Clinical features and signaling effects of RET D631Y variant multiple endocrine neoplasia type 2 (MEN2)

Background/Aims@#Germline mutations of the rearranged during transfection (RET) gene cause multiple endocrine neoplasia type 2 (MEN2). About 85% of RET mutations in MEN2 occur in codon Cys634. The RET D631Y mutation has recently been discovered, and we have studied its molecular expression and clinical consequences. @*Methods@#We analyzed the clinical characteristics of a total of 34 D631Y variant MEN2 individuals from seven families. We also constructed wild-type and mutant C630Y, D631Y, and C634R/W expression vectors and investigated their effects on signaling pathways and ability to correct the phenotypes of RET mutant cells. @*Results@#The median ages at diagnosis of pheochromocytoma and medullary thyroid carcinoma (MTC) were higher in patients with RET D631Y variant MEN2 than in those with the C634R/W variant (49:53.5 years vs. 33.5:27 years, respectively), and the penetration of the D631Y mutation with respect to MTC was lower than that of the C634R/W mutation (32.3% vs. 90%). The effects of the mutant vectors on phosphorylation of RET signaling molecules and focus formation were significantly different from those of wild type, but there were no significant differences between the mutants. D631Y scored significantly higher for chemotaxis and wound healing than C630Y, but lower than C634R and C634W. @*Conclusions@#We suggest that the tumorigenic potential conferred by the D631Y mutation is lower than that conferred by the C634R/W mutation, but higher than that conferred by C630Y. Thus, the risk level of the RET D631Y variant appears to be higher than that of C630Y and lower than that of C634R/W.

Functional Identification of Compound Heterozygous Mutations in the CYP17A1 Gene Resulting in Combined 17α-Hydroxylase/17,20-Lyase Deficiency

BACKGROUND: We previously reported a patient with congenital adrenal hyperplasia (CAH) with compound heterozygous mutations in the cytochrome P450 17A1 (CYP17A1) gene. One allele had a p.His373Leu and the other a new p.Glu383fsX36 mutation. The aim of this study was to investigate the functional properties of a new allele present in a compound heterozygote of CYP17A1. METHODS: To understand how p.His373Leu and p.Glu383fsX36 affect P450c17 enzymatic activity, wild type and mutant CYP17A1 cDNAs were cloned into flag-tagged pcDNA3 vector and introduced into human embryonic kidney cells 293T (HEK293T) cells. Protein expression levels of CYP17A1 were then analyzed. And the activities of 17α-hydroxylase and 17,20-lyase of CYP17A1 were evaluated by measuring the conversion of progesterone to 17α-hydroxyprogesterone and of 17α-hydroxypregnenolone to dehydroepiandrosterone, respectively. In addition a computer model was used to create the three-dimensional structure of the mutant CYP17A1 enzymes. RESULTS: Production of the p.His373Leu mutant protein was significantly lower than that of the wild type protein, and the p.Glu383fsX36 protein was hardly produced. Similarly the enzymatic activity derived from the p.His373Leu mutant vector was significantly lower than that obtained from the wild type vector, and little activity was obtained from the p.Glu383fsX36 vector. Three-dimensional modeling of the enzyme showed that p.His373 was located in region important for heme-binding and proper folding. Neither the p.His373Leu nor the p.Glu383fsX36 mutant protein formed a heme-binding structure. CONCLUSION: Enzyme activity measured in both mutants disappeared completely in both 17α-hydroxylase and 17,20-lyase. This result accounts for the clinical manifestations of the patient with the compound heterozygous CYP17A1 mutations.

Mutation of the NF1 Gene and the Associated Clinical Features in Family Members with Neurofibromatosis Type 1 / 대한내과학회지

With an incidence of 1 per 2,500-3,000 individuals, neurofibromatosis type 1 (NF1) is the most common autosomal dominant disorder in humans. NF1 is caused by germline mutations of the NF1 gene, but to date genotype-phenotype analyses have indicated no clear relationship between specific gene mutations and the clinical features of this disease, even among family members with the same mutation. The present study describes a case of two siblings with NF1 with the same genetic mutation but different clinical manifestations. The first patient was a female with iris Lisch nodules, an adrenal incidentaloma, Graves' disease, and skin manifestations, while the second patient, the first patient's younger brother, exhibited only skin neurofibromas and freckling. Further study is needed to reveal the molecular processes underlying gene expression and phenotypes. A better understanding of the genetics associated with NF1 will allow clinicians to detect complications earlier and provide better genetic counseling to NF1 families.

A Case of Ectopic Neurohypophysis Presenting with Hypogonadism

Pituitary stalk interruption and ectopic neurohypophysis seen on magnetic resonance Imaging (MRI) are often associated with either isolated growth hormone (GH) deficiency or combined anterior pituitary hormone deficiency, but their pathogenesis is not clear and the clinical data regarding these anatomical defect is limited. We experienced a 23-year-old male with the absence of secondary sexual characteristics and this was accompanied with pituitary stalk dysgenesis and ectopic neurohypophysis. He received growth hormone for a year when he was 12 years old due to his short stature. Sella MRI showed no visible pituitary stalk with minimal high signal change, suggesting ectopic neurohypophysis. The combined pituitary stimulation test revealed blunted responses of growth hormone, follicle stimulating hormone and luteinizing hormone. For the hypogonadotropic hypogonadism, the patient was given testosterone intramuscularly and he gradually developed secondary sexual characteristics. We concluded that the hypogonadism and growth hormone deficiency in this patient was caused by hypopituitarism due to pituitary stalk dysgenesis and ecopic nuerohypophysis.

Treatment of Type 1 Diabetes through Genetically Engineered K-cell Transplantation in a Mouse Model / 당뇨병

BACKGROUND: K-cells function as targets for insulin gene therapy. In a previous study, we constructed EBV-based plasmids expressing rat preproinsulin controlled by glucose-dependent insulinotropic polypeptide promoters. In the present study, we attempted to correct hyperglycemia in vivo using genetically engineered K-cells in a mouse model of type 1 diabetes. METHODS: K-cells expressing insulin were transplanted under the kidney capsules of STZ-induced diabetic mice. The blood glucose levels and body weights of the experimental animals were measured daily. After four weeks, the mice were injected intra-peritoneally with 2 g/kg glucose following a 6 hr fast. Blood glucose levels were measured immediately following glucose injections. All animals were sacrificed at the end of the glucose tolerance study, and pancreas and graft-bearing kidney tissue samples were stained with antibodies against insulin, glucagon, and C-peptide. RESULTS: The body weights of K-cell-transplanted diabetic mice increased after transplantation, whereas those of untreated diabetic control mice continued to decline. The blood glucose levels of K-cell-transplanted diabetic mice decreased gradually during the two weeks following transplantation. After intra-peritoneal injection of glucose into K-cell-transplanted diabetic mice, blood glucose levels increased at 30 minutes, and were restored to the normal range between 60 and 90 minutes, while untreated control diabetic mice continued to experience hyperglycemia. Kidney capsules containing transplanted K-cells were removed, and sections were stained with anti-insulin antibodies. We detected insulin-positive cells in the kidney capsules of K-cell-transplanted diabetic mice, but not in untreated control mice. CONCLUSION: We detected glucose-dependent insulin secretion in genetically engineered K-cells in a mouse model of type 1 diabetes. Our results suggest that genetically modified insulin producing K-cells may act as surrogate beta-cells to effectively treat type 1 diabetes.

A case of ectopic Cushing's syndrome combined with papillary thyroid carcinoma / 대한내과학회지

Locating a corticotropin-releasing hormone (CRH)- or adrenocorticotropic hormone (ACTH)-secreting tumor is challenging. A 69-year-old woman admitted to our hospital for generalized edema was diagnosed with ectopic Cushing's syndrome. We attempted to find an ectopic tumor and could establish no ectopic focus except a retropharyngeal mass in the neck. We diagnosed the retropharyngeal mass as thyroid papillary carcinoma and examined whether the thyroid papillary carcinoma was the ectopic focus. No relationship between thyroid papillary carcinoma and ectopic Cushing's syndrome has been established. We failed to find another ectopic focus, except for the increased uptake of the retropharyngeal mass on fluorodeoxyglucose positron emission tomography (FDG-PET). Ectopic Cushing's syndrome combined with thyroid papillary carcinoma is very rare, so we report this case along with reviews of related literatures.

A non-functioning pituitary macroadenoma detected incidentally with PET-CT / 대한내과학회지

Whole-body positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (18F-FDG) is a tomographic imaging technique that uses a radiolabeled analog of glucose, 18F-FDG, to image relative glucose uptake rates in various tissues. Since the glucose uptake is increased in many malignancies, 18F-FDG PET is a sensitive method for detecting, staging, and monitoring the effects of therapy on many malignancies. However, it is uncommon to discover an asymptomatic non-functioning pituitary tumor unexpectedly as a hypermetabolic lesion in PET studies. Here, we report a pituitary tumor that was detected incidentally by FDG-PET and ultimately turned out to be a non-functioning pituitary macroadenoma.

Idiopathic hypoparathyroidism: A rare cause of reversible heart failure / 대한내과학회지

A 65-year-old woman presented with acute pulmonary edema, generalized tetany, and paresthesia. She had severe hypocalcemia, a low intact parathyroid hormone level, and her echocardiogram revealed left ventricular dysfunction. She had no history of heart failure or thyroid surgery. The heart failure improved after calcium replacement and conventional heart failure management. She was diagnosed with hypocalcemia-induced heart failure caused by idiopathic hypoparathyroidism. Despite the crucial role of calcium in myocardial contractility, hypocalcemia is rarely reported as a cause of heart failure. In conclusion, plasma calcium should be measured in the initial workup of all patients with heart failure, and corrected if hypocalcemia is seen. Idiopathic hypoparathyroidism is a rare cause of reversible heart failure that should be considered in the etiologic assessment.

Killian-Jamieson Diverticula Mimicking a Right Thyroid Nodule on Ultrasonography: A Case Report

A Killian-Jamieson diverticulum is a type of pharyngoesophageal diverticuli and can be visualized on thyroid ultrasonography (US). Although most of the lesions are located in the deep layer of the left thyroid lobe, we encountered a case of a right-sided Killian-Jamieson diverticulum in a 64-year-old man that was mistaken for a thyroid nodule on US. We describe the US, computed tomographic, and esophagraphic findings of this case. In addition, we describe the US findings of a left Killian-Jamieson diverticulum in a 55-year-old woman that was seen as a hyperechoic mass in the thyroid on US.. The shape and echogenecity of the diverticulum changed with swallowing as depicted on real-time US and the need for a needle aspiration biopsy was avoided.

A case of Addison's disease due to tuberculosis: pathologic confirmation by laparoscopic biopsy / 대한내과학회지

Addison's disease is a rare disorder that is characterized by primary adrenal hypofunction and the underlying causes are various according to geographic regions. In order to establish an appropriate therapeutic regimen to treat adrenal insufficiency associated with Addison's disease, knowledge of the underlying adrenal abnormality is essential. We report a case of a 37-year-old man who showed biochemical evidence of adrenocortical insufficiency without signs of tuberculosis. Computed tomography showed bilateral adrenal enlargement and definitive diagnosis of adrenal tuberculosis was established by laparoscopic biopsy.

A case of adrenocortical adenoma clinically mimicking pheochromocytoma / 대한내과학회지

The coexpression of cortical and medullary features in a single adrenal cortical cell has been recognized, leading to terms such as cortico-medullary cells. Here, we reported a case of adrenocortical adenoma consisting of cortico-medullary cells that clinically mimicked pheochromocytoma. A 52-year-old woman was admitted to our hospital complaining of an 8-month history of paroxysmal palpitation with refractory hypertension. A 24-hour urine study revealed increased norepinephrine and metanephrine levels. Computed tomography of the abdomen revealed a 1.0x0.9-cm mass in the left adrenal gland. The patient subsequently underwent unilateral laparoscopic adrenalectomy for a presumptive pheochromocytoma. Light microscopic findings of the left adrenal mass indicated an adrenocortical adenoma, but electron microscopy identified lipid vacuoles and smooth endoplasmic reticulum, along with dense core neurosecretory granules, so-called cortico-medullary cells. This is the first report of the detection of cortico-medullary cells in adrenocortical adenoma presenting as pheochromocytoma in Korea.

The Effect of Oxidative Stress on the Proliferation and Differentiation of Human Bone Marrow Stromal Cell-Derived Osteoblasts / 대한내분비학회지

BACKGROUND: The objectives of our study were to assess the effects of oxidative stress on the proliferation, differentiation and apoptosis of human bone marrow stromal cell (BMSC)-derived osteoblasts and to explore pathways by which osteoblast cell apoptosis was induced. METHODS: Mononuclear cells including BMSCs were cultured to osteoblastic lineage. Different doses of hydrogen peroxide (H2O2) were added to the culture media. The colony forming units-fibroblastic (CFU-Fs) were stained with crystal violet and alkaline phosphatase (ALP). The MTT assay was done to see the effect of H2O2 on cell viability. The effect of H2O2 on osteocalcin gene expression was determined by RT-PCR. The matrix calcification measurement was performed. FACS analysis was performed to determine the osteoblasts apoptosis. Caspase-3, -8 and 9 activity assay and cytochrome c release were measured. RESULTS: The size and number of ALP (+) CFU-Fs were also decreased by H2O2 treatment. When compared with the control group, H2O2 significantly decreased the total number of cells of each culture well during MTT assay. H2O2 significantly diminished expression of osteocalcin mRNA. N-acetylcystein (NAC) blocked the diminution of cell viability and the inhibition of osteocalcin mRNA expression by H2O2. H2O2 reduced matrix calcification. FACS analysis revealed H2O2 increased percentage of apoptotic cells. Addition of H2O2 resulted in the increase of caspase-9 and -3 activity but not caspase-8, and release of cytochrome c to the cytosol. CONCLUSION: These data suggest that, in primary human BMSCs, oxidative stress inhibits proliferation of stromal cells and inhibits the differentiation to osteoblastic lineage. In addition, oxidative stress induces apoptosis of human BMSC-derived osteoblasts and this may be mediated by mitochondrial pathway of apoptotic signal.

The Effect of Simvastatin on the Proliferation and Differentiation of Human Bone Marrow Stromal Cells

Statins have been postulated to affect the bone metabolism. Recent experimental and epidemiologic studies have suggested that statins may also have bone protective effects. This study assessed the effects of simvastatin on the proliferation and differentiation of human bone marrow stromal cells (BMSCs) in an ex vivo culture. The bone marrow was obtained from healthy donors. Mononuclear cells were isolated and cultured to osteoblastic lineage. In the primary culture, 10(-6) M simvastatin diminished the mean size of the colony forming units-fibroblastic (CFU-Fs) and enhanced matrix calcification. At near confluence, the cells were sub-cultured. Thereafter, the alkaline phosphatase (ALP) activities of each group were measured by the time course of the secondary culture. Simvastatin increased the ALP activity in a dose dependent manner, and this stimulatory effect was more evident during the early period of culture. A 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay was performed during the secondary culture in order to estimate the effect of simvastatin on the proliferation of human BMSCs. When compared to the control group, simvastatin significantly decreased the proliferation of cells of each culture well. 10(-6) M of simvastatin also significantly enhanced the osteocalcin mRNA expression level. This study shows that simvastatin has a stimulatory effect on bone formation through osteoblastic differentiation, and has an inhibitory effect on the proliferative potential of human BMSCs.

The Changes in the Serum RANKL and OPG levels after Bone Marrow Transplantation: Association with Bone Mineral Metabolism / 대한내분비학회지

BACKGROUND: The loss of bone mass is usually detected after bone marrow transplantation(BMT), particularly during the early post-transplant period. We recently reported that enhanced bone resorption following BMT was related to both the steroid dose and increase in IL-6. It was also suggested damage of the marrow microenvironment due to myeloablation and changes in bone growth factors contribute to post-BMT bone loss. Recently, the interactions of OPG and RANKL have been reported to be crucial in osteoclastogenesis and therefore in bone homeostasis. There are few data on the changes in RANKL/OPG status during the post-BMT period. This study investigated the changes in the levels of RANKL and OPG during the post-BMT period, and also assessed whether the changes in these cytokine levels actually influenced bone turnover and post-BMT bone loss. METHODS: We prospectively investigated 110 patients undergoing allogenic BMT and analyzed 36 (32.4+/-1.3 years, 17 men and 19 women) where DEXA was performed before and 1 year after the BMT. The serum bone turnover marker levels were measured before and 1, 2, 3, 4 and 12 wks, 6 Ms, and 1 yr after the BMT. The serum sRANKL and OPG levels were measured in all patients before and 1, 3 and 12 wks after the BMT. RESULTS: The mean bone losses in the lumbar spine and total proximal femur, which were calculated as the percent change from the baseline to 1 yr, were 5.2(P<0.01) and 11.6%(P<0.01), respectively. The mean serum ICTP, a bone resorption marker, increased progressively until 3 and 6 months after the BMT, but decreased gradually thereafter, reaching the basal values after 1 year. The serum osteocalcin levels decreased progressively until 3 wks after the BMT, then increased transiently at 3 and 6 Ms, but returned to the basal level by 1 yr. The serum sRANKL and OPG levels had increased significantly by weeks 1 and 3 compared with the baseline(P<0.01), but decreased at 3 months. The sRANKL/OPG ratio increased progressively until 3 weeks, but then decreased to the basal values. During the observation period, the percent changes from the baseline in the serum RANKL levels and RANKL/OPG ratio showed positive correlations with the percent changes from the baseline serum ICTP levels. Patients with higher RANKL levels and RANKL/OPG ratio during the early post-BMT period lost more bone mass at the lumbar spine. CONCLUSION: In conclusion, dynamic changes in the sRANKL and OPG levels were observed during the immediate post-BMT period, which were related to a decrease in bone formation and loss of L-spine BMD during the year following the BMT. Taken together, these results suggest that increased sRANKL levels and sRANKL/OPG ratios could be involved in a negative balance in bone metabolism following BMT.

Primary aldosteronism due to unilateral adrenal hyperplasia: report of a case and review of the literature / 대한내과학회지

Unilateral adrenal hyperplasia (UAH) is a rare, surgically correctable subset of primary aldosteronism. It has similar clinical features to aldosterone-producing adenoma (APA), but different pathologic finding. We report a case of UAH in a 51-year-old Korean man. The patient had hypertension. Hypokalemia and suppressed plasma renin activity (PRA) with elevated plasma aldosterone concentration (PAC) was observed. The 1.5 cm-sized nodule in left adrenal gland was scanned by abdominal computed tomography (CT). The selective adrenal venous sampling for determinations of PAC showed an overfunctioning left adrenal gland, and laparoscopic left adrenalectomy was performed. Pathologically, 1.3 cm-sized nodular hyperplasia lesion was observed. Hypokalemia, hypertension, and endocrine data were corrected after surgery, and there was no sign of recurrence for eight months after surgery. Clinical features of UAH are also reviewed.

The Changes of Serum Growth Factors after Hematopoietic Stem Cell Transplantation: Impact on Bone Mineral Metabolism / 대한내분비학회지

BACKGROUND: A loss of bone mass is usually detected after a bone marrow transplantation (BMT), especially during the early post-transplant period. We recently reported that enhanced bone resorption following a BMT was related to both the steroid dose and the increase in IL-6. We also suggested damage to the marrow stromal microenvironment, by myoablation, partly explains the impaired bone formation following a BMT. It is well known that some growth factors play important role in bone growth and osteogenesis. However, the pathogenetic role of bone growth factors in post-BMT bone loss is unknown and data on the changes in the growth factors, in accordance with bone turnover markers and bone mineral density (BMD) changes are scarce. We investigated changes in bone growth factors such as IGF-I (Insulin-like growth factor-I), fibroblast growth factor-2 (FGF-2) and Macrophage colony stimulating factor (M-CSF), during the post-BMT period, and assessed whether the growth factor changes influenced the bone turnover and post-BMT bone loss. The present study is the first prospective study to describe the changes in bone growth factors following a BMT. METHODS: We prospectively investigated 110 patients undergoing a BMT, and analyzed 36 patients (32.4+/-1.3 years, 17 men and 19 women) whose BMDs were measured before, and 1 year after, the BMT. The serum biochemical markers of bone turnover were measured before, 1, 2, 3 and 4 weeks, 3 and 6 months, and 1 year, after the BMT. The serum FGF-2, IGF-I and M-CSF levels were measured before and 1 and 3 weeks, and 3 months after the BMT. The correlation between the changes of growth factors and various bone parameters was analyzed. RESULTS: The mean bone losses in the lumbar spine and total proximal femur, calculated as the percentage change from the baseline to the level at 1 year, were 5.2 (p<0.05) and 11.6% (p<0.01), respectively. The serum type I carboxyterminal telopeptide (ICTP), a bone resorption marker, increased progressively until 6 months after the BMT, but thereafter decreased, to the base value after 1 year. Serum osteocalcin, a bone formation marker, decreased progressively, until 3 weeks after the BMT but then increased transiently, and finally returned to the base level at 1 year. The serum IGF-I and FGF-2 also decreased progressively until 3 weeks and 1 week after the BMT, respectively, then increased to the base values at 3 months. The serum M-CSF increased briskly at 1 week post-BMT, then decreased to the base level. There were positive correlations between the percentage changes from the baseline proximal femur BMD and the IGF-I levels 3 weeks and 3 months (r=0.52, p<0.01, r=0.41, p<0.05) post BMT. A Significant correlation was found between the IGF-I and osteocalcin levels pre-BMT, and 3 weeks after the BMT. Another positive correlation was found between the M-CSF and the ICTP levels at 3 weeks post BMT (r=0.54, p<0.05). CONCLUSION: In conclusion, there were significant changes in the serum IGF-I, FGF-2 and M-CSF levels in the immediate post-BMT period, which were related to a decrease in bone formation and loss in the proximal femoral BMD during the year following the BMT

The Effect of Cilostazol on Glucose Tolerance and Insulin Resistance in a Rat Model of Non-insulin Dependent Diabetes Mellitus

BACKGROUND: It has been reported that many peripheral vasodilating drugs might improve insulin resistance. Cilostazol, a antithrombotic agent, increases peripheral blood flow in non-insulin dependent diabetic patients. The effect of cilostazol treatment on insulin resistance in streptozotocin (STZ)-induced non-insulin dependent diabetic Wistar rats was examined. METHODS: About a half of two-day old neonate siblings were injected intraperitoneally with STZ and maintained for six months, at which time they were compared with age-matched control rats for intraperitoneal glucose tolerance test (IPGTT) and for glucose infusion rate (GINF) in a euglycemic hyperinsulinemic glucose-clamp study. After that, these studies were also performed after feeding rat chow containing cilostazol (100 mg/kg/day) to rats with STZ-induced non-insulin dependent diabetes mellitus for four-weeks and compared with those of age-matched control rats. RESULTS: In the intraperitoneal glucose tolerance test studies, plasma glucose levels of STZ-induced non-insulin dependent diabetic rats were significantly higher and plasma insulin levels significantly lower than those of age-matched control rats in the age of six months. Glucose infusion rate was lower in STZ-induced non-insulin dependent diabetic rats than those of age-matched control rats. However, after a four-week cilostazol treatment, glucose infusion rate of STZ-induced non-insulin dependent diabetic rats was not significantly different from that of control rats. CONCLUSION: These findings suggested that cilostazol may improve insulin resistance in STZ-induced non-insulin dependent diabetic rats.

The Changes of Cytokines and Bone Turnover Markers after Bone Marrow Transplantation / 대한내분비학회지

BACKGROUND: Loss of bone mass is usually detected after BMT. The causes of bone loss are related with gonadal dysfunction and immunosuppressants. Cytokines, especially IL-6, play an important role in the pathogenesis of postmenopausal osteoporosis. However, the pathogenetic role of cytokines in post-BMT bone loss is unknown and data on the changes of cytokines in accordance with bone turnover markers are scarce. The aim of this study is to assess the relationship of bone turnover markers and cytokines of peripheral blood and bone marrow before and after allogeneic BMT. METHODS: This prospective study included two analyses. The first was a study of 46 BMT recipients, examining the relationship between bone turnover markers and cytokines of serum which were measured before and 1, 2, 3, 4 week and 3 months after BMT. The second was a study of 14 BMT patients, measuring bone marrow plasma cytokines such as IL-6 and TNF-alpha at post-BMT 3 week and bone turnover marker at the same time to assess the relationship between two parameters. RESULTS: Serum ICTP, bone resorption marker, increased progressively until 4 weeks (peak) after BMT and then decreased thereafter. Serum osteocalcin, bone formation marker, decreased progressively until 3 weeks after BMT and then increased thereafter. There was positive correlation between serum ICTP and bone marrow IL-6 levels at the post-BMT 3 week with a statistical significance, but the correlation between bone turnover markers and bone marrow TNF-alpha or peripheral blood cytokines was not found. CONCLUSION: Our data suggest that the progressive increase of bone resorption after BMT is related with the increase of bone marrow IL-6, which is a potent stimulator of bone resorption in vivo.

The Effect of Bone Marrow Transplantation on Bone Mineral Metabolism: 2 - Year Prospective Study / 대한내분비학회지

BACKGROUND: Loss of bone mass is usually detected after bone marrow transplantation (BMT), especially during the early post-transplant period. But little is known about the long-term effects of BMT on bone mineral metabolism. METHODS: We have investigated prospectively 12 patients undergoing BMT (4 autologous, 8 allogeneic) for hematologic diseases (8 leukemia, 3 SAA, 1 MDS). Serum concentrations of calcium, phosphorus, creatinine, gonadotropins, sex hormones and bone turnover markers (osteocalcin and ICTP) were measured. The samples were collected before BMT and 1, 2, 3, 4, and 12 weeks, 6 months and 1, 2 years thereafter. Bone mineral density (BMD) was measured with DEXA (Dual Energy X-ray Absorptiometry) before BMT, 1 year and 2 year after BMT. In patients with amenorrbea, hormone replacement therapy was started from around 1 year after BMT RESULTS: 1. The mean bone loss in the lumbar spine, calculated as the percent change from the baseline to the level at 1 year and 2 year was 7.3% and 1.9%, respectively. The mean bone loss in the total proximal femur from the baseline to the level at 1 year and 2 year was 8.0% and 8.3% respectively. 2. The serum ICTP increased progressively until four weeks after BMT. Thereafter, it decreased gradually to reach basal values after one year and thereafter no more change until 2 year. Serum osteocalcin decreased progressively until three weeks after BMT. After that, it increased and reached basal values after 3 months. Osteocalcin increased at 6 month transiently but thereafter, it decreased to the level of slightly above basal value at 2 year. 3. Patients who were treated with TBI or pateints with GVHD had a tendency of lower BMD at l year and 2 year after BMT than those of patients without TBI or GVHD. 4. Eight out of nine women went into a menopausal state immediately after BMT and remained amenorrhea, evidenced by high gonadotropins and low estradiol levels. In contrast to women, gonadotropins and testosterone levels were not changed significantly in men after BMT. CONCLUSION: The rapid impairment of bone formation and the increase in bone resorption, as shown by the biochemical markers in this study, might play a role in bone loss after BMT. The efficacy of HRT for the correction of hypogonadism and bone loss was evidenced by 2 year BMD which was much more increased compared to 1 year BMD, especially in vertebra.

The Effect of Hematopoietic Stem Cell Transplantation in the Origin and the Osteoblastic Differentiation of the Human Bone Marrow Stromal Cell / 대한내분비학회지

BACKGROUND: Bone marrow transplantation is the treatment of choice for patients with certain- hematological malignancies, many of whom will survive many years thereafter. Bone disease is a potential longterm complication. But, little is known about the effects of bone marrow transplantation on bone. METHODS: In this study, bone marrow was obtained from healthy donor and transplant recipients. Then mononuclear cells including marrow stromal cells were isolated and cultured. At near confluence, bone marrow stromal cells were subcultured. Thereafter alkaline phosphatase activities of each group were measured by time course of secondary culture. We also analysed the origin of marrow stromal cells by the polymerase chain reaction using YNZ 22 minisatellite probe. RESULTS: l. Cells cultured in our system showed the characteristics of marrow stromal cells differentiated to osteoblasts. They were in fibroblast-like spindle shape and positive to alkaline pbosphatase histochemistry and Von Kossa histochemistry in secondary cultures. 2. The time required for the near confluence in the primary culture was 15 days and 22.9 days on the average in healthy donors and transplant recipients, respectively (p=0.003). 3. In secondary cultures, healthy donors and transplant recipients showed peak alkaline phosphatase activity at 10 days and 17 days, respectively (p=0.031). Alkaline phosphatase activity was lower in BMT recipients than in healthy donors during the whole period of secondary cultures. 4. In polymerase chain reaction analysis using YNZ 22 minisatellite probe, bone marrow stromal cells were of recipient origin. CONCLUSION: Recipient-derived bone marrow stromal cells may be damaged secondary to the effect of chemotherapy, glucocorticoid & total body irradiation which have given before bone marrow transplantation. So it may affect the differentiation of bone marrow stromal cells into the osteoblasts.