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Enhanced short-term plasmid transfection of filtration surgery tissues.

PURPOSE: To quantify and localize plasmid transfection of filtration surgery tissues using two delivery techniques. METHODS: Full-thickness filtering procedures were performed on eyes of New Zealand albino rabbits. In 10 eyes, naked plasmid DNA in saline was either injected beneath Tenon's capsule at the filtration site or absorbed into a collagen shield that was then placed external to the sclerostomy and under the Tenon's capsule. Forty-eight hours after surgery, levels of the reporter gene, chloramphenicol acetyltransferase (CAT) were measured in samples of ocular tissues. In two additional eyes, the ss-galactosidase (ss-GAL:) reporter gene expression was localized histologically. RESULTS: Injection of plasmid DNA in saline vehicle into the filtration bleb produced readily detectable CAT activity in bleb tissue (conjunctiva, Tenon's capsule, and sclera) whereas CAT activity was nearly undetectable in samples of the cornea, iris-ciliary body, and tissues located opposite the bleb site. Delivery of the plasmid DNA into the bleb through a collagen shield increased CAT activity 30-fold over injection of plasmid in saline (2711 +/- 567 mU/mg versus 92 +/- 38 mU/mg). ss-Gal activity was imaged only in the region of the bleb, and microscopic examination showed ss-Gal activity localized to Tenon's capsule fibroblasts, with minimal ss-Gal activity observed in inflammatory cells or scleral fibroblasts. CONCLUSIONS: Transfection of filtration tissues is enhanced by absorption of naked DNA into a collagen shield. Furthermore, transfection is localized to the fibroblasts and inflammatory cells of the filtration bleb site. Gene therapy using naked plasmid DNA and a simple collagen shield delivery vehicle may be useful for regulating wound healing after glaucoma surgery.

Animals↗

The efficiency of an autotransfusion system for tumor cell removal from blood salvaged during cancer surgery.

The efficiency of a gravity-dependent autotransfusion system (ATS) for filtering tumor cells from blood was examined under laboratory and clinical conditions. In laboratory studies, reconstituted whole blood was seeded with known numbers of cultured A431 human vulva carcinoma cells then filtered through the ATS. Cancer cells were recovered from blood samples taken before and after filtration using a density gradient centrifugation procedure, and identified by immunocytochemical techniques, based upon their cytoskeletal intermediate filament proteins. It was estimated that 55%-76% of the A431 cells were retained by the ATS filters, and of those cancer cells that passed through the ATS, 62% suffered lethal trauma and the remainder showed morphologic damage. In clinical studies, blood was harvested from the surgical site during resection of primary cancers from three patients. In agreement with the laboratory studies, 50%-68% of tumor cells were filtered by the ATS from blood harvested during surgery. These results are discussed in terms of metastatic inefficiency and the potential for use of autotransfused blood salvaged during cancer surgery.

Blood Transfusion, Autologous↗

[Risk factors for encapsulated filtering bleb after trabeculectomy--own experience].

The aim of the study was to evaluate the incidence of encapsulated filtering bleb at patients after trabeculectomy. We analyzed risk factors, prognosis and treatment in cases of this complication. All 857 cases of trabeculectomies performed in Department of Ophthalmology of Medical University of Warsaw in years 2001-2003 were included in the study. Twenty two cases (2.5% of all trabeculectomies) of encapsulated filtering bleb were analyzed. Twenty patients (91%) underwent surgery procedure and two patients (9%) were treated medically. The encapsulated filtering blebs occurred mainly in patients after previous ocular surgery, in eyes with episodes of earlier ocular inflammation and in patients treated with many antiglaucoma drops.

Aged↗

Bradykinin-associated reactions in white cell-reduction filter.

PURPOSE: The purpose of this study was to examine the effect of temperature on bradykinin generation during blood transfusion using positively charged (positive filter), negatively charged (negative filter), and neutral (neutral filter) filters. MATERIALS AND METHODS: Whole blood collected from six volunteers at 4 degrees C or 37 degrees C was passed through the positive or negative filter. In six surgical patients during surgery, autologous blood transfusion at 37 degrees C was initiated through the positive filter, and the same transfusion was reintroduced through the negative filter. Whole blood from another six volunteers at 4 degrees or 37 degrees C was passed through the neutral filter. RESULTS: The positive filter did not generate bradykinin at any temperature, whereas the negative filter generated bradykinin by approximately 4,000-fold when warm blood was used but did not at cool blood. Blood pressure decreased and heart rate increased during warm blood transfusion using the negative filter but did not change using the positive filter. Plasma bradykinin levels increased in patients with use of the negative filter. The neutral filter generated bradykinin when warm blood was used but at levels lower than for the negative filter. CONCLUSIONS: Use of negative filter results in the temperature-dependent generation of bradykinin, which becomes a potential anaphylatoxin when warm blood is used.

Adult↗

Study of filtered light on potential retinal photic hazards with operation microscopes used for ocular surgery.

There have been numerous reports of retinal photic injury from operation microscopes used during cataract surgery. The risk of injury has been associated with the intensity of the light directed into the eye, short-wavelength emission, user technique, exposure time, and direct axial lighting. We evaluated use of light transmission filters to modify a tungsten-halogen light source spectrum to reduce the risk of retinal photic injury. A two-light source filter combination was found with a color profile acceptable for intraocular surgery that reduces the risk of retinal photic injury by a factor of approximately 2.5.

Filtration↗

Effects of tissue plasminogen activator on glaucoma filter blebs in rabbits.

Tissue plasminogen activator (tPA), a zymogen associated with fibrinolysis, was used in an attempt to prevent scarring and the consequent loss of glaucoma filtration blebs. Bilateral trephine filter procedures were performed in 10 new Zealand white rabbits. In a randomized, masked fashion, one eye received intracameral tPA (25 micrograms), and the fellow placebo, immediately following surgery. One week after surgery, outflow facility in the tPA-treated eyes was significantly greater than that in the control (P less than 0.01). Two weeks after surgery, the outflow facility returned to preoperative levels in all eyes. Eyes receiving tPA had larger blebs than the controls. No increase in postoperative complications, such as hemorrhage or wound leak, was attributable to tPA use. The results suggest that tPA interferes with the wound healing process after surgery and may promote glaucoma filter bleb formation.

Animals↗

Optional vena cava filters: preliminary experience with a new vena cava filter.

PURPOSE: To prevent pulmonary embolism, some clinical situations only need a vena cava filter for several days, without the inconveniences of temporary vena cava filters in the short-medium term and without the drawbacks of permanent ones in the long term. We report our initial experience with a new definitive vena cava filter, easy to retrieve when it becomes unnecessary. MATERIAL AND METHODS: From the beginning of January 1999 to December 2001, 18 ALN vena cava filters were deployed. The approach used was transbrachial in ten patients, transjugular in seven, and transfemoral in the others. The indications were pelvic trauma in eleven patients, hip replacement in three; four filters were "prophylactically" placed before surgery in patients at high risk of thromboembolic disease (three with ileal or femoral or ileo-femoral thrombosis, and one without clinically manifest thromboembolic disease). Optional vena cava filters were evaluated for malpositioning, caval perforation, filter migration, acute caval thrombosis or access site thrombosis. Seven optional vena cava filters were retrieved. CT was performed before retrieving the vena cava filters to document the absence of thrombi inside the filters. The transjugular ap-proach was used to retrieve the filters. RESULTS: Technical success was achieved in all patients. No complications were encountered during the procedure; no migration or rupture of the filters was detected during the follow-up. No thrombosis of the vena cava or at the insertion site was encountered. The median retrieval time for the filters was 12': only the transfemoral filters required 15' of fluoroscopy. The median permanence was 63 days. No thrombi were found inside the filters. DISCUSSION: A definitive vena cava filter, easy to retrieve when it becomes unnecessary, is the ideal device in many clinical conditions: young subjects with pelvic fractures orthopaedic and gynaecologic interventions.

Adult↗

Blue-light filtering intraocular lens in patients with diabetes: contrast sensitivity and chromatic discrimination.

PURPOSE: To evaluate potential changes in contrast sensitivity and color discrimination in diabetic patients who had cataract surgery and implantation of the blue-light filtering AcrySof Natural (SN60AT) intraocular lens (IOL) compared with an ultraviolet-only filtering (AcrySof SA60AT) IOL. SETTING: Refractive Surgery Unit, Hospital NISA Valencia al Mar, Valencia, Spain. METHODS: Forty-four eyes of 22 diabetic patients were enrolled in a blue-light filtering fellow-eye control study. Patients received yellow-tinted IOLs (AcrySof Natural) in 1 eye and non-yellow-tinted IOLs (AcrySof SA60AT) in the fellow eye. Three months after surgery, monocular contrast sensitivity function was measured with the CSV 1000-E contrast sensitivity chart at distance and color discrimination was tested with the Farnsworth-Munsell 100-hue test. RESULTS: Eyes implanted with the blue-light filtering IOLs showed better contrast sensitivity values than fellow eyes implanted with non-yellow-tinted IOLs (P<.05). The blue-light filtering IOL did not modify chromatic discrimination compared with the non-yellow-tinted IOL (P = .62). In the blue-yellow axis discrimination study, the eyes implanted with the AcrySof Natural IOL had statistically significant better color vision (P = .008). CONCLUSIONS: In diabetic patients, the AcrySof Natural IOL provides better contrast sensitivity than the AcrySof SA60AT. The blue-light filter of the AcrySof Natural IOL did not cause chromatic discrimination defects based on total error scores and improved color vision in the blue-yellow chromatic axis in diabetic patients.

Aged↗

Effects of aminoproprionitrile on glaucoma filter blebs in rabbits.

Aminoproprionitrile was used topically in rabbits for 4 weeks following glaucoma filtration surgery in an attempt to prevent loss of the filter bleb from scarring. At 2 and 4 weeks after surgery, the outflow facility in eyes receiving aminoproprionitrile was greater than in the fellow eyes which served as controls (p less than 0.002 at 2 weeks and p less than 0.015 at 4 weeks). By 8 weeks after surgery, there was no difference in the outflow facility of the eyes in each animal. No increase in postoperative complications was attributed to aminoproprionitrile. These results suggest that aminoproprionitrile, which interferes with collagen cross-linking, may promote filter bleb formation.

Aminopropionitrile↗

Effects of a leucocyte depleting arterial line filter on perioperative proteolytic enzyme and oxygen free radical release in patients undergoing aortocoronary bypass surgery.

BACKGROUND: Proteolytic enzymes and oxygen free radicals released from activated leucocytes contribute significantly to the organ dysfunction associated with cardiopulmonary bypass. Leucocyte depletion during extracorporeal circulation should reduce the release of these toxic compounds and thereby improve postbypass myocardial and pulmonary function. Recently, a leucocyte-specific arterial line filter to achieve leucocyte depletion during clinical perfusion has become commercially available. The aim of this study, therefore, was to evaluate the influence of the leucocyte depleting arterial line filter on proteolytic enzyme release, oxygen free radical release and postbypass pulmonary and myocardial function in patients undergoing bypass surgery. METHODS: Forty patients undergoing elective aortocoronary bypass surgery were included into this prospective, randomized clinical study, 20 in the leucocyte depletion (LG-6 group, leucocyte-specific arterial line filter) and 20 in the control group (AV-6 group, standard arterial line filter). White cell count, differential white cell count, plasma elastase concentration, plasma malondialdehyde concentration and C-reactive protein were determined before, twice during and immediately after cardiopulmonary bypass, at the end of surgery and 6 and 20 h thereafter. RESULTS: White cell count, differential white cell count, malondialdehyde and C-reactive protein were not significantly different between LG-6 and control patients. Plasma elastase concentrations were significantly (P < or = 0.03) higher during and immediately after extracorporeal circulation in LG-6 group patients. Need for inotropic support, arterial pO2 after extracorporeal circulation and perioperative CK MB mass and troponin I release were not different between the two groups of patients. CONCLUSION: The use of a leucocyte depleting arterial line filter is associated with an increased release of the proteolytic enzyme elastase, but does not reliably and consistently achieve effective leucocyte depletion during clinical perfusion. In contrast to previous studies, we could not demonstrate any significant difference in postbypass pulmonary or myocardial function between patients perfused with the leucocyte-specific arterial line filter and control patients. Our data do not support the routine use of a leucocyte depleting arterial line filter during clinical perfusion in patients undergoing elective aortocoronary bypass surgery.

Aged↗

Prevention of thrombosis with prostaglandin E1 in a patient with catastrophic antiphospholipid syndrome.

PURPOSE: Catastrophic antiphospholipid syndrome (CAPS) is a variant of antiphospholipid syndrome and presents with life-threatening symptoms of multiorgan failure due to thrombosis. We present a patient with CAPS secondary to an ovarian cancer. In such cases, it is believed that the thrombotic risk disappears after surgical removal of the cancer. The intraoperative management was challenging because of the risks of two opposing complications: catastrophic exacerbation of the thrombotic tendency triggered by the surgical stimulus and major bleeding due to the necessary anticoagulation. We describe the intraoperative management of hemostasis in a patient with CAPS. CLINICAL FEATURES: A 44-yr-old female patient with CAPS underwent resection of an ovarian cancer, which was suspected to be associated with her coagulation abnormality. She had both arterial and venous thromboembolism, including cerebral infarction, embolic gangrene, and pulmonary emboli. Serological examinations revealed increased anticardiolipin IgG antibody and decreased protein C activity. Before surgery, an inferior vena cava filter was placed to prevent perioperative pulmonary embolism. Prostaglandin E(1) (PGE(1); 100 ng.kg(-1).min(-1)) was given intraoperatively to suppress platelet aggregation and thrombin generation and to maintain arterial blood flow. No apparent coagulation abnormalities were observed during surgery, neither hypercoagulation nor a tendency to bleed. No additional thrombotic symptoms developed during a six-month follow-up. CONCLUSION: The use of PGE(1), an inhibitor of thrombin formation and platelet function, and placement of an inferior vena cava filter were associated with the uneventful surgical resection of an ovarian cancer in a patient with CAPS.

Adult↗

[Cesarean section using a temporary IVC filter in a pregnant woman with several histories of deep vein thrombosis].

A 31-year-old pregnant woman with a history of several episodes of deep vein thrombosis was scheduled for Caesarian section. The patient had an increased risk of intraoperative pulmonary thromboembolism due to thrombi isolated from deep veins. This is because a thrombus can be formed easily in deep veins by the influence of hypercoagulability in the third trimester and by the disturbance of venous return due to the pressure of the enlarged pregnant uterus. A temporary IVC filter (Filtre Thery, France) was inserted preoperatively. The filter basket was set in the IVC cephalad from the left renal vein and caudad from the hepatic vein. The operation was completed without any trouble. Rehabilitation was safely initiated just after the surgery by insertion of the filter and then the filter was removed on the third postoperative day. We conclude that the preoperative insertion of a temporary IVC filter is a useful technique to prevent intraoperative pulmonary thromboembolism in a patient with a history of deep vein thrombosis.

Adult↗

Migration of an inferior vena cava filter to the right ventricle and literature review.

Migration of an inferior vena cava (IVC) filter to the heart after placement is an extremely rare complication. The case of a 42-year-old man who presented with ventricular arrhythmia and tricuspid valve regurgitation, and underwent open heart surgery to extract an IVC filter from the right ventricle 12 days after infrarenal IVC filter placement, is reported.

Adult↗

Early postoperative prognostic indicators following trabeculectomy.

We compared prognostic indicators manifesting within the first 2 postoperative days, with filtration status 3 months following trabeculectomy in 51 primary open-angle glaucoma patients. Patients with an avascular area in the filtering bleb 2 days after surgery had a significantly lower (P less than .05) intraocular pressure (IOP) (12.6 mm Hg) 3 months postoperatively than patients with vascular blebs (16.3 mm Hg). However, neither the height, breadth, or transparency of the filtering bleb, presence of microcysts, anterior chamber depth, nor IOP during the first 2 postoperative days were related significantly to the filtration status at 3 months.

Female↗

Extracapsular cataract surgery and intraocular lens implantation in glaucomatous eyes that had a filtering bleb operation.

We studied 112 eyes of 80 glaucomatous patients who had filtering operations and also developed cataracts. Extracapsular cataract extraction (ECCE) was performed in all eyes. One hundred four (104) eyes had posterior chamber intraocular lenses (IOLs) implanted and eight had ECCE without IOLs; the latter were excluded from this clinical investigation. We evaluated intraocular pressure (IOP) and visual acuity and examined the visual fields during a follow-up period of eight months. We compared these results with the preoperative measurements. This study demonstrates that ECCE and posterior chamber IOL implantation is the optimal solution for glaucomatous eyes that have had a filtering bleb operation to obtain a good functional result and IOP stabilization.

Aged↗

Early technical and clinical results with retrievable inferior vena caval filters.

Deep venous thrombosis with or without subsequent pulmonary embolism is a common preventable cause of hospital death. Although anticoagulation is the accepted standard therapy for thromboembolic disease, in situations in which anticoagulation is contraindicated, interruption of the inferior vena cava (IVC) by means of percutaneous placement of a filter has become a widely used alternative. We report our initial experience with two retrievable IVC filters. Between July 2002 and April 2003, 13 patients (mean age 54 +/- 7 years; range 29-75 years) underwent percutaneous placement of either the Gunther Tulip (n = 5; Cook Inc., Bloomington, IN) or OptEase (n = 8; Cordis, Miami Lakes, FL) IVC filter. Five patients had filters placed prophylactically before major surgery. The remaining eight patients had had a contraindication to anticoagulation, and three had experienced a hemorrhagic complication as a result of anticoagulation following either a recently documented deep venous thrombosis (n = 3) or pulmonary embolism (n = 5). Filters were successfully placed in all 13 patients, with a duration of implantation ranging from 2 to 15 days. Retrieval was attempted in 12 patients (in 1 patient, permanent filtration was secondarily requested) and was achieved in 10 (84.6%) patients. In 2 patients, retrieval failure was due to device angulation within the vena cava precluding safe retrieval. In both instances, the device used was the Gunther Tulip filter. No patient developed symptomatic pulmonary embolism or insertion-site thrombosis following either filter deployment or removal. Trapped thrombus in the filters was seen in all patients. Retrieval required a mean of 6.8 minutes (range 5-10.2 minutes) of fluoroscopy time. Neither filter migration nor caval injury was observed. Temporary IVC filters are effective and are associated with a high retrieval success rate. Further study is warranted to determine the maximal duration of implantation and whether retrievable IVC filters should expand the indications for IVC filter placement.

Adult↗

Near-UV radiation from the operating microscope and pseudophakic cystoid macular edema.

We performed a prospective randomized study of 297 patients to determine the effect of a UV-blocking filter on the operating microscope on the angiographic incidence of cystoid macular edema in patients undergoing extracapsular surgery with implantation of a posterior chamber lens. Patients were randomly allocated preoperatively to two groups undergoing surgery with or without a UV filter in place. Of the 297 patients, 205 had angiograms readable for the presence or absence of cystoid macular edema. The incidence of aphakic cystoid macular edema in patients without the filter was 21% v 17.3% in the group with a filter. This difference was not significant. The presence of a UV-blocking filter on the operating microscope makes no difference in the angiographic incidence of cystoid macular edema or the visual outcome in these cases.

Cataract Extraction↗

[Is the elimination of osteosarcoma cells with intraoperative "mesh autotransfusion" and leukocyte depletion filters possible?].

UNLABELLED: Intraoperative autotransfusion is contraindicated in cancer surgery because of the possible risk of systemic tumor spread. The aim of the present study was to investigate whether a cell saver in combination with a white blood cell depletion filter can remove osteosarcoma cells. METHODS: A defined number of osteosarcoma cells from an established cell line were added to red cell concentrates and Ringer solution. The tumor cell concentration was 1000/ ml in the first five experiments, 7111/ml in test no. 6, 1667/ml in test no. 7 and 167/ml in test no. 8. Following thorough mixing, each unit was processed separately by a cell saver (DIDECO BT 795/P) in its normal operation mode to produce a red cell concentrate. This red cell concentrate was filtered using a leukocyte depletion filter (PALL BPF 4). Samples were taken before and after processing with the autotransfuser and after filtration with the white cell depletion filter. Cytospin specimens from all samples were examined for osteosarcoma cells by three different methods (Papanicolaou stain, Vimentin antibodies, DNA analysis). RESULTS: After processing with the autotransfuser, tumor cells were identified in the red cell concentrate. No osteosarcoma cells were evident after the combined use of cell saver and leukocyte depletion filter. CONCLUSION: The sole use of the autotransfuser DIDECO BT 795/P during osteosarcoma surgery is not recommended because of the potential danger of retransfusion of malignant cells. In combination with the leukocyte depletion filter PALL BPF 4, no osteosarcoma cells were identified in the red cell concentrate. Since the adhesiveness of tumor cells from established cell lines may be different from that of tumor cells in the intraoperative salvaged blood, further studies with blood from the surgical field are necessary to determine the efficacy of white cell depletion filters to eliminate osteosarcoma cells.

Blood Transfusion, Autologous↗