 patients who wanted to be treated without symptoms. The mean survival time of preoperative embolized patients was 3.1 +/- 5.11 years with a 5-year survival rate of 50 %. The mean survival time of palliative embolized patients was 0.67 +/- 0.76 years with initial metastases (n = 7) and 2.33 +/- 2.40 without metastases (n = 6). CONCLUSION: Palliative embolization of renal cell carcinomas is a safe therapeutic method to treat advanced renal cell carcinomas allowing control of symptoms such as hematuria and flank pain in more than 90 % of our cases. Preoperative embolization yields a patient survival time comparable to that of patients at earlier tumor stages and is dependent on the metastases.

Angiography↗

PubMed2005

InterProScan: protein domains identifier.

InterProScan [E. M. Zdobnov and R. Apweiler (2001) Bioinformatics, 17, 847-848] is a tool that combines different protein signature recognition methods from the InterPro [N. J. Mulder, R. Apweiler, T. K. Attwood, A. Bairoch, A. Bateman, D. Binns, P. Bradley, P. Bork, P. Bucher, L. Cerutti et al. (2005) Nucleic Acids Res., 33, D201-D205] consortium member databases into one resource. At the time of writing there are 10 distinct publicly available databases in the application. Protein as well as DNA sequences can be analysed. A web-based version is accessible for academic and commercial organizations from the EBI (http://www.ebi.ac.uk/InterProScan/). In addition, a standalone Perl version and a SOAP Web Service [J. Snell, D. Tidwell and P. Kulchenko (2001) Programming Web Services with SOAP, 1st edn. O'Reilly Publishers, Sebastopol, CA, http://www.w3.org/TR/soap/] are also available to the users. Various output formats are supported and include text tables, XML documents, as well as various graphs to help interpret the results.

Databases, Protein↗

PubMed2005

SOAP-based services provided by the European Bioinformatics Institute.

SOAP (Simple Object Access Protocol) (http://www.w3.org/TR/soap) based Web Services technology (http://www.w3.org/ws) has gained much attention as an open standard enabling interoperability among applications across heterogeneous architectures and different networks. The European Bioinformatics Institute (EBI) is using this technology to provide robust data retrieval and data analysis mechanisms to the scientific community and to enhance utilization of the biological resources it already provides [N. Harte, V. Silventoinen, E. Quevillon, S. Robinson, K. Kallio, X. Fustero, P. Patel, P. Jokinen and R. Lopez (2004) Nucleic Acids Res., 32, 3-9]. These services are available free to all users from http://www.ebi.ac.uk/Tools/webservices.

Biotechnology↗

PubMed2005

Maxillofacial intraoral distraction osteogenesis followed by elastic traction in cleft maxillary deformity.

We present a case of severe maxillary hypoplasia in a 16 years old cleft patient treated by distraction osteogenesis maxillary advancement. Initial evaluation showed vertical and antero-posterior maxillary deficiencies, and a Class III malocclusion. Two intraoral distractors (Zurich Pediatric Maxillary Distractor, KLS Martin, Tuttlingen, Germany) were placed in a high Le Fort I osteotomy. An initial advancement of 11 mm was obtained, but the resulting occlusion was unsatisfactory (end-to-end occlusion). The consolidation period was reduced to 3 weeks to allow the mechanical manipulation of the newly formed bone with Class III elastics. An additional advancement of 3 mm, caused by elastic orthodontic traction produced both normal skeletal relationship and satisfactory occlusion. This observation shows that it is possible to carry on a skeletal maxillary displacement by interdental elastics before the complete fusion of the callus. After 12 months of postoperative follow-up no osseous relapse could be detected and the occlusal result was stable.

Adolescent↗

PubMed2005

Description of inflammation and cytokine profile at the inoculation site and in heart tissue of mice re-infected with Trypanosoma cruzi vector derived-metacyclic trypomastigotes.

We studied the role of Trypanosoma cruzi reinfection in regard to inflammatory and cytokine response at the inoculation site, lymph node and heart. We reinfected Balb/c mice intradermically into the hind foot-pad with natural infective metacyclic trypomastigotes. They were followed from 24 h to 30 days after the last reinfection. At the inoculation site 24 h after the last re-infection, the infiltrating inflammatory cells increased dramatically with respect to baseline inflammation, reaching maximum infiltrates for the third day. In contrast, parasite DNA was undetectable 24 h after inoculation, despite poor cytokine induction, only IFN-gamma, IL-12 and TGF-beta were noticeable on days 7 and 15, whereas in the lymph nodes draining the inoculation site positive expression of IL-2, IL-4, IL-12 and TGF-beta were found to be induced as soon as 24 h after re-entry of parasite. In the heart, the inflammatory response increased immediately 24 h after re-entry of parasites, reaching its maximum on the 7th day and returning to baseline on day 30. In conclusion, although the inflammatory response is triggered in both compartments by re-entry of parasites, the inflammatory process returns almost to baseline after 30 days, leaving a persistent low-grade inflammation.

Animals↗

PubMed2005

Risk factors associated with house infestation by the Chagas disease vector Triatoma pallidipennis in Cuernavaca metropolitan area, Mexico.

Chagas disease caused by infection with Trypanosoma cruzi Chagas (Kinetoplastida: Trypanosomatidae) is widespread in Mexico, transmitted by various triatomine bugs (Hemiptera: Reduviidae). The only domestic vector in Cuernavaca (population 650 000) is Triatoma pallidipennis (Ståhl) with T. cruzi seroprevalence ranging from 1% to 9% in the resident human population. We surveyed possible risk factors for T. pallidipennis infestation at Cuernavaca (altitude 1200-2200 m) on south-western slopes of the Sierra Madre Occidental. This metropolitan area (with five administrative counties) has rapid urbanization, forested environs and proliferation of 'weekend housing' for visitors from Mexico City, 60 km to the north. To assess factors associated with T. pallidipennis infestation, we first stratified Cuernavaca by altitude and by socio-economic status of population catchment units (PCUs). Within each PCU, one to three blocks were chosen for cluster sampling (three houses/block) and information about Chagas disease was distributed. After obtaining signed consent from householders, representative houses were routinely and opportunistically inspected for T. pallidipennis and surveyed for demographic, economic, physical and other potential risk factors. Of the 1129 houses assessed, T. pallidipennis was found in 4.1% (range 3.0-6.8% per county) and the T. cruzi infection rate was approximately 50% in bugs. Rates of house infestation in poor PCUs were double those in higher socio-economic strata (odds ratio 2.12, confidence interval 1.03-4.3), with >4-fold greater crowding index of T. pallidipennis. The bug density index was inversely correlated with PCU altitude and socio-economic category (altitude of homes being associated with prosperity), while the bug colonization index (presence of nymphs indicating breeding) did not vary significantly across the PCU categories, but did vary according to altitude. Multivariate regression analysis showed that the most significant risk factors associated with T. pallidipennis infestation were lower altitude (linked with lower socio-economic status), garden area >80 m(2), dogs at liberty to enter the house, occurrence of squirrels and opossums around the house, presence of pigs in the surrounding area and having at least one of the adjacent lots empty (unconstructed). Householders who had received information about Chagas disease comprised 33% from infested houses (14/42) but only 15% from non-infested houses (148/984). Hence, the awareness of Chagas disease was significantly associated with having a bug-free house (P < 0.01). When shown specimens of T. pallidipennis, the proportions of householders who recognized them were 78% from infested houses but only 29% of those with uninfested houses. Given the low infestation rates and the high capacity of the population to act appropriately once they have received information regarding this disease and its vector, relevant health education is expected to have a significant impact on triatomine control in this metropolitan area.

Altitude↗

PubMed2004

Size-dependent optical properties of VO2 nanoparticle arrays.

The size effects on the optical properties of vanadium dioxide nanoparticles in ordered arrays have been studied. Contrary to previous VO2 studies, we observe that the optical contrast between the semiconducting and metallic phases is dramatically enhanced in the visible region, presenting size-dependent optical resonances and size-dependent transition temperatures. The collective optical response as a function of temperature presents an enhanced scattering state during the evolving phase transition. The effects appear to arise because of the underlying VO2 mesoscale optical properties, the heterogeneous nucleation behind the phase transition, and the incoherent coupling between the nanoparticles undergoing an order-disorder-order transition. Calculations that support these interpretations are presented.

Biosensing Techniques↗

PubMed2003

Plasmodium falciparum EBA-140 kDa protein peptides that bind to human red blood cells.

The erythrocyte-binding antigen 140 (EBA140) sequence was chemically synthesized in 61 20-mer sequential peptides covering the entire 3D7 protein strain, each of which was tested in erythrocyte-binding assays. Peptides 26135, 26144, 26147, 26160, 26170 and 26177 presented high erythrocyte-binding activity, with affinity constants ranging from 350 to 750 nM. Critical erythrocyte-binding residues were determined by competition-binding assays with glycine analogous peptides. Cross-linking assays with SDS-PAGE from high erythrocyte membrane protein binding peptides showed that all these peptides bound specifically to 25, 52 and 75 kDa erythrocyte membrane proteins. The nature of these receptor sites was studied in peptide-binding assays using enzyme-treated erythrocytes, showing that these protein receptors are susceptible to structural changes provoked by enzyme treatment (neuraminidase, trypsin or chymotrypsin). Inhibition invasion assays in 'in vitro' cultures showed that all specific high binding sequences were able to inhibit invasion by 11-69% at 200 microM concentration.

Amino Acid Sequence↗

PubMed2003

Influence of preapheresis clinical factors on the efficiency of CD34+ cell collection by large-volume apheresis.

We evaluated 120 leukapheresis procedures (93 patients), in order to detect clinical factors that influence the efficiency of CD34+ collection using Cobe Spectra trade mark cell separators. Hematocrit was >27% and platelet count >30 000/microl in >95% of patients. Platelet transfusions were given if the postprocedure count was &<20 000/microl. Multiple regression analysis was used to analyze putative factors, and a predictive equation defined by stepwise regression modeling. The mean efficiency was 0.59 (s.d. 0.27). Sex (M>F; P=0.01), the volume processed (inversely; P=0.01) and CD34+ cell count (inversely; P=0.04) were associated with efficiency, whereas hematocrit, platelet or leukocyte count, catheter type and patient weight were not. The effect size for predictive factors was small (R(2)=0.21). Adverse events were limited to hypocalcemia. We conclude that female sex, volume processed and CD34+ cell count adversely influence the efficiency of CD34+ cell leukapheresis. However, the impact of volume and CD34+ cell count is small, and likely to be offset by the influence of these same factors on overall yield. Leukapheresis appears to be safe and efficient for autologous blood and marrow transplantation patients with hematocrit >27% and platelet count >30 000/microl.

Antigens, CD34↗

PubMed2003

[Clinical significance of the Krogh-Poulsen bite test in mandibular dysfunction].

INTRODUCTION: The bite test was initially described as the Krogh-Poulsen test consists of biting a flat and thin wedge placed unilaterally between the molars. Temporomandibular joint (TMJ) pain located on the ipsilateral side is considered as muscular, when on the contralateral side pain signifies a joint problem. Although this test is widely used, no scientific evaluation of its real clinical value has been published. MATERIAL AND METHOD: A prospective study is conducted in 32 patients exhibiting temporomandibular pain (n=40) at the bite test. The results of the bite test were compared with results of computed tomography of the TMJ. Several criteria are studied: joint space narrowing, retrusion of the mandibular condyle in occlusal position, bony signs of joint degeneration. Chi-square and Student's t test were used for statistical analysis of correlations between clinical findings and radiological abnormalities. RESULTS: Significant results demonstrated a high degree of radiologically detectable disorders in patients with joint pain as defined by the bite test. All of these patients presented at least one radiological sign of joint disease. There was also a low degree of radiologically detected joint disturbance in patients with muscular pain according to the bite test, 70% of them presenting no radiological abnormality. DISCUSSION: It is concluded that the bite test is of significant value for evaluation of TMJ disorders and can be useful for the indication of complementary radiological examinations.

Adolescent↗

PubMed2002

Clinical and laboratory evaluation of the safety of a bioartificial liver assist device for potential transmission of porcine endogenous retrovirus.

BACKGROUND: The potential risk of transmission of porcine endogenous retroviruses (PERV) from xenogeneic donors into humans has been widely debated. Because we were involved in a phase I/II clinical trial using a bioartificial liver support system (BLSS), we proceeded to evaluate the biosafety of this device. MATERIALS AND METHODS: The system being evaluated contains primary porcine hepatocytes freshly isolated from pathogen-free, purpose-raised herd. Isolated hepatocytes were installed in the shell, which is separated by a semipermeable membrane (100-kD nominal cutoff) from the lumen through which the patients' whole blood is circulated. Both before and at defined intervals posthemoperfusion, patients' blood was obtained for screening. Additionally, effluent collected from a clinical bioreactor was analyzed. The presence of viral particles was estimated by reverse transcriptase-polymerase chain reaction (RT-PCR) and RT assays. For the detection of pig genomic and mitochondrial DNA, sequence-specific PCR (SS-PCR) was used. Finally, the presence of infectious viral particles in the samples was ascertained by exposure to the PERV-susceptible human cell line HEK-293. RESULTS: PERV transcripts, RT activity, and infectious PERV particles were not detected in the luminal effluent of a bioreactor. Culture supernatant from untreated control or mitogen-treated porcine hepatocytes (cleared of cellular debris) also failed to infect HEK-293 cell lines. Finally, RT-PCR, SS-PCR, and PERV-specific RT assay detected no PERV infection in the blood samples obtained from five study patients both before and at various times post-hemoperfusion. CONCLUSION: Although longer patient follow-up is required and mandated to unequivocally establish the biosafety of this device and related bioartificial organ systems, these analyses support the conclusion that when used under standard operational conditions, the BLSS is safe.

Animals↗

PubMed2002

Effect of acute cigarette smoking, alone or with alcohol, on gastric barrier function in healthy volunteers.

BACKGROUND: Smoking is a risk factor for gastroduodenal ulcer and gastric adenocarcinoma. However, the pathophysiological mechanisms induced by acute cigarette smoking in the human gastric mucosa are poorly understood. AIM: To evaluate the effect of acute cigarette smoking, alone or with alcohol, on the gastric permeability to sucrose, a specific marker of mucosal damage in the stomach. SUBJECTS AND METHODS: Twenty healthy volunteers (8 smokers/12 non-smokers) were studied. Each fasted subject ingested 500 ml of a 20% sucrose solution and the amount of sucrose excreted in a 5-hour urine collection was measured by gas chromatography Four sucrose permeability tests were carried out: 1. basal, 2. while smoking 5 cigarettes, 3. after drinking 50 ml of a 40 degrees alcoholic beverage, 4. a combination of 2+3. RESULTS: Sucrose excretion increased after alcohol ingestion (40.5 +/- 6.0 mg vs 143.1 +/- 28.9 mg, p = 0.002), but was not modified by acute cigarette smoking (34.4 +/- 5.9 mg). When alcohol and cigarettes were simultaneously consumed, the increase in alcohol-induced sucrose excretion was significantly reduced (73.1 +/- 16.6 mg, p = 0.03). Basal sucrose excretion was similar in smokers and non-smokers. However, in acute cigarette smoking, a decrease in sucrose excretion was observed in smokers (p = 0.02) but not in non-smokers. CONCLUSIONS: These results indicate that acute cigarette smoking may tighten the gastric mucosa in habitual smokers and this is associated with a smaller increase of gastric permeability induced by alcohol.

Adult↗

PubMed2002

Epidemiology of necrotizing ulcerative gingival lesions in adolescents.

OBJECTIVE AND BACKGROUND: Relatively little is known about the epidemiology of necrotizing ulcerative gingival lesions (NUG) in adolescent populations. Most studies have comprised special target groups, such as military recruits, HIV patients, or severely malnourished subjects. METHODS: A multistage random cluster sampling scheme was used to obtain a sample of 9203 students aged 12-21 years from 98 of a total of 618 high schools in Santiago, Chile. Students were given a clinical oral examination and questionnaire information was obtained on smoking and oral hygiene habits, dental attendance patterns, and diabetic status. The diagnostic criteria for NUG were the presence of necrosis and ulceration of at least one interproximal papillae. RESULTS: The estimated prevalence of NUG was 6.7% (95% CI = [6.2; 7.3]). A multivariable logistic regression analysis showed that last seeing a dentist more than 1 year ago (OR = 1.60), or never (OR = 1.93), and reporting diabetes (OR = 2.12) showed a significant positive association with the presence of NUG; whereas neither gender nor smoking were important predictors. Students aged 18-21 years were more, albeit statistically insignificantly, likely to have NUG than were younger students (OR = 1.40). CONCLUSIONS: Our observation that reporting to be diabetic was positively associated with the presence of NUG is interesting, as diabetes has never been addressed as a possible risk factor. As the association between diabetes and periodontitis in adults is thought to relate to impaired function of neutrophils, microangiopathy, and impaired wound healing this finding suggests a significant role of the host response also for the occurrence of NUG.

Adolescent↗

PubMed2002

Domestic scorpion control with pyrethroid insecticides in Mexico.

Scorpion stings cause more morbidity in Mexico than any other country, leading to about 100 deaths annually. In 1999, the State of Morelos reported nine deaths among 30663 cases of scorpion sting. To replace lindane used for scorpion control, field trials of pyrethroid pesticides were undertaken in Morelos during 1998-2000 at the village of Chalcatzingo (population initially with 2760 inhabitants and 530 houses). Pre-intervention surveys detected scorpions (Scorpiones: Buthidae) of two species in the majority of houses: Centruroides limpidus limpidus Karsch outnumbering Vaejovis mexicanus smithi Koch. Scorpion prevalence was assessed, pre- and post-spray, directly by searching (40 min/house) and by householder reports of sightings inside houses. Pre-intervention perceptions of scorpion abundance were similar for all areas, with sightings in 12-18% of houses, whereas daytime searches detected more infestations in eastern parts of the village (prevalence 17% indoors, 22% outdoors) than in other sectors (9% indoors, 14% outdoors). Pyrethroids were evaluated as residual treatments in separate sectors of Chalcatzingo, with almost complete coverage indoors and peridomestically, using the following four formulations: bifenthrin 10% wettable powder (WP) applied at 50mg a.i./m2, cyfluthrin 10% WP (Solfac 10 WP) at 44-55 mg a.i./m2, deltamethrin 2.5% suspension concentrate (Biothrin 25 SC) at 11 mg a.i./m2 and 5% WP (K-Othrine 50 WP) at 35 mg a.i./m2. Phase 1 compared bifenthrin 10 WP, Solfac 10 WP and Biothrin 25 SC sprayed in December 1998; phase 2 compared Solfac 10 WP and K-Othrine 50 WP sprayed in June and again in December 2000, with follow-up surveys of scorpions one month post-spray and subsequently. Scorpion prevalence was reduced by 64-77% peridomestically one month post-spray and by 83, 46 and 15% in houses sprayed with cyfluthrin WP, bifenthrin WP or deltamethrin SC, respectively. Householder reports of sighting scorpions indoors were 33-85% below pre-intervention levels. Cumulative effects of the three spray-rounds over 3 years reduced scorpion prevalence by approximately 60% in the deltamethrin WP re-sprayed area and by approximately 90% in the cyfluthrin WP re-sprayed area. Householder sightings also fell by 67 and 28% in the cyfluthrin and delta-methrin re-sprayed areas, respectively. Operational efficacy of these products against scorpions at the dosages applied was ranked as cyfluthrin WP > bifenthrin WP > deltamethrin SC > WP. Reported cases of scorpion sting intoxication fell by 17% during this study after having risen by approximately 40% over four previous years.

Animals↗

PubMed2002

Detection of central pelvic recurrent disease with transvaginal color Doppler ultrasound in women treated for gynecological malignancy.

OBJECTIVE: To evaluate color Doppler characteristics of small recurrent tumors detected within the central pelvis in follow-up patients treated for gynecological malignancy. PATIENTS AND METHODS: A prospective study was performed on 340 patients who were being monitored following treatment for gynecological malignancies. A selected group of 27 patients, with small pelvic masses located in the central region of the pelvis, underwent a color Doppler examination. A subjective assessment of the vascularization (vascular score), the lowest resistance index (RI), the highest peak velocity (PSV) and the highest time averaged maximum velocity (TAMXV) of the vessels detected within the lesion were analyzed. RESULTS: In 16 patients the pelvic mass was found to be benign while in 11 patients a malignant recurrence was diagnosed. Gray-scale examination could not differentiate between benign and malignant lesions. The color score of tumor recurrences was significantly higher in comparison to that in benign lesions (color score 3 in 54% vs. 0%, P < 0.005). The malignant lesions showed significantly lower mean values of RI and significantly higher mean values of PSV and TAMXV when compared with benign lesions (0.39 +/- 0.09 vs. 0.81 +/- 0.22, P < 0.0001; 19.3 +/- 4.7 vs. 10.5 +/- 5.6 cm/s, P < 0.0001; 8.9 +/- 3.7 vs. 4.3 +/- 2.7 cm/s, P < 0.005). CONCLUSIONS: Color Doppler analysis added to transvaginal gray-scale ultrasonography seems to be a helpful tool in the diagnosis of recurrent tumors in the central region of the pelvis.

Adult↗

PubMed2002

The need for continuous immunosuppression with cyclosporin A to maintain an experimental model of uveal melanoma.

We investigated the need for continuous immunosuppression to maintain experimental tumours derived from human uveal melanoma cells implanted in the choroid of pigmented rabbits. Two groups of pigmented rabbits immunosuppressed with cyclosporin A (CsA) were implanted with human uveal melanoma cells in the suprachoroidal space. After 5 weeks, CsA was discontinued in group 2. Animals were treated with prophylactic antibiotics and examined weekly for tumour growth, weight and secondary effects; blood urea nitrogen levels were measured every two weeks. Autopsies and histopathological studies were performed after death or euthanasia at the end of week 12. The difference between the groups in the development of ophthalmoscopic tumours was not statistically significant 5 weeks after implantation. Tumours in group 1 grew progressively throughout the experiment, whereas group 2 tumours showed marked regression 3-4 weeks after discontinuing CsA. Tumours in group 1 were significantly larger and had greater mitotic activity and showed more ciliary body, optic nerve and extrascleral invasion than tumours in group 2, which showed massive fibrosis, minimal mitotic activity and marked inflammatory cell infiltration. Continuous immunosuppression with CsA seems to be necessary to maintain tumour growth in this experimental model of uveal melanoma.

Animals↗