Concurrent chemoradiotherapy in patients with nasopharyngeal cancer: prognostic significance of low expression of bax

A randomized trial has demonstrated that concurrent chemoradiotherapy (CRT) is superior to radiotherapy (RT) alone in locally advanced nasopharyngeal cancer (NPC). Our study comprise 35 patients with locally advanced NPC (stage I: 1, II: 12, III: 7, IV: 15) with 1 cycle of induction chemotherapy (5-fluorouracil 1,000 mg/m(2)/day and cisplatin 20 mg/m(2)/day, days 1- 4) followed by concurrent CRT starting on day 22. Concurrent CRT consisted of RT (70 Gy/35 fractions for 7 weeks) with cisplatin 20 mg/m(2)/day for 4 days on weeks 1, 4, 7 of RT. Complete response (CR) was achieved in 33 patients (94%). Four-year progression-free survival (PFS) and overall survival (OS) of all patients were 57% and 65%, respectively. In analysis of prognostic factors, low expression of bax was the most significant independent predictor of poor prognosis in both PFS (p=0.002) and OS (p=0.008). In conclusion, the outcome of patients treated with this combined therapeutical modality appears to be comparable with that of Intergroup 0099 trial with high CR rate. Low expression of bax was significantly associated with poor PFS and OS.

Epidemiologic picture of Kawasaki disease in Korea, 2000-2002

BACKGROUND

The aim of this study was to investigate the incidence rate and epidemiologic patterns of Kawasaki disease in Korea for a 3 year period during 2000 to 2002.

METHODS

An epidemiologic survey on Kawasaki disease was retrospectively performed. The questionnaire was sent to all 112 hospitals having pediatric residency programs, and obtained data were analyzed.

RESULTS

The 9150 cases of Kawasaki disease from 92 hospitals which responded (response rate, 82.1%) included 5515 males and 3635 females (male : female ratio, 1.52:1). The incidence rate per 100,000 children <5 years old was 73.7 in 2000, and increased to 90.8 in 2001, and 95.5 in 2002 (average rate, 86.4). The monthly number of patients was slightly higher in May, June and July. Their mean age of onset, the proportion of sibling cases, and a rate of recurrent cases were 30.5 months, 0.17%, and 2.9%, respectively. Coronary arterial abnormalities occurred in 18.6% of cases including dilatations of 17.3% and aneurysms of 3.1%.

CONCLUSION

The average annual incidence, 86.4/100 000 in children <5 years old is the second highest rate in the world.

Morphology and kinetics studies on cephalosporin C production by Cephalosporium acremonium M25 in a 30-l bioreactor using a mixture of inocula

AIMS

In this study, the relationship between morphology and cephalosporin C (CPC) production in a 30-l bioreactor culture of Cephalosporium acremonium M25 using a 3:7 seed mixture was investigated. In addition, the kinetic model was established and applied.

METHODS AND RESULTS

CPC production was performed in a 30-l bioreactor using a 3:7 seed mixture. It was recognized that a 3:7 seed mixture was able to reduce lag phase and enhance CPC production. The maximum CPC production and cell mass were 1.96 and 81.5 g l-1 respectively. Through a morphology study by observation using image analysis, it was concluded that changes of morphological features predicted the progressive production of CPC and that a morphology study could be useful in monitoring the CPC fermentation by C. acremonium M25. In the kinetics study, a kinetic model of CPC fermentation was developed and applied. The proposed model could adequately describe the fermentation of C. acremonium M25 in a 30-l bioreactor.

CONCLUSIONS

CPC productivity was improved by using a 3:7 seed mixture in a 30-1 bioreactor. The changes in morphological features showed a very similar tendency with CPC production. A kinetic model of CPC fermentation was successfully established.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of the present study suggest that the use of a 3:7 seed mixture inocula has considerable possibilities for improving CPC productivity if applied to industrial scale fermentations. Through morphology and kinetics study, the kinetic model to describe the morphological differentiation and CPC production by C. acremonium M25 was established.

HMG-CoA reductase inhibition reverses LCAT and LDL receptor deficiencies and improves HDL in rats with chronic renal failure

Dyslipidemia is a prominent feature of chronic renal failure (CRF) and a major risk factor for atherosclerosis and the progression of renal disease. CRF-induced dyslipidemia is marked by hypertriglyceridemia and a shift in plasma cholesterol from HDL to the ApoB-containing lipoproteins. Several studies have demonstrated a favorable response to administration of 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitors (statins) in CRF. This study was intended to explore the effect of statin therapy on key enzymes and receptors involved in cholesterol metabolism. Accordingly, CRF ( nephrectomized) and sham-operated rats were randomized to untreated and statin-treated (rosuvastatin 20 mg·kg−1·day−1) groups and observed for 6 wk. The untreated CRF rats exhibited increased total cholesterol-to-HDL cholesterol ratio, diminished plasma lecithin:cholesterol acyltransferase (LCAT) and the hepatic LDL receptor, elevated hepatic acyl-CoA:cholesterol acyltransferase (ACAT), and no change in hepatic HMG-CoA reductase, cholesterol 7α-hydroxylase, or HDL receptor (SRB-1). Statin administration lowered HMG-CoA reductase activity, normalized plasma LCAT, total cholesterol-to-HDL cholesterol ratio, and hepatic LDL receptor but did not significantly change either plasma total cholesterol, hepatic cholesterol 7α-hydroxylase, total ACAT activity, or SRB-1 in the CRF animals. Statin administration to the normal control rats led to significant increases in plasma LCAT and hepatic LDL receptor, significant reductions of total cholesterol-to-HDL cholesterol ratio, hepatic HMG-CoA reductase activity, and cholesterol 7α-hydroxylase abundance with virtually no change in plasma cholesterol concentration. Thus administration of rosuvastatin reversed LCAT and LDL receptor deficiencies and promoted a shift in plasma cholesterol from ApoB-containing lipoproteins to HDL in CRF rats.

Molecular cloning of levan fructotransferase gene from Arthrobacter ureafaciens K2032 and its expression in Escherichia coli for the production of difructose dianhydride IV

AIMS

To clone and overexpress a novel levan fructotransferase gene lftA from Arthrobacter ureafaciens K2032.

METHODS AND RESULTS

The lftA gene, encoding a levan fructotransferase (LFTase) of 521 amino acids (aa) residues, was cloned from the genomic DNA of A. ureafaciens K2032, and overexpressed in Escherichia coli. The recombinant LFTase overexpressed in E. coli was then used to produce a difructose dianhydride (DFA IV) from levan. DFA IV crystals with 97% purity could be obtained from the reaction mixture in 83.7% yield by using a natural crystallization method.

CONCLUSIONS

The lftA gene cloned from A. ureafaciens K2032 encode a novel levan fructotransferase which produces difructose dianhydride (DFA IV) from levan.

SIGNIFICANCE AND IMPACT OF THE STUDY

Levan fructotransferase is a useful enzyme with great promise in the production of DFA IV and various fructosides.

Studies involving the GH-IGF axis: Lessons from IGF-I and IGF-I receptor gene targeting mouse models

The IGFs are ubiquitous and have pleoitropic effects. They are critical for normal growth and development, and for normal functioning of adult tissues. A liver-specific gene-deletion knockout of the IGF-I gene resulted in a mouse model with reduced circulating IGF-I levels, that led to insulin resistance due to the secondary elevation of circulating GH levels. The reduction in circulating IGF-I levels was also associated with a reduction in cancer growth and metastases in three cancer models, one for colon cancer and two for breast cancer. A second mouse model, using the transgenic approach, inhibited the IGF-I and insulin receptor function in skeletal muscle, and resulted in severe insulin resistance in muscle followed by insulin resistance in fat and liver and, eventually, beta-cell dysfunction and development of Type 2 diabetes. This progression from insulin resistance to Type 2 diabetes was most likely due to lipotoxicity with elevated serum and tissue triglyceride levels. Evidence supporting the hypothesis came from the use of fibrates and leptin injections, each of which enhanced fatty acid (FA) oxidation in liver and muscle and was associated with a reversal of the insulin resistance and diabetes.

Delayed bleeding after gamma knife surgery for meningioma

We report the occurrence of haemorrhage in a meningioma after gamma knife surgery.A 52-year-old woman had undergone gamma knife radiosurgery for a growing meningioma in the left tentorial hiatus three years earlier (A radiation dose of 15 Gy was administered to the margin, with a maximum dose of 30 Gy, Fig. 1a). The size of the mass decreased steadily, and central lucency was seen in the follow-up magnetic resonance images, a usual finding seen after gamma knife surgery (MRI, Fig. 1b). However, a MRI taken at the 30-month follow-up showed the tumour to be swollen, and peritumoural oedema had increased (Fig. 1c). Three years later, apoplectic symptoms occurred, and computed tomography revealed a peritumoural haemorrhage, with oedema (Fig. 1d). An emergency craniotomy was carried out, and the biopsy showed a transitional type of meningioma, with vasculopathy and necrosis. After operation she had a right hemiparesis and a visual defect.

Environmental assessment of water, sediment and plants in the Mankyeong River, ROK

This study was carried out to evaluate water quality, sediment and plant vegetation in eight tributaries of the Mankyeong River for enhancement of natural purification. Among the tributaries, the Iksancheon water had the highest concentration of BOD, T-N and NH4-N due to inflow of swine wastes from the livestock district. The Yucheon water had the highest level of electrical conductivity and SO4(2-) due to inflow of mis-treated wastewater from industrial districts. The Tabcheon had generally similar concentrations of nitrogen and phosphate to that of the upstream of the Mankyeong River: agricultural activity along the Tabcheon appeared to have little negative influence to the water quality. Among various sediments, concentration of organic matter, nitrogen and phosphate were high in the Iksancheon and the Yucheon due to the livestock wastes and industrial wastes. There were 282 species of plants during summer with 43 aquatic plants, 57 hydrophytes, 178 waterside plants and 4 terrestrial plants. Some plant resources were recommended due to much absorption of nitrogen and phosphate for enhancement of natural purification. C. demersum and H. verticillata were recommended in the submerged aquatic plants, H. dubia, N. indica and N. subinteperrimum in the floating leaf aquatic plants, P. communis, Z. latifolia and T. orientalis in the emerged aquatic plants, C. scutata and P. distichum in the waterside plants.

Cloning and expression of a novel esterase gene cpoA from Burkholderia cepacia

AIMS

To screen and clone a novel enzyme with specific activity for the resolution of (R)-beta-acetylmercaptoisobutyrate (RAM) from (R,S)-beta-acetylmercaptoisobutyrate [(R,S)-ester].

METHODS AND RESULTS

A micro-organism that produces a novel esterase was isolated and identified as the bacterium Burkholderia cepacia by using the analysis of cellular fatty acids, Biolog automated microbial identification/characterization system, and 16S rRNA gene sequence analysis. A novel esterase gene was cloned from the chromosomal DNA of B. cepacia and was designated as cpoA. The cpoA encodes a polypeptide of 273 amino acids which shows a strong sequence homology with many bacterial nonhaeme chloroperoxidases. In addition, a typical serine-hydrolase motif, Gly-X-Ser-X-Gly, and the highly conserved catalytic triad, Ser95, Asp224, and His253, were identified in the deduced amino acid sequence of cpoA by multiple sequence alignment.

CONCLUSION

The cpoA cloned from B. cepacia encodes a novel esterase which is highly related to the nonhaeme chloroperoxidases.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report that describes the isolation and cloning of a serine esterase gene from B. cepacia, which is useful in the chiral resolution of (R,S)-ester. The cloned gene will allow additional research on the bifunctionality of the enzyme with esterase and chloroperoxidase activity at the structural and functional levels.

Downregulation of hepatic acyl-CoA:diglycerol acyltransferase in chronic renal failure

Chronic renal failure (CRF) is associated with hypertriglyceridemia and elevated plasma VLDL and IDL concentrations. These events can be due to either increased production or depressed catabolism of triglyceride-rich lipoproteins. Several studies have documented downregulation of lipoprotein lipase, hepatic triglyceride lipase, and the VLDL receptor, leading to depressed clearance and elevated plasma concentration of triglyceride-rich lipoproteins and their remnants in CRF. However, the effect of CRF on the triglyceride biosynthetic pathway has not been explored. Diglycerol acyltransferase (DGAT) is a microsomal enzyme that joins acyl-CoA to 1,2 diacylglycerol and, as such, constitutes the final step in triglyceride biosynthesis. Two distinct forms of DGAT (DGAT-1 and -2) have thus far been identified. The present study was undertaken to examine the effect of CRF on DGAT gene expression and activity in the liver, which is the source of endogenous triglycerides in the circulation. Male Sprague-Dawley rats were studied 8 wk after 5/6 nephrectomy (CRF) or sham operation. DGAT-1 and DGAT-2 mRNA abundance and DGAT activity were quantified. The CRF group showed reduced creatinine clearance, elevated plasma triglycerides, and VLDL concentrations. This was accompanied by significant reductions in hepatic DGAT-2 mRNA abundance (P < 0.01) and total DGAT activity (P < 0.1), pointing to diminished hepatic triglyceride production capacity in CRF animals. In conclusion, CRF results in significant downregulation of hepatic DGAT gene expression and activity. Given the critical role of DGAT in triglyceride biosynthesis, the present study points to diminished, not increased, hepatic triglyceride synthetic capacity in CRF rats.

Estimation of the incidence of sudden infant death syndrome in Korea: using the capture-recapture method

This study was undertaken to estimate the incidence of sudden infant death syndrome (SIDS) for 2 years from 1997 to 1998 in Korea. The information on SIDS was obtained from three independent sources, the Korean Medical Insurance Corporation data, data from different medical facilities (Korean surveillance on SIDS) and mortality data from the Korean National Statistical Office. A log linear model with no interactions among the 3 sources was used with the selection criteria of both the Akaike Information Criterion and the Bayesian Information Criterion. The 95% confidence intervals of the estimated number of SIDS deaths were calculated using the goodness-of-fit-method. The estimated number of deaths who were not found in any of the sources was 535, and the estimated total number of SIDS deaths was 759. The 95% confidence interval for estimated total number of patients ranged from 642 to 1522. The estimated rate of SIDS cases was 0.56 per 1000 live births per annum, which is similar to the incidence in the USA or Japan.

Purification, cDNA cloning and expression of an insect defensin from the great wax moth, Galleria mellonella

An insect defensin, named Galleria defensin, was purified from the larval haemolymph of Galleria mellonella immunized against E. coli. The peptide was composed of forty-three amino acid residues containing six cysteines that might be engaged in intramolecular disulphide bridges. The primary structure of Galleria defensin shared about 90.7% identity to that of heliomicin, which was an insect defensin isolated from Heliothis virescens. The full-length cDNA encoding Galleria defensin was cloned from the fat body of the immunized G. mellonella larvae. Northern blot analysis revealed that Galleria defensin was expressed not only in the fat body but also in the midgut against invading bacteria into haemocoel. This is the first report presenting cDNA and expression of an insect defensin in the lepidopteran species.

Treatment of spent brine from a nitrate exchange process using combined biological denitrification and sulfate precipitation

A combined biological denitrification and sulfate precipitation process was developed to treat and reuse the spent brine produced by a nitrate exchange system. Although the spent brine contained a relatively high salt concentration, more than 80% of NO3(-)-N fed into the denitrification reactors was removed at a nitrate-N loading rate of 2.2 g NO3(-)-N/l x day, regardless of the presence or absence of sulfate up to 8,000 mg/l. Sulfate present in the spent brine was successfully removed by the addition of BaCl2 and the settling velocity of BaSO4 suspension was remarkably enhanced by FeCl3 coagulation. Since most of the chloride consumed in regenerating the exhausted resins was replaced during chemical treatment with BaCl2 and FeCl3, it was possible to reuse the treated spent brine as a regenerant after compensating for the small amount of unreplaced NaCl.

Holocord myelopathy with thoracic stenosis: case report and hypothesis

STUDY DESIGN

Case report

OBJECTIVE

To examine the resolution of holocord myelopathy based on the hypothesis of altered cerebrospinal fluid (CSF) dynamics.

SETTING

Seoul National University Hospital, Seoul, Korea.

METHOD

We describe a case of thoracic stenosis with holocord myelopathy, which suggests an alternative mechanism for the myelopathy.

RESULT

Decompression of the thoracic stenosis resulted in the resolution of holocord myelopathy.

CONCLUSION

Myelopathy may be caused by altered CSF dynamics and this type of myelopathy seems to be interstitial edema. Improvement of altered CSF flow dynamics could resolve this type of myelopathy.

Prevalence and risk factors for erectile dysfuntion in primary care: results of a Korean study

In order to assess the prevalence and associated factors for erectile dysfunction (ED) in primary care, a cross-sectional study was undertaken by questionnaire distributed to consecutive adult male attendees at 32 family practices. ED was assessed by the Korean five-item version of the International Index of Erectile Function (IIEF-5). In total, 3501 completed questionnaires were available for analysis. The prevalence of ED was severe (IIEF-5 score: 5-9) in 1.6% of cases, moderate (10-13) in 10.2%, mild (14-17) in 24.7%, and normal (18-25) in 63.4%. The prevalence of ED increased with age, lower educational status, heavy job-related physical activity, and lower income. ED prevalence was significantly higher in patients with chronic diseases such as diabetes, depression, and anxiety. These results suggest that the age-adjusted prevalence of ED among Korean men can be estimated as 32.2% (95% CI 30.6-33.7). Low socioeconomic status and several diseases such as diabetes, anxiety, and depression, as well as age, were associated with ED.

Effect of torso adipose tissue thickness on effective dose in a broad parallel photon beam

The effect of torso adipose tissue thickness on effective dose was studied for external broad parallel photon beams using the MCNP code and a mathematical anthropomorphic phantom. The variation of torso adipose tissue thickness was modeled by adding a layer of soft tissue (1-7 cm) around the torso of the phantom. This study found that effective dose varies almost linearly with the thickness of the adipose tissue layer. For most irradiation geometries (i.e., antero-posterior, postero-anterior, and lateral), effective dose decreases with the thickness of the adipose tissue layer due to the shielding effect of the layer. Effective dose decreases by 11-35% when the thickness of the adipose tissue layer increases from 0 to 7 cm considering all photon energies (0.08, 0.3, and 1.0 MeV) and irradiation geometries in this study. For overhead irradiation geometry, however, an increase of adipose tissue layer thickness results in an increase of effective dose. This is because the organs and tissues in the body are additionally exposed by the photons that are scattered from the added adipose tissue layer. For the overhead irradiation geometry, effective dose increases by 13-27% when the adipose tissue thickness increases from 0 to 7 cm.

Characterization of the protective response against a homologous challenge infection with Strongyloides venezuelensis in rats

The protective response in rats against a homologous challenge infection with Strongyloides venezuelensis was characterized. In an initial infection with 1000 filariform larvae and migrating larvae (L(3)) of S. venezuelensis, the population of L(3) in the lungs on day 3 postinfection (PI), and that of adult worms in the small intestine on day 7 PI, were 180.8+/-14.5 and 336.8+/-70.7, respectively. The latter were gradually expelled towards day 42 PI. After the initial infection, the rats developed strong immunity against a homologous challenge infection as manifested by a marked reduction in worm populations, stunted body length and width, damage to reproductive organs, impaired egg production and rapid expulsion of the worms by day 14 after challenge. Expulsion of the worms was preceded by a significantly elevated (P<0.05) peripheral blood eosinophil (PBE) count, both in the initial (200.0+/-26.5 x 10(3)ml) and the challenge infection (400.9+/-165.4 x 10(3)ml). These findings suggest that rats acquire strong homologous immunity following initial exposure to S. venezuelensis. It is suggested that PBEs are involved in worm expulsion. A major target of these effector mechanisms is the reproductive system of S. venezuelensis.

Development of Gerontological Nursing Curriculum Model

PURPOSE

This study was conducted to develop gerontological curriculum model which reflects the need of Korean society.

METHOD

Three round Delphi survey method was applied to find consensus of gerontological nursing competencies (knowledge, attitudes and skills) for graduates of nursing schools from the panel of gerontological nursing practice experts. Important concepts in gerontological nursing were delineated from literature review and discussions of gerontological nursing educators. Based on these results the gerontological nursing curriculum model was developed and course structure outlined by the researchers as a group.

RESULT

As the result of delphi survey, 32 items of knowledge, 29 items of attitude, and 21 items of skill were identified. The curriculum model constructed around a cube with three plane- functional capacity levels, settings, and nursing practice. Specific knowledge, attitudes and skills for gerontological theory and practicum course were suggested. Competency items were assigned to theory and/or practice.

CONCLUSION

A curriculum model for gerontological nursing has been developed by a group of gerontological nursing educators. The curriculum model should be further tested and developed with detailed theory and practicum course outline and textbooks.

Monte Carlo simulation of single and two-dosimeter approaches in a steam generator channel head

In a steam generator channel head, it was not unusual to see radiation workers wearing as many as twelve dosimeters over the surface of the body to avoid a possible underestimation of effective dose equivalent (H(E)) or effective dose (E). This study shows that only one or two dosimeters can be used to estimate H(E) and E without a significant underestimation. MCNP and a point-kernel approach were used to model various exposure situations in a steam generator channel head. The single-dosimeter approach (on the chest) was found to underestimate H(E) and E significantly for a few exposure situations, i.e., when the major portion of radiation source is located in the backside of a radiation worker. In this case, the photons from the source pass through the body and are attenuated before reaching the dosimeter on the chest. To assure that a single dosimeter provides a good estimate of worker dose, these few exposure situations cannot dominate a worker's exposure. On the other hand, the two-dosimeter approach (on the chest and back) predicts H(E) and E very well, hardly ever underestimating these quantities by more than 4% considering all worker positions and contamination situations in a steam generator channel head. This study shows that two dosimeters are adequate for an accurate estimation of H(E) and E in a steam generator channel head.

Anti-septicaemic effect of polysaccharide from Panax ginseng by macrophage activation

The aim of the present research was conducted to elucidate anti-septicaemic effect of a polysaccharide (PS) isolated from Panax ginseng C.A. Meyer (Araliaceae) by nitric oxide production from stimulated macrophage. In vitro assays for the activity measurement of PS, NO production test with Greiss reagent, phagocytic activity test using zymosan and cytokines production test using ELISA kit were also conducted. In vivo anti-septicaemic activity was assessed by using C57BL/6J mice. This was done with Staphylococcus aureus infection test. PS used at 0.025 mg/kg concentration showed a potent anti-septicaemic activity (80%, survival). However, it did not directly inhibit S. aureus in a minimum inhibitory concentration (MIC) test, conducted in vitro (data not shown). Nitric oxide production via macrophage activation showed the highest value of 5.5 nmol/ml at 1 microg/ml PS. In in vitro phagocytic activity test, PS at 10 microg/ml concentration showed a potent phagocytic activity for zymosan with 167% of the control. Production of TNF-alpha by macrophage activation at 10 microg/ml of PS was 96% lysis of L929. Also production of IL-1 and IL-6 by stimulation of macrophage with 100 microg/ml PS dose increased to 235 pg/ml and 0.47 ng/ml, respectively. The low mortality of PS treated (0.025 mg/kg) infected mice was concurrent with decreased bacterial content in the blood. Nitric oxide production in S. aureus infected mice whose macrophage was stimulated by PS (0.025 mg/kg) increased approximately 4 times than the untreated S. aureus infected group at 24 and 48 h incubation. In the PS treated (0.025 mg/kg) group, the intracellular concentration of S. aureus in macrophages decreased approximately by 50%, compared with the untreated group. Combine treatment with PS (0.025 mg/kg body weight) and vancomycin (10 mg/kg B.W.) resulted in 100% survival of the animals, whereas only 67% or 50% of the animals survived, respectively, when treated with PS or vancomycin alone. These results suggest that PS from Panax ginseng possess a potent anti-septicaemic activity by stimulating macrophage and a potentiality as an immunomodulator against sepsis occurred by Staphylococcus aureus.

A simple method for the detection of neurologic disorders associated with CAG repeat expansion using PCR-microtiter plate hybridization

A new screening method was developed for the detection of CAG expanded alleles in patients with hereditary ataxia using polymerase chain reaction-based microtiter plate hybridization (PCR-MPH). The system can be applied to detect pathologic alleles by hybridization with the immobilized (CAG)48 repeat probe derived from the unrelated gene 'ERDA1' except for the CAG repeats. We examined 10 individuals with SCA3, 10 with Huntington disease and 30 normal controls (31 controls for SCA3) using this method. The results showed that a clear discrimination was possible in all cases. We suggest that this system be made available for mass screening of patients with hereditary ataxia disorders. This report is the first to demonstrate that a PCR-MPH system can be successfully applied to DNA size differentiation in addition to base pair mismatches. Also, our design of the probe is unique in that the probe motif stem from the unrelated gene sequence and not from the synthetic oligonucleotides.

Mechanical consequence of trabecular bone loss and its treatment: a three-dimensional model simulation

Age-related changes in the microstructure of trabecular bone, such as decreases in trabecular number and trabecular thickness, lead to reductions in mechanical properties, such as Young's modulus and strength. Current drug therapy, such as bisphosphonate or parathyroid hormone, improves the mechanical properties of bone mainly by increasing the trabecular thickness, but not increasing the trabecular number. However, the mechanical efficacy of these treatments has not been fully quantified using trabecular bone models. In this study, we used an idealized three-dimensional (3D) microstructural model of trabecular bone to create bone loss either through trabeculae thinning or random removal of trabeculae, and simulated treatment by increasing the trabeculae thickness of the remaining trabeculae. The reduction in either the Young's modulus or the strength due to trabeculae loss was proportional to a much higher power of reduction in bone volume fraction than due to trabeculae thinning. This indicates that bone loss due to trabeculae loss is much more detrimental to Young's modulus and strength of trabecular bone than due to trabeculae thinning, indicating the importance of trabecular number and connectivity in the mechanical integrity of trabecular bone. In general, treatments by increasing the trabecular thickness of remaining trabeculae after trabeculae loss cannot fully recover the initial mechanical properties of intact bone, even if bone loss is fully recovered, whereas trabecular thickening can fully restore the mechanical properties after bone loss by trabeculae thinning. The results also show that the residual loss in mechanical properties is dependent on the extent of trabeculae loss.

Cerebral germinoma with hemiatrophy of the brain: report of three cases

BACKGROUND

The authors report three cases of cerebral germinoma that occurred in young adults with unusual presentation.

METHOD

All three patients presented with hemiparesis and were treated at Seoul National University. A histological diagnosis of germinoma was made by a stereotactic biopsy in all three cases.

FINDINGS

Magnetic resonance (MR) images showed that their tumors were located in the internal capsule and thalamus, and were associated with ipsilateral cerebral hemisphere and brain stem atrophy. The hemiparesis slowly progressed and this was accompanied by a haemorrhagic cyst in each patient.

INTERPRETATION

Clinical diagnosis was not easy because of the unusual clinical presentations and atypical MR imaging findings. It is suggested that cerebral germinoma should be included in the differential diagnosis of a haemorrhagic mass which is associated with cerebral atrophy in the thalamus, basal ganglia, or internal capsule, especially in adolescents or young adults.