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PubMed1994

Bovine bone morphogenetic protein (bBMP/NCP)-induced repair of skull trephine defects in pigs.

Bovine bone morphogenetic protein and associated noncollagenous proteins (bBMP/NCP) were implanted in skull trephine defects, 14 and 22 mm in diameter, in adult minipigs. The defects were larger than the critical size for repair of cranial bones in pigs observed for a period of six to 16 weeks. The trephines were placed either in the nasal bone at eye level, or in the frontal bone. In minipigs the repair was more advanced in trephines in the frontal bone than in the nasal region, but was incomplete in either bone bed. As in dogs, implants of bBMP/NCP in heterotopic sites were resorbed before a competent cell population could respond. Serum anti-BMP antibody was elevated. The IgG levels of the antibody titer showed a clearcut dose-response; the level was significantly higher in one pig with implants of 85 mg of bBMP/NCP proteins in a frontal bone trephine.

Animals↗

PubMed1996

Use of trephine stoma in sigmoid volvulus.

INTRODUCTION: Sigmoid volvulus is a disease of the elderly who often have severe comorbid conditions that increase their operative risk and limit treatment options. Conservative treatment with decompression via sigmoidoscopy with rectal tube placement has high success and recurrence rates. Surgical resection with primary anastomosis is the treatment of choice when decompression fails or if the volvulus recurs. Unfortunately, perioperative complications are frequent. Moreover, many patients with sigmoid volvulus are bedridden or incontinent of stool and do not benefit from extensive resection and maintenance of bowel continuity. METHODS: Twelve debilitated patients with sigmoid volvulus determined preoperatively to be poor candidates for laparotomy and reanastomosis were treated with a trephine stoma. Initially, each patient had decompression via rigid sigmoidoscopy and rectal tube placement. Surgical intervention consisted of formation of a small hole (trephine) in the left lower quadrant. Through this hole, a sigmoid resection and end colostomy were performed. No midline laparotomy was required. RESULTS: Operative times and analgesia requirements were significantly decreased (P = 0.05) compared with patients who underwent formal laparotomy. Length of hospital stay, complication rates, and length of bowel resected were similar using either surgical technique. CONCLUSIONS: The trephine stoma procedure offers significantly shorter operative times, with decreased perioperative morbidity. For high operative risk or debilitated patients with sigmoid volvulus, resection with end colostomy using the trephine stoma technique is the procedure of choice.

Adult↗

PubMed1982

[The conditions of motor trephining and their influence on time and velocity in cutting the isolated cornea (author's transl)].

A special experiment was constructed to measure the influence of factors such as trephine diameter, revolutions per second, sharpness, and cutting pressure on the incision velocity and incision time for a number of trephine specimens. These measurements show the characteristics of trephines. Different degrees of sharpness were determined by comparison of the characteristics. The dependency of rotation moment transferred to tissue, of revolutions per second, and of incision power is discussed. The results are discussed, and proposals are made to increase safety by application of motor trephines and to develop them further.

Animals↗

PubMed2001

MRI-guided trephine biopsy and fine-needle aspiration in the diagnosis of bone lesions in low-field (0.23 T) MRI system using optical instrument tracking.

The purpose of this study was to evaluate the feasibility of MRI-guided bone biopsy with optical instrument tracking and evaluate advantage of combined fine-needle aspiration (FNA) with trephine biopsy. Twenty trephine bone biopsies and 13 FNAs were performed under MRI and CT guidance in 14 patients. Informed consent was obtained from all patients. The evaluation of diagnostic accuracy was achieved by comparing the histopathological and cytological diagnosis with current or final diagnosis made during 6-month clinical follow-up. A 0.23-T open MRI scanner with interventional tools (Outlook Proview, Marconi Medical Systems, Cleveland, Ohio) was used. A surface coil was used. For trephine biopsy MRI-compatible bone biopsy set (Daum medical, Schwerin, Germany) was used. The FNA was performed with MRI compatible 20-G needle (Cook, Bloomington, Ind.). The diagnostic accuracy of MRI-guided trephine biopsy was 95%. The FNA sample diagnosis concurred with the histological in 54%. Our results show that MRI guidance in bone biopsies is accurate and safe. It is comparable to CT-guided or open biopsy. The role of combined FNA with bone biopsies remains controversial.

Biopsy↗

PubMed2001

Graft endothelium and thickness after penetrating keratoplasty, comparing mechanical and excimer laser trephination: a prospective randomised study.

PURPOSE: To assess the impact of nonmechanical trephination on the graft endothelium and thickness after penetrating keratoplasty (PK). METHODS: Inclusion criteria for this prospective, randomised, cross-sectional, clinical study were: (1) Treatment between October 1992 and December 1997; (2) one surgeon (G.O.H.N.); (3) primary central PK; (4) Fuchs' dystrophy (diameter 7.5/7.6 mm) or keratoconus (diameter 8.0/8.1 mm); (5) graft oversize 0.1 mm; (6) no previous intraocular surgery; (7) 16-bite double-running diagonal suture. In 179 patients (mean age 51+/-18 years), PK was performed using either the 193-nm Meditec MEL60 excimer laser ("Excimer") along metal masks with eight "orientation teeth/notches" (53 keratoconus, 35 Fuchs' dystrophy) or motor trephination with the Mikrokeratron (Geuder) ("Control": 53 keratoconus, 38 Fuchs' dystrophy). For donor trephination from the epithelial side an artificial anterior chamber was used in both groups. In 27% of the excimer and 29% of the control group a triple procedure was performed. Specular microscopy (EM-1000, Tomey) and pachymetry (SP-2000, Tomey) were performed before removal of the first suture (0.4+/-0.2 years postoperatively), before (1.1+/-0.4 years) and after (1.7+/-0.6 years) removal of the second suture but before any additional surgical intervention. RESULTS: Endothelial cell count: Neither "two-sutures-in" (1953+/-426/1804+/-385 cells/mm2, p=0.13), "one-suture-in" (1629+/-439/1765+/-440 cells/mm2, p=0.27), nor "all-sutures-out" (1259+/-493/1294+/-532 cells/mm2, p=0.83) differed significantly between Excimer and Control. Graft thickness: Neither "two-sutures-in" (527+/-58/524+/-16 mucrom, p=0.89), "one-suture-in" (537+/-72/551+/-40 microm, p=0.86), nor "all-sutures-out" (576+/-53/565+/-62 microm, p=0.38) differed significantly between Excimer and Control. Cell count and corneal thickness were not significantly different comparing Fuchs' dystrophy and keratoconus or comparing PK only and triple procedures. Graft thickness and endothelial cell count correlated highly significantly inversely with "all sutures out" (P<0.0001). CONCLUSIONS: Excimer laser trephination from the epithelial side using an artificial anterior chamber in donors seems to have no disadvantages concerning the graft endothelium after PK. Endothelial cell loss was not increased in eyes with Fuchs' dystrophy compared with keratoconus or after triple procedures compared with PK only.

Adolescent↗

PubMed1991

Histologic, immunophenotypic and genotypic analyses of bone marrow trephines from patients with non-Hodgkin's lymphoma.

Marrow involvement in 20 patients with non-Hodgkin's lymphoma (NHL) were studied by histology, immunophenotypic and genotypic methods. Eighteen of these trephines were histologically involved with recognizable lymphomatous infiltrates and five of these were the primary disease site. In the remaining two cases (with histologically involved lymph nodes) the trephines were uninvolved with tumour. Three B-cell cases expressing surface immunoglobulin (sIg) and/or CD37 and one case not analysed phenotypically showed Ig gene rearrangements. The two remaining cases with B NHL showed no gene rearrangements, however, in one of these the trephine was histologically uninvolved with tumour. Twelve out of 14 T-cell cases were characterized by variable or absent expression of one or more T-cell antigens from the tumour population, one case was negative for all T-cell antigens and the remaining case was not histologically involved with tumour. All three lymphoblastic lymphomas and only 4/11 peripheral T-cell lymphomas (PTCL) cases revealed T-cell receptor (TcR) gene rearrangements. One of the latter cases also exhibited Ig JH gene rearrangements. This study demonstrates the usefulness of bone marrow trephines (BMT) in histologic, phenotypic and genotypic analyses. However, although genotypic data confirm clonality in B NHL and the lymphoblastic lymphomas there was genotypic heterogeneity within the PTCL group.

Antigens, CD↗

PubMed2005

Anatomic analysis of the Genial Bone Advancement Trephine System's effectiveness at capturing the genial tubercle and its muscular attachments.

OBJECTIVE: The Genial Bone Advancement Trephine (GBAT) System (Stryker Leibinger Inc, Kalamazoo, MI) is a 1-step system that advances the genial tubercle for treatment of retrolingual obstruction in obstructive sleep apnea. The purpose of this project was to anatomically analyze the effectiveness of the GBAT System to capture the genial tubercle and its muscular attachments in the circular trephine. METHODS: Eight cadaveric heads (ages 54-89 years; 3 female and 5 male) were examined, and Panorex radiographs (Stryker Leibinger Inc, Kalamazoo, MI) were obtained. Seven specimens were selected on the basis of mandibular height and dentition to undergo the procedure. The procedure was performed using the GBAT system with the 14-mm trephine according to the stepwise instructions. The mandibles were dissected, and analysis of the location of the osteotomy with respect to the genial tubercle, genioglossus muscles, geniohyoid muscles, and mandibular dentition was performed. RESULTS: All 7 of the specimens had complete capture of the genial tubercle. The mean percentage of the genioglossus muscle captured in the circular trephine was 85% (50%-100%). All specimens had preservation of the posterior muscle fibers. The mean percentage of the geniohyoid muscle captured was 78% (15%-100%). No tooth roots were transected or contained in the bone plug. CONCLUSIONS: The GBAT System is an effective 1-step system for capturing and advancing the genial tubercle and its muscular attachments in the treatment of OSA.

Aged↗

PubMed1980

A clear view trephine and lamellar dissector for corneal grafting.

We designed a corneal trephine that permits a full view of the cornea while cutting. The drive mechanism of the trephine enables the surgeon to keep the central cutting axis of the instrument stable while the trephine is rotated. The instrument accepts variable sizes of disposable trephine blades, making it versatile and economical. We also devised a lamellar dissector with two blades to negate the splitting force that occurs during a closed lamellar dissection. It enables the surgeon to perform a closed lamellar dissection with minimal force applied to the globe and minimal risk of perforation.

Cornea↗

PubMed1999

Nonmechanical corneal trephination with the excimer laser improves outcome after penetrating keratoplasty.

OBJECTIVE: To assess the impact of nonmechanical trephination on the outcome after penetrating keratoplasty (PK). DESIGN: Prospective, randomized, cross-sectional, clinical, single-center study. PATIENTS: A total of 179 eyes of 76 females and 103 males, mean age at the time of surgery 50.6 +/- 18.5 (range, 15-83) years. Inclusion criteria were (1) time interval from October 1992 to December 1997; (2) one surgeon (GOHN); (3) primary central PK; (4) Fuchs dystrophy (diameter, 7.5 mm) or keratoconus (diameter, 8.0 mm); (5) graft oversize, 0.1 mm; (6) no previous intraocular surgery; and (7) 16-bite double-running diagonal suture. INTERVENTION: In a randomized fashion, eyes were assigned either to trephination with the 193-nm Meditec excimer laser (manually guided beam in patients, automated rotation device of artificial anterior chamber in donors) along metal masks with eight orientation teeth/notches (EXCIMER: 53 keratoconus, 35 Fuchs dystrophy; mean follow-up, 37 +/- 16 months) or with a hand-held motor trephine (Microkeratron; Geuder) ( CONTROL: 53 keratoconus, 38 Fuchs dystrophy; mean follow-up, 38 +/- 14 months). Subjective refractometry (trial glasses), standard keratometry (Zeiss), and corneal topography analysis (TMS-1; Tomey) were performed before surgery, before removal of the first suture (15.2 +/- 4.2 months), and after removal of the second suture (21.4 +/- 5.6 months). MAIN OUTCOME MEASURES: Keratometric and topographic net astigmatism as well as refractive cylinder; keratometric and topographic central power; best-corrected visual acuity (VA); surface regularity index (SRI), surface asymmetry index (SAI), and potential visual acuity (PVA) of the TMS-1. RESULTS: Before suture removal, mean refractive/keratometric/topographic astigmatism did not differ significantly between EXCIMER (2.5 +/- 1.8 diopters [D]/3.4 +/- 2.8 D/4.7 +/- 3.1 D) and CONTROL groups (3.0 +/- 1.8 D/3.7 +/- 2.4 D/4.3 +/- 2.1 D). After suture removal, respective values were significantly lower in the EXCIMER group (2.8 +/- 2.0 D/3.0 +/- 2.1 D/3.8 +/- 2.6 D) than in the CONTROL group (4.2 +/- 2.4 D/6.1 +/- 2.7 D/6.7 +/- 3.1 D) (P < 0.0009). In the EXCIMER versus CONTROL group, mean VA increased from 20/100 versus 20/111 (P > 0.05) before surgery, to 20/31 versus 20/38 before (P = 0.001) and to 20/28 versus 20/39 (P < 0.00001) after suture removal. Mean spherical equivalent was significantly less myopic in the EXCIMER group before (-0.9 +/- 3.6 D vs. -2.6 +/- 3.4 D) (P = 0.01) and after suture removal (-1.4 +/- 3.1 D vs. -2.4 +/- 3.5 D) (P = 0.02). Mean SRI (P = 0.04) and PVA (P = 0.007) were significantly more favorable in the EXCIMER versus CONTROL group after suture removal (0.91 +/- 0.45 and 0.82 +/- 0.15 vs. 1.05 +/- 0.46 and 0.73 +/- 0.18). CONCLUSIONS: Postkeratoplasty results seem to be superior using nonmechanical excimer laser trephination. Thus, this methodology is recommended as the procedure of first choice in avascular corneal pathologies requiring PK.

Adolescent↗

PubMed1988

Treatment of longitudinal injuries in avascular area of meniscus in dogs by trephination.

A study promoting the healing of longitudinal injuries in an avascular area of the meniscus in 21 male dogs is reported. One horizontal hole from the peripheral vasculature to one of the artificial longitudinal injuries to both medial menisci of the knee in each dog was made with a needlelike trephine. The knee joints were not immobilized and the samples were taken 2, 4, 8, 12, and 24 weeks, respectively, after the operation. [3H]Thymidine was injected into the joint cavity 72 h before the sample was taken. Healed lengths were measured, and pathologic examinations and autoradiography were performed. The results showed that all of the injuries treated with trephination were partly or totally healed whereas those in controls were not healed at all, suggesting that trephination may be the procedure of choice for clinic orthopedists dealing with such injuries. By the 8th week, the healed length stopped increasing, the scar tissue began to mature, and the DNA synthesis of the fibroblasts in the granulation tissue and the fibrochondrocytes in the trephined meniscus reduced. It is thought that the fibrochondrocyte of the meniscus and the fibroblast in the granulation might be capable of obtaining the thymidine directly from the synovia of knee joint for their DNA metabolism. Multiplication of the fibrochondrocyte in the injured meniscus was also found.

Animals↗

PubMed2002

The comparative values of bone marrow aspirate and trephine for obtaining bone scan-targeted metastases from hormone-refractory prostate cancer.

Samples of metastatic prostate cancer to bone are difficult to obtain. The aim of this study was to compare the results of bone marrow aspirate and trephine biopsy for obtaining metastatic hormone-refractory prostate cancer (HRPC) samples using previous diagnostic planar 99(m)Tc-HDP bone scans to guide the procedure. All samples taken were for the purposes of research and molecular studies on HRPC. Twenty patients with HRPC had bone marrow aspirate and trephines taken from lesions in the posterior superior iliac spine or sacro-iliac region when shown on diagnostic 99(m)Tc-HDP bone scans. Three patients also underwent plain X-ray, 18F-positron emission tomography bone scan, pelvic MRI scan and 99(m)Tc nanocolloid bone marrow scans. These images were used to assess if the extra imaging information provided, such as three-dimensional localisation of the bone metastases, was of value for target bone metastases. Cancer cells were obtained in 15/20 (75%) cases in which a trephine biopsy was attempted and 0/20 of cases in which a bone marrow aspiration was attempted. The additional information provided by the range of other imaging investigations was of little benefit in obtaining tumour samples, but did suggest why negative biopsies were obtained in some cases after targeting with planar bone scans. We recommend the use of bone marrow trephine biopsy alone, guided by previous diagnostic 99(m)Tc planar bone scan as a practical method to obtain prostate cancer cells from bone metastases.

Aged↗

PubMed2003

Clinical success in harvesting autogenous bone using a minimally invasive trephine.

PURPOSE: Autogenous bone grafting is well established for use in the maxillofacial skeleton. We present our experience with minimally invasive bone harvesting using a power-driven trephine, with favorable patient and clinical results. MATERIALS AND METHODS: This retrospective study evaluation patients requiring autogenous bone harvested using a trephine, treated consecutively over a 3-year period. Mean patient age was 27.2 years (range, 8 to 77 years). Only those patients requiring elective surgery and admission on the same day were included in the study. Intraoperative assessment included the description of complications and the quantity and volume of the bone cores harvested. The complications monitored included bleeding, nerve injury, and perforation of the medial or lateral walls of the ilium. Postoperatively, patients were assessed for ambulation, pain, bleeding, and suitability for discharge. The patients were evaluated 1 week after surgery and were examined for wound complications (incision breakdown, infection, paresthesia, pain) and ambulatory deficits. All patients were then surveyed using a questionnaire outlining short-term (1 to 14 days), and long-term (>6 months postoperative) deficits, pain, and general remarks about the procedure. RESULTS: A total of 84 patients underwent bone harvesting using a power-driven trephine. Bone was harvested from a total of 86 anterior iliac crest sites, for a total of 333 cores (3.96 cores per patient). Forty-one patients were discharged on the day of surgery. Intraoperatively, the volume of bone obtained ranged from 3 to 21 mL per harvest site (1 to 7 cores, 4 mm x 30 to 38 mm). The bone volume obtained was dependent on the size of the defect to be filled. Intraoperatively, 1 complication occurred (1 of 333 cores; 0.3%)-a broken instrument-and there were no perforations of the medial or lateral walls of the ilium or excessive bleeding. The complications totaled 3 (3.6%); none of these produced long term effects. Patients surveyed up to 6 months postoperatively noted positive results. CONCLUSIONS: The harvesting of bone from the anterior iliac crest using a power driven trephine appears to be safe and results in minimal morbidity and ample bone volume for many maxillofacial procedures, without delaying discharge from hospital.

Adolescent↗

PubMed2002

Treatment of chronic subdural haematoma with percutaneous needle trephination and open system drainage with repeated saline rinsing.

Fifty three patients with symptomatic chronic subdural haematomas were treated with single needle trephination followed by open system drainage with repeated saline rinsing for two days. After single trephination good outcome was achieved in 84% of the patients. Early recurrence was found in 11.3% of the cases. After a second needle trephination good outcome increased to 89%. Mortality rate was 4%. Long term follow up (mean 30 months) showed 6.7% recurrence rate. There were no complications. Single needle trephination with open system drainage and repeated rinsing is an effective and safe minimal invasive procedure for patients with chronic subdural haematomas.

Adolescent↗

PubMed2026

Volumetric bone marrow cellularity (VBMC) assessment from routinely processed trephines using three-dimensional x-ray histology and gaussian peak modelling.

Objective.Bone marrow cellularity is routinely estimated from a small number of two-dimensional histology sections, making assessment sensitive to section representativeness, processing artefacts and observer interpretation. Three-dimensional (3D) x-ray histology (XRH), using x-ray computed microtomography (µCT), enables non-destructive whole-block imaging of trephine biopsies. This study evaluated whether XRH combined with Gaussian peak modelling could provide a pragmatic whole-block volumetric bone marrow cellularity (VBMC) estimate from formalin-fixed paraffin-embedded (FFPE) trephine biopsy blocks.Approach.Six routinely processed FFPE bone marrow trephine blocks were imaged using µCT-based XRH at ∼15 µm spatial resolution. VBMC was defined as the red-marrow (RM) fraction of the marrow soft-tissue compartment, RM/(RM + intra-biopsy wax), with wax serving as the volumetric proxy for adipocyte/yellow marrow space. Whole-volume greyscale histograms were modelled using a three-peak Gaussian approach representing intra-biopsy wax, RM and demineralised trabecular matrix. Peak-height and area-under-the-curve metrics were compared with whole-volume 3D segmentation and clinical two-dimensional (2D) cellularity estimates.Main Results.Gaussian peak modelling successfully approximated the segmented tissue-phase distributions. The peak-height-derived VBMC metric showed the closest agreement with whole-volume 3D segmentation, with an average absolute percentage difference of 9.3%, compared with 18.6% for clinical expert 2D cellularity estimates. The area-under-the-curve metric followed similar trends but consistently overestimated VBMC. Clinical 2D cellularity broadly followed whole-biopsy trends but showed one discordant case not explained by slice-position sampling alone. XRH also enabled unrestricted virtual reslicing and visualisation of sectioning-associated artefacts prior to further microtomy.Significance.Pre-sectioning XRH combined with Gaussian peak modelling provides a rapid, segmentation-free route to volumetric cellularity estimation from intact clinical FFPE trephine blocks. The approach supports objective whole-biopsy assessment while remaining compatible with routine histopathology workflows, reflecting the expected limitations of section-based visual estimation despite its role as the current clinical standard. In the near term, it could provide a non-disruptive adjunct to conventional 2D cellularity reporting, pending larger validation studies.

Imaging, Three-Dimensional↗

PubMed2000

Centration of donor trephination in human corneal transplantation.

PURPOSE: To develop and evaluate a new method to quantify centration of the trephined donor cornea relative to the limbus. METHODS: After human donor corneas were trephined for penetrating keratoplasty, the remaining corneoscleral discs were stained and subjected to image analysis. The centration of the excised donor cornea relative to the limbus was calculated by measuring their centroids from the "captured" images. RESULTS: Fifty-two corneoscleral discs were analyzed. The average deviation from the centre was 0.32 mm (SD, 0.18 mm). Neither surgeon nor the type of trephine significantly influenced the mean centroid deviation. CONCLUSION: We have developed and evaluated a method to quantify centration of human donor cornea. In a small series, decentration did not correlate significantly with either the surgeon or the trephine.

Cornea↗

PubMed1992

Bone marrow involvement in non-Hodgkin's lymphoma: increased diagnostic sensitivity by combination of immunocytology, cytomorphology and trephine histology.

Diagnostic results from cytomorphology and immunocytology of aspirated bone marrow (BM) were compared with the findings from standard trephine histology of 100 adult patients with non-leukaemic non-Hodgkin's lymphomas (NHL) in a retrospective study. Immunocytological investigations were performed by the immunoenzymatic APAAP-technique on BM smears monoclonal antibodies against CD19, Cd3, CD10 or TdT antigens and determination of positive cells in relation to total BM leucocytes. Corresponding results were obtained for trephine histology and for the combination of cytomorphology and immunocytology in 93/100 cases. Four cases with BM involvement by trephine histology were missed by the combination of immunocytology and cytomorphology. In turn, three cases negative by trephine histology, were found to be positive by the combination of immunocytology and cytomorphology. Immunocytochemistry considerably increased the number of true positive detected BM-infiltrations by cytomorphology in low grade B-cell lymphoma from 58% to 97%. For the diagnosis of BM involvement in high-grade NHL cytomorphology of the aspirate was of equal sensitivity to the biopsy and was always confirmed by immunocytology. The high diagnostic sensitivity of immunocytology was mainly due to high B-cell counts in BM involved by B-cell lymphoma (means = 38%, s = 23) in contrast to low B-cell counts in BM not involved by NHL (means = 4.5%, s = 3.8). We conclude from our data that immunocytology in addition to standard cytomorphology improves diagnostic sensitivity in the detection of BM involvement by NHL.

Adolescent↗

PubMed1994

Bone marrow trephines. Findings in patients with hairy cell leukaemia before and after treatment.

Bone marrow trephine biopsies from 20 patients with hairy cell leukaemia were reviewed at diagnosis and during therapy with alpha-interferon (IFN) and with 2-chlorodeoxyadenosine (2-CdA). At time of diagnosis the trephines revealed classical features of hairy cell leukaemia and profound alterations of haematopoiesis. All three lines showed dysplastic features with architectural, qualitative and quantitative changes. Review of consecutive trephine biopsies in patients that received IFN showed that a complete remission with disappearance of the tumour was never achieved and that the dysplastic features persisted. An improvement of haematopoiesis was noted, but recovery, especially of the myelopoiesis, was never completely achieved. By contrast, patients treated with 2-CdA de novo and previously treated with IFN achieved a complete remission in all but three cases. The trephine biopsies showed an improvement of haematopoiesis with progressive disappearance of the dysplastic features and a good recovery of myelopoiesis. A residual lymphocytosis was present, but as it was also present in age-matched control cases it could not be considered as a residual tumour. The disappearance of the leukaemic infiltrate probably constitutes a prerequisite for the recovery and normalization of haematopoiesis, while the dysplastic changes present at diagnosis could be the result of cytokine production by the leukaemic cells.

2-Chloroadenosine↗

PubMed1988

Techniques for obtaining differential cell counts from bone marrow trephine biopsy specimens.

Differential cell counts were performed on 200 paired bone marrow aspirates and trephine biopsy specimens to compare the distribution of cell types. Relatively more immature myeloid cells were found in the trephine biopsy specimens and relatively more polymorphs and lymphocytes in the aspirates. Two methods for sampling areas of the trephine biopsy specimens for counting were assessed, and the differences between aspirates and trephine specimens were found to be more consistent when the second, more extensive, sampling method was used. This method also permitted quantitation of some features of bone marrow topography and provided information that would not normally be obtainable from aspirated material. The techniques were easy to apply and took relatively little time to perform. They could offer useful information in the study of bone marrow disorders, particularly those such as myelodysplastic syndromes in which disturbances of marrow architecture are prominent.

Biopsy↗