Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Trephining”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,297 records · Page 72Linked to original sources
PubMed1993

Megakaryocyte markers in myeloproliferative disorders.

Identification of megakaryocyte precursors with immunohistochemical methods in bone marrow trephine biopsy specimens (embedded in a plastic resin, Immuno-Bed) was performed from patients with blastic phase of chronic granulocytic leukaemia (five cases), from chronic megakaryocytic-granulocytic myelosis (four cases) and from acute megakaryoblastic leukaemia (11 cases). In megakaryoblasts of bone marrow biopsies immunohistochemical reactions using the ABC method and monoclonal antibodies against von Willebrand antigen and GpIIb/IIIa (CD41) were visible in various percentages depending on the maturation's degree of megakaryocyte precursors. The number of circulating blast cells determined by flow cytophotometry was nearly similar to those of observed in biopsies. The greatest bone marrow reticulin content could be detected in acute megakaryoblastic leukaemia cases. Despite the different clinicopathological entities, the presence of the same phenotype (megakaryoblasts) was associated with a short survival in these haematological malignancies (in CGL MKB phase 4.0, in CMGM MKB phase 4.2, and in AML M7 5.8 months, respectively).

Adult↗
PubMed1997

Cranioplasty: cosmetic or therapeutic?

Cranioplasty is among the oldest surgical procedures. Trauma, infections, tumors and compression caused by brain edema are some of the reasons for the removal of bone. The indications for cranioplasty after resolution of the primary process that led to the bone defect were never well defined, and many were the "cosmetic" indications for cranioplasty. However, there are many theories suggesting that an underlying physiological alteration may occur which may require the correction of the bone defect; many patients improve after surgery. We discuss the physiopathological basis of the "syndrome of the trephined" and try to achieve a better understanding of the present status of cranioplasty and its possible therapeutic role.

Brain Injuries↗
PubMed1987

Chronic myeloid leukemia presenting as a gynecological emergency.

An unusual case of chronic myeloid leukemia presenting to the gynecological unit as a case of septic abortion is presented. Though history and clinical examination suggested the possibility of double pathology of septic abortion and chronic myeloid leukemia, histology of the products removed from the uterus showed it to be leukemic deposits. The diagnosis of leukemia was confirmed by marrow aspiration (trephine biopsy). Careful clinical examination and systematic investigation helped in diagnosing the pathology and to treat her appropriately.

Abortion, Septic↗
PubMed2003

Bone ingrowth in bFGF-coated hydroxyapatite ceramic implants.

This experimental study was performed to evaluate angiogenesis, bone formation, and bone ingrowth in response to osteoinductive implants of bovine-derived hydroxyapatite (HA) ceramics either uncoated or coated with basic fibroblast growth factor (bFGF) in miniature pigs. A cylindrical bone defect was created in both femur condyles of 24 miniature pigs using a saline coated trephine. Sixteen of the 48 defects were filled with HA cylinders coated with 50 microg rhbFG, uncoated HA cylinders, and with autogenous transplants, respectively. Fluorochrome labelled histological analysis, histomorphometry, and scanning electron microscopy were performed to study angiogenesis, bone formation and bone ingrowth. Complete bone ingrowth into bFGF-coated HA implants and autografts was seen after 34 days compared to 80 days in the uncoated HA group. Active ring-shaped areas of fluorochrome labelled bone deposition with dynamic bone remodelling were found in all cylinders. New vessels could be found in all cylinders. Histomorphometric analysis showed no difference in bone ingrowth over time between autogenous transplants and bFGF-coated HA implants. The current experimental study revealed comparable results of bFGF-coated HA implants and autogenous grafts regarding angiogenesis, bone synthesis and bone ingrowth.

Animals↗
PubMed1999

Incorporation of three types of bone block implants in the facial skeleton.

The regenerative response on autogenous cancellous and cortical bone grafts, and on a commercial available xenogenous resorbable bone mineral (RBM) (Bio-Oss, Geistlich-Pharma, Wolhusen, Switzerland) was compared in standardized bony defects related to a paranasal sinus. On 15 skeletally mature goats four critical sized full thickness bone defects were trephined in the frontal bone. These defects were filled at random with a cortical bone plug, a cancellous bone plug, a plug of spongious RBM cut into shape or left empty. Fluorochrome bone markers were injected subcutaneously 1 and 5 weeks after transplantation, and one week before the animals were killed. The animals were killed at 3, 6, 12 and 24 weeks after surgery. Histological evaluation showed that autogenous bone grafts were all accepted and incorporated in a similar way as in calvarial defects. RBM was only osteoconductive. New bone was formed at the margins of the defects, and only little of the RBM was incorporated. Most of the RBM was gradually resorbed by multinucleated osteoclast-like cells.

Absorbable Implants↗
PubMed2000

Gamma irradiation of human bone allografts alters medullary lipids and releases toxic compounds for osteoblast-like cells.

The uncertainties about the transmission of prion proteins from xenogenic grafts prepared from bovine bone has led to the reconsideration of allogenic bone as a grafting material. Allografting is a complementary technique to autografting nowadays when large bone volumes are necessary. Several preparation techniques have been proposed. Fresh-frozen, freeze-dried and gamma irradiation are the most common. However, a large amount of lipids is present in the medullary spaces (near 70% in weight for a human femoral head). They are known to strongly influence the biocompatibility of the bone graft. The exact changes of lipids upon the sterilization and storage processes are poorly known. The aims of the present study were to appreciate the effects of gamma irradiation on medullary lipids and to identify the cytotoxicity of gamma-irradiated bank bone with/without lipid on cultures of osteoblast-like cells. Bone cores from 8 femoral heads retrieved during prosthesis surgery for arthritis were prepared with a drilling trephine. Cores were either sterilized by gamma radiations (25000 gray) or kept frozen until lipid extraction and lipofuschine-like dosage by Folch's method and fluorometric study. Peroxidated lipids appeared 2 to 3-fold higher in the gamma-irradiated cores than in frozen ones. Slices were prepared from bone cores and were transferred on confluent osteoblast-like cell layers (Saos-2). The raw slices (containing lipids) did not induce cell death. On the other hand, cell death was dramatically increased around the gamma-irradiated slices. Defatted slices which had been sterilized by gamma radiations or UV did not induce cell death. Defatting procedures should be added when preparing bone allografts in human bone banks.

Bone Transplantation↗
PubMed2000

P53 overexpression in bone marrow biopsies in refractory anemia and aplastic anemia: impact of antibody selection.

There is a growing interest in studying cell cycle and apoptosis in the myelodysplastic syndromes (MDS). p53 has been a major target of several studies. We examined the impact of antibody selection on p53 overexpression in bone marrow (BM) biopsies of 28 patients with refractory anemia (RA) in addition to 10 cases of aplastic anemia (AA) using three antibodies DO-7, PAb 1801, and PAb 240. DO-7 was positive in 68%, PAb 1801 in 18% and PAb240 in 4% of RA patients. All three antibodies were negative in AA. We conclude that antibody selection is an important variable in studying p53 in MDS regardless of the method of fixation or decalcification of BM trephine biopsies.

Anemia, Aplastic↗
PubMed1978

A method for ipsilateral rotational autokeratoplasty.

Rotational ipsilateral penetrating autokeratoplasty is useful in the treatment of certain nonprogressive corneal scars. The procedure alleviates difficulties with the availability of donor tissue and with graft rejection. A method is presented for determining the maximum clear central corneal area that can be obtained by rotational autokeratoplasty and the most appropriate trephine size and placement. Two dimensions must be obtained either at the slit lamp or from photographs: the diameter of the largest circle of clear cornea and the shortest distance from the edge of this circle (edge of the scar) to the center of the cornea. An illustrative case is presented.

Cataract↗
PubMed1982

A new and effective protective agent for intraocular lens insertion.

Chondroitin sulfate (CDS) has been found to serve as an excellent protective coating for intraocular lens (IOL) implantation to avoid any damage to the corneal endothelium; the protection is total. Using a new vital dye, acid violet 49, as a stain, a series of possible coatings including albumin and hyaluronic acid was evaluated in vitro and in vivo. Some 600 animal corneas were trephined, and the sample buttons submitted to the dragging of variously coated lenses across the endothelium. The animal species were rabbit, pig, cow, dog, cat, and monkey. IOLs were traumatically inserted in rabbits and monkeys. Chondroitin sulfate surpassed by far the protective qualities of other compounds: albumin was second best; hyaluronic acid third, the latter two yielding substantial damage in our tests. Comparisons with the commercially available Healon still revealed chondroitin sulfate to be the most efficacious protective agent. The material was eliminated from the anterior chamber in periods less than 40 hours. Monitoring of postoperative intraocular pressures revealed only normal pressures in our animals.

Albumins↗
PubMed1983

Inexpensive device to reduce surgical light exposure.

An inexpensive device that reduces light exposure to the retina during intraocular surgery is described. This disposable cap, which shields out 75% of the light, is cut from brown, rubber, surgical gloves by a 9.0 mm corneal trephine. The rubber cap is readily available, easy to use, and an inexpensive solution for surgeons concerned about possible retinal phototoxicity from the operating microscope.

Cataract Extraction↗
PubMed1984

Alloplastic implants for the correction of refractive errors.

Convex-shaped, hydrophilic lenticles of various water content were implanted into microkeratome-dissected corneal pockets in a baboon model. Freshly trephined, cryolathed, and factory-lathed hydrogels were evaluated for periods exceeding 15 months, documenting clinical response, corneal curvature shifts, and morphologic features. Previously implanted hydrogels were subsequently removed, documenting the reversibility of the procedure while allowing the corneas to return to their preoperative condition. Various alloplastic materials were then reimplanted into the same intrastromal pockets. Medium and high water content lenses produced good results without affecting the recipient cornea, whereas thick or low water content materials extruded or produced severe anterior segment inflammation. The use of medium and high water content, convex-shaped lenticles for the correction of aphakia is possible using current techniques.

Animals↗
PubMed1986

Histological study of epikeratophakia tissue lenses for myopia removed from two patients.

Epikeratophakia tissue lenses for the correction of myopia were removed from two patients as a result of postoperative complications such as stromal folds, complaints of glare, and decreased visual acuity. Light and electron microscopic analysis showed protrusions in Bowman's membrane and the anterior stroma corresponding to corneal folds that had been observed clinically. The epithelial cells in these areas contained many vacuolations and a thickened basement membrane. Hemidesmosomes were decreased in number. The tissue lenses had been cut 1.5 mm larger in diameter than the trephined recipient bed into which they were placed. Excess tissue lens material in the central area may have been thrown into folds by mechanical pressure, resulting in the histological changes, clinical signs, and optical distortion that necessitated removal of these grafts. Recently, the surgical technique has been modified, in an attempt to eliminate this problem.

Adult↗
PubMed1987

The value of calcofluor white in the diagnosis of mycotic and Acanthamoeba infections of the eye and ocular adnexa.

In search of an easy and quick method for the diagnosis of fungal and Acanthamoeba infections of the eye, the authors have used calcofluor white (CFW), a fluorescent brightener with marked affinity for chitin and cellulose which are present in the cell walls of fungi and cysts of Acanthamoeba. Paraffin-embedded tissues containing mycotic organisms were stained with CFW and examined under a fluorescent microscope. Several fungi such as Candida sp, Aspergillus sp, Phycomycetes, Fusarium solani, Histoplasma capsulatum, Cryptococcus neoformans, Rhinosporidium seeberi, and others were studied. Trephine corneal biopsy specimens (2 mm) and methanol-fixed corneal scrapings containing Acanthamoeba sp were also examined. The walls of fungi and Acanthamoeba cysts stained bright greenish white in contrast to the reddish-orange background of the supporting tissues. The results demonstrate that the CFW method is a highly reliable and rapid technique for identification of mycotic organisms as well as cysts of Acanthamoeba. This method may also be applied in surgical pathology when performing frozen sections, as well as cytologic examination of corneal smears, vitrectomy specimens, and others.

Amebiasis↗
PubMed1988

Fistula excision and peripheral grafts in the treatment of persistent limbal wound leaks.

Most small scleral wound leaks at the limbus are treated successfully with suturing, patching, bandage lenses, or cyanoacrylate adhesive, but occasionally a wound leak may continue and a fistula may develop. Although rare, most such fistulas are usually associated with cataract surgery or trauma. Failure of a scleral fistula to close may be due to epithelialization or chronic necrosis of the lumen. In three cases, persistent fistulas of the limbal sclera were excised with a trephine, and a peripheral graft using corneal donor tissue was used to seal the circular defect. This resulted in permanent wound closure and provided a tissue diagnosis of epithelial downgrowth (2 cases) and chronic scleral necrosis (1 case).

Adult↗
PubMed1994

Randomized clinical trial comparing astigmatism and visual rehabilitation after penetrating keratoplasty with and without intraoperative suture adjustment.

PURPOSE: The authors performed a prospective, randomized clinical trial to compare postoperative astigmatism and visual rehabilitation after penetrating keratoplasty with and without intraoperative suture adjustment. METHODS: Twenty-five patients undergoing penetrating keratoplasty for avascular corneal pathology randomly were assigned to two groups. All surgery was performed by one surgeon (ONS) using the same technique (except for intraoperative suture adjustment) with Hanna trephination (8 mm) and a running 10-0 nylon suture. Postoperative suture adjustment was done during the first postoperative month in all patients who had more than 3.5 diopters of astigmatism. Refraction and computerized topographic analysis were performed at 1 and 6 months postoperatively. RESULTS: Intraoperative suture adjustment significantly decreased postkeratoplasty topographic (P = 0.0001) and refractive (P = 0.0001) astigmatism and improved best spectacle-corrected visual acuity (P = 0.0019) during the first postoperative month. Seventy-seven percent of control patients (mean topographic astigmatism, 4.89 +/- 1.99 D at 1 month), but no patients who underwent intraoperative suture adjustment (mean topographic astigmatism, 1.50 +/- 0.74 D at 1 month), required at least one postoperative suture adjustment that delayed optical stability and increased postoperative complications. At 6 months postoperatively, mean topographic (P = 0.06) and refractive (P = 0.0001) astigmatism were smaller in the intraoperatively adjusted group than in the control group with postoperative suture adjustments. After intraoperative adjustment, best spectacle-corrected visual acuity was better (P = 0.0168, P = 0.0434) and corneal topography was more regular (P = 0.02, P = 0.07, NS) at 1 and 6 months, respectively, than after postoperative adjustment. CONCLUSION: Visual rehabilitation with decreased postkeratoplasty astigmatism and more regular corneal topography was attained more rapidly and safely with intraoperative suture adjustment.

Adult↗
PubMed1995

Retinal photoreceptor density decreases with age.

PURPOSE: To evaluate the effect of age on the density of retinal photoreceptors in humans. METHODS: Fifty-five normal eyes from human donors, with a mean age of 58.7 +/- 19.1 years and an axial length of less than 27 mm, were examined. After opening of the globes by a 16-mm corneoscleral trephination, 25 retinal tissue samples were obtained in four meridians. The photoreceptors were counted on photographs taken from the photoreceptor inner segments after sonographic removal of the outer segments. The cones in the foveal center could not be evaluated. RESULTS: Outside the foveal center, the photoreceptor density decreased significantly with increasing age. In absolute and relative terms, the decline was more marked for the rods (mean rod loss, 236 +/- 63 cells or 0.37% +/- 0.10%/mm2 and year of a mean density of 62.987 rods/mm2) than for the cones (mean cone loss, 5.90 +/- 0.68 cells or 0.18% +/- 0.02%/mm2 and year of a mean density of 3320 +/- 578 cones/mm2). For both cones and rods, the cell loss was more marked at an eccentricity of approximately 5-8 mm than in the retinal periphery at an eccentricity of 14 to 20 mm. There were no significant differences between the superior, inferior, temporal, or nasal meridian nor between women and men. CONCLUSIONS: The photoreceptors decrease in density with increasing age. The annual cell loss of approximately 0.2% to 0.4% is similar to the age-related loss of retinal ganglion cells and pigment epithelium cells. The decline in photoreceptor count affects more rods than cones. It does not prefer special age groups. It is more pronounced at an eccentricity of 5 to 8 mm than in the retinal periphery at an eccentricity of more than 14 mm. It may be important for an age-related decrease in visual functions and for diseases affecting the photoreceptors in elderly patients.

Adolescent↗
PubMed1995

Randomized clinical trial of penetrating keratoplasty. Before and after suture removal comparison of intraoperative and postoperative suture adjustment.

PURPOSE: The authors performed a prospective, randomized clinical trial of penetrating keratoplasty and compared visual acuity, refraction, and topography up to 15 months postoperatively (3 months after suture removal) after intraoperative and postoperative suture adjustment. METHODS: Twenty-five patients undergoing penetrating keratoplasty for avascular corneal pathology were randomly assigned to two groups. All surgery was done by one surgeon using the same technique (except for intraoperative suture adjustment) with suction trephination (8 mm) and a running 10-0 nylon suture. Intraoperative suture adjustment was performed in the test group and was not performed in the control group. Postoperative suture adjustment was done during the first postoperative month and up to 4 months postoperatively in all patients who had more than 3.5 diopters (D) of astigmatism. The running suture was removed at approximately 12 months postoperatively. Refraction and computed topographic analysis to compare patients with intraoperative and postoperative suture adjustment were performed at 1, 3, 6, 9, 12 (before suture removal), and 15 (after suture removal) months. RESULTS: There was less (P = 0.004) topographic astigmatism up to 12 months postoperatively (pre-suture removal) in patients adjusted intraoperatively (mean +/- standard deviation, 1.53 +/- 0.72 D) than in patients adjusted postoperatively (2.83 +/- 1.19 D). After suture removal, at 15 months postoperatively, astigmatism was still less in the intraoperative adjustment group (1.75 +/- 1.04 D) than in the postoperative adjustment group (2.23 +/- 17.2 D), but the authors could not demonstrate statistical significance. After intraoperative adjustment, no significant change in mean astigmatism occurred, and no patient had more than a 1.18-D change in the amount of astigmatism or more than a 22 degrees change in axis (75% < 10 degrees change) after suture removal. Corneas were more regular until suture removal in the group with intraoperative adjustment, but differences decreased after suture removal. Best spectacle-corrected visual acuity was better in the intraoperatively adjusted group until suture removal with no significant changes in best spectacle-corrected visual acuity between 1 and 15 months. Best spectacle-corrected visual acuity improved more slowly after postoperative adjustment and was different at 1 and 15 months (P = 0.0005). CONCLUSION: The authors demonstrated low astigmatism and good visual results at 15 months postoperatively after either intraoperative or postoperative running suture adjustment, but intraoperative suture adjustment permitted more rapid visual rehabilitation, increased safety, and increased refractive stability.

Astigmatism↗
PubMed1998

Intraoperative cauterization of the cornea can reduce postkeratoplasty refractive error in patients with keratoconus.

OBJECTIVE: This study aimed to evaluate the effect of intraoperative corneal cauterization on the postkeratoplasty refraction of patients with keratoconus. DESIGN: A randomized clinical trial. PARTICIPANTS: Thirty eyes of 29 patients with keratoconus undergoing standard penetrating keratoplasty by the same surgeon were evaluated (MB). INTERVENTION: Standard penetrating keratoplasty included the use of an 8.0-mm donor button sutured into a 7.5-mm recipient bed by means of two running 10-0 nylon sutures with 16 bites each. Before trephination of the recipient bed, superficial cauterization causing tissue shrinkage was applied to a 6-mm central area of the cornea of only 15 eyes (group A). The remaining 15 eyes (group B) did not undergo intraoperative cauterization. Before surgery, 6 months, and 13 months after surgery, a complete ophthalmologic examination was performed on each patient, including uncorrected and best-corrected visual acuity, refraction, keratometry, computerized corneal topography, as well as A-scan contact ultrasonography. MAIN OUTCOME MEASURES: Postkeratoplasty refractive error was measured. RESULTS: Both 6 months (sutures still in place) and 13 months (suture removal performed in all patients) after surgery, the average spherical equivalent was significantly less myopic in the patients undergoing cauterization. At 6 months, it was +1.72 diopters (D) +/- 1.13 D in group A and -3.16 D +/- 2.84 D in group B; at 13 months, it was +0.09 D 1.52 D in group A and -3.89 D +/- 3.01 D in group B. The average keratometric astigmatism also was significantly lower in group A than in group B both at 6 (2.5 D +/- 1.6 D vs. 4.1 D +/- 2.3 D) and 13 months (2.7 D +/- 1.5 D vs. 4.4 D +/- 2.4 D) after surgery. CONCLUSION: Cauterization of the central cornea improves the postkeratoplasty refractive results of patients with keratoconus.

Adolescent↗