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Comparing radioactive and trephine-disk bioassays of dicloxacillin and gentamicin in ocular tissues in vitro.

Trephined disks of tissue (6 mm diameter) from fresh rabbit eyes were immersed overnight in solutions of radioactive carbon (14C)-dicloxacillin or gentamicin, then assayed by one of two methods: agar-diffusion bioassay, using filter-paper disks immersed in known concentrations of antibiotic as standards, or radioactive assay. The bioassay underestimated the concentrations of antibiotic in sclera and iris by 38 to 72%, and slightly overestimated those in the cornea. A corrected bioassay was calculated, based on the differences in fluid mass between tissue specimens and filter-paper disks; this value was within 20% of the radioactive assay in 18 of 24 experiments with dicloxacillin, and in 14 of 24 with gentamicin. There was evidence of pronounced binding of gentamicin to ocular tissues (iris greater than sclera greater than cornea); this appeared to be a saturable and reversible phenomenon. Less marked binding of dicloxacillin to iris and sclera was noted. The results indicated that, depending on the degree of accuracy required, the corrected trephine-disk agar-diffusion bioassay provides a reasonable estimate of the antibiotic content of ocular tissues.

Animals↗

Morphologic classification of the myelodysplastic syndromes (MDS): combined utilization of bone marrow aspirates and trephine biopsies.

In a retrospective and prospective follow-up study from 1975 to 1991, bone marrow biopsies, aspirates and clinical features of 495 patients with MDS were investigated. Sections of undecalcified plastic embedded biopsies and smears of bone marrow aspirates were stained according to Giemsa. Bone marrows with MDS were characterized by three main categories of morphologic alterations: (1) cellular abnormalities, (2) architectural disorganization in the bone marrow and (3) stromal changes; the combined use of aspirates and trephine biopsies enabled a more reliable and accurate diagnosis of MDS than either one alone. The bone marrow findings fell into one of 7 subtypes, with the frequencies and median survivals in brackets: (1) MDS sideroblastic (19%, 62 months), (2) MDS megaloblastoid (13%, 56 months), (3) MDS proliferative (22%, 31 months), (4) MDS blastic (15%, 9 months), (5) MDS hypoplastic (15%, 26 months), (6) MDS fibrotic (6%, 29 months), and (7) MDS inflammatory (10%, 42 months). In follow-up studies patients with secondary MDS were excluded and the prognosis and subsequent evolution for each of the morphologic subtypes were evaluated. The conclusion is drawn that aspirates and trephine biopsies are complementary procedures and both are required for diagnosis, classification and decisions on current treatment modalities of patients with MDS.

Adolescent↗

Previously unreported complication of trephine reamers in revision total hip arthroplasty.

Trephine reamers have been used in revision total hip arthroplasty to facilitate the removal of femoral prostheses without creating additional osteotomy sites. These reamers are available in graduated sizes so as to minimize bone loss. We present a complication not previously reported in the literature. While performing the extraction of a well-fixed femoral prosthesis, the trephine reamer broke at its distal end, expanded, and created a cortical defect distal to the prosthesis.

Arthroplasty, Replacement, Hip↗

Rescue of failed filtering blebs with ab interno trephination.

We evaluated the effectiveness of ab interno automated trephination as a technique for rescuing failed mature filtering blebs. A retrospective chart review of 40 failed blebs of 38 patients who had a posttrephination follow-up period of at least 3 months was done. With success defined as intraocular pressure (IOP) <21 mm Hg and at least a 20% reduction from baseline on the same or fewer number of pretrephination medications, 30/40 eyes (75%) fit these criteria over the entire course of follow-up. Among all 40 eyes, there was a significant reduction of IOP from pretrephination to 3 months (P<.001). The percentage of patients requiring 2 or more medications declined from 90% pretrephination to 21% at 3 months (P<.0001), and was stable thereafter. Some patients were able to eliminate all medications. Patients who did not meet the criteria of success regained successful IOP control with other modalities of management. Complications were few. We believe that ab interno trephination is an excellent option for rescuing selected failed filtering blebs.

Adult↗

The role of the Genial Bone Advancement Trephine system in conjunction with uvulopalatopharyngoplasty in the multilevel management of obstructive sleep apnea.

OBJECTIVES: The successful surgical management of obstructive sleep apnea (OSA) requires surgical procedures that address both retropalatal and retrolingual airway obstruction. The Genial Bone Advancement Trephine (GBAT) system is a new, 1-step system that allows for isolation and advancement of the genioglossus muscle via a guided trephine system. The purpose of this project was to describe our experience using the GBAT system to perform genioglossus advancement (GGA) in conjunction with uvulopalatopharyngoplasty (UPPP) in the surgical management of OSA. STUDY DESIGN: Retrospective analysis of 35 consecutive patients undergoing GGA using the GBAT system in conjunction with UPPP for the management of OSA during a 3-year period (1999 to 2002). RESULTS: Twenty-four patients had complete preoperative and postoperative polysomnographic data. A 70% reduction in the Respiratory Disturbance Index (RDI) and Apnea Index (AI) in the preoperative versus postoperative PSG (RDI, 52.9 +/- 17.1 versus 15.9 +/- 7.5; AI, 20.1 +/- 6.7 versus 6.1 +/- 4.5; P < or = 0.0001). The lowest oxygen desaturation increased from 80% to 88% (P = 0.0002), and the posterior airway increased from 7.9 to 12.6 mm (P < 0.0001). With a surgical cure defined as a greater than 50% reduction in the RDI and a final postoperative RDI of less than 20 events per hour, the true surgical cure rate was 67% (16 of 24 patients). CONCLUSIONS: The GBAT system performed in conjunction with UPPP can produce significant reductions in RDI and AI while improving the oxygen desaturation and enlarging the posterior airway space. The effective cure rates using the GBAT system are in agreement with previous reports in the literature using various GGA techniques. The GBAT may have some advantages in terms of simplicity and safety.

Adult↗

Noncontact trephination of the cornea using a pulsed hydrogen fluoride laser.

We used a pulsed hydrogen fluoride infrared laser and a specially designed axicon lens to perform circular corneal trephinations in ten eye bank eyes. This noncontact system focused each laser pulse into an annulus on the cornea. Corneal perforation was achieved in seven to nine seconds at a repetition rate of 10 Hz, using a laser output energy of 100 mJ per pulse. A trephination, 90% of corneal thickness, 6.5 mm in diameter, was produced with 70 pulses.

Cornea↗

Demonstration of light chain restricted clonal B-lymphoid infiltrates in archival bone marrow trephines by quantitative real-time polymerase chain reaction.

Assessment of clonality either by demonstrating light chain restriction or showing monoclonal immunoglobulin gene rearrangement is a valuable and indispensable adjunct to diagnosis in hematopathology. The study of light chain restriction by immunohistochemistry on archival material is hampered by a very low sensitivity especially regarding low grade lymphomas of B cell origin. DNA rearrangement studies of the immunoglobulin locus do improve sensitivity markedly but for lymphomas of follicle center origin they are prone to false negative results due to hypermutations. Therefore we developed a new clonality assay based on the quantification of immunoglobulin light chain transcripts using real-time polymerase chain reaction technology, which is also suitable for the analysis of archival bone marrow trephines. We tested the reproducibility and sensitivity of this approach by comparatively analyzing a series of bone marrow trephines with multiple myeloma (n = 26), reactive lymphoid hyperplasia (n = 37), and focal infiltration by low grade B cell lymphoma (n = 29). We could raise the detection rate of clonality from an average of 17% by immunohistochemistry and 66% as assessed by polymerase chain reaction rearrangement studies to 83% by this new technique. Despite false negative results due to light chain hypermutation in some cases, the detection rate of clonality could be improved even for B cell lymphomas of follicle center origin (follicular lymphoma or marginal zone lymphoma) thus making this novel approach a valuable additional tool for the hematopathologist.

B-Lymphocytes↗

Endoscopic-guided trephination dacryocystorhinostomy (Hesham DCR): technique and pilot trial.

OBJECTIVES: (1) Test the feasibility and the safety of guided transnasal trephination in creating a nasolacrimal fistula. (2) Develop an appropriate lacrimal maintainer and test its value in modulating healing at the fistula site. DESIGN: Prospective, noncomparative interventional case series. PARTICIPANTS: Five cadavers and 19 patients. METHOD: A transcanalicular lacrimal probe penetrated the lacrimal fossa to guide the passage of a flexible trephine up the nose, which created the nasolacrimal communication. A special wide-caliber lacrimal maintainer was inserted along lacrimal tubes within the created passage. OUTCOME MEASURES: For cadaveric study, direct inspection after dissection of the facial flap was performed. For the clinical trial, subjective improvement in watery eye, dye testing, lacrimal probing, lacrimal irrigation, and endoscopic nasal examination. RESULTS: The technique resulted in the creation of a regular fistula of reproducible diameter into which a standard-shaped wide caliber maintainer could be inserted. Three months after removal of the maintainer and 6 months after surgery, a patent ostium was achieved in 17 of 18 (94%) patients who had a completed procedure. Relief of symptoms was achieved in 83%. CONCLUSIONS: Guided endoscopic dacryocystorhinostomy provides a simple and safe option for the treatment of nasolacrimal duct obstruction. The lacrimal maintainer is a useful device to achieve a large patent nasolacrimal communication.

Adult↗

Increased immunoglobulin A and immunoglobulin A1 cells in bone marrow trephine biopsy specimens in immunoglobulin A nephropathy.

The origin of mesangial immunoglobulin A (IgA) in IgA nephropathy remains unknown. To investigate potential abnormalities within the bone marrow in this condition, bone marrow trephine biopsy specimens from seven patients and matched controls were studied using two-color immunofluorescence. In addition, serum levels of IgA and IgA1 were determined by radial immunodiffusion. Serum levels of IgA and IgA1 were higher in patients than in controls (4.53 +/- 1.38 g/L v 2.56 +/- 1 g/L, P < 0.01 and 3.68 +/- 1.11 g/L v 1.92 +/- 0.7 g/L, P < 0.005, respectively). In addition, patient trephine biopsy specimens contained an increased percentage of IgA plasma cells (61.6% +/- 4.4%) compared with controls (47.3% +/- 2.5%) (P < 0.02). The proportion of IgA plasma cells bearing subclass IgA1 was also greater in the patient biopsy specimens (91.6% +/- 1.9%) compared with controls (81.4% +/- 2.7%) (P < 0.01). In patients a positive correlation between the percentage of marrow IgA plasma cells and serum IgA levels was found (r = 0.94, P < 0.002). However, our studies failed to demonstrate a similar correlation between serum IgA1 levels and IgA1 marrow cells. These findings support the hypothesis that mesangial IgA may derive from the bone marrow.

Adult↗

Trephination of incomplete meniscal tears.

The meniscus performs several roles that are important to the function of the knee joint. In an effort to preserve these functions of the meniscus, methods to promote the healing of meniscal lesions have been investigated. One such method involves trephination or the creation of vascular access channels by removal of a core of tissue from the periphery of the meniscus to the tear, thus connecting a lesion in the avascular portion of the meniscus to the peripheral blood supply. The purpose of this study is to describe our experience with arthroscopic trephination of symptomatic incomplete meniscal tears in humans. This is a simple technique that avoids the risk associated with suture repair of the meniscal tissue, yet preserves the meniscus. Overall results were good or excellent in 90% of the cases. In conclusion, symptomatic incomplete meniscal tears can be treated by stimulation of vascular channels without the risk associated with suturing of this tissue, while preserving the important functions of the meniscus.

Adult↗

Quantitative intra-individual monitoring of BCR-ABL transcript levels in archival bone marrow trephines of patients with chronic myeloid leukemia.

We established a quantitative real-time RT-PCR assay for the detection of chimeric BCR-ABL transcripts in archival formalin-fixed bone marrow trephines, both acrylate-embedded and paraffin-embedded. This new methodology enables determination of transcript levels in direct comparison to histopathological findings and therapeutic interventions during the time course of the disease in a retrospective and a prospective manner. We found an excellent correlation between the quantitative molecular data and the morphological evaluation as well as the clinical outcome for a cohort of chronic myeloid leukemia patients (n = 10). To the best of our knowledge, this is the first study demonstrating the feasibility of large-scale quantitative expression analysis in archival bone marrow trephines for monitoring molecular markers over several years or even decades.

Base Sequence↗

Assessing mineral density in small trephined jawbone biopsy specimens.

This study reports the test of the hypothesis that mineral density can be precisely assessed in small trephined jawbone biopsy specimens. Mineral density was measured by dual-energy X-ray absorptiometry (DEXA) and peripheral quantitative computed tomography (pQCT). Ten fresh and ten histologically processed specimens, which were not the same, were measured. The coefficient of variations (CVs) for the alcohol stored and the histologic specimens by DEXA were respectively 1.60 and 1.71%. The CVs by pQCT for the total bone density in the alcohol stored and the histologic specimens were respectively 0.07 and 0.16%, for the trabecular bone density 0.69 and 1.04% and for the cortical bone density 0.07 and 0.12%. It was concluded that DEXA and pQCT are precise for mineral density assessment of small trephined jawbone biopsy specimens both alcohol stored and histologically processed.

Absorptiometry, Photon↗

The use of the same size host and donor trephine in penetrating keratoplasty for keratoconus.

The results of a retrospective analysis of 49 eyes (40 patients) that underwent penetrating keratoplasty for keratoconus are presented. All grafts had the same size trephine for both host and donor corneas. Ninety-eight per cent of eyes achieved a post-operative visual acuity of 6/12 or better; 43% of eyes attained this level of acuity unaided, although more than half of these required spectacles or contact lenses to reach their best corrected acuity. The average post-operative spherical ametropia was -0.5 dioptre (SD 2.97 dioptres) and the average post-operative cylinder was -3.8 dioptres (SD 2.63 dioptres). Three eyes (6%) required keratorefractive surgery to reduce astigmatism. Wound integrity was satisfactory using the same (size) trephine for both host and donor, with no patient suffering a post-operative wound leak or iris prolapse. The reduction of post-operative myopia and astigmatism is discussed.

Adolescent↗

Organization of corneal collagen fibrils during the healing of trephined wounds in rabbits.

The purpose of this study was to investigate the structure and organization of collagen during the healing of penetrating rabbit corneal wounds. Full-thickness wounds were produced in both corneas of six New Zealand White rabbits with a 2-mm trephine. After 5, 10, and 16 months, wounds were examined using transmission electron microscopy and wide-angle synchrotron X-ray diffraction, which allowed the quantification of the relative amount of collagen and fibril orientation in different parts of the cornea. The intensity of the diffraction patterns taken from the wound edge was much higher than patterns collected at the wound center, indicating a greater amount of collagen near the wound edge. This collagen was shown to have a preferred orientation, forming a circular pattern around the wound. As the wounds healed, the amount of preferentially aligned collagen decreased and lamella formation and ordered fibrillar arrangement increased as shown by electron microscopy. The orientation of collagen fibrils in healing penetrating corneal wounds is not random. Instead, fibrils tend to be circularly arranged within and without the wound, gradually becoming more normal over time. We speculate that collagen is artefactually displaced during trephination, resulting in an abnormal alignment of the fibrils surrounding the wound edge, and that this influences the wound healing process.

Animals↗

Comparison of nail bed repair versus nail trephination for subungual hematomas in children.

Fifty-three fingers in 52 children were divided into 2 groups, operative and nonoperative, after fingernail crush injury. Criteria for inclusion into the study were an intact nail and nail margin with subungual hematoma and no previous nail abnormality. The length of the follow-up period averaged longer than 2 years for each group. Twenty-six fingers in 26 children were treated by nail removal, exploration, and repair of nail bed lacerations (operative group). Twenty-seven fingers in 26 children were treated by evacuation of hematoma by nail trephination without nail removal in 11 fingers and by observation in the other 16 fingers (nonoperative group). In the operative group, transient abnormalities (nail depression or hypertrophy), which resolved by 4 months, occurred in 3 patients. In the group treated by simple decompression, there were no complications except for 1 transient nail depression at 3 months. The average cost to the operative group was $1,263 compared with $283 to the trephination group. Although formal nail bed reconstruction has been advocated for hematomas larger than 25%, we found no notable difference in outcome between the 2 groups regardless of hematoma size, presence of fracture, injury mechanism, or age. Charges, however, were 4 times greater for the operative group. Based on the results of this study, we do not feel that nail removal and nail bed exploration is indicated or justified for children with subungual hematoma and an intact nail and nail margin.

Adolescent↗

[Long-term study in goniotrepanation with various trephine diameters].

Over a mean observation period of 3 1/2 years. 45 eyes operated on with the trephine diameter of 1.0 mm and 43 eyes operated on with the trephine diameter of 1.5 mm showed the same results with regard to the regulation of IOP, postoperative complications, the number of failures and the period of time elapsing between the operation and its failure.

Adult↗

Detecting disseminated Mycobacterium avium complex infections in HIV-positive patients. The usefulness of bone marrow trephine biopsy specimens, aspirate cultures, and blood cultures.

Disseminated Mycobacterium avium complex (MAC) infections are common in patients with acquired immunodeficiency syndrome (AIDS). These patients frequently seek care with fever accompanied by generalized systemic symptoms and undergo bone marrow biopsy. It is our practice to stain all bone marrow trephine biopsy specimens from patients infected with HIV for acid-fast bacilli (AFB). We evaluated this practice by comparing the sensitivity and turnaround time for detection of MAC by biopsy specimen staining, bone marrow aspirate culture, and blood culture. Bone marrow trephine biopsy specimens with corresponding bone marrow aspirate and blood cultures from 86 HIV-positive patients were reviewed. Of the 86 patients, 30 had positive results for disseminated MAC infection, and all 30 of those patients had positive blood cultures. Bone marrow aspirate cultures identified 17 MAC-positive cases, and AFB staining of the biopsy specimen identified 9. The mean times to detection of MAC positivity were 1.1 days for AFB staining of the biopsy specimen, 19 days for bone marrow aspirate culture, and 16 days for blood culture. While AFB staining of biopsy specimens was the least sensitive of the detection methods, it was useful for the rapid diagnosis of disseminated MAC infection, allowing for prompt initiation of antimycobacterial therapy in one third of patients.

Biopsy↗

Comparison of the efficacies of closed trephine needle biopsy, aspirated paraffin-embedded clot section, and smear preparation in the diagnosis of bone-marrow involvement by lymphoma.

Bone marrow aspirates totaling 1,024 and trephine biopsies totaling 386 were obtained from 234 patients with various diagnoses of lymphoma. The study analyzed the morphologic patterns of bone-marrow involvement by each entity and compared the sensitivity of aspiration versus biopsy for detecting lymphomatous involvement of bone marrow. Lymphoma may appear in one of three forms: nodular, diffuse (packed bone marrow), and diffusely infiltrative. Trephine biopsy was superior to aspiration in most instances, especially for the nodular form. In some cases, however, examination of paraffin-embedded clot sections and smears was diagnostic of lymphoma whereas the biopsy section appeared negative.

Biopsy, Needle↗