Optimal ropivacaine concentration for ultrasound-guided erector spinae plane block in patients who underwent video-assisted thoracoscopic lobectomy surgery

Background

An ultrasound-guided erector spinae plane block (ESPB) has emerged as an effective way to control postoperative pain and may be a good alternative way to an epidural block. However, relevant research on the appropriate concentration of local anesthetics for an ESPB remains scarce.

Aims

This study aimed to investigate the optimal concentration of ropivacaine for an ESPB in patients undergoing video-assisted thoracoscopic surgery (VATS).

Methods

A total of 68 patients who underwent a VATS lobectomy were enrolled. An ipsilateral ultrasound-guided ESPB was performed with three different ropivacaine concentrations as a local anesthetic: 0.189% (G1), 0.375% (G2), and 0.556% (G3). The total amount of perioperative remifentanil administered, patient-controlled analgesia (PCA) applied, and rescue drugs for postoperative analgesia during the 24 h after surgery were acquired, and numeric rating scale (NRS) scores were obtained.

Results

The total amount of intraoperative remifentanil administered was 7.20 ± 3.04 mcg/kg, 5.32 ± 2.70 mcg/kg, and 4.60 ± 1.75 in the G1, G2, and G3 groups, respectively. G2 and G3 had significantly lower amounts of remifentanil administered than the G1 group (P = 0.02 vs. G2; P = 0.003 vs. G3). The G3 group needed more inotropes than the G1 and G2 groups in the perioperative period (P = 0.045). The NRS scores, PCA, and rescue drug were not significantly different in the three groups.

Conclusion

The optimal concentration of ropivacaine recommended for an ESPB was 0.375%, which was effective in controlling pain and reducing the intraoperative opioid requirements with minimal adverse reactions such as hypotension.

The requirements of nucleic acid test for COVID-19 during public health emergency: Current regulatory in Taiwan, Singapore, and the United States

In mid-2022, the COVID-19 cases have reached close to 562 million, but its overall infection rate is hard to confirm. Even with effective vaccines, break-through infections with new variants occur, and safe and reliable testing still plays a critical role in isolation of infected individuals and in control of an outbreak of a COVID-19 pandemic. In response to this urgent need, the diagnostic tests for COVID-19 are rapidly evolving and improving these days. The health authorities of many countries issued requirements for detecting SARS-CoV-2 diagnosis tests during the pandemic and have timely access to these tests to ensure safety and effectiveness. In this study, we compared the requirements of EUA in Taiwan, Singapore, and the United States. For the performance evaluations of nucleic acid extraction, inclusivity, limit of detection (LoD), cross-reactivity, interference, cutoff, and stability, the requirements are similar in the three countries. The use of natural clinical specimens is needed for clinical evaluation in Taiwan and the United States. However, carry-over and cross-contamination studies can be exempted in Taiwan and the United States but are required in Singapore. This review outlines requirements and insight to guide the test developers on the development of IVDs. Considering the rapidly evolving viruses and severe pandemic of COVID-19, timely and accurate diagnostic testing is imperative to the management of diseases. As noted above, the performance requirements for SARS-CoV-2 nucleic acid tests are similar between Taiwan, Singapore and the United States. The differences are mainly in two points: the recommended microorganisms for cross-reactivity study, and the specimen requirement for clinical evaluation. This study provides an overview of current requirements of SARS-CoV-2 nucleic acid tests in Taiwan, Singapore, and the United States.

BDNF elevates the axonal levels of hnRNPs Q and R in cultured rat cortical neurons

Local translation plays important roles in the maintenance and various functions of axons, and dysfunctions of local translation in axons are implicated in various neurological diseases. Heterogeneous nuclear ribonucleoproteins (hnRNPs) are RNA binding proteins with multiple functions in RNA metabolism. Here, we identified 20 hnRNPs in the axons of cultured rat cortical neurons by interrogating published axon mass spectrometric databases with rat protein databases. Among those identified in axons are highly related hnRNPs Q and R. RT-PCR analysis indicated that axons also contained low levels of hnRNPs Q and R mRNAs. We further found that BDNF treatments raised the levels of hnRNPs Q and R proteins in whole neurons and axons. BDNF also increased the level of poly(A) RNA as well as the proportion of poly(A) RNA granules containing hnRNPs Q and R in the axon. However, following severing the connection between the cell bodies and axons, BDNF did not affect the levels of hnRNPs Q and R, the content of poly(A) RNA, or the colocalization of poly(A) RNA and hnRNPs Q and R in the axon any more, although BDNF still stimulated the local translation in severed axons as it did in intact axons. The results are consistent with that BDNF enhances the axonal transport of RNA granules. The results further suggest that hnRNPs Q and R play a role in the mechanism underlying the enhancement of axonal RNA transport by BDNF.

Outcomes after extensive manual curettage and limited burring for atypical cartilaginous tumour of long bone

AIMS

Adjuvant treatment after intralesional curettage for atypical cartilaginous tumours (ACTs) of long bones is widely accepted for extending surgical margins. However, evaluating the isolated effect of adjuvant treatment is difficult, and it is unclear whether not using such adjuvants provides poor oncological outcomes. Hence, we analyzed whether intralesional curettage without cryosurgery or chemical adjuvants provides poor oncological outcomes in patients with an ACT.

PATIENTS AND METHODS

A total of 24 patients (nine men, 15 women) (mean age 45 years; 18 to 62) were treated for ACTs of long bones and followed up for a median of 66 months (interquartile range 50 to 84). All patients were treated with extensive manual curettage and limited burring. Bone cement and grafts were used to fill bone defects in 16 and eight patients, respectively. No chemical adjuvants or cryosurgery were used.

RESULTS

No local recurrence was detectable on plain radiographs and MRI or CT images. At the last follow-up, there were no distant metastases or disease-specific deaths. No procedure-related complications or postoperative fractures developed.

CONCLUSION

Intralesional curettage without cryosurgery or chemical adjuvants may provide excellent oncological outcomes for patients with ACTs of long bones, without the risk of complications related to adjuvant use. Our investigation suggests thorough curettage alone is a reasonable treatment option for ACT. However, we acknowledge the limited size of our investigation warrants a multicentre collaborative study to confirm our findings. Cite this article: Bone Joint J 2018;100-B:256-61.

Direct-growth carbon nanotubes on 3D structural microelectrodes for electrophysiological recording

Direct growth of CNTs on 3D microelectrodes could detect distinguished zebrafish ECG resulting from the interfacial improvement analyzed by EIS.

Glutamate Stimulates Local Protein Synthesis in the Axons of Rat Cortical Neurons by Activating α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid (AMPA) Receptors and Metabotropic Glutamate Receptors

Glutamate is the principal excitatory neurotransmitter in the mammalian CNS. By analyzing the metabolic incorporation of azidohomoalanine, a methionine analogue, in newly synthesized proteins, we find that glutamate treatments up-regulate protein translation not only in intact rat cortical neurons in culture but also in the axons emitting from cortical neurons before making synapses with target cells. The process by which glutamate stimulates local translation in axons begins with the binding of glutamate to the ionotropic AMPA receptors and metabotropic glutamate receptor 1 and members of group 2 metabotropic glutamate receptors on the plasma membrane. Subsequently, the activated mammalian target of rapamycin (mTOR) signaling pathway and the rise in Ca(2+), resulting from Ca(2+) influxes through calcium-permeable AMPA receptors, voltage-gated Ca(2+) channels, and transient receptor potential canonical channels, in axons stimulate the local translation machinery. For comparison, the enhancement effects of brain-derived neurotrophic factor (BDNF) on the local protein synthesis in cortical axons were also studied. The results indicate that Ca(2+) influxes via transient receptor potential canonical channels and activated the mTOR pathway in axons also mediate BDNF stimulation to local protein synthesis. However, glutamate- and BDNF-induced enhancements of translation in axons exhibit different kinetics. Moreover, Ca(2+) and mTOR signaling appear to play roles carrying different weights, respectively, in transducing glutamate- and BDNF-induced enhancements of axonal translation. Thus, our results indicate that exposure to transient increases of glutamate and more lasting increases of BDNF would stimulate local protein synthesis in migrating axons en route to their targets in the developing brain.

The prognostic significance of pretreatment [18F]FDG-PET/CT imaging in patients with uterine cervical cancer: preliminary results

PURPOSE OF INVESTIGATION

To evaluate the prognostic significance of positron emission tomography/computed tomography (PET/CT) in patients diagnosed with cervical cancer.

MATERIALS AND METHODS

Patients with cervical cancer in FIGO Stages IB1 to IVB were imaged with PET/CT prior to treatment during one of the staging work-ups. The patients were observed for a median of 31.4 months (range, six to 89 months) after the initial treatment. The standardized uptake value (SUV) max of the primary cervical tumor mass was compared with the prognostic factors. RESULTs: A total of 81 patients who were primarily treated with radical hysterectomy (RH, n = 45) or concurrent chemoradiation (CCRT, n = 36) were analyzed. Multivariate analysis indicated that larger tumor size (> 4 cm, OR 8.694, 95% CI, 1.638-46.146), deep stromal invasion (≥ 1 cm, OR 7.249, 95% CI, 1.141-46.039) by the primary tumor, and pathologically confirmed pelvic lymph node involvement (positive, OR 14.586, 95% CI, 2.072-102.674) were significantly associated with recurrence after treatment. However, pretreatment SUVmax was not a significant independent predictor of disease recurrence (OR 1.058, 95% CI, 0.255-4.398).

CONCLUSION

[18F]Fluorodeoxyglucose (FDG) uptake by the primary tumor showed a significant association with several risk factors that have been identified as treatment predictors. However, a high pretreatment SUVmax was not predictive of recurrence in uter- ine cervical cancer patients.

Retinal sensitivity assessed by microperimetry and corresponding retinal structure and thickness in resolved central serous chorioretinopathy

PURPOSE

To investigate the relationship between retinal sensitivity (RS) assessed by microperimetry (MP) and retinal structural changes in patients with resolved central serous chorioretinopathy (CSC).

METHODS

Spectral domain optical coherence tomography (OCT) examination and MP tests were performed in patients with resolved CSC. Point-to-point correlation was performed between RS and corresponding retinal structural changes using Pearson's correlation analysis. In addition, in a 1-mm zone in the central fovea, a correlation was calculated between the mean RS and the mean central retinal thickness (CRT).

RESULTS

Eighty-four eyes were analyzed. The total number of MP test points was 1092 (84 eyes × 13 points). The mean RS and retinal point thickness (RPT) of all test points were 13.53±3.84 dB and 208.6±48.0 μm, respectively. The RS and RPT were significantly decreased in the test points with loss of the ellipsoid portion of the inner segments (EPIS) (P<0.0001). Within the 1-mm foveal center zone, there was a significant correlation between mean RS and mean CRT (r=0.432, P<0.0001) and between RS and the corresponding RPT (r=0.339, P<0.0001).

CONCLUSION

RS was dependent on the status of the EPIS in patients with resolved CSC. The correlation between mean RS and mean CRT was compatible with the point-to-point correlation between RS and the corresponding RPT.

MRI to differentiate benign from malignant soft-tissue tumours of the extremities: a simplified systematic imaging approach using depth, size and heterogeneity of signal intensity

OBJECTIVE

Differentiating between malignant and benign lesions on the basis of MR images depends on the experience of the radiologist. For non-experts, we aimed to develop a simplified systematic MRI approach that uses depth, size and heterogeneity on T(2) weighted MR images (T(2)WI) to differentiate between malignant and benign lesions, and evaluated its diagnostic accuracy.

METHODS

MR images of 266 patients with histologically proven soft-tissue tumours of the extremities (102 malignant, 164 benign) were analysed according to depth (superficial or deep), size (<50, ≥50 mm) and signal intensity (homogeneous or heterogeneous) on T(2)WI, to determine the ability of each to predict benign and malignant tumours. These three parameters were categorised into systematic combinations of different orders of application, and each combination was assessed for its ability to differentiate between benign and malignant lesions.

RESULTS

Univariate analysis showed that depth, size and heterogeneity on T(2)WI differed significantly between benign and malignant masses (p<0.0001 each). Multiple logistic regression analysis, however, showed that depth was not helpful in distinguishing benign from malignant lesions. The systematic combination of signal intensity, size and depth, in that order, was superior to other combinations, resulting in higher diagnostic values for malignancy, with a sensitivity of 64%, a specificity of 85%, a positive predictive value of 32%, a negative predictive value of 59% and an accuracy of 77%.

CONCLUSION

A simplified systematic imaging approach, in the order signal intensity, size and depth, would be a reference to distinguish between benign and malignant soft-tissue tumours for non-experts.

A chip-based method for studying the effects of exogenous proteins on neuronal axons

Axons are long, slender processes of neurons that have various functions at different stages of development. Here, we report the use of a chip device to study the effects of various exogenous proteins on the growth and presynaptic differentiation of axons in a high-throughput manner. The device consists of a glass chip whose surface contains a protein-coated micropattern. When neurons are maintained on the chip, a specific region of the chip surface will be occupied exclusively by axons. The axons and clusters of release-competent synaptic vesicles, a presynapse-like specialization in the axon, can be quantified as the proportions of this specific region's area occupied respectively by these subcellular structures. By using chips with this specific region coated with different proteins, these proteins' effects on the growth and presynaptic differentiation of the axon were investigated by comparing the amounts of axons and clusters of release-competent synaptic vesicles in this region of the chip. We also demonstrate another application of this chip device by investigating the effective range of the signal produced by the interaction between neurons and neuroligin 1 in neurons. These results indicate the diverse applications of the chip device in exploring various issues pertaining to axonal functions.

Susceptibility-weighted imaging in patients with pyogenic brain abscesses at 1.5T: characteristics of the abscess capsule

BACKGROUND AND PURPOSE

SWI is a high-resolution 3D, fully velocity-compensated gradient-echo sequence that uses both magnitude and phase data. The purpose of this study was to investigate the phase behavior of the capsule of pyogenic brain abscesses with noncontrast SWI.

MATERIALS AND METHODS

Fourteen patients with pyogenic brain abscesses were studied at 1.5T. In all of the patients, SWI images were obtained and reviewed in addition to conventional MR images. Phase values within the abscess capsule were measured and compared with those from the abscess cavities and contralateral normal white matter using 1-way repeated measures ANOVA with post hoc Bonferroni analysis.

RESULTS

SWI phase images showed mild hypointesity in 6 patients, isointensity in 3 patients, and mixed iso- to mild hypointensity in 5 patients. The means of phase in the cavity, rim of abscesses, and contralateral normal white matter were -7.552 × 10(-3) ± 0.024, -0.105 ± 0.080, and +0.029 ± 0.011 radians, respectively. Post hoc comparisons showed significant differences between any pair of the 3 regions (abscess cavity, rim capsule, and normal white matter) in SWI (all Ps < .005).

CONCLUSIONS

SWI phase imaging shows evidence of paramagnetic substances in agreement with the presence of free radicals from phagocytosis. SWI may provide additional information valuable in the characterization of pyogenic brain abscesses.

Diallyl sulfide induces cell cycle arrest and apoptosis in HeLa human cervical cancer cells through the p53, caspase- and mitochondria-dependent pathways

Diallyl sulfide (DAS), one of the main active constituents of garlic, causes growth inhibition of cancer cells in vitro and promotes immune responses in vivo in experimental settings. However, its effects on the induction of cell cycle and apoptosis in human cervical cancer cells are still unclear. The aims of this study were to explore the anti-cancer effects of DAS in HeLa human cervical cancer cells and to investigate the underlying mechanisms in vitro. Cytotoxicity and apoptosis in HeLa human cervical cancer cells were examined by the morphological changes, viability assay, 4',6-Diamidino-2-phenylindole dihydrochloride (DAPI) staining, comet assay, Western blotting and confocal microscopy examination. The results showed that DAS treatment for 24-72 h resulted in a marked decrease in cell viability time- and dose-dependently. Flow cytometric analysis showed that a 48-h treatment of 75 µM DAS induced G0/G1 cell cycle arrest and sub-G1 phase (apoptosis) in HeLa cells. Typical apoptotic nucleus alterations were observed by fluorescence microscopy in HeLa cells after exposure to DAS using DAPI staining. Cells treated with different concentrations of DAS also showed changes typical of apoptosis such as morphological changes, DNA damage and fragmentation, dysfunction of mitochondria, cytochrome c release and increased expression of pro-caspase-3 and -9. DAS also promoted the release of AIF and Endo G from mitochondria in HeLa cells. In conclusion, DAS induced G0/G1 cell cycle arrest and apoptosis in HeLa cells through caspase- and mitochondria and p53 pathways providing further understanding of the molecular mechanisms of DAS action in cervical cancer. This study, therefore, revealed that DAS significantly inhibits the growth and induces apoptosis of human cervical cancer HeLa cells in vitro.

Longitudinal split of the posterior cruciate ligament: description of a new MR finding and evaluation of its potential clinical significance

AIM

To evaluate the clinical significance of the intra-substance longitudinal split of the posterior cruciate ligament (LS-PCL) and to evaluate its potential clinical significance on MRI.

MATERIALS AND METHODS

The databases of two centres were searched for LS-PCL, 6917 knee magnetic resonance imaging (MRI) examinations undertaken were retrospectively reviewed. LS-PCL was defined as increased signal intensity in a PCL in the longitudinal direction, but with an intact ligament outer surface on MRI. Twelve patients were enrolled in this study. Available arthroscopic results, degree of posterior knee instability, and changes in MRI findings, or the degree of instability during follow-up (FU), were reviewed from the patients medical records and via their MRI images. MRI images were reviewed by two musculoskeletal radiologists in consensus for presence and location of LS-PCL and any combined injuries: menisci lesions, ligament injuries, and bone marrow changes.

RESULTS

Seven of 12 patients (58.3%) had morphological or functional evidence of PCL injury or insufficiency according to the change of posterior instability on FU stress testing (n=3), insufficiency during arthroscopy (n=2), or decreased extent and altered shape of the PCL split on the FU MRI (n=3). One patient revealed both change of posterior instability on FU stress testing and insufficiency during arthroscopy. Combined injuries were revealed in seven patients. Five patients had isolated LS-PCL: two patients underwent arthroscopic PCL reconstructions; and another three patients revealed knee instability on stress testing.

CONCLUSION

Although LS-PCL has not been described before, it can be a type of partial tear of the PCL, which causes PCL insufficiency.

Mistaken diagnosis of optic neuritis and the possible role of phosphodiasterase-5 inhibitors (Sildenafil/Viagra)

The diagnosis of optic neuritis and particularly retrobulbar optic neuritis when atypical and not responsive to corticosteroid treatment may need to be revised. This is now especially so in male patients who should be questioned regarding their taking a phosphodiasterase-5 inhibitor in particular Viagra. The case history of such a patient is presented who sustained posterior ischaemic optic neuropathy mistaken for retrobulbar neuritis resulting in bilateral severe visual loss.

Poly-epsilon-caprolactone/gel hybrid scaffolds for cartilage tissue engineering

The aim of this study was to determine the suitability of hybrid scaffolds composed of naturally derived biopolymer gels and macroporous poly-epsilon-caprolactone (PCL) scaffolds for neocartilage formation in vitro. Rabbit articular chondrocytes were seeded into PCL/HA (1 wt % hyaluronan), PCL/CS (0.5 wt % chitosan), PCL/F (1:3 fibrin sealant plus aprotinin), and PCL/COL1 (0.24% type I collagen) hybrids and cultured statically for up to 50 days. Growth characteristics were evaluated by histological analysis, scanning electron microscopy, and confocal laser scanning microscopy. Neocartilage was quantified using a dimethyl-methylene blue assay for sulfated glycosaminoglycans (sGAG) and an enzyme-linked immunosorbent assay for type II collagen (COL2), normalized to dsDNA content by fluorescent PicoGreen assay. Chondrocytes were homogenously distributed throughout the entire scaffold and exhibited a predominantly spheroidal shape 1 h after being seeded into scaffolds. Immunofluorescence depicted expanding proteoglycan deposition with time. The sGAG per dsDNA increased in all hybrids between days 25 and 50. PCL/HA scaffolds consistently promoted highest yields. In contrast, total sGAG and total COL2 decreased in all hybrids except PCL/CS, which favored increasing values and a significantly higher total COL2 at day 50. Overall, dsDNA content decreased significantly with time, and particularly between days 3 and 6. The PCL/HA hybrid displayed two proliferation peaks at days 3 and 25, and PCL/COL1 displayed one proliferation peak at day 12. The developed hybrids provided distinct short-term environments for implanted chondrocytes, with not all of them being explicitly beneficial (PCL/F, PCL/COL1). The PCL/HA and PCL/CS hybrids, however, promoted specific neocartilage formation and initial cell retention and are thus promising for cartilage tissue engineering.

A high yield of fetal nucleated red blood cells isolated using optimal osmolality and a double-density gradient system

OBJECTIVES

To increase the yield of fetal nucleated red blood cells (NRBCs) from maternal blood using a discontinuous Percoll gradient and to determine the effects of osmolality on NRBC yield.

METHODS

Fetal NRBCs were isolated from combined umbilical cord blood and adult female blood, or from maternal blood using single or double Percoll gradients with different osmolalities. Magnetic activated cell sorting was used to enrich isolated NRBCs, and morphological differentiation was performed with Kleihauer-Betke stain. We also isolated fetal NRBCs from 25 10 mL samples of maternal blood and determined fetal sex by fluorescence in situ hybridization (FISH), using X-Y probes.

RESULTS

For single-density Percoll columns, the greatest number of NRBCs was isolated using 280 mOsm/kg H(2)O with 1.077 g/mL Percoll and 520 mOsm/kg H(2)O with 1.119 g/mL Percoll. Significantly more fetal NRBCs were isolated with double Percoll density gradients than with double-Histopaque gradients (p = 0.043). FISH analysis on NRBC in 25 cases correctly identified 15 male and 9 female euploid fetuses and one Trisomy 21 fetus.

CONCLUSION

The NRBC enrichment method we present requires less maternal blood and yields more NRBCs compared to previous methods.

Spinal epidural hemangiomas: various types of MR imaging features with histopathologic correlation

BACKGROUND AND PURPOSE

Because of the high vascularization of hemangiomas, preoperative misinterpretation may result in unexpected intraoperative hemorrhage and incomplete resection, which results in the persistence of clinical symptoms or recurrence. Our purpose was to analyze various MR imaging features of a spinal epidural hemangioma with histopathologic correlation.

MATERIALS AND METHODS

After searching through the pathology data bases in 3 hospitals, we included 14 patients (9 male and 5 female; mean age, 38 years; age range, 2-62 years) with spinal epidural hemangiomas confirmed by surgical resection after MR imaging. Three radiologists reviewed the MR imaging in consensus and categorized the features into subtypes on the basis of histopathologic findings.

RESULTS

We categorized the MR imaging features as follows: type A for a cystlike mass with T1 hyperintensity (2 cases, arteriovenous type with an organized hematoma), type B for a cystlike mass with T1 isointensity (3 cases, venous type), type C for a solid hypervascular mass (7 cases, cavernous type), and type D for an epidural hematoma (2 cases, cavernous type with hematoma). Types A and B had frequent single segmental involvement (4/5), whereas types C and D had multisegmental involvement in all. Regardless of MR types, lobular contour (8/14) and a rim of low T2 signal intensity (8/14) of the mass were common. T1 hyperintensity of the mass was occasionally seen (5/14).

CONCLUSIONS

Spinal epidural hemangiomas can have various MR imaging features according to their different histopathologic backgrounds. In addition to common features such as solid hypervascularity, lobular contour, and a rim of low T2 signal intensity, T1 hyperintensity or multisegmental involvement may also be a clue in the differential diagnosis of a spinal epidural hemangioma.

Genetic polymorphisms of OPG, RANK, and ESR1 and bone mineral density in Korean postmenopausal women

To evaluate the effects of genetic polymorphisms of OPG, RANK, and ESR1, which regulate osteoclastogenesis, on bone mineral density (BMD), a cross-sectional study was conducted in 650 Korean postmenopausal women. BMDs of the distal radius and the calcaneus were measured by dual energy X-ray absorptiometry (DXA). Genetic polymorphisms of OPG 163 A > G, 1181 G > C; RANK 421 C > T, 575 T > C; and ESR1 1335 C > T, 2142 G > A were determined by matrix-assisted laser desorption/ionization-time of flight (MALDI-ToF) mass spectrometry. The differences between the BMDs of the genotypes of OPG, RANK, and ESR1 were analyzed by multiple linear regression model adjusted for age and body mass index. Women with the OPG 1181 CC genotype had higher BMDs at the distal radius (7%) and calcaneus (10%) than those with the GG genotype; and these differences were statistically significant (P = 0.001 and P = 0.007, respectively). A significant association was also observed between RANK 575 T > C and calcaneus BMD (P for trend = 0.017). No significant association was observed between BMDs and the polymorphisms of ESR1. The association between OPG 1181 G > C and BMD was profound in subjects with the RANK 575 TT or ESR1 2142 GG genotypes; women with OPG 1181 CC had higher BMDs at the distal radius (11%) and calcaneus (11%) than those with OPG 1181 GG only in women with RANK 575 TT genotype (P = 0.002 and P = 0.021, respectively). These results suggest that OPG genetic polymorphisms, especially with the RANK 575 TT or ESR1 2142 GG genotypes, are related to low BMD in postmenopausal Korean women.

Chromosome aberration and lipid peroxidation in chromium-exposed workers

Chromosome aberration frequency and lipid peroxidation levels were analyzed to investigate their efficacy as biological markers for monitoring the genotoxicity and oxidative damage in Korean chromium (Cr)-exposed workers. Fifty-one Cr-exposed workers and 31 age-matched controls in ten chrome-plating plants were sampled. The Cr level was measured in the workers' blood and urine, and in the ambient air at the workplaces. The conventional Giemsa staining method and fluorescence in situ hybridization (FISH) technique were used for chromosome aberration analysis. Spectrum green whole chromosome paint specific for chromosome 4 was used in the FISH procedure. As for lipid peroxidation, malondialdehyde (MDA) was measured in the blood plasma as thiobarbituric acid-reactive substances (TBARS). The blood Cr concentration was statistically correlated with both the frequency of chromatid exchange and the total frequency of chromosome/chromatid breaks and exchanges, as detected by the Giemsa staining. Meanwhile, the frequency of translocation, as detected by the FISH technique, was significantly higher in the Cr-exposed workers than in the controls and it correlated with the blood Cr concentration. Although the concentration of MDA, the metabolite of lipid peroxidation, in the exposed workers was higher than that of the controls, no statistically significant correlation between the MDA level and the blood or urine Cr levels was observed. Accordingly, the genotoxicity and oxidative damage (plasma lipid peroxidation) in the Korean Cr-exposed workers were consequential at quite low exposure levels, plus chromosome rearrangement, especially translocation, was clearly evident as a biological response marker for Cr exposure based on a significant positive correlation between the translocations detected by FISH and the Cr in the blood.

Time course of cerebral infarction in the middle cerebral arterial territory: deep watershed versus territorial subtypes on diffusion-weighted MR images

PURPOSE

To examine possible differences between the evolution of cerebral watershed infarction (WI) and that of territorial thromboembolic infarction (TI) by using diffusion-weighted (DW) and T2-weighted magnetic resonance (MR) images and apparent diffusion coefficient (ADC) maps.

MATERIALS AND METHODS

Fourteen patients with TI and nine with WI underwent MR imaging from the acute to chronic infarction stages. ADC maps were derived from DW images. Lesion-to-normal tissue signal intensity ratios on ADC maps (rADC), echo-planar T2-weighted images, and DW images were calculated. Lesion volumes at acute or early subacute infarction stages were measured on DW images, and final lesion volumes were estimated on fluid-attenuated inversion-recovery images.

RESULTS

Analysis of variance revealed a significant difference in temporal evolution patterns of rADC between WI and TI (P <.001). rADC pseudonormalization following TI began about 10 days after symptom onset, but that following WI did not occur until about 1 month after symptom onset. The Pearson correlation coefficient between final and initial infarct volumes was 0.9899 for both infarction subtypes, indicating that the initial ischemic injury volume measured at the acute or early subacute stage predicted the final lesion volume fairly well.

CONCLUSION

The evolution time of ADC is faster for TI than for WI. This difference, which likely originates from the different pathophysiologic and hemodynamic features of the two infarction types, might account for the relatively large range of ADC values reported for the time course of ischemic strokes.

MR findings of tuberculous dactylitis: case report

A case of tuberculous dactylitis in an immunocompetent patient is presented and the radiographic findings and differential diagnosis discussed. MR image, although nonspecific, was helpful for differential diagnosis and evaluating the extent of the lesion. Although this is a rare condition, the diagnosis should be considered when dealing with an unusual destructive bony lesion.

Expression and Tyrosine Phosphorylation of E-Cadherin, β- and γ-Catenin, and Epidermal Growth Factor Receptor in Cervical Cancer Cells

OBJECTIVES

The cadherin/catenin adhesion complex is fundamentally involved in epithelial cancer invasion and metastasis. Much evidence suggesting that epidermal growth factor (EGF) induced the scattering and invasion of cancer cells, probably by affecting E-cadherin function, has been reported. The present study aimed to confirm the hypothesis that EGF/epidermal growth factor receptor (EGFR) was related with the E-cadherin adhesion system in cervical cancer cells and that EGF might induce tyrosine phosphorylation of beta- and gamma-catenin.

METHODS

Cervical cancer cells were treated for different time durations with 30 ng/ml of EGF. Alteration of the cell morphology was examined by light microscopy and the expression of E-cadherin, beta-catenin, gamma-catenin, EGFR, and activated EGFR was assayed using Western blotting. Tyrosine phosphorylation of beta- and gamma-catenin was also examined using immunoprecipitation.

RESULTS

E-cadherin and EGFR were expressed in CaSki, HT-3, and ME-180 cell lines, which showed epithelial contact growth. The expression of E-cadherin and beta- and gamma-catenin did not change after treatment with EGF. The expression of EGFR decreased and activated EGFR expression increased in 30 min and then decreased subsequently. The simultaneous expression of activated EGFR and tyrosine phosphorylation of beta- and gamma-catenin was found.

CONCLUSIONS

EGF-induced scattering of the E-cadherin-positive cervical cancer cells might be the result of tyrosine phosphorylation of the beta- and gamma-catenin. Phosphorylation of the beta- and gamma-catenin may hamper the adhesive function of the E-cadherin-catenin complex.

[Reverse transcriptase PCR (RT-PCR) and quantitative-competitive PCR (QC-PCR)]

Due to its extraordinarily high sensitivity, polymerase chain reaction (PCR) is widely used for amplifying cDNA copies of low abundance mRNA. However, quantitation is unreliable because the amount of PCR product increases exponentially with each cycle of amplification; therefore, minute differences in any of the variables that affect the efficiency of amplification can dramatically alter product yield. Coamplification with a different reporter gene product is a semiquantitative mRNA quantitation method. Thus, we constructed an internal standard with a defined deletion fragment from the target cDNA, and used the same primers to coamplify the unknown and the competitor, allowing us to quantify the amount of specific target cDNA available. In addition, because the efficiency of amplification of the internal control molecules is identical to that of the target template, quantitative PCR can avoid the discrepancies associated with tube-to-tube or sample-to-sample variations in the kinetics of the RT reaction. For RNA quantitation, Northern blots are widely used. However, the Northern blot technique requires at least 10mg of total RNA for semiquantitation while QC-PCR requires only 1mg of total RNA and is useful when only small amounts of tissue are available. QC-PCR is a simple, and inexpensive method in which competitive PCR is used for highly accurate quantitation of mRNA and DNA from a small number of cells.

Tuberculous versus pyogenic arthritis: MR imaging evaluation

PURPOSE

To assess magnetic resonance (MR) imaging features in differentiating tuberculous arthritis from pyogenic arthritis.

MATERIALS AND METHODS

Findings in 29 patients with tuberculous arthritis were compared with those of 13 patients with pyogenic arthritis. Bone erosion, marrow signal intensity, synovial lesion signal intensity, boundaries (smooth or irregular) for extraarticular extension of infection, and abscess rim enhancement (thin and smooth or thick and irregular) were analyzed.

RESULTS

Bone erosion was more common in patients with tuberculous arthritis (24 [83%] of 29) than in those with pyogenic arthritis (six [46%] of 13) (P =.026), while subchondral marrow signal intensity abnormality was seen more frequently in patients with pyogenic arthritis (12 [92%] of 13) than in those with tuberculous arthritis (17 [59%] of 29) (P =.036). On T2-weighted images, there was no significant difference between the synovial lesion signal intensities of tuberculous arthritis and pyogenic arthritis. Lesions in 16 (70%) of 23 patients with tuberculous arthritis and two (17%) of 12 patients with pyogenic arthritis had smooth extraarticular boundaries, while those in seven (30%) of 23 patients with tuberculous arthritis and 10 (83%) of 12 patients with pyogenic arthritis had irregular boundaries (P =.005). Tuberculous abscesses (16 [100%] of 16) had thin and smooth rim enhancement, while most pyogenic abscesses (five [71%] of seven) had thick and irregular rims (P =.001).

CONCLUSION

MR imaging of bone abnormalities, extraarticular lesions, and associated abscesses provides useful information in the differentiation of tuberculous arthritis and pyogenic arthritis.

Interleukin-1beta regulates urokinase plasminogen activator (u-PA), u-PA receptor, soluble u-PA receptor, and plasminogen activator inhibitor-1 messenger ribonucleic acid expression in cultured human endometrial stromal cells

The interleukin-1 (IL-1) system plays an integral role in local intercellular interactions during implantation. In addition, the plasminogen activator system, especially urokinase plasminogen activator (u-PA), plasminogen activator inhibitor (PAI-1), and u-PA receptor (u-PAR), are crucial during embryo implantation. Decidualization and implantation are complex processes dependent upon several proteases, including u-PA, and IL-1 is known to affect PA activity in several cell types. We investigated the role of IL-1beta in regulating u-PA, PAI-1, u-PAR, and soluble u-PAR messenger ribonucleic acid (mRNA) expression in cultured human endometrial stromal cells using quantitative competitive PCR. For confirmation of the mRNA data, we measured PAI-1 and u-PAR protein by enzyme-linked immunosorbent assay. Confluent stromal cell cultures treated with progesterone and estradiol for 9 days were stimulated with IL-1beta, and IL-1beta plus IL-1beta antibody for an additional 24 h. Total RNA was extracted, reverse transcribed, and coamplified using quantitative and competitive PCR with internal standards. IL-1beta increased PAI-1, u-PAR, and soluble u-PAR expression in a dose-dependent manner, and this result was reversed by anti-IL-1beta antibody treatment. u-PA mRNA expression was not dependent on IL-1beta. These results suggest that IL-1 may be important in regulating PAI-1 and u-PAR during stromal cell decidualization before implantation.

Sonography of acute osteomyelitis in rabbits with pathologic correlation

RATIONALE AND OBJECTIVES

Ultrasonography (US) has a potential role in the diagnosis of osteomyelitis. The purpose of this study was to determine the characteristic sonographic features of acute osteomyelitis and correlate them with pathologic findings.

MATERIALS AND METHODS

An experimental model of acute osteomyelitis was produced in the tibiae of 20 rabbits. Daily US and plain radiography were performed for 2 weeks. The authors evaluated periosteal reaction, subperiosteal fluid collection, and soft-tissue changes seen with US. A hypoechoic band and a hyperechoic line lying along the cortex were considered positive signs of subperiosteal fluid collection and periosteal reaction, respectively. The findings of periosteal reaction were compared for US and radiography, and pathologic findings were also correlated.

RESULTS

The most common sonographic finding was a hypoechoic band along the cortex (21 [75%] of 28 tibiae), usually associated with a linear periosteal reaction (20 [71%] of 28). This juxtacortical abnormal echogenicity corresponded to periosteal elevation with loose fibrovascular connective tissue and granulation, associated with subperiosteal abscess formation. The periosteal reactions were detected with US before they were seen on radiographs. The periosteum showed gradual thickening during the disease process. In 50% of infected tibiae, inflammation or abscess formation was observed in the surrounding soft tissue.

CONCLUSION

US readily demonstrates juxtacortical abnormal echogenicity and soft-tissue infection related to acute osteomyelitis. The abnormal echogenicity correlated well with the pathologic findings of periosteal reaction and subperiosteal abscess.

Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-3 mRNA expression in ectopic and eutopic endometrium in women with endometriosis: a rationale for endometriotic invasiveness

OBJECTIVE

To investigate mRNA expression of metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-3 (TIMP-3) in ectopic endometriosis tissue and uterine endometrium from women with and without endometriosis throughout the menstrual cycle.

DESIGN

Molecular studies in human tissue.

SETTING

Department of Gynecology and Obstetrics, Reproductive Immunology Laboratory, Stanford University Medical Center.

PATIENT(S)

Fifty-three premenopausal woman (23 women with endometriosis and 30 women without endometriosis undergoing laparoscopic surgery). Endometrium and ectopic endometriosis tissue were obtained at the time of surgery.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

mRNA expression from eutopic and ectopic endometrium was analyzed by quantitative, competitive PCR.

RESULT(S)

Both uterine endometrium and ectopic endometriotic tissue from women with endometriosis expressed significantly (P<.05) lower levels of TIMP-3 than endometrium from normal women. Also, ectopic endometrium expressed higher levels of MMP-9 and a higher ratio of MMP-9/TIMP-3 than eutopic endometrium from normal and endometriosis patients.

CONCLUSION(S)

These results suggest that ectopic and eutopic endometrium from endometriosis patients may be more invasive and prone to peritoneal implantation because of greater MMP and less TIMP-3 mRNA expression than endometrium from women without endometriosis. Thus, increased proteolytic activity may be one of the reasons for the invasive properties of the endometrium, resulting in the development of endometriosis.

Malignant melanoma of the sinonasal cavity: explanation of magnetic resonance signal intensities with histopathologic characteristics

PURPOSE

To evaluate the magnetic resonance (MR) findings of malignant melanoma of the sinonasal cavity and compare these findings with those of the histopathological examination.

MATERIALS AND METHODS

The MR images of 11 patients with malignant melanoma of the sinonasal cavity were retrospectively reviewed. Ten patients had primary malignant melanoma of the sinonasal cavity and one had a local recurrence. The imaging findings were evaluated with special attention given to the signal intensity of the tumor, internal characteristics, and growth pattern on MR. Signal intensity and enhancement patterns of the tumors were compared with the histopathological findings.

RESULTS

On T1-weighted image, 6 tumors were hyperintense (5 melanotic and one amelanotic melanoma), and 5 tumors were isointense or hypointense (4 amelanotic and one melanotic). On T2-weighted images, 2 amelanotic tumors showed hyperintensity, and 5 melanotic tumors showed hypointensity. Four tumors (one melanotic and 3 amelanotic) were isointense. Four of the 7 tumors with hyperintensity on T1-weighted images showed patchy, higher-signal intensity areas. In 3 of them, patchy areas of a higher degree of pigmentation were found on histopathological examination. There were multiple linear dark signal intensities on T2-weighted images and/or linear-enhancing areas on enhanced T1-weighted images within the masses in 5 of the 11 patients. These findings could be explained as intratumoral vessels in 4 tumors and fibrous septa in one tumor on histopathological examinations.

CONCLUSION

Malignant melanoma of the sinonasal cavity shows characteristic MR signal intensity, which is mainly attributable to the degree and distribution of melanin pigmentation, and partly attributable to hemorrhage within the mass. The linear, low-signal intensity on T2-weighted images or enhanced lines are intratumoral vessels or fibrous septa.

T2-Weighted fast MR imaging with true FISP versus HASTE: comparative efficacy in the evaluation of normal fetal brain maturation

OBJECTIVE

This study compares the relative efficacy of two fast T2-weighted MR imaging techniques-fast imaging with steady-state free precession (true FISP) and half-Fourier acquisition single-shot turbo spin-echo (HASTE)-in the evaluation of the normal fetal brain maturation during the second and third trimesters of gestation.

SUBJECTS AND METHODS

The brain maturation of 10 normal nonsedated fetuses (5 during the second trimester and 6 during the third trimester of gestation [1 fetus underwent 2 examinations]) was examined by both techniques using a Vision+ 1.5-T MR system. We specifically looked for developing events, including white matter myelination, neuronal migration, and cortical sulcation. Image quality was graded according to the presence or absence of undesirable blurring.

RESULTS

The specific absorption rate was lower for true FISP than for HASTE by a factor of 3 at equivalent imaging conditions. HASTE and true FISP provide comparable image quality in the second trimester when myelination of the cerebrum has not begun. Neuronal migration could be recognized as hypodense bands on both sequences during the second trimester. Myelination beginning at the third trimester was better delineated with true FISP than with HASTE because of point spread function-related blurring effects inherent in HASTE that hampered visualization of short-T2 structures. Cortical sulcation was well delineated by both sequences.

CONCLUSION

With relatively superior image quality and significantly lower radiofrequency absorption than HASTE, true FISP is a safer and more effective alternative in the prenatal evaluation of normal fetal brain.

Heroin-induced spongiform leukoencephalopathy: value of diffusion MR imaging

The diffusion-weighted (DW) magnetic resonance (MR) imaging findings of a patient with subacute stage of heroin-induced vacuolating myelinopathy are reported. The diffuse decrease of apparent diffusion coefficient (ADC) of the white matter on DW imaging is attributed to restricted water diffusion, which is known to be caused by fluid entrapment within the myelin lamellae without demyelination.

Juxtacortical chondromyxoid fibroma arising in an apophysis

We present a rare case of juxtacortical chondromyxoid fibroma arising in the lesser trochanter of the right femur which corresponds to an apophysis. Radiography showed a well-defined expansive lesion with a sclerotic margin measuring 5x3.5 cm in diameter in the lesser trochanter. On spin echo T1-weighted images, the lesion revealed low signal intensity similar to muscle. On spin echo T2-weighted images, the lesion revealed high heterogeneous signal intensity, which after gadolinium injection showed heterogeneous enhancement. The inner margin of the cortex was intact and adjacent bone marrow was of normal signal intensity. The outer margin of the lesion was also clearly defined and extension into adjacent soft tissue beyond the exophytic cortical outgrowth was not evident.

Indirect signs of anterior cruciate ligament injury on SPET: comparison with MRI and arthroscopy

Indirect signs of anterior cruciate ligament (ACL) injury on magnetic resonance imaging (MRI) include bony contusions in the lateral femoral condyle and the posterior portion of the lateral tibial plateau. This study was undertaken to assess the value of single photon emission tomography (SPET) in the diagnosis of ACL injury by examining the uptake pattern in the distal femur and the proximal tibia. Thirty-five patients were examined using SPET, MRI and arthroscopy. Seventeen patients were found to have ACL tears on arthroscopy. The duration of symptoms was 4 days to 10 years (mean 26.4 months). MRI and SPET images were analysed retrospectively without information from arthroscopic examination. Radionuclide uptake in the lateral femoral condyle and the posterior lateral tibial plateau was considered an indirect sign of ACL injury on SPET. We evaluated the diagnostic value of indirect signs of ACL injury obtained on SPET by comparing these findings with arthroscopic and MRI results. Fifteen of 17 patients with ACL injury showed indirect signs on SPET. The sensitivity, specificity, positive predictive value and negative predictive value for indirect signs of ACL injury were 88%, 56%, 65% and 83% on SPET and 59%, 94%, 91% and 71% on MRI, respectively. However, despite the higher sensitivity of indirect signs on SPET than on MRI, the overall diagnostic value of MRI is better than that of SPET. In the clinical setting, indirect signs of ACL injury may be of value in interpreting incidental findings on SPET.

Analysis of chromosome aberrations in nuclear-power-plant workers considering the lifetime of lymphocytes

PURPOSE

To analyse chromosome aberrations in nuclear-power-plant workers taking account of the mean lifetime of lymphocytes (MLTL).

MATERIALS AND METHODS

Analysis of chromosome aberrations was performed on peripheral lymphocytes from 395 nuclear-power-plant workers and 135 controls. An equivalent acute dose (EAD) was calculated utilizing MLTL values of either 4.3 or 10 years.

RESULTS

Using an MLTL value of 10 years produced an EAD range of 0.O1 mSv -182mSv(mean 46.6mSv), while using an MLTL, of 4.3 years produced results ranging from 0.01 mSv to 86.2 mSv (mean 23.4 mSv). A significant increase of chromosome-type exchange by the equivalent acute dose was observed using an MLTL of either 10 or 4.3 years when including the control in the analysis, but a significant increase was not seen when only the exposed was considered. A significant increase of chromosome-type deletion by EAD was seen even when only the exposed group was considered.

CONCLUSIONS

EAD values based on an MLTL of either 4.3 or 10 years, as well as cumulative dose, showed no significant association with chromosome aberrations, when radiation workers only were analysed. The narrow dose range examined in this study might have contributed to this finding.

Fractal analysis of nuclear medicine images for the diagnosis of pulmonary emphysema: interpretations, implications, and limitations

OBJECTIVE

The purpose of this study was to investigate, on images obtained in nuclear medicine examinations, the physical meanings and consequent implications of fractal analysis developed in a recent study that was reported to be effective in quantifying the heterogeneous distribution of carbon particle radioaerosol in the lungs.

MATERIALS AND METHODS

Fractal dimensions were computed for 108 sets of radionuclide imaging data from 28 patients according to the methods in a previous report, and were then correlated with the ratio of tissue areas segmented at two thresholds (15% and 35% of maximal radioactivity).

RESULTS

Fractal dimension was found to linearly correlate with the ratio natural logarithm of tissue areas segmented at two different threshold levels (n = 108, r = 0.999), with regression slope accurately predicted (error = 0.06%). Bland-Altman analysis showed that fractal dimensions ranging from 0.2 to 1.9 can be explained by this area ratio with disagreement of only 5.13% at two standard deviations; thus, fractal dimension seems to be an over-simplified parameter unrelated to spatial heterogeneity of radioaerosol distribution.

CONCLUSION

The analysis of this study suggested that the fractal dimension defined in a previous report was limited to the indication of the percentage area of low-radioactivity regions with respect to total tissue area in the image. Because the fractal dimension partially reflects, but is not specific to, a certain degree of focal spots of low radioactivity, we suggest using fractal analysis in clinical practice only with careful control and thorough understanding of the physical meanings.

Automatic spike detection via an artificial neural network using raw EEG data: effects of data preparation and implications in the limitations of online recognition

OBJECTIVE

Automatic detection of epileptic EEG spikes via an artificial neural network has been reported to be feasible using raw EEG data as input. This study re-investigated its suitability by further exploring the effects of data preparation on classification performance testing.

METHODS

Six hundred EEG files (300 spikes and 300 non-spikes) taken from 20 patients were included in this study. Raw EEG data were sent to the neural network using the architecture reported to give best performance (30 input-layer and 6 hidden-layer neurons).

RESULTS

Significantly larger weighting of the 10th input-layer neuron was found after training with prepared raw EEG data. The classification process was thus dominated by the peak location. Subsequent analysis showed that online spike detection with an erroneously trained network yielded an area less than 0.5 under the receiver-operating-characteristic curve, and hence performed inferiorly to random assignments. Networks trained and tested using the same unprepared EEG data achieved no better than about 87% true classification rate at equal sensitivity and specificity.

CONCLUSIONS

The high true classification rate reported previously is believed to be an artifact arising from erroneous data preparation and off-line validation. Spike detection using raw EEG data as input is unlikely to be feasible under current computer technology.

The visible man: three-dimensional interactive musculoskeletal anatomic atlas of the lower extremity

A personal computer-based interactive musculoskeletal anatomic atlas of the lower extremity has been created by using the Visible Human Male data set. A semiautomatic segmentation program was developed by using an intelligent scissors approach and shape-based interpolation, thus considerably reducing the laborious work of the segmentation and labeling process. Manual contour extractions at 3-mm section intervals and shape-based interpolations of intervening sections of the musculoskeletal structures of the lower extremity were performed. For interactive and realistic three-dimensional display, an efficient binary volume rendering method was developed that introduces the concept of shear-warp factorization and applies a newly developed normal calculation technique. Binary volume rendering reconstructs various structures from a series of two-dimensional sections in a few seconds, thus enabling real-time manipulations of the computerized atlas. All of the muscles, tendons, and bones of the lower extremity have been segmented and labeled. The volume-based three-dimensional interactive atlas supports various interactions including rotation, removal, highlighting with artificial colors, arbitrary cutting operation, transparent view, and descriptive knowledge representation. In addition, browsing through the two-dimensional images of transverse, coronal, and sagittal views with labeling and segmentation information is possible.

Frame-shift mutation in hormone binding domain of human androgen receptor gene causes complete androgen insensitivity

Mutation of the human androgen receptor gene impairs normal sexual differentiation and development in karyotypic males, resulting in a spectrum of external genital phenotypes ranging from complete female to nearly complete male. The androgen insensitivity syndrome (AIS) is an X-linked disorder in which genetic males fail to undergo normal fetal masculinization or pubertal virilization. PCR amplification of AR exons followed by SSCP analysis was performed with the genomic DNA of a patient having complete AIS. Mutation was observed at the exon E, where a single nucleotide deletion of T at the nucleotide 3286 was observed by cyclic sequencing. A single base deletion in Exon E in the hormone binding domain causes a frame-shift mutation, which leads to changes in the open reading frame, and causes the early termination of AR synthesis. The structural change of the hormone binding domain and AR might cause an insensitivity to the androgen thus leading to AIS.

Genetic integrity of transforming growth factor beta (TGF-beta) receptors in cervical carcinoma cell lines: loss of growth sensitivity but conserved transcriptional response to TGF-beta

Transforming growth factor beta (TGF-beta) exerts an inhibitory effect on the growth of most epithelial cell types, and the loss of responsiveness to this growth inhibition has been implicated in the development of a variety of human cancers. The genetic alteration of TGF-beta receptors is known to play a critical role in this escape from growth regulation. We asked whether there is a correlation between TGF-beta sensitivity and the genetic status of TGF-beta type I and type II receptors (RI and RII, respectively) in human cervical carcinoma cell lines. Among 8 cell lines examined, 3 (ME-180, C-33A and HeLaS3) showed resistance to TGF-beta and 3 (SiHa, CaSki and HeLa229) showed minimal response to the growth inhibitory effect of TGF-beta; the other cell lines (HeLa and HT-3) were sensitive. Northern blot analysis revealed that the RII mRNA was not expressed in 2 TGF-beta-resistant cell lines (ME-180 and C-33A) but was expressed in the other cell lines. Southern blot analysis of RI and RII revealed a homozygous deletion of the entire TGF-beta RII gene in the cell line ME-180. We then asked whether the other TGF-beta-resistant or refractory cell lines had microsatellite instability and/or poly-adenine tract mutations of RII. We also checked for point mutations in the individual exons of the entire RII using polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP). Although C-33A exhibited poly-adenine microsatellite instability, its RII gene showed no signs of mutation. The molecular integrity of the TGF-beta, receptors in all cell lines, except ME-180 and C-33A, could be confirmed by examining the distinct transcriptional induction of plasminogen activator inhibitor-1 (PAI-1), p21(WAF1/CIP1) and, in some cases, the accompanying downregulation of c-myc in response to TGF-beta. Our observations, taken together, indicate that inactivation of the RII contributes to the resistance to TGF-beta of some cervical carcinoma cell lines. Loss of or attenuated sensitivity to TGF-beta growth inhibition in other cells may be attributed to the disruption of distal components in the TGF-beta signal pathway, but not to the receptor system.

A novel ets-related transcription factor, ERT/ESX/ESE-1, regulates expression of the transforming growth factor-beta type II receptor

A 2.5-kilobase cDNA clone that encodes a 371-amino acid novel transcription factor was isolated from a human placenta cDNA library using a yeast one-hybrid system. The novel ets-related transcription factor (ERT) showed a homology with the ETS DNA-binding domain. Using constructs of the transforming growth factor-beta (TGF-beta) type II receptor (RII) promoter linked to the luciferase gene, we have demonstrated that ERT activates transcription of the TGF-beta RII gene through the 5'-TTTCCTGTTTCC-3' response element spanning nucleotides +13 to +24 and multiple additional ETS binding sites between -1816 and -82 of the TGF-beta RII promoter. A specific interaction between ERT and the ETS binding sites was also demonstrated using an electrophoretic mobility shift assay. Deletion mapping of ERT protein suggests that the transactivation domain resides in the amino terminus while the DNA-binding domain is localized to the carboxyl-terminal region. Our results suggest that ERT might be a major transcription factor involved in the transcriptional regulation of the TGF-beta RII gene.

Chromosome aberrations in workers of nuclear-power plants

The frequencies of chromosome aberrations in 135 workers from nuclear- power plants were compared with those in 135 age-matched controls. A total of 135,000 cells was scored. The frequencies of dicentric chromosome were 1.67 x 10(-3) in the exposed group and 0.49 x 10(-3) in the control group and those of chromosome-type deletion were 3.33 x 10(-3) and 1.10 x 10(-3), respectively. The frequencies of all types of chromosome aberrations in the exposed subjects were higher than those in the control group, but no significant trend of dose-dependent increase was observed when only the exposed group were considered. Poisson regression analysis, with both exposed and control included, showed that there was a significant association of chromosome aberration with radiation dose and the duration of work, but not with age, smoking habit and alcohol intake. It was also found that recent exposure to radiation, within the last 5 years, had contributed more to the observed chromosome aberration than earlier exposure.

Three-dimensional nuclear magnetic resonance microimaging of trabecular bone

The conventional approach to measuring structural parameters in trabecular bone rests on stereology from optical images, derived from sections of embedded bone. In order to provide data that are statistically representative of a sufficiently large volume, multiple sections need to be analyzed in each of the three orthogonal planes. In this work, an alternative technique is presented which is based on three-dimensional (3D) volumetric proton nuclear magnetic resonance (NMR) microimaging. The method presented provides from 9 x 9 x 4 mm3 volumes of defatted bone specimens in 15-20 minutes scan time at isotropic resolution corresponding to (78 microm)3 voxel size. Surface-rendered images of bovine and human trabecular bone are shown and an algorithm was developed and implemented for determining the orientation and magnitude of the principle axes of the mean intercept length tensor.

Quantitative analysis of trabecular microstructure by 400 MHz nuclear magnetic resonance imaging

A new approach for the quantitative analysis of trabecular microstructure, based on high-field proton nuclear magnetic resonance (NMR) imaging, is presented. NMR is ideal because it provides high contrast between the marrow proton signal and the bone, which appears with background intensity. Images from 1 cm3 defatted specimens of trabecular bone, suspended in water doped with 1 mM Gd(DTPA) to shorten T1 to about 300 ms, can be obtained at a resolution on the order of 30-50 microns and slice thickness of 150 microns, in 10 minutes at 400 MHz proton frequency. Digital image processing algorithms were designed and evaluated for the measurement of bone area fraction, perimeter length, mean trabecular thickness, and separation. Bone area fraction derived from the NMR images was found to be in excellent agreement with bone volume fraction measured independently (slope = 0.96, r2 = 0.924, p < 0.0001). Errors in the mean trabecular thickness and separation were < 6%. The effects of finite imaging slice thickness and signal-to-noise ratio (SNR) were also evaluated. The data suggest a resolution of 50 x 50 x 200 microns 3 and an SNR on the order of 10 to provide safe margins for precise and accurate structural analysis by means of the algorithms presented in this paper. The method allows simultaneous measurement at multiple locations within the specimen volume without the need for physical sectioning.