Comparison of All Arthroscopic Implantation of Chitosan-Based Liquid Scaffold and Hyaluronan-Based Soft Scaffold in the Treatment of Condylar Osteochondral Lesions in the Knee.

Cell-free scaffolds used in cartilage regeneration are produced from different materials. The aim of this study is to compare the clinical and radiological results of two different scaffolds with hyaluronan- or chitosan-based structure used in the treatment of symptomatic condylar osteochondral lesions. The study comprises 69 patients who were operated for osteochondral lesion repair with hyaluronan- (n = 37) or chitosan-based (n = 32) scaffold. The International Knee Documentation Committee (IKDC), Lysholm Knee Scoring Scale and Visual Analog Scale (VAS) scores were collected for both groups at the preoperative and postoperative 3rd, 12th, and 24th months. Magnetic resonance imaging was performed between the 12th and 15th months postoperatively and this with magnetic resonance observation of cartilage repair tissue (MOCART) scoring were compared. Within group assessments demonstrate significant improvement in IKDC, Lysholm, and VAS scores at postoperative 3rd and 12th months. However, in both groups, IKDC, Lysholm and, VAS scores at the postoperative 24th month indicate no significant further improvement, compared with the 12th month results. There was no significant difference between the groups in terms of IKDC, Lysholm, VAS, and MOCART scores at any time period. This study shows that both scaffolds are useful in cartilage regeneration but have no clinical or radiological superiority to each other. Surgeons should select the method with which they feel comfortable. This is a level III, retrospective comparative study.

Both Granulocytic and Non-Granulocytic Blood Cells Are Affected in Patients with Severe Congenital Neutropenia and Their Non-Neutropenic Family Members: An Evaluation of Morphology, Function, and Cell Death

Objective: To examine granulocytic and non-granulocytic cells in children with severe congenital neutropenia (SCN) and their non-neutropenic parents. Materials and Methods: Fifteen patients with SCN and 21 non-neutropenic parents were evaluated for a) CD95, CD95 ligand, annexin V, propidium iodide, cell cycle, and lymphocyte subsets by flow cytometry; b) rapid cell senescence (of leukocytes) by senescence-associated ß-galactosidase stain; c) aggregation tests by aggregometer; d) in vitro bleeding time by PFA-100 instrument; e) mepacrine-labeled dense granule number of thrombocytes by fluorescence microscope; and f) hematomorphology by light and electron microscope. HAX1, ELANE, G6PC3, CSF3R, and JAGN1 mutations associated with SCN were studied in patients and several parents. Results: Significant increase in apoptosis and secondary necrosis in monocytes, lymphocytes, and granulocytes of the patients and parents was detected, irrespective of the mutation type. CD95 and CD95 ligand results implied that apoptosis was non-CD95-mediated. Leukocytes of 25%, 12.5%, and 0% of patients, parents, and controls showed rapid cell senescence. The cell cycle analysis testable in four cases showed G1 arrest and apoptosis in lymphocytes of three. The patients had HAX1 (n=6), ELANE (n=2), G6PC3 (n=2), and unidentified (n=5) mutations. The CD3, CD4, and NK lymphocytes were below normal levels in 16.6%, 8.3%, and 36.4% of the patients and in 0%, 0%, and 15.4% of the parents (controls: 0%, 0%, 5.6%). The thrombocytes aggregated at low rates, dense granule number/thrombocyte ratio was low, and in vitro bleeding time was prolonged in 37.5%-66.6% of patients and 33.3%-63.2% of parents (vs. 0% in controls). Under electron and/or light microscope, the neutrophils, monocytes, lymphocytes, and thrombocytes in the peripheral blood of both patients and parents were dysplastic and the bone marrow of patients revealed increased phagocytic activity, dysmegakaryopoiesis, and necrotic and apoptotic cells. Ultrastructurally, thrombocyte adhesion, aggregation, and release were inadequate. Conclusion: In cases of SCN, patients' pluripotent hematopoietic stem cells and their non-neutropenic parents are both affected irrespective of the genetic defect.

The role of vitamin E in the prevention of zoledronic acid-induced nephrotoxicity in rats: a light and electron microscopy study.

INTRODUCTION: Bisphosphonates are widely used in metastatic cancer such as prostate and breast cancer, and their nephrotoxic effects have been established previously. In this study we aimed to evaluate both the nephrotoxic effects of zoledronic acid (ZA) and the protective effects of vitamin E (Vit-E) on this process under light and electron microscopy. MATERIAL AND METHODS: A total of 30 male Sprague-Dawley rats were divided into 3 groups. The first group constituted the control group. The second group was given i.v. ZA of 3 mg/kg once every 3 weeks for 12 weeks from the tail vein. The third group received the same dosage of ZA with an additional i.m. injection of 15 mg Vit-E every week for 12 weeks. Tissues were taken 4 days after the last dose of ZA for histopathological and ultrastructural evaluation. Paller score, tubular epithelial thickness and basal membrane thickness were calculated for each group. RESULTS: For group 2, the p-values are all < 0.001 for Paller score, epitelial thickness, and basal membrane thickness. For group 3 (ZA + Vit. E), the p-values are < 0.001 for Paller score, 0.996 for epitelial thickness, and < 0.001 basal membrane thickness. Significant differences were also observed in ultrastructural changes for group 2. However, adding Vit-E to ZA administration reversed all the histopathological changes to some degree, with statistical significance. CONCLUSIONS: Administration of ZA had nephrotoxic effects on rat kidney observed under both light and electron microscopy. Concomitant administration of Vit-E significantly reduces toxic histopathological effects of ZA.

The evaluation of xenotransplantation of feline ovarian tissue vitrified by needle immersed vitrification technique into male immunodeficient mice.

In this study, the efficiency of the "Needle Immersed Vitrification" technique was tested on cryopreserved feline ovarian tissue. For vitrification, ovarian fragments (0.5-1.5 mm2) from each ovary were collected; the grafts were exposed to 7.5-15% ethylene glycol and 7.5-15% dimethyl sulfoxide at room temperature and stored in liquid nitrogen at least 1 week. Morphologic examinations, expression of genes such as B cell lymphoma 2, B-cell lymphoma-2-associated X protein, Bone morphogenetic protein 15, zone of polarizing activity, zona pellucida C protein and DNA (cytosine-5)-methyltransferase 1, ultrastructural analysis and viability tests were carried out from collected grafts. Light microscopy examinations revealed the percentage of morphologically normal primordial follicles in a fresh group which was significantly higher than the treatment groups (p < 0.001). Terminal deoxynucleotidyl transferase dUTP nick end labeling and anti-caspase-3 staining observed in oocytes, follicle cells, interstitial tissue showed higher rates of apoptosis for post-vitrification and -transplantation groups than freshly grafted ovarian tissues. Furthermore, we observed significant downregulation of zone of polarizing activity and zona pellucida C protein gene expression in vitrified ovarian tissue grafts than in the fresh grafts (p < 0.05). In conclusion, we suggest that the needle immersed vitrification method is a convenient, cheap, and feasible vitrification method for cat ovarian tissues. However, further studies need to be performed to determine more optimal vitrification solutions and equilibration times for the needle immersed vitrification method in order to adapt it for cat ovaries.

Mouse ovarian tissue vitrification on copper electron microscope grids versus slow freezing: a comparative ultrastructural study.

There are many reasons, including cancer therapy, for premature ovarian failure and infertility. Oocyte, embryo and ovarian cryopreservation are current options for fertility preservation. Ovarian tissue cryopreservation is essential in patients whose cancer therapy cannot be delayed, including prepubertal girls, and is mostly performed using slow freezing. In the present study, mouse ovarian tissues were vitrified on copper electron microscope grids (n=18) or conventionally slow frozen (n=18). Post-thaw tissues were examined histologically using light and electron microscopy and compared with the control group. According to light microscopy observations, antral follicles were found to be better preserved with the slow freezing technique rather than vitrification. Electron microscopy revealed swollen mitochondria in the oocyte cytoplasm, condensations in the zona pellucida, breakages in the junctions of granulosa cells and vacuolisation in the extracellular space in pathologic follicles, which were relatively more frequent, in the vitrification group after thawing. These results indicate that ovarian slow freezing is preferable than vitrification on copper electron microscope grids, especially for larger follicles. Conversely, vitrification of ovarian pieces using cooper grids is user-friendly and provided good protection for primordial follicles and stromal cells. There is a need for further studies into advanced tissue vitrification techniques and carriers.

Biochemical, radiologic, ultrastructural, and genetic evaluation of iron overload in acute leukemia and iron-chelation therapy.

Iron overload in hereditary hemochromatosis and hematologic malignancy has unfavorable effects on morbidity. Herein, 53 children (age 108.4±58.3 mo, 25 girls and 28 boys) with acute myeloblastic and lymphoblastic leukemia, who received 4 different chemotherapy protocols, were evaluated for iron overload throughout chemotherapy. Iron overload arose: (1) before chemotherapy, which was dependent on neither chemotherapy nor packed red blood cell transfusions and (2) after chemotherapy, which was dependent on the duration and nature of chemotherapy and partially on transfusion of packed red blood cells. Iron overload was documented in 75% of patients with a ferritin level >1000 ng/mL, by liver and heart magnetic resonance imaging, and they were administered iron-chelation therapy with success. Three of 10 radiologically iron-overloaded patients were heterozygous for H63D mutation. Aminolevulinic acid and porphobilinogen levels were normal. Light microscopic examination of the bone marrow revealed increased iron granules in erythroblasts, platelets, and megakaryocytes, iron-laden macrophages, free iron in the matrix, dyshematopoiesis, and apoptotic cells. Electron microscopic examination revealed iron-laden secondary lysosomes and autolysosomes in normoblasts and iron-laden primary granules in promyelocytes, irrelevant to the ferritin level, implying autophagia due to chemotherapy as a source of the excess iron. We think that iron overload, which is an important complication of acute leukemia, should be evaluated separately from "transfusion overload," and the management principles specific to leukemia should be implemented.

Effects of Helicobacter pylori infection and long-term proton pump inhibitor use on enterochromaffin-like cells.

BACKGROUND: Excessive release of gastrin leads to hypertrophy and hyperplasia of enterochromaffin-like cells (ECL) and prolonged stimulation of these cells causes functional impairment. The purpose of this study was to investigate the effect of Helicobacter pylori (H. pylori) infection and long-term proton pump inhibitors (PPI) use on ECL cells. METHODS: Fifteen patients who underwent endoscopy because of dyspeptic symptoms were enrolled in the present study. Biopsies were taken from corpus and antrum and existence of H. pylori was investigated with culture, cytology and CLOtest. The patients were divided into 3 groups. Group-A: H. pylori-negative, never treated previously with PPI; Group-B: H. pylori-positive, never treated previously with PPI; and group-C: H. pylori-negative and continuously treated with PPI for more than 6 months before the subject recruitment period. The features of ECL cell in oxyntic glands were examined with electron microscopy on biopsy specimens. RESULTS: ECL cells were completely normal in Group A. In group B, moderate hyperplasia and vacuolization was seen in ECL cells. In group C, ECL cell hyperplasia was observed and vacuoles with greater amounts of granules in enlarged vesicles were found more intensely in cytoplasm. CONCLUSION: The use of PPI for a long period of time and presence of H. pylori infection are risk factors for ECL hyperplasia.

The effect of vitamin D prophylaxis on radiation induced pulmonary damage.

Vitamin D has a selective radio and chemosensitizing effect on tumor cells. In vitro and in vivo studies have shown that vitamin D inhibits collagen gel construction, induces type II pneumocyte proliferation and surfactant synthesis in the lungs, and decreases vascular permeability caused by radiation. The aim of this experimental study was to determine if vitamin D has a protective effect against radiation-induced pulmonary damage. Adult Wistar rats were divided into 4 groups. Group 1 was comprised of control animals. Group 2, which was administered 0.25 µg/kg/day of vitamin D3 for 8 weeks, was the vitamin D control group. Rats in groups 3 and 4 were given 20 Gy right hemithorax radiotherapy, and in addition group 4 was given vitamin D3 treatment, which began the day before the radiotherapy and continued for 8 weeks. At the 8(th) and the 12(th) weeks of the study 4 rats from each group were sacrificed. Right lungs were dissected for light and electron microscopic study. The electron microscopy examinations revealed statistically significant differences between group 3 and 4, and in group 4 there was less interstitial inflammation and collagen deposition, and the alveolar structure and the cells lining the alveolar walls were protected. These results confirm that vitamin D has a protective effect against radiation-induced pulmonary toxicity. These findings should be evaluated with further clinical studies.

Lysosomal rupture, necroapoptotic interactions and potential crosstalk between cysteine proteases in neurons shortly after focal ischemia.

Ischemic cell death is a complex process and the initial distinction between apoptosis and necrosis appears to be an oversimplification. We previously reported that in ischemic neurons with disrupted plasmalemma, apoptotic mechanisms were also active. In the present study, we investigated cellular co-localization of another necrotic feature, lysosomal rupture, with apoptotic mechanisms in the mouse brain and assessed the potential interactions between cysteine proteases. The lysosomal enzymes were spilled into the cytoplasm 1-4h after ischemia/reperfusion, suggesting that lysosomal membrane integrity was rapidly lost, as occurs in necrosis. The same neurons also exhibited caspase-3 and Bid cleavage, and cytochrome-c release. Caspase-3 activity preceded cathepsin-B leakage in most neurons, and declined by 12h, while lysosomal leakage continued to increase. Concurrent inhibition of cathepsin-B and caspase-3 provided significantly better neuroprotection than obtained with separate use of each inhibitor. These data suggest that necrotic and apoptotic mechanisms may act both in concert as well as independently within the same cell beginning at the onset of ischemia to ensure the demise of damaged neurons. Therefore, combined inhibition of cysteine proteases may abrogate potential shifts between alternative death pathways and improve the success of stroke treatments.

Bone Fracture Healing with Umbilico-Placental Mononuclear Cells: A Controlled Animal Study.

BACKGROUND: Fracture healing is a significant process in orthopedics. In this controlled animal study, our aimis to expose the healing effects of cord blood umbilico-placental mononuclear cells (UPMNCs) on bone fractures. MATERIALS AND METHODS: Caesarean sections were performed on five pregnant New Zealand rabbits at term. Placentas and cords were collected. Standard closed transverse shaft fractures were created on both tibial bones of 15 baby rabbits. The right tibias were given UPMNCs; the left tibias were the control group. Histological examinations, osteoblast and osteoclast cell counts, and mechanical stabilities were compared. Anchorage of the donor cells was shown by the fluorescence in situ hybridization (FISH) technique. RESULTS: In the group injected with UPMNCs, histopathological fracture healing was faster, osteoblast and osteoclast counts were significantly increased, and the maximum load capacity was higher. The presence of XX and XY chromatins on the same slide revealed the anchorage of female donor cells on male tissues. CONCLUSION: The effects of umbilico-placental mononuclear cells on bone healing are histopathological healing priority, increased osteoblastic and osteoclastic activities (bone turnover), and better mechanical stability.

Effects of recombinant human erythropoietin on mandibular distraction osteogenesis.

PURPOSE: To evaluate the effects of subcutaneous administration of recombinant human erythropoietin (rHuEPO) on regeneration formation and quality during mandibular distraction osteogenesis. MATERIALS AND METHODS: Sixteen adult male New Zealand rabbits were used in this study. Ethical approval was obtained from the Animal Research Institute of Selcuk University, Konya, Turkey. Subjects were randomly divided into 2 groups. Distraction osteogenesis (DO) was performed with a custom-made distractor on the left mandibles of rabbits. In the experimental group, 4 doses of 150 IU/kg rHuEPO were administered at 48-hour intervals. The first dose was given immediately after surgery. Control subjects received 0.5 mL/kg isotonic solution in the same manner. After 2 days of latency, mandibles were distracted 1 mm/day at 12-hour intervals for 5 days. A 5-mm lengthening was achieved. All animals were sacrificed after 30 days of consolidation. Afterward, samples were prepared for histomorphometric evaluation of newly formed bone area. RESULTS: The number of osteoblasts and blood vessels was significantly higher, whereas the number of osteoclasts was significantly lower, in the experimental group than in the control group (P < .05). In the experimental group, the area of new bone formation was greater than in the control group (P < .05). Moreover, fibroblast and collagen numbers per unit area were higher in the experimental group. However, this finding was not statistically significant (P > .05). CONCLUSION: The subcutaneous administration of rHuEPO improves the rate and quality of bone-healing during distraction osteogenesis. However, the short-term favorable effects of rHuEPO in this study should be extended with long-term investigations before clinical application.

Excessive naked megakaryocyte nuclei in myelodysplastic syndrome mimicking idiopathic thrombocytopenic purpura: a complicated pre- and post-transplantation course.

A boy 3 years 7 months old with thrombocytopenia and history of intracranial hemorrhage who underwent bone marrow transplantation is presented. He was refractory to steroids, immunoglobulin G, vincristine, azathioprine, cyclosporine A, interleukin-11, chemotherapy, and splenectomy. Idiopathic thrombocytopenic purpura was excluded by light /electron microscopic and flow cytometric findings; the diagnosis of refractory cytopenia, a subgroup of pediatric myelodysplastic syndrome, was made. Naked megakaryocyte nuclei were 55.38 +/- 28.2% vs. 31.67 +/- 23.22% of all megakaryocytes in the patient and the control group of 9 patients with idiopathic thrombocytopenic purpura, respectively (p = .016). The posttransplatation course was complicated by delayed platelet engraftment, bronchiolitis obliterans associated with pneumocystis carinii pneumonia, which resolved completely.

Effects of carbamazepine on spinal cord ischemia.

BACKGROUND: Prophylactic treatment with carbamazepine has been shown to reduce the cerebral damage and neurologic deficit in ischemic conditions. A randomized controlled study based on a rabbit model was designed to study the effect of carbamazepine on a spinal cord ischemic reperfusion injury. METHODS: Thirty New Zealand rabbits were randomly assigned to 1 of the 2 groups (n = 15 per group): group I (control group) and group II (carbamazepine group). Spinal cord ischemia was induced by infrarenal aortic crossclamp for 25 minutes in both groups. Functional evaluation with the Tarlov score during a 2-day observation period and histopathologic assessment of the lumbar spinal cord were performed. Changes in spinal cord morphology were observed with hematoxylin-eosin staining and electron microscopy. Gray matter damage was assessed on the basis of the number of normal neurons in the ventral horn. RESULTS: Diffuse destruction of gray matter with moderate to severe vacuolization and essentially no normal ganglion cells was observed in the spinal cord of rabbits in the control group, whereas specimens of rabbits assigned to the carbamazepine group showed ganglion cells with normal nuclei and cytoplasm (P < .0001). Neurologic impairment was significantly attenuated in the carbamazepine group compared with the Tarlov scores of the control group (P < .0001 at day 2). CONCLUSION: Carbamazepine may protect the spinal cord from ischemic reperfusion injury that is associated with ameliorated neurologic and histopathologic results.

Effects of cryopreservation on sperm parameters and ultrastructural morphology of human spermatozoa.

PURPOSE: Cryopreservation of sperm is a widely used technique to maintain and protect the fertility in various occasions such as infertility and malignancy treatments. This study aims to reveal the effects of freezing and thawing on human spermatozoa. MATERIALS AND METHODS: To evaluate the effects of freeze-thawing, semen samples were evaluated by light microscopy by means of morphology, motility and viability, by scanning and transmission electron microscopy for detailed ultrastructural changes. RESULTS: After cryopreservation, a significant decrease in spermatozoa viability was observed (p < 0.01). Group a, b and c motility according to World Health Organization criteria decreased considerably (p < 0.05, p < 0.01, p < 0.05, respectively), whereas there was a substantial increase in group d motility. A strong correlation between rise in number of immotile spermatozoa and decrease in viability was also noted (r = -0.848, p < 0.01). Post-thaw light microscopic studies revealed a considerable decrease in rate of normal spermatozoa (p < 0.05). A considerable decline in the rate of normal sperm was also observed by TEM (p < 0.05). Statistically, acrosomal changes and subacrosomal swelling were found to be significantly increased (both p < 0.05), where the latter appears to be a novel finding in literature. CONCLUSION: Cryopreservation has deleterious effects on spermatozoa, especially on plasmalemma, acrosomes and tails. Electron microscopy is the ultimate modality to investigate spermatogenic cells.

The effects of scolicidal agent propolis on liver and biliary tree.

BACKGROUND: This study was designed to examine the effects of propolis on the liver and biliary system when used as a scolicidal agent. MATERIALS AND METHODS: Thirty Wistar-Albino rats were divided into two groups. Propolis and 0.9% saline (NaCl) were injected into the biliary tract of the rats. Three rats from control group and four rats from propolis group died within 5 days after the procedure. Blood samples of remaining 23 rats were obtained 1 week after and at the end of the experimental study for liver function tests. Six months after the procedure, retrograde and magnetic resonance cholangiography were performed and liver, common bile duct, and duodenum were excised en bloc for histopathological examination. RESULTS: Liver function tests were slightly elevated 1 week after the procedure and were found to be normal at the end of the sixth month in both groups. No stricture in the biliary tree was found on the retrograde and magnetic resonance cholangiograms. The tissue samples of the propolis group showed no histomorphological difference from the control group. CONCLUSIONS: Propolis may be used as a scolicidal agent even in the case of cystobiliary communication with no side effects on liver and biliary tree.

Effects of honey as a scolicidal agent on the hepatobiliary system.

AIM: To examine the effects of 10% diluted honey, which has been shown to be scolicidal, on the liver and biliary system and determine whether it could be used as a scolicidal agent in the presence of biliary-cystic communication. METHODS: Thirty Wistar-Albino rats were divided into two groups. Honey with 10% dilution in the study group and 0.9% saline (NaCl) in the control group were injected into the common bile ducts of rats through a 3-mm duodenotomy. The animals were sacrificed 6 mo after the procedure. Histopathological, biochemical, and radiological examinations were performed for evaluation of side effects. RESULTS: At the end of the sixth month, liver function tests were found to be normal in both groups. The tissue samples of liver and ductus choledochus of the honey group showed no histomorphologic difference from the control group. No stricture on the biliary tree was detected on the retrograde cholangiograms. CONCLUSION: According to these results, we concluded that 10% diluted honey could be used as scolicidal agent safely in the presence of biliary-cystic communication.

The ultrastructural research of liver in experimental obstructive jaundice and effect of honey.

BACKGROUND: To examine the effects of honey on oxidative stress and apoptosis in experimental obstructive jaundice model. METHOD: Thirty rats were divided into 3 groups: group I, sham-operated; group II, ligation and division of the common bile duct (BDL); group III, BDL followed by oral supplementation of honey 10 g/kg/d. Liver samples were examined under light microscope and transmission electron microscope. Hepatocyte apoptosis was quantitated using the terminal deoxy-nucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. Plasma and blood malondialdehyde (MDA) and glutation activities were measured for determining the oxidative stress. RESULTS: The liver levels of MDA and GSH were significantly different between the honey and BDL groups (P = .006 and .001, respectively). However, there was no significant difference between the plasma MDA and GSH levels of these groups (P > .05). In group III, significant reductions in the size of enlarged hepatocytes and the edema were demonstrated. The dilatation of the bile canaliculi dramatically turned to original dimention. By TUNEL assay, it was shown that administration of honey decreased the number of apoptotic cells. CONCLUSIONS: In the present study, we found that honey diminished the negative effects of BDL on the hepatic ultrastructure. We conclude that this effect might be due to its antioxidant and anti-inflammatory activities.

Rapid cell senescence and apoptosis in lymphocytes and granulocytes and absence of GM-CSF receptor in congenital dysgranulopoietic neutropenia.

A girl with congenital dysgranulopoietic neutropenia (CDN) and her non-neutropenic mother with aphthae (A) were investigated. Apoptosis in lymphocytes and granulocytes of both patients (mother A+) were documented by high annexin and electron microscopic morphology. CD11b/CD18 of the daughter's granulocytes ranged between low to normal while that of the mother changed between very low to high levels through A(-) to A(+) periods. In both patients, CD11b/CD18 on lymphocytes were high; GM-CSF receptor was negative; CD4-/CD8- lymphocytes were high and the leukocytes which showed abnormal cell cycle were stained by senescence associated beta-galactosidase. We think that increased apoptosis and rapid cell senescence of leukocytes underlies the pathophysiology of CDN.

Congenital dysgranulopoietic neutropenia.

We investigated a 15-year-old female with congenital dysgranulopoietic neutropenia (CDN) and her non-neutropenic mother who had recurrent stomatitis. In both patients, cells of the neutrophilic, eosinophilic, monocytic, megakaryocytic, and basophilic series were dysmorphic. Plasmacytoid lymphocytes and mild megaloblastic erythroid precursors were present. Bleeding times of both patients were prolonged. The mother had a secondary aggregation defect; the number of the plasmacytoid lymphocytes, dense granules of platelets, and dysmorphic neutrophils, neutrophil chemotaxis, and myeloperoxidase content fluctuated according to the presence or not of aphthae. The daughter's karyotype revealed 46,XX/46,XX, t(1;8). No ELA2 or G-CSFR mutation was detected. These findings support stem cell involvement in CDN.