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Biomedical subjects

A Capone

Publications and source records attributed to A Capone.

At least 55 records · Page 3Linked to original sources
PubMed1997

Effects of hemodilution on long-term survival in an uncontrolled hemorrhagic shock model in rats.

Prehospital guidelines for the treatment of penetrating trauma recommend rapid volume resuscitation to normal blood pressure. There is evidence, however, that fluid resuscitation to normal blood pressure in the setting of uncontrolled hemorrhagic shock (UHS) causes increased bleeding, hemodilution, and mortality. To test this hypothesis, we evaluated the effects of blood pressure and hemodilution on survival in a rat model of UHS. UHS was produced in rats by preliminary bleed of 3 mL/100 g followed by a 75% tail amputation. Experimental design consisted of three phases: a prehospital phase, with uncontrolled bleeding and resuscitation to either 40 or 80 mm Hg with lactated Ringer's solution (LR) or lactated Ringer's solution and whole blood (WB); followed by a hospital phase, with control of the bleeding and continued resuscitation to mean arterial pressure (MAP) > 80 mm Hg and hematocrit near 30%; followed by a 3-day observation phase. There were four treatment groups, n = 8 in each group: group I, MAP = 80 mm Hg with LR only; group II, MAP = 80 mm Hg with WB and LR; group III, MAP = 40 mm Hg with LR only; and group IV, MAP = 40 mm Hg with WB and LR. All group I rats died within 2.5 hours. There were no significant differences in survival among groups II, III, and IV. Base deficit, arterial pH, and lactate levels were significantly worse in the rats resuscitated to a MAP of 80 mm Hg with LR (group I). The effects of blood pressure alone, hemodilution alone, and their interaction were significantly related to base deficit and arterial pH. Hemodilution, but not blood pressure as an end point in resuscitation, was significantly related to lactate levels. The high mortality in this model of uncontrolled hemorrhage was attributable to the effects of blood pressure, hemodilution, and the interaction between the two variables, rather than simply continued blood loss from increased hydrostatic pressure.

Animals↗
PubMed1996

The primary role of steroids on the osteoporosis in juvenile rheumatoid patients evaluated by dual energy X-ray absorptiometry.

Osteoporosis, a common clinical feature in children affected with Juvenile Rheumatoid Arthritis (JRA), is generally divided into two forms, a localized juxta-articular osteoporosis of the single joints and a generalized reduction of bone mass due to the disease itself, joint involvement and steroid treatment. Recently Dual Energy X-ray Absorptiometry (DEXA) has been suggested for Bone Mineral Density (BMD) measurement. In the present study DEXA has been used to investigate the lumbar spine BMD in JRA patients as compared to healthy children. Our results showed that BMD is reduced in JRA patients (BMD 0.685 g/cm2) when compared to healthy children (BMD 0.722 g/cm2), and it is significantly lower in the group of patients treated with steroids (BMD 0.623 g/cm2) when compared to those treated with nonsteroidal antiinflammatory drugs (BMD 0.710 g/cm2). The analysis of all risk factors of bone loss indicated that steroids represent the only parameter of significant negative correlation with BMD.

Absorptiometry, Photon↗
PubMed1996

Ultrastructural features of tissue removed during idiopathic macular hole surgery.

PURPOSE: To compare the ultrastructural features of excised tissue removed during surgery for idiopathic macular holes with the preoperative stage of the macular hole. METHODS: Twelve consecutive patients with a unilateral idiopathic macular hole underwent vitrectomy with surgical removal of the internal limiting membrane of the retina and epiretinal tissue overlying and surrounding the hole. The excised specimens were evaluated with transmission electron microscopy, and findings were compared with the preoperative stage of the macular hole according to the classification of Gass. RESULTS: Surgery was performed on 12 eyes of 12 patients with stage 2, 3, or 4 macular holes. Internal limiting membrane was present in 11 of 12 specimens. Tissue from one of two eyes with stage 2 holes showed cellular elements enmeshed in cortical vitreous. Tissue from four of seven eyes with stage 3 holes and three of three eyes with stage 4 holes had cellular proliferation on the internal limiting membrane. Cells with myofibroblastic differentiation were present in five of the eight cellular proliferations. CONCLUSION: Our results support the clinical stages of idiopathic macular holes described by Gass. Idiopathic macular holes appear to form from contraction of the prefoveal vitreous, and the hole enlarges because of contraction of myofibroblasts on the inner surface of the internal limiting membrane. On the basis of the mechanical mechanisms of idiopathic macular hole formation, removal of the internal limiting membrane and adherent epiretinal tissue surrounding and overlying the macular hole is a reasonable surgical approach to close idiopathic macular holes.

Aged↗
PubMed1996

Postoperative hypopyon after intravitreal bovine thrombin for macular hole surgery.

PURPOSE: We used intravitreal autologous fibrinogen with bovine thrombin for the surgical closure of macular holes in 60 cases. METHODS: Pars plana vitrectomy with separation of the posterior cortical vitreous was performed after air/fluid exchange. One to two drops each of autologous fibrinogen and bovine thrombin (20 to 80 U) were instilled in each patient. RESULTS: Five (8%) of 60 patients developed a hypopyon without unusual pain on the first postoperative day. Inflammation responded to frequent topical corticosteroids within 48 to 72 hours. CONCLUSION: Postvitrectomy hypopyon after the use of bovine thrombin may represent an immune reaction that must be differentiated from endophthalmitis. We recommend careful observation and frequent topical corticosteroids.

Adult↗
PubMed1996

Subfoveal choroidal neovascularization in punctate inner choroidopathy. Surgical management and pathologic findings.

PURPOSES: To evaluate submacular surgery for the management of subfoveal choroidal neovascularization in punctate inner choroidopathy, to describe the histopathology and ultrastructure of the excised subretinal tissue, and to propose a staging system that characterizes the development of choroidal neovascularization with associated subretinal fibrosis. METHODS: The authors reviewed the records of five patients (6 eyes) with punctate inner choroidopathy who underwent submacular surgery for subfoveal choroidal neovascularization. Surgical specimens were examined using light and transmission electron microscopy. RESULTS: Visual improvement was noted postoperatively in all six eyes, with follow-up ranging from 8 to 36 months (median, 14 months). Recurrences (6 in 4 eyes) were common. Five of the six recurrences required additional procedures: three were managed surgically, two with laser photocoagulation, and one with observation. "Bridging" of separate foci of choroidal neovascularization resulted in stellate or "dumbbell-shaped" areas of subretinal fibrosis in four of six eyes. Histopathologic evaluation of the excised tissue showed endothelial-lined vascular channels, retinal pigment epithelium, lymphocytes, plasma cells, fibrocytes, collagen fragments, and rarely, outer retinal elements. CONCLUSIONS: Subfoveal choroidal neovascularization in punctate inner choroidopathy may be managed with submacular surgery. Recurrences are common and may result in substantial loss of vision. Choroidal neovascular membranes with an accompanying fibrotic reaction are responsible for the stellate or dumbbell-shaped areas of subretinal fibrosis. No beneficial effect was demonstrated using corticosteroid treatment of the choroidal neovascularization.

Adult↗
PubMed1996

Lens preservation after intraocular foreign body injuries.

PURPOSE: Ocular missile injuries often involve the lens. Some have suggested that lens capsular violation by a foreign body is an indication for immediate lens removal. Sometimes, however, the resultant lens opacity may remain localized without visual compromise. The authors report a series of patients who had lens capsular disruption from an intraocular foreign body that resulted in visually insignificant lens opacities. METHODS: A series of five patients with lens capsular disruption as a result of an intraocular foreign body injury were reviewed retrospectively. RESULTS: All five patients had lens injury from a small foreign body in a peripheral lenticular location. In three patients the foreign body was intralenticular, whereas in the other two patients the foreign body transversed the lens and was located in the posterior segment. In two patients, the foreign body was not removed. Three of the patients required pars plana vitrectomy. In all patients, final visual acuity was at least 20/40, and the lenticular opacity remained localized to an eccentric location. CONCLUSIONS: A progressive, visually significant cataract is not the inevitable result of lens injury by an intraocular foreign body. When indicated, surgical removal of the foreign body may be attempted using a lens-sparing procedure.

Adult↗
PubMed1996

Ciliary body endophotocoagulation during pars plana vitrectomy in eyes with vitreoretinal disorders and concomitant uncontrolled glaucoma.

PURPOSE: To investigate the efficacy of ciliary body endophotocoagulation during pars plana vitrectomy in eyes with medically uncontrolled glaucoma and concomitant vitreoretinal disorders. METHODS: The authors compared preoperative and postoperative intraocular pressure (IOP) and visual acuity in 21 eyes of 21 patients undergoing ciliary body endophotocoagulation with pars plana vitrectomy. RESULTS: Preoperative IOPs ranged from 22 to 59 mmHg (median, 46 mmHg). Visual acuity ranged from 20/200 to light perception (median, hand motions). Follow-up ranged from 3 to 18 months (median, 10 months). Postoperative IOPs ranged from 11 to 19 mmHg (median, 16 mmHg) at 6 weeks, 4 to 20 mmHg (median, 14 mmHg) at 3 months, 1 to 26 mmHg (median, 12 mmHg) at 6 months, and 0 to 48 mmHg (median, 12 mmHg) at 12 months. Postoperative visual acuity was statistically improved from preoperative visual acuity by 6 weeks. CONCLUSION: Ciliary body endophotocoagulation combined with pars plana vitrectomy can effectively treat concomitant glaucoma and vitreoretinal disorders.

Adult↗
PubMed1996

Complete recovery after normothermic hemorrhagic shock and profound hypothermic circulatory arrest of 60 minutes in dogs.

OBJECTIVE: We hypothesize that during severe normothermic hemorrhagic shock (HS), induction of profound hypothermic circulatory arrest (PHCA) of 60 minutes to allow repair of otherwise lethal injuries in a bloodless field, can be survived without brain damage. In previous dog studies, normothermic HS with mean arterial pressure (MAP) of 40 mm Hg for 30 minutes, followed by PHCA of 2 hours at brain (tympanic membrane) temperature of 5 to 10 degrees C and core temperature of 10 degrees C, induced and reversed with cardiopulmonary bypass, resulted in survival with mild histopathologic brain damage. This study was designed to determine the severity of HS that can safely allow 1 hour of PHCA. In pilot studies with HS at MAP 30 mm Hg for 90 minutes with or without subsequent PHCA of 60 minutes there were no survivors. METHODS: In the definitive study, outcomes in four groups of five dogs each were compared: group I, HS at MAP 30 mm Hg for 60 minutes and normothermic fluid resuscitation; group II, HS at MAP 30 mm Hg for 60 minutes, PHCA for 60 minutes, and resuscitation; group III, HS at MAP 40 mm Hg for 60 minutes and normothermic fluid resuscitation; and group IV, HS at MAP 40 mm Hg for 60 minutes, PHCA for 60 minutes, and resuscitation. Controlled ventilation was maintained for at least 20 hours and intensive care for 72 hours. RESULTS: In groups I and II, two of five dogs in each group survived to 72 hours. In groups III and IV, all ten dogs survived. All survivors were functionally normal, with neurologic deficit scores (0% = normal, 100% = brain dead) of < 10%. Light microscopic scoring of 18 brain regions revealed no ischemic changes. All nonsurvivors had a severe metabolic acidemia after HS and developed multiple organ failure, including pulmonary edema, pneumonia, and intestinal necrosis. CONCLUSIONS: The critical level of hypotension during 60 minutes normothermic HS that is compatible with survival in dogs is a MAP of between 30 and 40 mm Hg. After otherwise survivable severe normothermic HS of 60 minutes, PHCA of 60 minutes does not add brain damage or mortality, and may allow survival from injuries that would otherwise be irreparable.

Animals↗
PubMed1996

Resuscitation from severe hemorrhage.

The potential to be successfully resuscitation from severe traumatic hemorrhagic shock is not only limited by the "golden 1 hr", but also by the "brass (or platinum) 10 mins" for combat casualties and civilian trauma victims with traumatic exsanguination. One research challenge is to determine how best to prevent cardiac arrest during severe hemorrhage, before control of bleeding is possible. Another research challenge is to determine the critical limits of, and optimal treatments for, protracted hemorrhagic hypotension, in order to prevent "delayed" multiple organ failure after hemostasis and all-out resuscitation. Animal research is shifting from the use of unrealistic, pressure-controlled, hemorrhagic shock models and partially realistic, volume-controlled hemorrhagic shock models to more realistic, uncontrolled hemorrhagic shock outcome models. Animal outcome models of combined trauma and shock are needed; a challenge is to find a humane and clinically realistic long-term method for analgesia that does not interfere with cardiovascular responses. Clinical potentials in need of research are shifting from normotensive to hypotensive (limited) fluid resuscitation with plasma substitutes. Topics include optimal temperature, fluid composition, analgesia, and pharmacotherapy. Hypotensive fluid resuscitation in uncontrolled hemorrhagic shock with the addition of moderate resuscitative (28 degrees to 32 degrees C) hypothermia looks promising in the laboratory. Regarding the composition of the resuscitation fluid, despite encouraging results with new preparations of stroma-free hemoglobin and hypertonic salt solutions with colloid, searches for the optimal combination of oxygen-carrying blood substitute, colloid, and electrolyte solution for limited fluid resuscitation with the smallest volume should continue. For titrating treatment of shock, blood lactate concentrations are of questionable value although metabolic acidemia seems helpful for prognostication. Development of devices for early noninvasive monitoring of multiple parameters in the field is indicated. Molecular research applies more to protracted hypovolemic shock followed by the systemic inflammatory response syndrome or septic shock, which were not the major topics of this discussion.

Animals↗
PubMed1996

Suspended animation for delayed resuscitation.

Suspended animation is defined as the therapeutic induction of a state of tolerance to temporary complete systemic ischemia, i.w., protection-preservation of the whole organism during prolonged circulatory arrest ( > or = 1 hr), followed by resuscitation to survival without brain damage. The objectives of suspended animation include: a) helping to save victims of temporarily uncontrollable (internal) traumatic (e.g., combat casualties) or nontraumatic (e.g., ruptured aortic aneurysm) exsanguination, without severe brain trauma, by enabling evacuation and resuscitative surgery during circulatory arrest, followed by delayed resuscitation; b) helping to save some nontraumatic cases of sudden death, seemingly unresuscitable before definite repair; and c) enabling selected (elective) surgical procedures to be performed which are only feasible during a state of no blood flow. In the discussion session, investigators with suspended animation-relevant research interests brainstorm on present knowledge, future research potentials, and the advisability of a major research effort concerning this subject. The following topics are addressed: the epidemiologic facts of sudden death in combat casualties, which require a totally new resuscitative approach; the limits and potentials of reanimation research; complete reversibility of circulatory arrest of 1 hr in dogs under profound hypothermia ( < 10 degrees C), induced and reversed by portable cardiopulmonary bypass; the need for a still elusive pharmacologic or chemical induction of suspended animation in the field; asanguinous profound hypothermic low-flow with cardiopulmonary bypass; electric anesthesia; opiate therapy; lessons learned by hypoxia tolerant vertebrate animals, hibernators, and freeze-tolerant animals (cryobiology); myocardial preservation during open-heart surgery; organ preservation for transplantation; and reperfusion-reoxygenation injury in vital organs, including the roles of nitric oxide and free radicals; and how cells (particularly cerebral neurons) die after transient prolonged ischemia and reperfusion. The majority of authors believe that seeking a breakthrough in suspended animation is not utopian, that ongoing communication between relevant research groups is indicated, and that a coordinated multicenter research effort, basic and applied, on suspended animation is justified.

Animals↗
PubMed1995

Uncontrolled hemorrhagic shock outcome model in rats.

During uncontrolled hemorrhagic shock (UHS) in acute animals models, attempts to achieve normotension with i.v. fluid resuscitation (FR) caused further bleeding and higher acute mortality. In the absence of a published clinically realistic long-term animal outcome study of UHS, we developed such a model in rats. In the preliminary study, phase I of the model involved 60 min of simulated 'pre-hospital' UHS by tail amputation and different FR regimens. Phase II involved 120 min of simulated 'hospital' treatment with hemostasis and all-out FR, including blood infusion. Phase III involved observing recovery and survival to 72 h (3 days). Rats were maintained under very light N2O-O2-halothane anesthesia and spontaneous breathing via mask during phases I and II and were awake during phase III. Tail amputation-induced UHS alone, studied in 4 groups of 10 rats each, resulted in unpredictable spontaneous hemostasis and great variability in shed blood volume, severity of shock, and mortality. The final model, which achieved consistent blood loss and outcome, included an initial volume-controlled hemorrhage of 3 ml/100 g over 15 min and untreated HS for another 15 min, followed by tail amputation for UHS over another 60 min. This phase I of 90 min was followed by phase II of 60 min. In group 1, without FR in phases I and II, all 10 rats died by 12 h. In group 2, without FR in phase I and hemostasis plus all-out FR with lactated Ringer's solution and blood to hematocrit (Hct) 30% in phase II, 5 of 10 rats died at the end of phase I and 9 of 10 died at the end of phase III. This final volume-initiated UHS model may be suitable for comparing different pre-hospital treatment modalities in terms of outcome.

Animals↗
PubMed1995

Ovadendron sulphureo-ochraceum endophthalmitis after cataract surgery.

PURPOSE: We examined an 82-year-old woman with delayed-onset endophthalmitis caused by an opportunistic pathogen, Ovadendron sulphureo-ochraceum. METHODS: Tissue obtained during vitrectomy was cultured and examined by light and electron microscopy. An enucleation specimen was examined by light microscopy. RESULTS: The patient had fungal endophthalmitis, with O. sulphureo-ochraceum present in the lens capsule. The eye developed a necrotizing scleritis secondary to O. sulphureo-ochraceum. The patient failed to respond to intravitreous, subconjunctival, and systemic amphotericin B, and the eye was enucleated. CONCLUSION: In this case of O. sulphureo-ochraceum as a human pathogen, the organism caused endophthalmitis after cataract extraction.

Aged↗
PubMed1995

Selective use of indocyanine green angiography for occult choroidal neovascularization.

PURPOSE: Indocyanine green angiography is useful in situations where fluorescein angiography shows occult choroidal neovascularization or pigment epithelial detachment. We sought to determine how often the selective application of indocyanine green angiography results in useful information for eyes with occult choroidal neovascularization. METHODS: We reviewed 153 consecutive indocyanine green angiograms and identified 77 in which corresponding fluorescein angiograms showed occult choroidal neovascularization or pigment epithelial detachment. We examined the indocyanine green angiograms to detect areas of hyperfluorescence and to classify the margins of hyperfluorescence as well demarcated or poorly demarcated. RESULTS: Of 77 eyes, 42 (55%) eyes had occult choroidal neovascularization by fluorescein angiography, seven (9%) eyes had both classic and occult choroidal neovascularization by fluorescein angiography, and 28 (36%) eyes had pigment epithelial detachments. Of 42 eyes with occult choroidal neovascularization by fluorescein angiography, 21 (50%) had well-demarcated margins, 13 (31%) had poorly demarcated margins, and eight (19%) had no detectable hyperfluorescence by indocyanine green angiography. Of seven eyes with both classic and occult choroidal neovascularization by fluorescein angiography, two had both poorly demarcated and well-demarcated borders, two had only poorly demarcated borders, and three had well-demarcated borders by indocyanine green. The indocyanine green angiogram showed 23 (82%) of 28 pigment epithelial detachments to have well-demarcated borders of hyperfluorescence; 13 (57%) of 23 were treated. CONCLUSION: Indocyanine green angiography adds clinically useful information to fluorescein angiography by demonstrating well-demarcated areas of hyperfluorescence in 50% of eyes selected because of diagnosis of occult choroidal neovascularization and in 82% of eyes selected because of pigment epithelial detachment.

Choroid↗
PubMed1995

Submacular hemorrhage removal.

PURPOSE: To determine whether pars plana vitrectomy combined with tissue plasminogen activator for evacuation of submacular hemorrhage results in improved visual acuity. METHODS: Retrospective review of 18 patients who received a subretinal injection of tissue plasminogen activator during a pars plana vitrectomy to evacuate dense submacular hemorrhages. RESULTS: Diagnoses included age-related macular degeneration (16 patients), ruptured macroaneurysm (1 patient), and penetrating ocular trauma (1 patient). Preoperative visual acuity ranged from 20/200 to counting fingers (median visual acuity, counting fingers). Follow-up ranged from 10 to 104 weeks (median, 33 weeks). Best postoperative visual acuity ranged from 20/30 to counting fingers (median, 20/300). Best postoperative visual acuity improved two or more lines in 11 (61%) of 18 eyes, remained unchanged in 4 (22%) of 18 eyes, and decreased two or more lines in 3 (17%) of 18 eyes (P = 0.10, Wilcoxon sign-rank test). Final visual acuity ranged from 20/40 to light perception (median, counting fingers). Final visual acuity improved two or more lines in 5 (28%) of 18 eyes, remained unchanged in 6 (33%) of 18 eyes, and decreased two or more lines in 7 (39%) of 18 eyes (P = 0.53, Wilcoxon sign-rank test). CONCLUSIONS: Pars plana vitrectomy to evacuate massive subretinal hemorrhage can improve visual acuity, but final visual acuity is limited by the underlying disease.

Adult↗
PubMed1995

[Fabry disease, an ophthalmo-neuro-dermato-cardio-nephrologic problem].

We want to present a 47-years-old patient suffering of a histologically and biochemically confirmed M. Fabry. Besides the ocular findings, we list the systemic findings and discuss the diagnostic and therapeutic possibilities. We especially want to point out the interdisciplinary collaboration in dealing with this condition.

Capillaries↗
PubMed1995

Electroretinographic findings in stage 5 retinopathy of prematurity after retinal reattachment.

BACKGROUND: Infants with stage 5 retinopathy of prematurity (ROP) usually experience severe visual loss, even when the retina is reattached surgically. Such visual loss has been attributed to persistent retinal dysfunction in most cases, but this has not been established electroretinographically. METHODS: Electroretinograms (ERGs) were performed on 5 eyes of 4 children with partial or complete retinal attachment after vitreoretinal surgery for stage 5 ROP. Duration of detachment before surgery was 2 weeks in 1 eye, 4-5.5 weeks in 3 eyes, and 15 weeks in 1 eye. The ERG findings for these eyes were then compared with ERG findings in a child with regressed ROP after laser photoablation of the peripheral avascular retina. RESULTS: All of the eyes with surgically repaired stage 5 ROP had nonrecordable ERGs. The child with regressed ROP after laser photoablation had an attenuated but recordable ERG. CONCLUSION: Severe retinal dysfunction persists in eyes with stage 5 ROP even after the retina is surgically reattached, which is probably one of the primary reasons that these eyes continue to have a poor visual outcome.

Electroretinography↗