Gul Gumuser

Bone mineral density in girls and boys at different pubertal stages: relation with gonadal steroids, bone formation markers, and growth parameters

Puberty has a key role in bone development. During puberty, several nutritional and hormonal factors play a major role in this process. The aim of this study was to determine the changes in areal bone mineral density (BMD), gonadal steroids, bone formation markers, and growth parameters in healthy Turkish pubertal girls and boys at different pubertal stages. In additional, we aimed to detect the relationship between BMD, sex steroids, and growth parameters, and to reveal the most important determinant of BMD in the pubertal period. BMD of the lumbar spine and total body was performed by dual-energy X-ray absorptiometry (Lunar DPX series) in 174 healthy pubertal children (91 girls, 83 boys), aged 11–15 years. Height and weight were measured. Pubertal stages were assesed. Bone formation markers and gonadal steroids were measured. BMD values significantly increased until stage IV in girls. In boys, BMD values also increased during puberty (P < 0.05), but it was significantly higher in stage IV compared with that in other pubertal stages (P < 0.01). Testosterone levels increased until stage IV in both sexes, particularly in boys. Estrogen levels significantly increased during puberty in girls, whereas it was significantly higher at stage IV in boys (P < 0.001). Bone-specific alkaline phosphatase (BAP) level was higher in early and midpuberty, and decreased in late puberty in girls (P < 0.001). BAP level was higher in stage IV in boys. Osteocalcin level was shown not to change significantly in pubertal stages. There was a modest correlation between BMD values and estrogen and testosterone levels in boys. In girls, there was a correlation between BMD values and estrogen levels only (P < 0.05). Weight was significantly associated with BMD in both sexes (P < 0.05). Estrogen had a significant influence on BMD in boys and girls. In conclusion, bone mass increased throughout puberty in both sexes. Peak bone mass was not achieved in girls, but was obtained at stage IV in boys. Bone formation markers were good predictors of bone mass in girls, but not in boys. Estrogen level made the greatest contribution to bone mineral acquisition in boys and girls. The achievement of peak bone mass was sustained by estrogen in boys. The major independent determinant of BMD in both sexes was weight.

Comparative effects of risedronate, atorvastatin, estrogen and SERMs on bone mass and strength in ovariectomized rats

OBJECTIVE The aim of this study was to investigate bone protective effects of risedronate, atorvastatin, raloxifene and clomiphene citrate in ovariectomized rats. METHODS Our study was conducted on 63 rats at Experimental Research Center of Celal Bayar University. Six-month-old rats were divided into seven groups. There were five drug administered ovariectomized groups, one ovariectomized control group without drug administration and one non-ovariectomized control group without drug administration. Eight weeks postovariectomy, rats were treated with the bisphosphonate risedronate sodium, the statin atorvastatin, the estrogen 17beta-estradiol and the selective estrogen receptor modulators (SERMs) raloxifene hydrochloride and clomiphene citrate by gavage daily for 8 weeks. At the end of the study, rats were killed under anesthesia. For densitometric evaluation, left femurs and tibiae were removed. Left femurs were also used to measure bone volume. Right femurs were used for three-point bending test. RESULTS Compared to ovariectomized group, femur cortex volume increased significantly in non-ovariectomized group (p=0.016). Compared to non-ovariectomized group, distal femoral metaphyseal and femur midshaft bone mineral density values were significantly lower in ovariectomized group (p=0.047). In ovariectomy+atorvastatin group, whole femur and femur midshaft bone mineral density and three-point bending test maximal load values were significantly higher than ovariectomized group (p=0.049, 0.05, and 0.018). When compared to the ovariectomized group, no significant difference was found with respect to femoral maximum load values in groups treated with risedronate, estrogen, raloxifene and clomiphene (p=0.602, 0.602, 0.75, and 0.927). In ovariectomy+risedronate group, femur midshaft bone mineral density values were significantly higher than the values in ovariectomized group (p=0.023). When compared to ovariectomized group, no significant difference was found with respect to femur midshaft bone mineral density values in groups treated with estrogen, raloxifene and clomiphene (p=0.306, 0.808, and 0.095). CONCLUSIONS While risedronate sodium prevented the decrease in bone mineral density in ovariectomized rats, atorvastatin maintained mechanical characteristics of bone and also prevented the decrease in bone mineral density as risedronate sodium.

Effects of 99mTc-MIBI and 99mTc-MDP administration on dual-energy X-ray absorptiometry bone mineral density measurements.

ObjectiveNuclear medicine procedures are often performed in close-time proximity to bone densitometry studies. The purpose of this study was to determine the effects of 99mTc-hexakis-2-methoxyisobutyl isonitrile (MIBI) and 99mTc-methylene diphosphonate (MDP) on the accuracy of bone mineral density (BMD) measurements performed using dual-energy X-ray density. MethodsThe effect of a diagnostic dose of 99mTc-MIBI on BMD estimations in the lumbar spine and the left total hip was assessed in 30 patients (19 female, 11 male; mean age: 55.5±10.5 years) by using a Lunar DPX-NT scanner. Thirty patients, admitted to the nuclear medicine department for bone scintigraphy (15 female, 15 male; mean age: 56±15.92 years), were included into the study. Each patient underwent dual-energy X-ray density assessment for which a Lunar DPX-NT scanner was used before and 2 h after intravenous injection of 99mTc-MDP (925 MBq) and 99mTc-MIBI (1110 MBq). BMD measurements were calculated from lumbar spine (including L2–4) and left hip (including femoral neck, trochanter, and total hip). For statistical analysis, the Wilcoxon test was used and a P value of less than 0.05 was accepted as statistically significant. ResultsAccording to Wilcoxons statistical test, we found extremely significant changes on the measured BMD, T-score, before and 2 h after the injection of 99mTc-MIBI for lumbar spine and left hip in 30 patients. We found statistically significant decrement on measured BMD from lumbar spine and trochanter before and 2 h after the injection of 99mTc-MDP. Although MDP BMD values in femoral neck and total hip were decreased after the injection of Tc-99m, they did not reach a statistically significant value. The comparison of pre-T-score and post-T-score values showed a statistically significant decrease after the injection for only L2–4 lumbar spine (P = 0.002), but left hip of pre-T-score and post-T-score values did not reach a statistically significant value. ConclusionIn this study, it was determined that measured BMD values are decreased in lumbar spine for all patients. The magnitude of the effect is dependent on the location of the activity. We assume that some radioactivity from 99mTc is counted by the densitometers detector, thus resulting in a decrease in the measured BMD. Scintigraphy and bone densitometry should be performed on different days to avoid artifactual reduction in BMD measurements.

The evaluation of urine activity and external dose rate from patients receiving radioiodine therapy for thyroid cancer

The aim of this study was to determine the external dose rate of iodine retention as a function of time in the bodies of thyroid cancer patients during their isolation period in the hospital. Urine samples were collected at 6th, 12th, 18th, 24th h and 2nd, 3rd, 4th, 5th d from 83 patients after oral administration of (131)I and counted. The external dose rates were also simultaneously determined at the same time points. Then, it was expressed as retained radioiodine body activity versus dose rate. Effective half life calculated from urine sample measurements was found as 18.4±1.8 h within the first 24 h and 64±2.7 h between 48 and 120 h. According to this results, the external dose rate (<20 µSv h(-1)), which patients could be discharged, was achieved after 48 h for 3700 and 5550 MBq, and after 72 h for 7400 MBq of (131)I treatments.

Early renal parenchymal histological changes in an experimental model of vesico-ureteral reflux and the role of apoptosis.

Objectives. To observe early renal parenchymal cellular changes in an experimental model of vesico-ureteral reflux (VUR) and to show whether the apoptotic pathway plays a role in these cellular changes. Material and methods. Fourteen New Zealand breed rabbits were used and were divided into two equal groups (control and experimental groups). Urine samples were obtained in a sterile manner and cultured. In the study group, reflux was created in the right kidneys surgically. Renal scintigraphy and voiding cystourethrography (VCUG) were performed in both groups on Day 17. The kidneys were examined in terms of histology, apoptotic activity and caspase activity. Results. No growth was observed in urine cultures in either group. VUR was manifested in only two rabbits in the experimental group on VCUG. On renal scintigraphy, no renal scarring was observed in either of the groups and renal uptake values were in the normal range. There was a greater increase in collagen in the right kidneys in the experimental group than in the control group and apoptotic activity was significantly increased in the study group: 0% in the control group, 10.8%±0.7% in the experimental group (p<0.001). Caspase-6 activity was strongly positive and caspase-8 and -9 activities were moderately positive in the right kidneys of the experimental group. Caspase-6 activity was moderately positive, and caspase-8 and -9 activities were weakly positive in the contralateral kidneys of the experimental group. Caspase activities in the control group were negative (p<0.001). Conclusions. In this experimental model of VUR, apoptotic activity was initiated via the caspase-8 and -9 pathway and collagen tissue increased in the renal parenchyma where reflux occurred. The balance of apoptotic activity may play a key role in the occurrence of reflux nephropathy.

Evaluation of abnormal radiological findings in children aged 2 to 36 months followed by recurrent urinary tract infection: a retrospective study

Abstract Our aim is to determine the rational usage of imaging techniques in order to prevent or minimize permanent renal damage in recurrent urinary tract infections (UTIs). This study was enrolled children aged between 2 and 36 months, following-up with the diagnosis of recurrent UTI. All children had ultrasonography (USG) and dimercaptosuccinic acid scanning, 39 of them had underwent on voiding cystourethrography. There were 133 children (87 girls, 46 boys) with the mean age of 32.82 ± 38.10 months included into the study. Forty-three kidney units were normal in ultrasonogram of which seven units had reflux whereas among 35 units with hydronephrosis 22 units had reflux. Sensitivity and specificity presence of hydronephrosis in ultrasonogram for prediction of reflux was 75.9% and 73.5%, respectively. There were 19 dilated ureters in ultrasonogram, and among them 14 had reflux. Sensitivity and specificity of presence with ureteral dilatation in ultrasonogram for prediction of reflux was found as 48.3% and 89.8%, respectively. The sensitivity of parenchymal thinning seen in ultrasonogram for the evaluation of renal parenchyma was 15.9%, whereas specificity was 98.2% .Sensitivity and specificity of dimercaptosuccinic acid for prediction of reflux was 51.6% and 72.3%, respectively. The normal ultrasonogram findings cannot rule out neither possibility of reflux presence nor development of renal scarring. Therefore, DMSA scanning has major role both in determination of parenchymal damage and prevention of scarring. Also we get an important result as ureteral dilatation seen in USG, related to presence of reflux.

Samarium-153 therapy for prostate cancer: the evaluation of urine activity, staff exposure and dose rate from patients

The aim of this study was to determine the excretion of Samarium-153-ethylenediaminetetramethylphosphonic acid ((153)Sm-EDTMP) in urine and to calculate the dose rate of its retention in the body as a function of time and the dose received by the skin of laboratory staffs finger. Urine samples were collected from 11 patients after intravenous injection of (153)Sm-EDTMP. The measurements of dose rate were performed. Thermoluminescent dosemeters were used for absorbed dose measurements. Effective half-lives that were calculated from urine sample measurements were found as 7.1±3 h within the first 24 h. Whole body dose rates before collecting urine of patients were 60.0 ± 15.7 µSv h(-1) for within 1 h following (153)Sm-EDTMP administration. The highest finger radiation dose is to the right-hand thumb (3.8 ± 2 mGy). The results of the study imply that patients who recieved (153)Sm-EDTMP therapy should be kept a minumum of 8 h in an isolated room at hospital and that one staff should give therapy at most two patients per week.

The effects of lornoxicam on brain edema and blood brain barrier following diffuse traumatic brain injury in rats

BACKGROUND In this experiment, the effects of lornoxicam on brain edema and the blood brain barrier (BBB) following diffuse traumatic brain injury (TBI) were studied. METHODS Twenty adult male Wistar albino rats were anesthetized, and experimental closed head trauma was induced by the Marmarou method. After head injury, the rats were randomly divided into two groups: Group I was the control group, to which 2 ml saline was administered intraperitoneally, and Group II was the lornoxicam group, to which 2 ml 1.3 mg kg-1 lornoxicam was administered intraperitoneally. Twenty-four hours after head trauma, 99 mTc pentetate (DTPA) was injected at a dose of 37 MBq, and posterior planar images of each rat were obtained using an Infinia gamma camera. After imaging of BBB permeability, brain tissues were dissected from the cranium. The brain water content (BWC) of each sample was calculated using the wet-dry method. RESULTS The lesion/background (L/b) ratio of Group I was 3.76±0.46 and 3.02±0.66 for early (5th min) and late (60th min) imaging, respectively. In Group II, the L/b ratios were 3.52±0.96 and 2.63±0.63 for early and late imaging, respectively (p>0.05). BWC was 79.6±2.5% and 77.5±1.1% for Groups I and II, respectively (p<0.05). CONCLUSION In this rat model of TBI, lornoxicam reduced brain edema but did not affect BBB permeability.

Multifunctional molecular imaging probes for estrogen receptors: 99mTc labeled diethylstilbestrol (DES) conjugated, cuinp quantum dot nanoparticles (DESCIP)

A theranostic nanoparticle was synthesized based on diethylstilbestrol conjugated with phosphate, copper, and indium (DESCIP) and labelled with 99mTc which can be used for SPECT imaging of ER-enriched cancers. In vitro biological activity of 99mTc-DESCIP was examined in breast adenocarcinoma cells (MCF-7), prostatic carcinoma cells (PC-3), and pulmonary epithelial cells (A-549). In vivo lymph node imaging was performed in normal and receptor blocked female New Zealand rabbits. Results demonstrated that 99mTc-DESCIP and DESCIP has potential for imaging ER-enriched tumors such as breast and prostate tumors, and their metastases in the lung, as well as improving management for their therapies.

Samarium-153 Therapy and Radiation Dose for Prostate Cancer

Prostate cancer (PC) is one of the most frequent malignancies in Western countries. At initial diagnosis, bone metastases are present in 15–30% of cases. These metastases cause some complications including bone fracture, hypercalcemia, and bone pain, which significantly affect patients’ quality of life. Radionuclide treatment was created as an alternative to external palliative radiotherapy in the treatment of bone pain arising from bone metastasis of PC. The basic principle of the radionuclide treatment of pain is that the uptake of radioactive material is kept in a high amount that is enough to consti‐ tute a proper clinical impact in the tumor, and it is kept at a low dose enough to avoid the occurrence of significant adverse effects in other organs (commonly in the bone marrow). Samarium-153 ethylenediaminetetramethylenephosphonic acid (153SmEDTMP) is a radiopharmaceutical compound that has an affinity for skeletal tissue and concentrates in areas of increased bone turnover, localizes in the skeleton, and is excreted via glomerular filtration. Medical staff preparing and administering radio‐ pharmaceuticals in nuclear medicine, whether for diagnostic imaging or for therapeu‐ tic application, may receive significant radiation doses to their hands, particularly the fingers. Sm-153 treatment can be used as an effective and safe treatment alternative in the management of metastatic bone pain. Radiation protection of the public and the environment after Sm-153 EDTMP therapy is important.