Technetium-99m methoxyisobutylisonitrile chest imaging for small-cell lung cancer. Relationship to chemotherapy response (six courses of combination of cisplatin and etoposide) and p-glycoprotein or multidrug resistance related protein expression

AIMS

This is a retrospective and adaptive randomization study. The purpose of this study was to evaluate the relationship between technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) chest-imaging results, chemotherapy response and P-glycoprotein (Pgp) or multidrug resistance related protein (MRP) expression in small-cell lung cancer (SCLC).

PATIENTS AND METHODS

Before chemotherapy, 30 patients (11 females, 19 males, ages: 52-69 years) with SCLC, including 14 extensive diseases without localized problems and 16 limited diseases in excess of solitary pulmonary nodule, underwent early chest imaging, including visual interpretation and quantitative analyses of tumor uptake ratio (TUR), 10 minutes after intravenous injection of Tc-99m MIBI. Immunohistochemical analyses were performed, using multiple nonconsecutive sections of the biopsy specimens, to detect Pgp and MRP expressions. Chemotherapy response was evaluated in the third month after completion of treatment by clinical and radiological methods.

RESULTS

All 15 (100%) of the SCLC patients with complete or partial response had positive Tc-99m MIBI chest SPECT results, but negative ones for both Pgp and MRP expression. Twelve of the 15 (80%) SCLC patients with no response or progressive disease had negative Tc-99m MIBI chest SPECT results and were positive for either Pgp or MRP expression (P < 0.05). Negative Tc-99m MIBI chest SPECT results predicted complete or partial response. The TUR of patients with complete or partial response (1.91 +/- 0.29 with a 95% confidence interval (95% CI): 1.75-2.07) was significantly higher than that of patients with no response or progressive disease (1.19 +/- 0.28 with a 95% CI: 1.04-1.35).

CONCLUSION

Tc-99m MIBI chest images are a potential tool for understanding Pgp and MRP expressions in SCLC and for predicting patient chemotherapy response.

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.

The C terminus of the Ca channel alpha1B subunit mediates selective inhibition by G-protein-coupled receptors

Inhibition of calcium channels by G-protein-coupled receptors depends on the nature of the Galpha subunit, although the Gbetagamma complex is thought to be responsible for channel inhibition. Ca currents in hypothalamic neurons and N-type calcium channels expressed in HEK-293 cells showed robust inhibition by G(i)/G(o)-coupled galanin receptors (GalR1), but not by Gq-coupled galanin receptors (GalR2). However, deletions in the C terminus of alpha(1B-1) produced Ca channels that were inhibited after activation of both GalR1 and GalR2. Inhibition of protein kinase C (PKC) also revealed Ca current modulation by GalR2. Imaging studies using green fluorescent protein fusions of the C terminus of alpha(1B) demonstrated that activation of the GalR2 receptor caused translocation of the C terminus of alpha(1B-1) to the membrane and co-localization with Galphaq and PKC. Similar translocation was not seen with a C-terminal truncated splice variant, alpha(1B-2). Immunoprecipitation experiments demonstrated that Galphaq interacts directly with the C terminus of the alpha(1B) subunit. These results are consistent with a model in which local activation of PKC by channel-associated Galphaq blocks modulation of the channel by Gbetagamma released by Gq-coupled receptors.

The role of technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography (SPECT) in the detection of cardiovascular involvement in systemic lupus erythematosus patients with non-specific chest complaints

OBJECTIVES

Systemic lupus erythematosus (SLE) can affect multiple organs. Coronary artery disease has received increasing recognition as a major cause of morbidity and mortality in SLE in recent years. The purpose of this study was to evaluate the utility of technetium-99m sestamibi single-photon emission computed tomography ((99m)Tc-sestamibi SPECT) in the detection of cardiovascular involvement in SLE patients with non-specific clinical chest symptoms such as chest discomfort and/or dyspnoea and/or occasional palpitation.

METHODS

Thirty-three SLE female patients (age range: 22-45 yr) with non-specific complaints such as chest discomfort and/or dyspnoea and/or occasional palpitation were investigated using a (99m)Tc-sestamibi myocardial perfusion SPECT scan at rest and after dipyridamole infusion in a stress study. The age- and sex-matched healthy group (24 cases) and SLE patients without any cardiovascular symptoms/signs (28 cases) were also included as controls in this study. The results of the uptake pattern of (99m)Tc-sestamibi were classified into four types including normal, persistent perfusion defect, reversible perfusion defect and reverse redistribution.

RESULTS

Perfusion abnormalities were detected in 27 cases (seven patients had persistent perfusion defects, 15 patients had reversible perfusion defects, one patient had both persistent and reversible perfusion defects, two patients showed a reverse redistribution pattern and two patients had both reversible perfusion defects and a reverse redistribution pattern). The results of the SPECT in the healthy group were all normal. However, perfusion abnormalities were detected in 12 cases in the group of asymptomatic SLE patients.

CONCLUSIONS

(99m)Tc-sestamibi myocardial perfusion SPECT is a useful non-invasive imaging modality to detect cardiovascular involvement in SLE patients with non-specific clinical complaints of heart disease.

GL331 induces down-regulation of cyclin D1 expression via enhanced proteolysis and repressed transcription

GL331 is a novel podophyllotoxin-derived compound. In this study, GL331 induced human lung adenocarcinoma cell line CL1-5 growth arrest before death during the initial 24-h incubation period. We found that GL331 had no inhibitory effect on the expression of cyclins E, A, B1, CDK 4, and CDK 2; instead, its cell growth-inhibitory effect was partly attributable to an early down-regulation of cyclin D1 expression and in turn the reduction of retinoblastoma protein phosphorylation. GL331 enhanced the proteolysis of cyclin D1, and a proteasome inhibitor was able to block GL331-caused cyclin D1 reduction, suggesting that GL331-stimulated cyclin D1 degradation was through proteasomal processes. Additionally, GL331 reduced cellular cyclin D1 mRNA level down to 45% of control in 4 h and further to around 20% in 12 h. However, GL331 did not accelerate the disappearance of cyclin D1 mRNA under the condition of transcription blockage induced by actinomycin D. It was reported that a certain region in the 3'-untranslated region (UTR) of cyclin D1 mRNA mediated the mRNA degradation upon extracellular stresses. Herein, transient transfection studies demonstrated that the 3'-UTR insertion did not confer the susceptibility of luciferase reporter gene to the GL331 treatment. Together, these data suggested that GL331 did not decrease the stability of cyclin D1 mRNA. On the other hand, we found that GL331 specifically inhibited the cyclin D1 promoter-driven luciferase reporter activity. Western blot analyses showed that GL331 decreased the level of phosphorylated extracellular signal-regulated kinase (Erk), with no effect on p38 or c-Jun NH(2)-terminal kinase. Furthermore, GL331's inhibition of cyclin D1 promoter was attenuated by ectopic Erk-2 overexpression. These data suggested that GL331 inhibited cyclin D1 gene transcription via the Erk signaling pathway. In summary, we report that GL331 induced an early decline of cyclin D1 expression by dual mechanisms: 1) enhancement of protein turnover and 2) repression of Erk-mediated gene transcription.

Hair removal by long-pulse alexandrite laser in oriental patients

The laser depilation system, cleared by the Food and Drug Administration since 1995, is evolving rapidly. However, the parameters in the hair removal function of these devices emphasize use for white people with fair skin (Fitzpatrick types I, II, or III). The characteristics of oriental skin and hair are black, coarse hairs in darker skin (Fitzpatrick types IV or V). As seen, the higher the skin melanin content, the more difficult to remove hair by laser. The authors report 146 oriental patients (156 body sites) who underwent treatment with the long-pulse alexandrite laser (wavelength, 755 nm) depilation system since November 1997. Percentage of hair removal (clearance rate) was assessed, and the histological change from laser pulse damage was observed. After two treatments, the clearance rates in the axillae and the leg were 61% and 62% respectively in the 15 to 20-J group (N = 47), and were 66% and 67% respectively in 21 to 25-J group (N = 64). After five treatments, 59 patients (37 axillae and 22 legs, all of which received 21-25 J per square centimeter of laser energy treatment during the course) had an average clearance rate of 91% (axillae) and 86% (leg), and the clearance rates have been maintained near 90% after long-term follow-up (average follow-up, 17 months). Minimal and transient complications are noted. In conclusion, using a combination of longer wavelength (but still in the optimal window of 630-870 nm), long pulse duration (10-40 msec), high fluence (but limited up to 25 J per square centimeter), multiple treatments, and concomitant direct cooling applied to the skin of oriental patients (Fitzpatrick types IV and V) with black, moderately coarse hair shafts achieves satisfying long-term hair removal results.

Data mining with decision trees for diagnosis of breast tumor in medical ultrasonic images

To increase the ability of ultrasonographic (US) technology for the differential diagnosis of solid breast tumors, we describe a novel computer-aided diagnosis (CADx) system using data mining with decision tree for classification of breast tumor to increase the levels of diagnostic confidence and to provide the immediate second opinion for physicians. Cooperating with the texture information extracted from the region of interest (ROI) image, a decision tree model generated from the training data in a top-down, general-to-specific direction with 24 co-variance texture features is used to classify the tumors as benign or malignant. In the experiments, accuracy rates for a experienced physician and the proposed CADx are 86.67% (78/90) and 95.50% (86/90), respectively.

Comparison of technetium-99m tetrofosmin and gallium-67 citrate scintigraphy for detecting malignant lymphoma

The aim of this study was to compare the value of technetium-99m tetrofosmin (Tc-TF) scintigraphy with that of gallium-67 citrate (Ga-67) scintigraphy for detecting malignant lymphoma. In this study, 50 patients with malignant lymphoma underwent Tc-TF and Ga-67 scintigraphy before receiving any therapy. Tc-TF scintigraphy detected malignant lymphoma in 44 (88%) patients, but was false-negative in 4 cases of infradiaphragmatic malignant lymphoma and in 2 cases of malignant lymphoma with chemotherapy resistance. Ga-67 scintigraphy detected malignant lymphoma in 45 (90%) patients, but was false-negative in 3 cases of low-grade non-Hodgkin's lymphoma and in 2 cases of malignant lymphoma with bone marrow involvement. There was no significant difference in sensitivity between Tc-TF and Ga scintigraphy. However, a combination of Tc-TF and Ga-67 scintigraphy detected malignant lymphoma in all 50 patients (100%). We conclude that it is necessary to combine Tc-TF and Ga-67 scintigraphy to accurately detect malignant lymphoma.

Less reversal of liver fibrosis after prolonged carbon tetrachloride injection

BACKGROUND/AIMS

It was generally believed, but not proved, that early cirrhosis may be reversible, while advanced cirrhosis may not. This present study is to compare in mice the spontaneous regression of liver fibrosis between early and more advanced stage.

METHODOLOGY

Liver fibrosis in mice was induced by intraperitoneal injection of carbon tetrachloride for 4, 10, and 16 weeks. After the last dose of each schedule, mice were sacrificed 1 day later (progression model) or left untreated for 10, 20, and 60 days (regression model). Tissue sections were stained by Sirius red. Liver hydroxyproline levels were determined to assess severity of fibrosis. Gelatinases in tissue extracts were assayed by zymography.

RESULTS

During regression, diminution of fibrotic bands was more prominent in the 4-week group than in the others. Liver hydroxyproline levels in the progression model increased and resolution of liver fibrosis in the regression model decreased as carbon tetrachloride injection was prolonged. Liver matrix metalloproteinase-2 and -9 activities in the progression model also decreased as the injection was prolonged.

CONCLUSIONS

These data demonstrated that reversibility of liver fibrosis would be gradually lost as liver injuries were prolonged. Gradual loss of the expression of matrix metalloproteinases may be responsible for the loss of reversibility.

Comparison of photosensitizer (AIPcS2) quantification techniques: in situ fluorescence microsampling versus tissue chemical extraction

A noninvasive in situ fluorescence-based method for the quantification of the photosensitizer chloroaluminum disulfonated phthalocyanine was compared to the highly accurate but nonreal time ex vivo spectrofluorometry method. Our in vivo fluorescence technique is designed to allow real-time assessment of photosensitizer in tumor and normal tissues and therefore temporally optimal light delivery. Laser-induced fluorescence was used to measure photosensitizer concentration from multiple microscopic regions of tissue. Ex vivo chemical extraction was used to quantify photosensitizer concentration in the same volume of tissue. The amount of photosensitizer in the vascular and/or parenchymal compartments of skeletal muscle and liver was determined by quantifying fluorescent signal in vivo, ex vivo and after blood removal. Confocal microscopy was used to spatially document photosensitizer localization 30 min and 24 h after delivery. While a linear correlation can exist between the fluorescence intensity measured by our fiber-optic bundle system and actual tissue concentration, temporal changes to this calibration line exist as the photosensitizer changes its partitioning fraction between the blood (vasculature) and the tissue parenchyma. In situ photosensitizer fluorescence microsampling (dosimetry) systems can be performed in real time and linearly correlated to actual tissue concentration with minimal intertissue variance. Tissue-specific differences may require temporal alterations in the calibration.

Prenatal diagnosis of partial monosomy 18p(18p11.2-->pter) and trisomy 21q(21q22.3-->qter) with alobar holoprosencephaly and premaxillary agenesis

A prenatal diagnosis of partial monosomy 18p(18p11.2-->pter) and trisomy 21q(21q22.3-->qter) in a fetus with alobar holoprosencephaly (HPE) and premaxillary agenesis (PMA) but without the classical Down syndrome phenotype is reported. A 27-year-old primigravida woman was referred for genetic counselling at 21 weeks' gestation due to sonographic findings of craniofacial abnormalities. Level II ultrasonograms manifested alobar HPE and median orofacial cleft. Cytogenetic analysis and fluorescence in situ hybridization (FISH) on cells obtained from amniocentesis revealed partial monosomy 18p and a cryptic duplication of 21q,46,XY,der(18)t(18;21)(p11.2;q22.3), resulting from a maternal t(18;21) reciprocal translocation. The breakpoints were ascertained by molecular genetic analysis. The pregnancy was terminated. Autopsy showed alobar HPE with PMA, pituitary dysplasia, clinodactyly and classical 18p deletion phenotype but without the presence of major typical phenotypic features of Down syndrome. The phenotype of this antenatally diagnosed case is compared with those observed in six previously reported cases with monosomy 18p due to 18;21 translocation. The present study is the first report of concomitant deletion of HPE critical region of chromosome 18p11.3 and cryptic duplication of a small segment of distal chromosome 21q22.3 outside Down syndrome critical region. The present study shows that cytogenetic analyses are important in detecting chromosomal aberrations in pregnancies with prenatally detected craniofacial abnormalities, and adjunctive molecular investigations are useful in elucidating the genetic pathogenesis of dysmorphism.

High-resolution cranial ultrasound in the shaken-baby syndrome

With limited near-field resolution and accessible acoustic windows, sonography has not been advocated for assessing central nervous system injuries in the shaken-baby syndrome. Our purpose was to correlate high-resolution ultrasonographic characteristics of central nervous system injuries in whiplash injuries and the shaken-baby-syndrome with MRI and CT. Ultrasonographic images of 13 infants, aged 2-12 months, with whiplash or shaking cranial trauma were reviewed and compared with MRI in 10 and CT in 10. Five patients had serial ultrasonography and MRI or CT follow-up from 1 to 4 months after the initial injury. With ultrasonography we identified 20 subdural haematomas. MRI and CT in 15 of these showed that four were hyperechoic in the acute stage, three were mildly echogenic in the subacute stage, and that one subacute and seven chronic lesions were echo-free. Five patients had acute focal or diffuse echogenic cortical oedema which evolved into subacute subcortical hyperechoic haemorrhage in four, and well-defined chronic sonolucent cystic or noncystic encephalomalacia was seen at follow-up in two. Using ultrasonography we were unable to detect two posterior cranial fossa subdural haematomas or subarachnoid haemorrhage in the basal cisterns in three cases, but did show blood in the interhemispheric cistern and convexity sulci in two. U1-trasonography has limitations in demonstrating abnormalities remote from the high cerebral convexities but may be a useful adjunct to CT and MRI in monitoring the progression of central nervous system injuries in infants receiving intensive care.

A current concept of trauma-induced multiorgan failure

Trauma deaths continue to show a trimodal distribution: immediately at the scene, within the first 24 hours during initial resuscitation, and in the next 3 to 4 weeks as a result of multiple organ failure.(1) Failure to resuscitate adequately in the emergency department can lead to acidosis, hypothermia, and coagulopathy, which can result in multiple organ failure and cause death in these patients. Our current understanding of the initial response to shock and trauma and the development of the systemic inflammatory response syndrome and progressive organ failure is one of a continuum initiated and perpetuated by inflammation and inflammatory mediators. The pathophysiologic character, diagnosis, prevention, and treatment of traumatic injury-induced multiple organ failure are discussed.

Investigation of the functional role of active site loop II in a hypoxanthine phosphoribosyltransferase

Hypoxanthine phosphoribosyltransferases (HPRTs) are of biomedical interest because defects in the enzyme from humans can result in gouty arthritis or Lesch-Nyhan syndrome, and in parasites these enzymes are potential targets for antiparasite chemotherapy. In HPRTs, a long flexible loop (active site loop II) closes over the active site during the enzyme catalyzed reaction. Functional roles for this loop have been proposed but have yet to be substantiated. For the present study, seven amino acids were deleted from loop II of the HPRT from Trypanosoma cruzi to probe the functional role of this active site loop in catalysis. The mutant enzyme (Deltaloop II) was expressed in bacteria, purified by affinity chromatography, and kinetic constants were determined for substrates of both forward (purine salvage) and reverse (pyrophosphorolysis) reactions catalyzed by the enzyme. Loop II deletion resulted in moderate (0.6-2.7-fold) changes in the Michaelis constants (K(m)s) for substrates other than pyrophosphate (PP(i)), for which there was a 5.8-fold increase. In contrast, k(cat) values were severely affected by loop deletion, with rates that were 240-840-fold below those for the wild-type enzyme. Together with previously reported structural data, these results are consistent with active site loop II participating in transition-state stabilization by precise positioning of the substrates for in line nucleophilic attack and in the liberation of PP(i) as a product of the salvage reaction.

Mutation analysis of type II Gaucher disease in five Taiwanese children: identification of two novel mutations

Gaucher disease (GD), one of the most prevalent lysosomal storage diseases, is caused by deficiency of lysosomal acid beta-glucosidase (GBA). It is divided into three types according to the presence and progression of neurologic symptoms. Of those, type II is relatively rare and most severe; patients usually die before the age of two years. Using polymerase chain reaction (PCR) and direct sequencing of GBA gene in five Taiwanese type II GD patients, we identified two novel mutations: G355D and three-nucleotide insertion in exon 7 of GBA. The latter resulted in an in-frame insertion of a methionine residue between Leu241 and Ser242. L444P, the second most common GD allele among non-Jewish Caucasian population, was found in all five type II GD patients (50%). Overall, 9 out of 10 GD alleles were identified in this study. Direct sequencing of all PCR products led to high detection rate of GD alleles and identification of the RecNci 1 alleles. In the future, high throughput sequencing will make it possible identifying more rare mutations in type II GD patients.

The use of dual phase 201Tl thyroid scan for equivocal fine-needle aspiration results in cold thyroid nodules

We assessed the usefulness of dual phase 201Tl thyroid scan for equivocal fine-needle aspiration (FNA) biopsy results to differentiate malignant from benign lesions. The findings of the dual phase 201TI thyroid scan were compared with those of surgical histopathology for 27 patients with cold thyroid nodules. The FNA results were assessed and classified by experienced pathologists equivocal ENS results. Dual phase thyroid scan, including an early image and a delayed image, were acquired 10 minutes and 3 hours, respectively after mCi (74 MBq) of 201TI was injected intravenously. Dual phase 201Tl thyroid scan findings were visually interpreted as positive or negative results. Based on the final diagnoses of the surgical histopathology results, the dual phase Tl thyroid scan showed a sensitivity, specificity, and accuracy of 100%, 90%, and 96%, respectively. We concluded that dual phase Tl thyroid scan was very helpful in differentiating between benign and malignant thyroid nodules when FNA results were equivocal.

Oxidative stress and liver toxicity in rats and human hepatoma cell line induced by pentachlorophenol and its major metabolite tetrachlorohydroquinone

Pentachlorophenol (PCP) is a pesticide used worldwide in industrial and domestic applications. It is used extensively as biocide and wood preservatives. Metabolic studies carried out in rodents and human liver homogenates have indicated that PCP undergoes oxidative dechlorination to form tetrachlorohydroquinone (TCHQ). Free radical catalyzed tissue injury is thought to play a fundamental role in human disease. In the present study, we examined the effects of PCP and TCHQ on the induction of lipid peroxidation and liver injury in rats. In addition, the cytotoxic dose, cell death mechanisms and related gene expressions induced by PCP and TCHQ were also determined for human hepatoma cell line (Hep G2). The results indicated that more toxic effects could be observed both in rats and human hepatoma cell line treated with TCHQ than its parent compound, PCP. Oxygen species may be involved in the mechanism of TCHQ intoxication since the urinary 8-epi-PGF2alpha and AST, ALT activities can be induced by TCHQ and attenuated by vitamin E treatment. Apoptosis features were found in cells treated with TCHQ but not PCP. TCHQ-induced cell damage may issue signals for the induction of HSPs, the decrease of the bcl/bax protein ratio and the decrease of CAS gene, whereas the PCP-induced damage may not.

Nonredundant roles of the mPer1 and mPer2 genes in the mammalian circadian clock

Mice carrying a null mutation in the Period 1 (mPer1) gene were generated using embryonic stem cell technology. Homozygous mPer1 mutants display a shorter circadian period with reduced precision and stability. Mice deficient in both mPer1 and mPer2 do not express circadian rhythms. While mPER2 regulates clock gene expression at the transcriptional level, mPER1 is dispensable for the rhythmic RNA expression of mPer1 and mPer2 and may instead regulate mPER2 at a posttranscriptional level. Studies of clock-controlled genes (CCGs) reveal a complex pattern of regulation by mPER1 and mPER2, suggesting independent controls by the two proteins over some output pathways. Genes encoding key enzymes in heme biosynthesis are under circadian control and are regulated by mPER1 and mPER2. Together, our studies show that mPER1 and mPER2 have distinct and complementary roles in the mouse clock mechanism.

Mutation analysis of Crouzon syndrome and identification of one novel mutation in Taiwanese patients

BACKGROUND

Crouzon syndrome is an autosomal dominant disorder causing premature fusion of the cranial suture. Mutations have been reported in exon IIIa or IIIc of the fibroblast growth factor receptor 2 (FGFR2) gene.

METHODS

In the present study, nine unrelated Crouzon syndrome patients were screened for mutations in the two exons of FGFR2 by polymerase chain reaction and direct sequencing.

RESULTS

Mutations were detected in 67% (6/9) of all cases. More than half the studied Crouzon patients carried a mutation resulting in either the loss or gain of a cysteine residue. A novel mutation, Tyr281Cys substitution, was discovered at exon IIIa.

CONCLUSIONS

The mechanisms by which the same genotypes cause different phenotypes for each type of craniosynostosis syndrome in still uncertain. However, the molecular identification of the FGFR gene has made a great impact on the clinical classification of craniosynostosis syndromes; a new classification based on genotypes seems to be unavoidable.

A novel topoisomerase II poison GL331 preferentially induces DNA cleavage at (C/G)T sites and can cause telomere DNA damage

PURPOSE

Topoisomerase II (Topo II) preferentially cuts DNA at alternating purine-pyrimidine repeats. Different Topo II poisons may affect Topo II to produce distinct drug-specific DNA cleavage patterns. GL331 is a new podophyllotoxin derivative exhibiting potent Topo II-poisoning activity. Therefore, the sequence selectivity of GL331-induced DNA cleavage was determined.

METHODS

Human gastric adenocarcinoma SC-M1 cells were treated with GL331, and the resultant DNA fragments were isolated by SDS-K+ precipitation. These DNA fragments were further cloned and sequenced to exhibit GL331-induced DNA cleavage sites. In addition, the telomere damage was detected by Southern blot analyses using a (TTAGGG)4 probe. GL331's effect on telomerase was examined using the TRAP assay.

RESULTS

The selective sequences of GL331-induced DNA cleavage were analyzed. The first nucleotide 3'-terminal to the cleavage sites was preferentially C or G and followed by the second nucleotide T. More than 50% of GL331-induced DNA cleavage fragments exhibited AT-rich sequences in the first 20 nucleotides. In addition, the telomeric damage was observed both from GL331-treated SC-M1 cells and in vitro incubation of genomic DNA with GL331 and purified human Topo II. Although GL331 treatment reduced cellular telomerase activity, in vitro reaction data suggested that GL331 was not a telomerase inhibitor.

CONCLUSION

GL331 preferentially induced Topo II-mediated DNA cleavage at (C/G)T sites. Because the telomeric repeat sequence contains GL331's GT preference site, the telomere was identified as one of the targets of GL331-induced DNA damage.

Identification of mutations including de novo mutations in Korean patients with hypokalaemic periodic paralysis

BACKGROUND

Hypokalaemic periodic paralysis (hypoPP) is an autosomal dominant disorder involving the abnormal function of ion channels and it is characterized by paralysis attacks of varying severity, accompanied by a fall in blood potassium levels. Linkage analysis showed that the candidate locus responsible for hypoPP was localized to chromosome 1q31-32, and this locus encoded the muscle dihydropyridine-sensitive calcium channel alpha(1)-subunit (CACNA1S). So far, three different mutations in CACNA1S gene have been identified in patients with hypoPP: Arg528His, Arg1239His and Arg1239Gly in Caucasian patients. However, there are few reports about the mutations of CACNA1S gene in other races.

METHODS

In this study, four Korean families with five hypoPP patients were screened for mutations of CACNA1S gene with polymerase chain reaction-based restriction analysis and single-strand conformation polymorphism analysis. To determine the mode of inheritance, haplotype analysis was done with three microsatellite markers (D1S1726, CACNL1A3, and D1S1723).

RESULTS

Arg528His mutation was detected in three families, and one family had no known mutations. Moreover, for the first time, we detected de novo Arg528His mutations in two out of three families with hypoPP. Haplotype analysis using three microsatellite markers (D1S1726, CACNL1A3, and D1S1723) suggested the occurrence of de novo Arg528His mutations in two of the three families with Arg528His mutation.

CONCLUSIONS

Arg528His mutations of CACNA1S, including de novo Arg528His mutations, were found in Korean patients with hypoPP. These results imply that de novo mutation, in addition to non-penetrance, is one of the genetic mechanisms that can explain the previous clinical observation that hypoPP occurs sporadically without family history.

Low-Loss Dielectric Mirror with Ion-Beam-Sputtered TiO 2-SiO 2 Mixed Films

Ion-beam-sputtered TiO(2)-SiO(2) mixed films with 17% SiO(2) concentration were used as high-refractive-index layers in a multilayered-stack dielectric mirror. Experimental results indicated that total loss of the as-deposited mirror was 34% lower than that of the as-deposited conventional mirrors with pure TiO(2) films used as high-refractive-index layers. In addition, annealing reduced total loss of the mirrors. Although decreasing with an increasing annealing temperature, total loss of the conventional mirrors dramatically increased above ~200 degrees C annealing temperature, owing to increased scattering from an amorphous-to-crystalline phase transition in the TiO(2) films. In addition, total loss of the mirrors with the mixed films continuously decreased with an increasing annealing temperature up to 400 degrees C without the phase transition. Total loss was reduced 88% by means of decreasing absorption in the mixed films. Moreover, the annealed mirror with mixed films was better than both the as-deposited mirror and the conventional mirror with pure films in terms of laser-damage resistance.

Evaluation of five commercial serological tests for the detection of Helicobacter pylori infection in Chinese

BACKGROUND

Commercial serological tests for the detection of Helicobacter pylori infection must be locally validated. We evaluated the accuracy of five commercial tests in the Chinese population.

METHODS

Serum samples were collected from patients referred for upper endoscopy. Antral biopsies were taken for histological examination and culture of H. pylori. The gold standard for diagnosing H. pylori infection was positive histological staining and/or positive H. pylori culture. The serum samples were tested for H. pylori antibodies using the following tests: (i) Cobas Core Anti-H. pylori EIA; (ii) GAP IgG; (iii) GAP IgM; (iv) H. pylori microwell EIA (Quidel); and (v) Premier H. pylori. The sensitivity, specificity and accuracy of each test was calculated according to the manufacturers' instructions or according to a new cut-off value.

RESULTS

A total of 158 patients were recruited amongst whom 114 (72%) were H. pylori-positive. Indeterminate results varied from 7% to 19%. The accuracy of the tests varied from 57% to 85%. By using new cut-off values, the accuracy was much improved, ranging from 73.4% to 86.7%.

CONCLUSIONS

By defining new cut-off values for the Chinese population, we were able to improve the performance of some of the serology tests. This illustrates the importance of local validation.

An E. coli expression system for the extracellular secretion of barley alpha-amylase

Libraries of modified genes are often screened during the process of genetically engineering enzymes with specifically tailored activities. It is important, therefore, to create expression systems which allow for the rapid screening of many clones. We developed an Escherichia coli expression system which will secrete enzymes into the growth medium. We describe the first reported expression of barley alpha-amylase in E. coli. The enzyme is secreted onto solid media containing starch to produce easily visualized halos. In addition, the enzyme is secreted into liquid media in an intact, active form.

Treatment of intractable generalized dystonia by bilateral posteroventral pallidotomy--one-year results

BACKGROUND

Recent study has revealed that bilateral posteroventral pallidotomy (PVP) significantly improve dystonic movements and improve motor function of those patients with generalized dystonia (GD). However, there is only a limited number of patients who have been reported so far.

METHODS

This study was conducted to evaluate the clinical efficacy of surgical treatment with bilateral PVP on patients with intractable GD. All the studied patients were regularly rated with standardized scales (Burke-Fahn-Marsden Evaluation Scale for Dystonia) for dystonic movement and living disability before and after surgery.

RESULTS

There were 18 patients, 8 males and 10 females with an average age of 24.8 years, included in the study. Postoperatively, there were slow, partial, but steady improvements of the dystonic movement and daily living function. Maximal effects were noted at the sixth month and the clinical benefits were sustained one year after the surgical treatment when there were statistically significant improvements in 13% of total dystonia movement score and 9% of the total disability score (p < 0.05). Upon further analysis, improvements of dystonic movements were statistically significant in the regions of mouth (50%), speech/swallowing (19%) and neck (43%), and daily living functions in speech (14%) and eating/swallowing (29%).

CONCLUSIONS

Bilateral posteroventral pallidotomy was only partially effective for the treatment of GD, and it produced clinical improvement in the dystonic movement limited to the craniocervical region. We therefore suggest that patients with GD should be carefully selected for the treatment of bilateral posteroventral pallidotomy, despite the surgery having a partially beneficial effect on this kind of movement.

MPer1 and mper2 are essential for normal resetting of the circadian clock

Mammalian Per1 and Per2 genes are involved in the mechanism of the circadian clock and are inducible by light. A light pulse can evoke a change in the onset of wheel-running activity in mice by shifting the onset of activity to earlier times (phase advance) or later times (phase delays) thereby advancing or delaying the clock (clock resetting). To assess the role of mouse Per (mPer) genes in circadian clock resetting, mice carrying mutant mPer1 or mPer2 genes were tested for responses to a light pulse at ZT 14 and ZT 22, respectively. The authors found that mPer1 mutants did not advance and mPer2 mutants did not delay the clock. They conclude that the mammalian Per genes are not only light-responsive components of the circadian oscillator but also are involved in resetting of the circadian clock.

ATP7A gene mutations in 16 patients with Menkes disease and a patient with occipital horn syndrome

Genomic DNA of 17 unrelated Japanese males with Menkes disease and 2 Japanese males with occipital horn syndrome were studied for mutations in the ATP7A gene. Using SSCP analysis and direct sequencing of the exons and the 5'-upstream region of the gene amplified by PCR, we identified 16 mutations in 16 of 17 males with Menkes disease, including 4 deletions, 2 insertions, 6 nonsense mutations, 2 missense mutations, and 2 splice-site mutations. All these mutations were those that affect the function of the gene. Of the two males with occipital horn syndrome, one had a splice-site mutation in intron 6 that led to normal-size and smaller-size transcripts. The amount of the normal-size transcripts in his cultured skin fibroblasts was 19% of the normal level. His serum copper and ceruloplasmin levels were normal, whereas his cultured skin fibroblasts contained increased levels of copper. These findings indicate that his mild clinical manifestations were due to the presence of normal-size and presumably functional transcripts of the gene. DNA sequencing analysis of the exons and 5'-upstream region of the ATP7A gene in 20 normal individuals and the 19 affected males identified 25 polymorphisms.

Prenatal diagnosis of oculocutaneous albinism two mutations located at the same allele

A pregnant woman accepted amniocentesis on account of the previous birth of type 1 oculocutaneous albinism (OCA1). PCR revealed that the fetus had two mutations (862delTT, Arg 299His). The father had one missense mutation (Arg 299Ser) and the mother had the same mutations as the fetus. Two mutations of the fetus located at the same allele were suspected. Postpartal follow-up confirmed his carrier status. For recessive disorders, faced with a fetus with two mutations, the importance of performing segregation analysis of mutation on both parents is emphasized. This could exclude two mutations located at the same allele and prevent the unnecessary termination of a fetus with carrier status.

Endotracheal tube fires during carbon dioxide laser surgery on the larynx--a case report

Endotracheal tube (ETT) fire is a catastrophic disaster that may occur during laser surgery of the upper airway. Several means are available for protection of polyvinyl chloride (PVC) tube from fire, but they are not perfect in prevention of fires caused by laser beam. The PVC tube is hazardous for carbon dioxide (CO2) laser surgery if it is not well wrapped with metallized foil tape. We report a case that a PVC ETT wrapped with aluminum foil ignited during CO2 laser surgery of the larynx. In this report, we emphasize the shaft of the PVC tube must be completely wrapped with aluminum foil to prevent exposure of any surface if it is used in CO2 laser surgery of the upper aero digestive tract.

Molecular analysis of Wilson disease in Taiwan: identification of one novel mutation and evidence of haplotype-mutation association

Wilson disease (WND) is caused by a deficiency of the copper-transporting enzyme, P-type ATPase (ATP7B). Twelve different mutations have previously been identified in Taiwan Chinese with Wilson disease. We, herein, report another 4 missense mutations, 1 of which is novel. We did haplotype analysis of Taiwanese WND chromosomes, using three well characterized short tandem repeat markers (haplotype was assigned in the order of D13S314-D13S301-D13S316). Association correlation was found between the mutations and their respective haplotypes. Haplotype-deduced pedigree analysis was shown to be helpful in the mutation analysis of WND chromosomes and in the molecular assessment of both pre-symptomatic WND patients and carriers. Given the complexity and heterogeneity of the mutation spectrum of ATP7B, we suggest that haplotype analysis should be performed before full-scale mutation analysis.

Reflection and transmission phenomena of waves propagating between an isotropic medium and an arbitrarily oriented anisotropic medium

We theoretically analyze waves propagating between an isotropic medium and an anisotropic medium. Closely examining the boundary condition reveals that the phenomenon of nonsymmetrical reflection occurs when the wave propagates from an anisotropic to an isotropic medium. Calculating the reflection of thin films requires correcting the phase change in each reflected trip in the Airy formula. Analytical results of measurement of the elliptical surface of a wave-vector distribution in an anisotropic medium indicate that reflection and transmission still occur when the reflected and the refracted angles are larger than 90 degrees .

Prenatal diagnosis of mosaic ring chromosome 13 with anencephaly

We report on the prenatal diagnosis, genetic analysis and clinical manifestations of a second-trimester fetus with mosaic ring chromosome 13 and anencephaly. A 35-year-old, gravida 3, para 2 woman was referred for genetic counselling at 23 weeks' gestation because of an elevated maternal serum alpha-fetoprotein level of 2.386 multiples of the median. Prenatal ultrasonography showed intrauterine growth retardation and anencephaly. Amniocentesis revealed a karyotype of de novo mos 46,xx,r(13)(p11q32)/45,xx,-r(13) [corrected] (77%/23%). Molecular genetic analysis by quantitative fluorescent polymerase chain reaction (PCR) with small tandem repeat markers specific for chromosome 13 rapidly confirmed the maternal origin of the aberrant chromosome and determined the breakpoint at 13q32 between D13S225 (present) and D13S147 (absent). Our present finding indicates that anencephaly can be due to mosaic r(13) with a terminal deletion of 13q32-13q34 and an additional secondary rearrangement of loss of r(13). We propose that cytogenetic analysis is beneficial and warranted in pregnancies with fetal neural tube defects.

Polymorphic DNA haplotypes at the human low-density lipoprotein receptor gene locus in Koreans

Many low-density lipoprotein (LDL) receptor mutations have been identified and characterized, demonstrating a high degree of allelic heterogeneity at this locus. The ability to identify mutant LDL-receptor genes for prenatal diagnosis of familial hypercholesterolemia (FH) or to study the role of the LDL-receptor gene in polygenic hypercholesterolemia requires the use of closely linked restriction fragment lenghth polymorphisms (RFLPs). In the present study nine different RFLPs (TaqI, StuI, HincII, BstEII, AvaII, PvuII, MspIA, MspIB, and NcoI) and a sequence variation at Arg450 were used to clarify the characteristics of the LDL-receptor gene in Koreans. A total of 978 LDL-receptor alleles from 244 members of 43 different pedigrees (15 normal and 28 FH pedigrees) and 245 individuals (187 normal and 58 FH) were analyzed. Frequencies of these polymorphisms did not differ significantly between controls and FH patients. Individually, seven sites--TaqI, BstEII, AvaII, MspIA, MspIB, NcoI and Arg450--had heterozygosity indices ranging from 0.3610 to 0.4601, whereas the PvuII site displayed low levels of polymorphism and StuI was monomorphic. Haplotypes were constructed for 215 individuals of 13 normal and 24 FH pedigrees using the nine polymorphisms. Of 512 (= 2(9)) possible combinations for the nine polymorphic sites, 39 unique haplotypes were detected. The frequency distribution of individual haplotypes ranged from 1/155 (0.65%) to 40/155 (25.8%). The four most common haplotypes accounted for 59.4% of those sampled. Statistical analysis of the haplotypes indicated marked linkage disequilibrium for these 10 sites and throughout the region containing the LDL-receptor gene. Owing to the high degree of linkage disequilibrium over the entire locus, not all RFLPs were informative. We rank each RFLP according to its informativeness and present a strategy for the optimal selection of RFLPs for pedigree analysis.

Rapid monitoring assay of congenital adrenal hyperplasia with microbore high-performance liquid chromatography/electrospray ionization tandem mass spectrometry from dried blood spots

17-hydroxyprogesterone (17OHP) is the most important plasma parameter for diagnosing and monitoring congenital adrenal hyperplasia (CAH) caused by 21-hydroxylase deficiency. A rapid, simple, and specific method based on microbore high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (micro-HPLC/ESI-MS/MS) was developed to determine the presence of 17OHP on dried filter-paper blood samples from patients with CAH caused by 21-hydroxylase deficiency. 17OHP from dried blood spots formed by the action of Girard reagent P (GirP) turned out to be a water-soluble hydrazone complex. Derivatization with GirP led to higher ESI sensitivity for 17OHP. The LC/MS/MS detection of GirP-derivatized 17OHP (GirP-17OHP) was rapid (<3 min). The method is repeatable and reproducible, with CVs <7% and 12%, respectively. This new method was used for direct determination of 17OHP in dried blood specimens obtained from abnormal children and infants of various ages with a detection limit of 10 ng/mL ( approximately 12 microL blood). The method described allows for rapid and reliable measurements of 17OHP in dried blood specimens from patients affected by CAH.

Delineation of CTG repeats and clinical features in a Taiwanese myotonic dystrophy family

Myotonic dystrophy (DM) is an inherited, autosomal dominant muscular disease which is primarily caused by a CTG trinucleotide expansion mutation on chromosome 19q13.3. The size of this trinucleotide repeat is related both to the age of onset and to the severity of the clinical manifestation. This disease is very rare in Taiwan, and clinical and genetic study on DM has not yet been documented in this area. Here, we present both clinical features and degrees of CTG expansion for a Taiwanese DM family. All of the DM patients examined in this family showed obvious clinical manifestations by age 30, which included facial and limb muscle weakness with atrophy, myotonia, and ptosis. In addition, individual DM members also exhibited variable phenotypes, which may reflect the complexity of the pathogenic mechanism. Because the collection of blood specimens was considered to be an invasive procedure, a genetic study on this DM family was performed using buccal cells. Our results confirmed that four members showing classic symptoms of DM had CTG repeat expansion in the DMI locus, and that one member with ptosis and minor muscle weakness in the right foot was a normal homozygote for CTG repeat. These data demonstrate that buccal cells can provide clear and reliable results, and thus, are suitable for a family study of DM.

The combination of zidovudine and interferon alpha-2B in the treatment of adult T-cell leukemia/lymphoma

Adult T-cell leukemia/lymphoma (ATL) is frequently a very aggressive malignancy with a poor survival despite aggressive multiagent chemotherapy. The combination of the antiretroviral drug zidovudine (AZT) and interferon alpha (IFNalpha) has been reported to induce remissions in patients with ATL. The purpose of this study was to evaluate the clinical response and toxicity following administration of a combination of IFNalpha-2b and AZT in patients with human T-cell lymphotropic virus type I (HTLV-I)-associated ATL. Eighteen patients with ATL (chronic. crisis, acute or lymphoma type) were treated with the combination of AZT (50 - 200 mg orally 5 times a day) and IFNalpha-2b (2.5 - 10 million units subcutaneously daily). Three patients had objective responses lasting more than one month. One patient had a clinical complete remission, lasting 21.6 months and two patients had partial remissions lasting 3.7 and 26.5 months. Six patients were not considered evaluable for response due to short and/or interrupted periods of treatment. Seventeen patients have died with a median survival time after initiation of therapy of 6 months. Neutropenia and thrombocytopenia were the dose limiting toxicities. In conclusion, the response rate in this study was lower than noted in the two previous published series. This may be due to the amount and type of prior treatment our patients had received.

Single-longitudinal-mode operation of a grating-based fiber-ring laser using self-injection feedback

A fiber Bragg grating- (FBG-) based fiber-ring laser that utilizes the transmitted light of the FBG as self-injection feedback for single-longitudinal-mode (SLM) oscillation is proposed and demonstrated. This laser is simply constructed by means of feeding back the transmitted light of the FBG and is coupled into the main ring cavity through an optical coupler. The self-injection feedback is the key to ensuring SLM laser oscillation. The SLM operation principle is discussed in detail, and a SLM laser with output power of 6.6 dBm, an optical signal-to-noise ratio of 57 dB at 1549.19 nm, and a short-term linewidth of 3.5 kHz is reported.