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PubMed2004

Age- and region-dependent changes in human lumbar vertebral bone: a histomorphometric study.

STUDY DESIGN: Histomorphometric evaluation of autopsy material. OBJECTIVES: To explore region-dependent changes that occur with aging in trabecular and cortical bone of the human vertebral body. SUMMARY OF BACKGROUND DATA: Human vertebral bone is continuously subjected to external forces (loads) that promote changes in inner architecture. This functional adaptability is limited, however, and when lost, vertebral bone progressively deteriorates and becomes subject to injury with increases in mechanical loading. METHODS: Bone cylinders were drilled with a trephine from three regions (central anterior, central posterior, and lateral) of the third lumbar vertebral bodies of 48 autopsy cases 31 to 76 years old. Two consecutive 5-microm sections obtained 150 microm apart were stained with toluidine blue and Masson trichrome and photographed at x40. Differences in numerous morphometric factors were evaluated by age and region of the vertebra using repeated-measures analysis of variance and Tukey's Honestly Significant Difference test. RESULTS: Starting at about 50 years of age, significant, linearly progressive decreases occurred in trabecular and cortical bone volume (P < 0.005), trabecular surface area (P < 0.001), number of trabeculae (P < 0.001), and thickness of trabeculae (P < 0.001). Space between trabeculae increased from ages 31 to 70 years and then decreased (P < 0.001). Trabecular deterioration was significantly more pronounced in central versus lateral regions (P < 0.001). Cortical bone thickness decreased significantly with aging in central regions but increased in lateral regions between ages 61 and 70 years (P < 0.001). CONCLUSIONS: The balance between cortical and trabecular bone maintains the strength of the vertebral body until about the age of 50 years, when irreversible deterioration begins in central regions and subsequently involves lateral regions.

Adult↗
PubMed2005

Histological evaluation of biopsies obtained from vertebral compression fractures: unsuspected myeloma and osteomalacia.

STUDY DESIGN: A histological evaluation of biopsies obtained from presumed osteoporotic vertebral compression fractures (VCF) to confirm possible osteomalacia after tetracycline labeling. OBJECTIVE: To describe the results of a series of biopsies obtained at the time of vertebral augmentation in presumed osteoporotic VCF, with special reference to the presence of unmineralized bone (osteomalacia) and occult or unconfirmed plasma cell dyscrasia. SUMMARY OF BACKGROUND DATA: Vertebral augmentation is now widely performed as a method to treat osteoporotic or osteolytic VCF. However, the influence of underlying pathology on the effect of treatment is unclear. METHODS: As of October 2003, 178 biopsies were obtained from 142 patients with VCF during 246 kyphoplasty procedures. There were 110 one-level, 28 two-level, and 4 three-level biopsies. Patients included 41 men and 101 women, with an average age of 72 years (range 40-90). The patients consented to this procedure, and 25 received tetracycline (1g/day, in 2 doses separated by 6 days). Vertebral body biopsies were taken using a trephine just before the kyphoplasty procedure. The biopsies were fixed, embedded, and stained with toluidine blue and hematoxylin eosin, and were viewed with transmitted light. Unstained sections were viewed under fluorescent light to detect tetracycline labels. RESULTS: The 178 biopsy levels included: T4 (3), T5 (1), T6 (4), T7 (13), T8 (12), T9 (8), T10 (11), T11 (17), T12 (28), L1 (25), L2 (14), L3 (13), L4 (17), and L5 (12). All specimens showed fragmented bone with variable amounts of unmineralized bone (osteoid), suggesting bone remodeling and/or fracture healing. Woven bone and cartilaginous tissue were often present, representing fracture callus formation. The biopsies obtained from 30 patients (21%), including 4 who received tetracycline, showed significantly increased osteoid, suggesting either increased bone remodeling activity or mineralization defect (osteomalacia). One sample from these 4 patients who received tetracycline showed no tetracycline labels, essentially diagnostic of osteomalacia. The biopsies also provided definitive diagnoses for one case of unsuspected and 3 cases of unconfirmed plasma cell dyscrasia. CONCLUSIONS: The majority of biopsies from this series of patients revealed findings consistent with various stages of fracture healing. Osteoid seams were increased in 30 patients, representing either increased bone remodeling or osteomalacia. More cases with tetracycline labeling will help elucidate the true incidence of osteomalacia in this population. As we confirmed 4 cases of plasma cell dyscrasia, we advocate a biopsy during each first-time vertebral augmentation procedure.

Adult↗
PubMed2004

Electron microscopic study of anterior lens capsule allotransplants in chronic corneal ulcers.

PURPOSE: This study provides ultrastructural morphology and quantitative analysis of allotransplants of anterior lens capsule in the treatment of recurrent corneal ulcers. METHODS: Mechanical ulcers of uniform size were created with a 6-mm corneal trephine in 9 eyes at one-third corneal depth in 6 white New Zealand male rabbits. Following initial epithelial regrowth, an identical injury was created in the same area of each cornea a second time. In 6 eyes (treated group), an anterior lens capsule from a healthy donor rabbit was sutured into the ulcer bed, followed by antibiotic/steroid drops 3 times daily for 1 week. The remaining 3 control eyes were allowed to heal without surgical intervention using the same antibiotic/steroid drops only. Slit-lamp examination, histopathology, and electron microscopic findings with hemidesmosome counts and size were recorded over a 3-month follow-up period. RESULTS: The control injured group had discontinuous epithelial basement membrane with significant reduction in hemidesmosome count compared with noninjured controls (P<0.0001). The treated subgroup 7 days after surgery showed linear basement membrane with identifiable lamina lucida and densa and newly-formed hemidesmosomes, which were significantly more numerous than in the injured but nontreated group (P<0.0001). Numerous hemidesmosomes and firm adhesion of epithelium to underlying stroma were seen in this group with lens capsule allografts 3 months after surgery. The number and size of hemidesmosomes did not significantly differ between groups 7 days and 3 months after surgery. CONCLUSIONS: On the ultrastructural level, anterior lens capsule allotransplants in mechanically induced corneal ulcer heal with continuously formed epithelial basement membrane and numerous hemidesmosomes. This enables significant reformation of hemidesmosomes that are identical in size to hemidesmosomes in healthy corneas and helps forming a stronger apposition for epithelial cells to underlying structures in eyes where epithelial basement membrane has been destroyed from chronic ulceration.

Animals↗
PubMed2005

Biocompatibility of a nonpenetrating synthetic cornea in vascularized rabbit corneas.

PURPOSE: This study was designed to assess feasibility and biocompatibility of a lamellar, nonperforating supraDescemetic Synthetic Cornea (sDSC) implanted in rabbit eyes after a corneal injury. METHODS: Corneal vascularization and scarring was induced in the right eye of 15 rabbits by application of 1-heptanol and complete surgical removal of the limbus. An sDSC (7-mm diameter, 450-microm-thick optical zone, 100-microm-thick outer flange) was implanted after 45 +/- 5 days. The keratoprostheses were implanted with their central optic part positioned on a completely exposed Descemet's membrane (DM) while the outer flange was located in deep stroma. Three different materials were tested: hydrophobic PMMA (n = 5) and hydrophilic HEMA-MMA (n = 5) and HEMA-NVP (n = 5) with a water content of 34% and 75%, respectively. The corneal surface was covered with a conjunctiva-Tenon flap. Central flap trephination was performed after 63 +/- 7 days. DM vascularization and scarring was assessed and graded after flap opening and weekly thereafter. RESULTS: In all 15 consecutive cases implantation could be completed successfully without perforation of DM. Repair of the conjunctival flap had to be performed in five rabbits. Four months postoperatively, the flaps were opened. Four of five corneas (80%) with a PMMA implant and three of five (60%) with a HEMA-NVP75 implant had retained their original transparency. The others had developed significant neovascularization in the Descemet-sDSC optic interface. All corneas (100%) that received an sDSC made of HEMA-MMA34 displayed a completely clear DM without any vessels or scarring. DM was found firmly attached to the posterior surface of the optic. CONCLUSION: Implantation of a nonperforating synthetic cornea on top of an exposed DM is feasible. HEMA-MMA34 showed the most promising results. Because opening of the anterior chamber is not required, a lamellar supraDescemetic Synthetic Cornea would theoretically reduce some of the risks attributed to penetrating keratoprostheses.

Animals↗
PubMed2005

Epithelial innervation of human cornea: a three-dimensional study using confocal laser scanning fluorescence microscopy.

PURPOSE: Evaluation of a new method to visualize distribution and morphology of human corneal nerves (Adelta- and C-fibers) by means of fluorescence staining, confocal laser scanning microscopy, and 3-dimensional (3D) reconstruction. METHODS: Trephinates of corneas with a diagnosis of Fuchs corneal dystrophy were sliced into layers of 200 microm thickness using a Draeger microkeratome (Storz, Germany). The anterior lamella was stained with the Life/Dead-Kit (Molecular Probes Inc.), examined by the confocal laser scanning microscope "Odyssey XL," step size between 0.5 and 1 microm, and optical sections were digitally 3D-reconstructed. RESULTS: Immediate staining of explanted corneas by the Life/Dead-Kit gave a complete picture of the nerves in the central human cornea. Thin nerves running parallel to the Bowman layer in the subepithelial plexus perforate the Bowman layer orthogonally through tube-like structures. Passing the Bowman layer, Adelta- and C-fibers can be clearly distinguished by fiber diameter, and, while running in the basal epithelial plexus, by their spatial arrangement. Adelta-fibers run straight and parallel to the Bowman layer underneath the basal cell layer. C-fibers, after a short run parallel to the Bowman layer, send off multiple branches penetrating epithelial cell layers orthogonally, ending blindly in invaginations of the superficial cells. In contrast to C-fibers, Adelta-fibers show characteristic bulbous formations when kinking into the basal epithelial plexus. CONCLUSIONS: Ex-vivo fluorescence staining of the cornea and 3D reconstructions of confocal scans provide a fast and easily reproducible tool to visualize nerves of the anterior living cornea at high resolution. This may help to clarify gross variations of nerve fiber patterns under various clinical and experimental conditions.

Cornea↗
PubMed2005

Femtosecond laser-assisted intracorneal keratoprosthesis implantation: a laboratory model.

PURPOSE: To demonstrate femtosecond laser-assisted intracorneal keratoprosthesis implantation and determine the mechanical stability as a function of intraocular pressure. METHODS: Eight human corneoscleral rims were mounted on an artificial anterior chamber. The femtosecond laser microkeratome was used to create a 2.5-mm diameter posterior corneal cap. A 7.2-mm-diameter lamellar stromal pocket was then created at mid-corneal depth. Finally, a 6-mm arc opening to the corneal surface was created at the periphery of the lamellar cut. The posterior lenticule was removed using corneal forceps and a 7.0-mm biopolymer keratoprosthesis was inserted into the stromal pocket. The surface wound was sealed using two 10-0 nylon sutures. A 3.0-mm anterior corneal opening was trephined to expose the keratoprosthesis. Intrachamber pressure was raised until wound leak was observed. RESULTS: Seven of the 8 implants withstood pressures of at least 135 mm Hg without implant extrusion. CONCLUSION: Femtosecond laser corneal dissection provides an alternative to more challenging manual dissection methods for keratoprosthesis implantation. Use of the femtosecond laser microkeratome will further refine keratoprosthesis surgical technique and may allow rapid and easy execution of the surgery.

Biomechanical Phenomena↗
PubMed2006

Cutting and pasting corneas: combination of a corneal allograft with relocation of a crescent of autologous corneal tissue in therapeutic penetrating keratoplasty.

PURPOSE: A therapeutic penetrating keratoplasty (TPKP) technique that achieves satisfactory visual rehabilitation with a minimal risk of rejection is described. METHODS: A patient presented with a central corneal perforation in the left eye extending to the temporal limbus. We performed a novel surgical procedure, in which a corneal allograft was combined with relocation of a crescent of autologous corneal tissue. RESULTS: The TPKP placed the optical zone of the donor cornea over the center of the entrance pupil. The chances of an immunologic rejection were minimized by intercalating a crescent of autologous tissue between the allograft and the limbal vessels. CONCLUSION: The combination of an allograft with a crescent of autologous corneal tissue minimizes the disadvantages associated with eccentric or oversized trephination.

Aged↗
PubMed2006

Effects of autologous serum eye drops on corneal wound healing after superficial keratectomy in rabbits.

PURPOSE: : To study the effects of topically applied autologous serum on the wound healing process of mechanically produced corneal ulcers. METHODS: : A superficial keratectomy was done in 1 eye from each of 28 rabbits, using a corneal trephine. Four groups of 7 rabbits were treated topically 4 times a day with nondiluted autologous serum; diluted autologous serum (20%); unpreserved pharmaceutical tear substitute; and physiologic saline. The saline-treated group served as a control. The healing of the ulcers was followed on a slit-lamp biomicroscope regarding its size, infiltration, and neovascularization on alternate days up to day 10 with and without fluorescein staining. RESULTS: : Autologous serum significantly accelerated the corneal wound healing process in both concentrations compared with either the unpreserved pharmaceutical tear substitute or physiologic saline solutions, but the process was faster with the nondiluted concentration. CONCLUSION: : Autologous serum eye drops could be used as a corneal wound healing adjuvant in mechanical corneal ulcers. To accelerate the wound healing process, the blood-derived factors were brought externally to the avascular cornea through autologous serum eye drops. The importance of the vascular supply on the wound healing process of vascular tissues is well known, and this study considers the benefit of blood-derived factors on the healing process of cornea.

Administration, Topical↗
PubMed2006

Posterior lamellar keratoplasty using descemetorhexis and organ-cultured donor corneal tissue (Melles technique).

PURPOSE: To report the clinical results of posterior lamellar keratoplasty (PLK) using predissected organ-cultured donor corneal tissue implanted after stripping of the Descemet membrane. METHODS: Twenty-two eyes of 22 patients in whom a PLK procedure was performed for pseudophakic bullous keratopathy and/or Fuchs endothelial dystrophy were evaluated. In all eyes, the recipient Descemet membrane was excised by performing a descemetorhexis. Just after harvesting the donor tissue, each cornea had a posterior lamellar dissection made at approximately 80% stromal depth, and each cornea was preserved in an organ culture system for 10 to 21 days. During surgery, a posterior lamellar disk was trephinated from the predissected donor cornea and inserted through a 5.0-mm scleral incision into the anterior chamber of the recipient by folding the donor. Specular microscopy was performed at 6, 12, and 18 months to measure the endothelial cell density. RESULTS: In 3 eyes (14%), the posterior donor disk did not attach to the recipient posterior stroma, so a penetrating keratoplasty was performed in a secondary procedure. The transplants in the remaining 19 eyes cleared and maintained clarity throughout the follow-up period. In these eyes, best corrected visual acuity (BCVA) ranged from 0.25 to 1.0 up to 27 months of follow-up. Postoperative astigmatism averaged 1.7 +/- 1.0 D. Endothelial cell density averaged 1650 +/- 390 cells/mm at 6 months, 1560 +/- 350 cells/mm at 12 months, and 1500 +/- 430 cells/mm at 24 months. Two eyes developed mild interface haze. CONCLUSION: PLK can be performed using an organ-cultured donor posterior disk. Visual rehabilitation may be slower than in PLK with fresh donor tissue.

Aged↗
PubMed2006

Risk factors for the first episode of corneal graft rejection in keratoconus.

PURPOSE: To evaluate the relationship between topical corticosteroids and other variables and the risk for rejection after penetrating keratoplasty for keratoconus. METHODS: The records of all keratoconus patients who, after their first penetrating keratoplasty in that eye, experienced a first episode of corneal graft rejection during a specific 3-year period were retrospectively reviewed in a case-control fashion. Twenty-three cases were identified, and they were matched with 3 controls each, for a total of 69 controls and 92 total patients. Multiple variables including steroid potency, recent steroid tapering, and length of time on the current level of steroids were analyzed to see whether there were any significant relationships between postoperative changes in steroid management and rejection. In addition, other variables such as graft size, suture technique, recent suture removal, suture status at the time of the rejection episode, and prior grafting in the fellow eye were examined to determine if any of these factors were associated with a higher risk of graft rejection. RESULTS: Most of the proposed risk factors, including steroid dose and tapering, differing suturing techniques, loose and/or broken sutures at the time of rejection, percentage of sutures remaining at the time of rejection, and prior grafting in the fellow eye, did not correlate with the risk of rejection. Only graft size had a correlation, with host trephination size > or = 8.25 mm having a nearly sixfold increased risk of rejection (P = 0.015). Most patients (70%) were diagnosed with rejection at a scheduled office visit rather than at an emergency visit, and correspondingly, nearly one half (43%) had no symptoms when rejection was identified. There was no significant difference in final best-corrected visual acuities between the cases and controls, and 91% of the corneas that underwent rejection did not progress to graft failure, remaining centrally clear at most recent follow-up. CONCLUSION: In this study, the most important risk factor for rejection after corneal transplantation for keratoconus was the size of the graft. Physician detection of rejection is paramount, because a graft rejection episode is more often diagnosed at a scheduled office visit than at an emergency visit. Fortunately, progression to graft failure can usually be prevented if treatment is started promptly and intensively.

Adolescent↗
PubMed2006

Collagen fiber orientation near a fractured dental implant after a 5-year loading period: case report.

PURPOSE: Fracture of an implant is one of the possible complications of dental implants. It is a quite rare event but of high clinical relevance. Nevertheless, it represents an important opportunity for evaluating the peri-implant bone-tissue response to implant overloading in human beings. The aim of the present study was a scanning electron microscopy evaluation of a screw-shaped implant retrieved because of fracture and a birefringence analysis of the tissue near the fractured implant. MATERIALS AND METHODS: There was 1 fractured screw-shaped implant retrieved from a patient with a trephine bur, and it was processed for histology. The specimen was analyzed under both scanning electron microscopy and circularly polarized light microscopy. RESULTS: The scanning electron microscopy fractography analysis showed the typical signs of a fatigue-fracture, with large plastic deformations on the implant. The fracture seemed to start from the internal coil of the implant. Under circularly polarized light microscopy investigation, a bone-implant contact percentage of 81.6% +/- 1.5% (mean +/- standard deviation) was found. The amount of the transverse collagen fibers was of 68.3%, and the amount of the longitudinal collagen fibers was of 31.7%. The difference was statistically significant for z = 2.247 (P = 0.025). CONCLUSION: The fracture of the implant was most probably correlated to a fatigue of the material mainly associated to a lesion of the internal coil. The high level of bone-implant contact percentage was correlated to a predominant transverse collagen fiber orientation of the collagen fibers in the peri-implant bone.

Bone Remodeling↗
PubMed2006

Reintegration success of osseotite implants after intentional countertorque liberation in the endentulous human mandible.

PURPOSE: Implants that rotate during abutment screw tightening may not necessarily constitute implant failure. This prospective study was designed to determine to what degree integrated implants could gain a state of reintegration after intentional countertorque to liberation from the bone. MATERIALS AND METHODS: There were 11 patients with fully edentulous mandibles restored with 2 "clinical" implants (3.75 x 10 mm) placed in the canine sites and an additional nonused "test" implant (3.75 x 10 mm) placed at the symphysis of the anterior mandible. At second-stage surgery, the test implant was countertorqued (T1) using a torque-metering wrench until it detached from the bone. The implant was returned to its original position and allowed to heal for a period until a second countertorque test (T2) was performed. In group A, patients (n = 5) received the countertorque T1 at 3 months and T2 at 5 months. In group B (n = 6) T1 was at 1.5 months, and T2 was at 3.5 months. After completion of T2, the group A test implants were removed with a 5-mm trephine for histologic examination. RESULTS: For both groups, peak forces, all higher than 37.4 Ncm at T1, indicate that all implants were integrated. At T2, torque values were higher than T1 values for most of the test implants. The clinical implants were restored with "patrix" abutments and an overdenture. Histology staining showed distinction between old and new bone, which formed during the remodeling process. DISCUSSION: The increase in peak forces needed to detach implants at T2 may be explained by bone-to-bone healing or the additional bone contact promoted by bleeding that occurred during the T1 procedure. CONCLUSION: The results suggest that all implants were reintegrated after being intentionally countertorqued to liberation and resumed healing in the original osteotomy position.

Aged↗
PubMed2006

Histologic evaluation of 3 retrieved immediately loaded implants after a 4-month period.

OBJECTIVE: To perform a histologic and histomorphometric analysis of the peri-implant tissue reactions and bone-titanium interface in 3 immediately loaded (provisional loaded) titanium implants retrieved from a man after a loading period of 4 months. MATERIALS & METHODS: A 35-year-old patient with a maxillary partial edentulism did not want to wear a provisional removable prosthesis during the healing period. It was decided to insert 3 definitive implants and use 3 provisional implants for the transitional period. The provisional implants were loaded the same day with a resin prosthesis in occlusal contact. During the second surgical phase, after 4 months, the provisional prosthesis was removed, and the provisional implants were retrieved with a trephine bur. Before retrieval, all implants appeared to be clinically osseointegrated. The specimens were processed for observation under light microscopy. RESULTS: At low magnification, it was possible to observe that bone trabeculae were present around the implant. Areas of bone remodeling and haversian systems were present near the implant surface. Under polarized-light microscopy, it was possible to observe that in the coronal aspect of the thread, the lamellar bone showed lamellae that tended to run parallel to the implant surface, while in the inferior aspect of the thread, the bone lamellae ran perpendicular to the implant surface. CONCLUSIONS: Histologic data pertaining to these 3 immediately loaded implants, and retrieved after a 4-month loading period, show that immediate loading did not produce untoward effects on peri-implant bone healing.

Adult↗
PubMed2003

Bilateral dynamic proptosis due to frontoethmoidal sinus mucocele.

A 34-year-old man presented with bilateral inferior and lateral globe displacement and spontaneous, dynamic proptosis in both eyes, pulsatile in nature. Computed tomography and magnetic resonance imaging scans confirmed bilateral frontoethmoidal mucoceles with erosion of the orbital roof, and intracranial extension. Following a transcutaneous mini-trephine of the left orbital mucocele, the dynamic proptosis disappeared, and both proptosis and restriction of eye movements in the left eye improved. This is the first reported case of frontoethmoidal sinus mucocele causing bilateral spontaneous dynamic proptosis.

Adult↗
PubMed2004

CD25 indicates the neoplastic phenotype of mast cells: a novel immunohistochemical marker for the diagnosis of systemic mastocytosis (SM) in routinely processed bone marrow biopsy specimens.

The diagnosis of systemic mastocytosis (SM) is based primarily on the histologic and immunohistochemical evaluation of a bone marrow trephine biopsy specimen. Although mast cell (MC) specific antigens like tryptase and chymase are detectable in routinely processed tissue, no immunohistochemical markers that can be used to discriminate between normal and neoplastic MCs are yet available. We have investigated the diagnostic value of an antibody against CD25 for the immunohistochemical detection of MCs in bone marrow sections in 73 patients with SM and 75 control cases (reactive marrow, n = 54; myelogenous neoplasms, n = 21) and correlated the results with the presence of c-kit mutations. While MCs in almost all patients with SM (72 of 73) expressed CD25, none of the control samples contained CD25-positive MCs. Irrespective of the SM subtype, most of neoplastic MCs expressed CD25. In 3 patients with advanced MC disease, pure populations of neoplastic MCs were obtained and found to express CD25 mRNA by RT-PCR analysis. In addition, all patients with CD25-positive MCs contained c-kit mutations, while all control cases exhibited wild type c-kit. CD25 therefore appears to be a reliable immunohistochemical marker for the discrimination of neoplastic from normal/reactive MCs, with potential as a diagnostic tool in SM.

Biomarkers, Tumor↗
PubMed2005

Bone marrow biopsy involvement by non-Hodgkin's lymphoma: frequency of lymphoma types, patterns, blood involvement, and discordance with other sites in 450 specimens.

To evaluate the features of bone trephine biopsy involvement by non-Hodgkin lymphoma, 450 specimens were evaluated for percentage of marrow involvement, pattern of involvement, presence of germinal centers or follicular structures, and discordance with other involved sites. A subset of 197 cases was evaluated for evidence of concurrent peripheral blood involvement. Follicular grade 1 lymphoma (30.4%) was the most common type to involve the marrow, followed by diffuse large B-cell lymphoma (16.0%), mantle cell lymphoma (9.3%), low-grade B-cell lymphoma, not otherwise specified (8.7%), lymphoplasmacytic lymphoma (8.4%), follicular grade 2 lymphoma (7.1%), and mature T- and NK-cell lymphomas (6.4%). A mixed pattern of infiltration was most common, followed by paratrabecular, nodular, diffuse, and interstitial patterns. Greater than 90% of follicular lymphomas had at least a focal paratrabecular infiltration pattern, but this pattern was also seen with other lymphoma types. Interstitial disease infiltration tended to correlate with lymphoplasmacytic lymphoma but was also not specific. The presence of germinal centers or follicular structures was associated with follicular lymphoma in 88% of cases. Discordance between the bone marrow morphology and other tissue sites was observed in 24.9% of cases and was most often seen with follicular or diffuse large B-cell lymphoma. Peripheral blood involvement by lymphoma was observed in 29% of cases, found in all disease groups except for follicular grade 3 lymphoma. This study highlights the frequency of different lymphoma patterns in the marrow, limitations of primary lymphoma classification on biopsy material alone, and the relative frequency of marrow discordance and peripheral blood involvement by marrow lymphoma.

Adolescent↗
PubMed2003

Volume maintenance of inlay bone grafts in the craniofacial skeleton.

Although the clinical use of inlay bone grafts is widespread in craniofacial surgery, the dynamics of inlay bone grafting to the craniofacial skeleton have never been well characterized. Previous work demonstrated that volume maintenance of bone grafts in the onlay position is a consequence of their microarchitectural features, rather than their embryological origins. The purpose of this study was to investigate whether the properties determining the volume maintenance of bone grafts in the onlay position in the craniofacial skeleton could be extended to bone grafts in the inlay position. It was hypothesized that volume maintenance of an inlay bone graft could be better explained on the basis of the microarchitectural features of the graft (cortical versus cancellous composition), rather than its embryological origin (membranous versus endochondral), and that the primary determinant of bone graft behavior is the interaction between the microarchitectural features of the bone graft and the local mechanical environment in which the bone graft is placed. Cortical and cancellous bone grafts were harvested from the iliac crest (endochondral origin) of 25 New Zealand white rabbits, and cortical bone was harvested from the mandible (membranous origin) of each rabbit. Four 7-mm trephine holes were made in the cranium of each rabbit, posterior to the coronal suture. Each defect was filled with endochondral cortical bone, endochondral cancellous bone, or membranous cortical bone or was left as an ungrafted control specimen. Animals were killed at 3, 8, or 16 weeks. Crania were subjected to micro-computed tomographic and histological assessments. Micro-computed tomographic analysis demonstrated significant increases in actual bone volume from time 0 to the time of death for all types of grafts. Cortical bone demonstrated significant increases in space-occupying volume at all time points. By 16 weeks, no statistically significant difference in either the actual bone volume or the space-occupying volume according to graft type could be detected. There was no resorption of the inlay bone grafts; in fact, all bone types exhibited increased volume. Cancellous bone demonstrated the greatest capacity to increase actual bone volume. All bone graft types seemed to reach a steady-state bone volume, as if controlled by a local regulator. The regulator is likely the local mechanical environment in which the grafts were placed, as corroborated by the findings that the bone grafts seemed to recapitulate the characteristics of the bone in which they were placed, rather than maintaining their native characteristics.

Animals↗
PubMed2006

The utility of bone marrow examination in renal transplantation: nine years of experience from north India.

Renal transplantation may be complicated by persistent fever and cytopenia. Bone marrow examination, though painful and invasive, may be of value because it can be performed in most peripheral hospitals, and the results are rapidly available. In a retrospective analysis, clinical records, marrow aspirates, and trephine biopsies were assessed to determine the indications for bone marrow examination and the findings in 132 patients over a 9-year period. In 7 of 61 (11%) patients with fever, a specific infection or a malignancy was identified, and hypocellularity was seen in 85% of cases. Nutritional deficiency with megaloblastosis or diminished iron stores was noted in 29% of cases. Malignancies were relatively infrequent (3%). Overall, in 12% of the cases, bone marrow examination provided useful information. Examination of the bone marrow may be a useful diagnostic test in pyrexia of unknown origin and cytopenia, particularly in developing countries.

Biopsy↗