Regulation of the rat interstitial collagenase promoter by IL-1 beta, c-Jun, and Ras-dependent signaling in growth plate chondrocytes

In an attempt to better define molecular influences on rat interstitial collagenase gene expression in cartilage, the promoter function was characterized using transient transfection assay, electrophoresis mobility shift assay, and genetic analysis in isolated growth plate chondrocytes. Data from 5'-flanking deletion and selected mutations suggest that multiple cis elements in both the proximal and distal regions of the promoter were important in the regulation of promoter activity. A proximal tumor response element (TRE) was shown to be necessary for basal and interleukin (IL)-1 beta-inducible reporter gene activity. Cells stimulated by IL-1 beta (1 ng/ml; 18 h) had elevated TRE binding activity, and one of the factors involved was identified as the nuclear protein, c-Jun. Indeed, c-Jun directed antisense oligonucleotides reduced rat interstitial collagenase mRNA. A sense oligonucleotide was ineffective. Regulation of promoter activity was susceptible to Ras-dependent signaling as expression of dominant negative mutant of Ras kinase (pZIP-RasN17) reduced reporter gene activity. In a comparison of proximal promoter reporter plasmid activity between proliferative and hypertrophic cells, inhibition of Ras-dependent signaling was less effective in the later cell type. This study suggests that the activation of nuclear binding proteins that bind TRE may be a common event with IL-1 beta regulation. Moreover, these data suggest that the regulation of rat interstitial collagenase gene expression is a combinatorial process and multiple cis-acting regulatory sites may interact to exert different effects dependent on the stage of chondrocyte differentiation.

Semi-automated radioassay for determination of dihydropyrimidine dehydrogenase (DPD) activity. Screening cancer patients for DPD deficiency, a condition associated with 5-fluorouracil toxicity

Dihydropyrimidine dehydrogenase (DPD) catalyzes the reduction of the naturally occurring pyrimidines, uracil and thymine, and the fluoropyrimidine anticancer drug, 5-fluorouracil (FUra) to 5,6-dihydropyrimidines. Previous studies have demonstrated that cancer patients who are DPD deficient exhibit severe toxicity (including death) following treatment with FUra. To date, the direct measurement of DPD enzyme activity has been the only reliable method to identify DPD deficient cancer patients. We now report a semi-automated radioassay for measuring DPD activity in human peripheral lymphocytes. Following incubation of lymphocyte cytosol (at a fixed protein concentration of 200 micrograms) with [6-14C]FUra at timepoints ranging from 0 to 30 min, samples are ethanol precipitated, filtered and analyzed by HPLC. Determination of radioactivity is accomplished using an in-line flow scintillation analyzer with automatic quantitation of peaks. This method provides the first specific assay for DPD enzyme activity which is rapid, reproducible and sensitive enough to be used in the routine screening of cancer patients for DPD deficiency prior to treatment with FUra.

Detection of hepatitis G virus RNA in patients with hepatitis B, hepatitis C, and non-A-E hepatitis by RT-PCR using multiple primer sets

Hepatitis G virus(HGV)/GB virus C(GBV-C) is a newly identified virus associated with human hepatitis. The preliminary prevalence studies of HGV infection in Japan were entirely based on the detection of HGV RNA by RT-PCR. However, the selection of the different primer sets in such assay may influence sensitivity of the test because of the extensive genetic heterogeneity of HGV, and influence the estimation of the prevalence of HGV. To address this potential problem, we designed two primer sets from well conserved domains in the 5'NC and NS5 regions of HGV genome, and tested them together with the NS3-derived primer set in RT-PCR for their ability to detect HGV RNA in serial dilution of synthetic viral RNA templates. Subsequently, we used these three primer sets to detect HGV RNA in the sera of 371 Japanese patients with hepatitis B, hepatitis C, and non-A-E hepatitis. The results indicated that the primer set derived from the 5'NC region appeared to be most effective in detecting HGV RNA. The results also showed that only two out of the 126 patients (1.6%) with non-A-E hepatitis were positive for HGV RNA although the RNA were detected more frequently in patients with hepatitis B (2/38; 5.3%) and hepatitis C (17/207; 8.2%), suggesting that HGV is not a common causative agent for non-A-E hepatitis in Japan.

Maximal aerobic capacity and its relationship with physical growth in Chinese children

Maximal aerobic capacity and its relationship to physical growth in 463 Chinese children and adolescents aged 10-19 is reported. Results show that VO2max, VO2max/height and VO2max/HRmax positively relate to measures of physical growth such as height, weight and lean body mass (LBM). Correlation of VO2max/weight with physical growth variables is high and positive in boys and low and negative in girls. The sample is divided to two groups on each variable: well-developed and relatively poorly-developed according to height, weight and LBM. SDS values of VO2max, VO2max/height and VO2max/HRmax are higher in the first group than in the second group. In contrast, SDS values of VO2max/weight and VO2max/LBM are greater in second group. The similarity of results between SDS values with correlation analysis suggest that weight and LBM are probably the decisive factors that influence VO2max.

Fuzzy reasoning morphological operators and their optical implementation

Fuzzy-reasoning theory is widely used in industrial control. Mathematical morphology is a powerful tool to perform image processing. We apply fuzzy-reasoning theory to morphology and suggest a scheme of fuzzy-reasoning morphology, including fuzzy-reasoning dilation and erosion functions. These functions retain more fine details than the corresponding conventional morphological operators with the same structuring element. An optical implementation has been developed with area-coding and thresholding methods.

Three-dimensional imaging characteristics of the HEAD PENN-PET scanner

A volume-imaging PET scanner, without interplane septa, for brain imaging has been designed and built to achieve high performance, specifically in spatial resolution and sensitivity. The scanner is unique in its use of a single annular crystal of Nal(Tl), which allows a field of view (FOV) of 25.6 cm in both the transverse and axial directions. Data are reconstructed into an image matrix of 128(3) with (2 mm)3 voxels, using three-dimensional image reconstruction algorithms.

METHODS

Point-source measurements are performed to determine spatial resolution over the scanner FOV, and cylindrical phantom distributions are used to determine the sensitivity, scatter fraction and counting rate performance of the system. A three-dimensional brain phantom and 18F-FDG patient studies are used to evaluate image quality with three-dimensional reconstruction algorithms.

RESULTS

The system spatial resolution is measured to be 3.5 mm in both the transverse and axial directions, in the center of the FOV. The true sensitivity, using the standard NEMA phantom (6 liter), is 660 kcps/microCi/ml, after subtracting a scatter fraction of 34%. Due to deadtime effects, we measure a peak true counting rate, after scatter and randoms subtraction, of 100 kcps at 0.7 mCi for a smaller brain-sized (1.1 liter) phantom, and 70 kcps for a head-sized (2.5 liter) phantom at the same activity. A typical 18F-FDG clinical brain study requires only 2 mCi to achieve high statistics (100 million true events) with a scan time of 30 min.

CONCLUSION

The HEAD PENN-PET scanner is based on a cost-effective design using Nal(Tl) and has been shown to achieve high performance for brain studies and pediatric whole-body studies. As a full-time three-dimensional imaging scanner with a very large axial acceptance angle, high sensitivity is achieved. The system becomes counting-rate limited as the activity is increased, but we achieve high image quality with a small injected dose. This is a significant advantage for clinical imaging, particularly for pediatric patients.

Presence of methylthioadenosine phosphorylase (MTAP) in hematopoietic stem/progenitor cells: its therapeutic implication for MTAP (-) malignancies

Methylthioadenosine phosphorylase (MTAP) is important for the salvage of adenine and methionine. Recently, we found frequent deletion of MTAP in T-cell acute lymphoblastic leukemia (T-ALL) patients both at diagnosis and at relapse (A. Batova et al., Blood, 88: 3083-3090, 1996). In addition, MTAP deficiency has been reported in other cancers. Thus, MTAP deficiency in cancer may offer opportunities for developing selective therapy, which would spare normal cells. It is therefore important to document the presence of MTAP activity in hematopoietic stem/progenitor cells. Our approach was to investigate whether hematopoietic stem/progenitor cells can be rescued from the cytotoxicity of an AMP synthesis inhibitor, L-alanosine, by 5'-deoxyadenosine, a process that requires MTAP. Erythroid burst-forming unit, granulocyte/monocyte colony-forming unit, or granulocyte/erythrocyte/macrophage/megakaryocyte colony-forming unit progenitors and the primitive high proliferative potential colony-forming cells in the purified CD34(+) cells were cultured in horse serum-containing medium, and their colony growth was found to be suppressed by incubation with 5 microM or greater concentrations of L-alanosine. However, in the presence of 5-10 microM of 5'-deoxyadenosine, colony formation of hematopoietic stem/primitive progenitors was restored. On the other hand, 5'-deoxy-5'-methylthioadenosine, the endogenous substrate of MTAP, was toxic to hematopoietic stem/progenitors (ID50 < 1 microM), presumably due to inhibition of methylation reactions or polyamine synthesis. We also compared the effects of L-alanosine and 5'-deoxyadenosine on MTAP (+) and MTAP (-) T-ALL cell lines. Treatment of MTAP (+) Molt 4 and MTAP (-) CEM cell lines with L-alanosine in the presence of 5'-deoxyadenosine resulted in killing of MTAP (-), but not MTAP (+) cells. Therefore, our findings demonstrate the presence of MTAP in human hematopoietic stem/progenitor cells and support the possibility of targeting MTAP in the design of an enzyme-selective therapy for T-ALL and other MTAP-deficient malignancies.

Parallel optical negabinary arithmetic based on logic operations

On the basis of signed-digit negabinary representation, parallel two-step addition and one-step subtraction can be performed for arbitrary-length negabinary operands. The arithmetic is realized by signed logic operations and optically implemented by spatial encoding and decoding techniques. The proposed algorithm and optical system are simple, reliable, and practicable, and they have the property of parallel processing of two-dimensional data. This leads to an efficient design for the optical arithmetic and logic unit.

[A prevalence study on risk factors of cardiovascular disease during childhood]

A small size of sample for risk factors of cardiovascular disease, such as blood pressure, plasma lipids profile, obesity, dietary status, and family history of cardiovascular disease, etc. were studied in children aged eight to eleven years. Results showed that prevalence of hypertension, systolic blood pressure > 16.0 kPa (120 mmHg) or/and diastolic blood pressure > 10.7 kPa (80 mmHg), in them was 7.2 percent, blood lipid level in 21.9 percent of the children exceeded the recommended criteria of dietary intervention, and prevalence of simple obesity was 11.7 percent. The most prominent problem in dietary status was high cholesterol intake, with a daily intake of 483.4 mg in average, and 72 percent of the children exceeded 300 mg daily, as compared with previous data, and they exposure to higher level of risk factors for cardiovascular disease. It suggests that it is necessary to strengthen surveillance for risk factors of cardiovascular disease and intervention.

Regulation of rat interstitial collagenase gene expression in growth cartilage and chondrocytes by vitamin D3, interleukin-1 beta, and okadaic acid

The interstitial collagenase produced by the rat growth plate chondrocytes is the homologue of the human collagenase-3, or matrix metalloproteinase-13. This enzyme is responsible for the loss of collagen during hypertrophy of chondrocytes and for the degradation of transverse septa in long bone growth. Rachitic rats (42 days, male Sprague-Dawley) had an 8-fold higher level of collagenase mRNA in the hypertrophic versus proliferative zone of growth plate cartilage. Intramuscular injection of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3; 1.0 micrograms/kg body weight) in rachitic rats increased collagenase mRNA another 1.5-fold in the hypertrophic zone. The regulation of collagenase gene by 1,25-(OH)2D3 and interleukin (IL)-1 beta in cultured proliferative chondrocytes was studied by means of steady-state mRNA and half-life determination of mRNA using the transcriptional inhibitor actinomycin D, and nuclear run-on transcription analyses. Treatment of cells with 1,25-(OH)2D3 (10(-6) M) and IL-1 beta (2 ng/ml) increased collagenase mRNA 8- and 13-fold, respectively. Additionally, the collagenase mRNA half-life was increased by 1,25-(OH)2D3 and IL-1 beta. In the presence of a protein kinase C inhibitor, staurosporine, 1,25-(OH)2 D3 induction of collagenase mRNA was blocked. Here the addition of phorbol 12-myrisate 13-acetate (PMA) to activate protein kinase C increased collagenase mRNA 10-fold. However, in the presence of staurosporine (50 nM), PMA induction was blocked, whereas IL-1 beta was not. IL-1 beta is known to activate several phosphorylation pathways. Okadaic acid (500 nM), a protein phosphatase inhibitor, increased the relative collagenase mRNA abundance 10-fold. The rate of the rat collagenase gene transcription in nuclei was increased with 1,25-(OH)2D3, IL-1 beta and okadaic acid. In separate experiments, the collagenase promoter was ligated to a reporter plasmid and the plasmid was transfected into chondrocytes. The results showed that 1,25-(OH)2D3, IL-1 beta, and PMA increased reporter activity 2.5-, 2.8-, and 3.27-fold, respectively. Thus, there are multiple nuclear and cytoplasmic mechanisms by which cartilage modulators regulate rat interstitial collagenase gene expression.

Sequence of hepatitis G virus genome isolated from a Japanese patient with non-A-E-hepatitis: amplification and cloning by long reverse transcription-PCR

The nucleotide sequence of hepatitis G virus (HGV) genome was determined by analysis of cDNA clones obtained by long reverse transcription-polymerase chain reaction (long RT PCR) and 5'- and 3'-rapid amplification of cDNA ends (RACE) from a Japanese patient (Iw) with non A-E hepatitis. The HGV-Iw genome, consisting of 9375 nucleotides, contains a long open reading frame encoding 2873 amino acid residues. Comparison of HGV-Iw with two American isolates of HGV and one African isolate of GB virus C (GBV-C) indicates that although the nucleotide sequences of these isolates were considerably divergent (86.2% to 93.3%), the deduced amino acid sequences shared an extremely high degree of identity (96.1% to 100%). It was also found that HGV-Iw was more closely related to the HGV isolates from USA than to the GBV-C isolate from Africa.

Intracellular localization of the herpes simplex virus type-1 origin binding protein, UL9

UL9 is the origin binding protein of herpes simplex virus type-1 (HSV-1). A UL9-specific monoclonal antibody (17B) whose epitope maps to the N-terminal 33 amino acids was used to study the localization of UL9 in infected and transfected cells. We demonstrate the colocalization of UL9 and the HSV-1 single-strand DNA binding protein (ICP8 or UL29) in replication compartments, sites of viral DNA synthesis. On the other hand, UL9 does not completely colocalize with ICP8 in prereplicative sites, structures observed under conditions that inhibit viral DNA polymerase. Cells transfected with various deletion or pyruvate kinase fusion constructs were analyzed by indirect immunofluorescence assay to define the nuclear localization signal (NLS) of UL9. Deletion analysis showed that the region required for nuclear localization lies within the C-terminal DNA binding domian (amino acids 535-851). Various regions of UL9 were tested in fusion constructs for their ability to direct the normally cytoplasmic chicken pyruvate kinase protein to the nucleus. A fusion construct containing the carboxy-terminal 107 residues (amino acids 745-851) localized efficiently to the nucleus, whereas a fusion construct containing the N-terminal 660 amino acids of UL9 was unable to do so. Mutations designed to alter a potential NLS sequence (793-KREFAGARFKLR-804) within the C-terminal 107 residues result in a mutant UL9 protein which falls to localize efficiently to the nucleus. These results suggest that the major NLS of UL9 maps within the C-terminal 107 amino acids.

Circular dichroism studies of the mitochondrial channel, VDAC, from Neurospora crassa

The protein that forms the voltage-gated channel VDAC (or mitochondrial porin) has been purified from Neurospora crassa. At room temperature and pH 7, the circular dichoism (CD) spectrum of VDAC suspended in octyl beta-glucoside is similar to those of bacterial porins, consistent with a high beta-sheet content. When VDAC is reconstituted into phospholipid liposomes at pH 7, a similar CD spectrum is obtained and the liposomes are rendered permeable to sucrose. Heating VDAC in octyl beta-glucoside or in liposomes results in thermal denaturation. The CD spectrum irreversibly changes to one consistent with total loss of beta-sheet content, and VDAC-containing liposomes irreversibly lose sucrose permeability. When VDAC is suspended at room temperature in octyl beta-glucoside at pH < 5 or in sodium dodecyl sulfate at pH 7, its CD spectrum is consistent with partial loss of beta-sheet content. The sucrose permeability of VDAC-containing liposomes is decreased at low pH and restored at pH 7. Similarly, the pH-dependent changes in the CD spectrum of VDAC suspended in octyl beta-glucoside also are reversible. These results suggest that VDAC undergoes a reversible conformational change at low pH involving reduced beta-sheet content and loss of pore-forming activity.

Optical intrinsically fuzzy mathematical morphology for gray-scale image processing

Intrinsically fuzzy morphological erosion and dilation are extended to a total of eight operations that have been formulated in terms of a single morphological operation-biased dilation. Based on the spatial coding of a fuzzy variable, a bidirectional projection concept is proposed. Thus, fuzzy logic operations, arithmetic operations, gray-scale dilation, and erosion for the extended intrinsically fuzzy morphological operations can be included in a unified algorithm with only biased dilation and fuzzy logic operations. To execute this image algebra approach we present a cellular two-layer processing architecture that consists of a biased dilation processor and a fuzzy logic processor.

[A comparative study of cervical and thoracic anastomoses after esophagectomy for esophageal carcinoma]

From April 1979 to December 1984, esophagectomy was performed in 552 cases of esophageal cancer of which 108 received cervical anastomosis and 444 intrathoracic anastomosis. The total postoperative complications and operative mortality rates of the two groups were very close. Leakage was significantly more frequent after cervical anastomosis, but mortality due to leakage was less frequent than that in thoracic anastomosis. The 1-, 3-, 5-, 10-year survival rates of cervical anastomosis were apparently higher than those of intrathoracic anastomosis, but the differences were not statistically significant. The 5-year survival rates of patients with the same TNM stage failed to demonstrate any significant difference between the two groups. The quality of life among the groups was satisfactory. There was no deterioration of the quality of life in cervical anastomosis. It caused less gastroesophageal reflux than did intrathoracic anastomosis. We hold that esophagectomy with cervical anastomosis and extensive lymphadenectomy is a better treatment of choice for carcinoma of the esophagus.

The product of a 1.9-kb mRNA which overlaps the HSV-1 alkaline nuclease gene (UL12) cannot relieve the growth defects of a null mutant

Alkaline nuclease, a relatively abundant viral phosphoprotein in herpes simplex virus type 1 (HSV-1)- or HSV-2-infected cells, is encoded by a 2.3-kb mRNA (R. H. Costa, K. G. Draper, L. Banks, K. L. Powell, G. Cohen, R. Eisenberg, and E. K. Wagner, 1983. J. Virol. 48, 591-603). This mRNA is a member of a family of five unspliced 3'-coterminal messages. Costa et al. proposed that another member of this family of mRNAs (1.9-kb) may encode an N-terminally truncated protein which shares its carboxy-terminus with the alkaline nuclease protein. We previously described the isolation of AN-1, a deletion/insertion mutant of the alkaline nuclease gene (S. K. Weller, R. M. Seghatoleslami, L. Shao, D. Rowse, and E. P. Carmichael, 1990. J. Gen. Virol. 71, 2941-2952). The deletion in AN-1 would be predicted to abolish gene products of both the 2.3- and the 1.9-kb mRNAs. To investigate whether the putative truncated version of alkaline nuclease encoded by the 1.9-kb mRNA has enzymatic activity and plays a role in the viral life cycle, a viral mutant (AN-F1) was constructed which is predicted to abolish the gene product of the 2.3-kb mRNA (full-length alkaline nuclease) but leave intact the putative product of the 1.9-kb mRNA. Using a highly sensitive polyclonal antiserum raised against a bacterially expressed full-length alkaline nuclease, we observed a 60-kDa protein in KOS- and AN-F1-infected cells but not in AN-1-infected cells. This suggests that the 60-kDa protein is likely to be expressed from the 1.9-kb mRNA; the open reading frame is now designated UL12.5. Despite the presence of the 60-kDa band, AN-F1 failed to exhibit any alkaline exonuclease activity. This result suggests that the truncated polypeptide (UL12.5) is not enzymatically active, has low levels of activity, or possesses enzymatic activity which is not detected because of the low abundance of the polypeptide. AN-1 and AN-F1 are both severely restricted with respect to growth in Vero cells, as viral yields are 100- to 1000-fold lower than those of wild-type virus. We previously reported that the major defect in AN-1 is in the ability of DNA-containing capsids which form in the nucleus to mature into the cytoplasm (L. Shao, L. M. Rapp, and S. K. Weller, 1993. Virology 196, 146-162); AN-F1 exhibits the same defect. These results indicate that although the 1.9-kb mRNA encodes a 60-kDa protein presumably from the UL12.5 open reading frame, this polypeptide cannot substitute for the full-length UL12 product.

A suppressive protein generated in peripheral lymph tissue induced by restraint stress

The results discussed here indicate that under the conditions of restraint stress and under the control of CNS, a suppressive protein (NIP) was generated in peripheral lymph tissue and released into the blood stream, which acts as a immune suppressor. It is potentially a very important molecule that could be very important to our understanding of the interaction between CNS and immune function.

[Clinical evaluation of cervical esophageal reconstruction after resection of thoracic esophageal carcinoma]

From Apr. 1979 to Dec. 1994, a total of 3,714 patients with thoracic esophageal carcinoma were surgically treated. As a standard operative procedure for thoracic esophageal cancer, cervical esophagogastrostomy was performed. While this operative procedure was rarely used (accounting for only 8.8% the treated cases) in early years, it has been recently carried out in the overwhelming majority of our patients (94.1%). This technic offers the advantages of resecting the lesions radically, dissecting the regional lymph nodes in both the neck and the mediastinum, reducing the incidence of postoperative complications and improving the quality of life after operation. In this paper the operative indication, approach and the surgical efficacy are discussed.

Test of a slow off-axis parabola at its center of curvature

We describe the interferometric testing of a slow (ƒ/16 at the center of curvature) off-axis parabola, intended for use in an x-ray spectrometer, that uses a spherical wave front matched to the mean radius of the asphere. We find the figure error in the off-axis mirror by removing the theoretical difference between the off-axis segment and the spherical reference from the measured wave-front error. This center of curvature test is easy to perform because the spherical reference wave front has no axis and thus alignment is trivial. We confirm that the test results are the same as the double-pass null test for a parabola that uses a plane autocollimating mirror. We also determine that the off-axis section apparently warped as the result of being cut from the symmetric parent part.

A factor in lymph node and spleen induced by restraint stress in mice and rats suppresses lymphocyte proliferation

Extracts from lymph node and spleen in mice and rats subjected to restraint stress significantly suppressed lymphocyte proliferation, but extracts from brain, skeletal muscle, and thymus gland had no effect on lymphocyte proliferation, suggesting that a suppressive factor for lymphocyte proliferation might selectively be induced in lymph node and spleen. Further experiments showed that biochemical properties, molecular weight, correlation between suppressive factors in serum and in extract of the lymph tissue from stressed animals, and control of the generation, all indicated that under the conditions of restraint stress and under the control of central nervous system a suppressive factor was generated in peripheral lymph tissue and then released into the blood-stream, which acted as a strong suppressor of lymphocyte proliferation.

Identification of hepatitis C virus by immunoelectron microscopy

Sequencing of the hepatitis C virus (HCV) has provided a better understanding of the natural history, immunology, and epidemiology of this virus. However, the morphology of HCV has not been definitively characterized. In this study, through a sequence of concentration processes, virus-like particles were isolated from human serum and liver tissue, visualized by transmission electron microscopy and identified as hepatitis C virion by immunoelectron microscopy. Spherical flavi-like virus particles, approximately 70 nm in diameter, were observed in the fraction with 1.04-1.12 g ml-1 sucrose density and bound to immunogold particles with monoclonal antibodies (mAb) against hepatitis C. The nucleocapsid of the particles, which were 50 nm in diameter, appeared to be icosahedral in structure and surrounded by an envelope covered with surface projections. A 'tadpole' form of particles was also observed. The findings indicate that the low buoyant density in sucrose and the morphological features of the hepatitis C virion are consistent with the characteristics of flaviviruses and pestiviruses.

Modified direct twos-complement parallel array multiplication algorithm for complex matrix operation

A direct twos-complement parallel array multiplication algorithm is introduced and modified for digital optical numerical computation. The modified version overcomes the problems encountered in the conventional optical twos-complement algorithm. In the array, all the summands are generated in parallel, and the relevant summands having the same weights are added simultaneously without carries, resulting in the product expressed in a mixed twos-complement system. In a two-stage array, complex multiplication is possible with using four real subarrays. Furthermore, with a three-stage array architecture, complex matrix operation is straightforwardly accomplished. In the experiment, parallel two-stage array complex multiplication with liquid-crystal panels is demonstrated.

PET imaging studies of dopamine D2 receptors: comparison of [18F]N-methylspiperone and the benzamide analogues [18F]MABN and [18F]MBP in baboon brain

A series of positron emission tomography (PET) imaging studies was conducted in a baboon with the benzamide derivatives [18F]2,3-dimethoxy-N-[9-(4-fluorobenzyl)-9-azabicyclo[3.3.1]non an-3 beta-yl]benzamide ([18F]MABN) and [18F]2,3-dimethoxy-N-[1-(4-fluorobenzyl)piperidin-4-yl]be nza mide ([18F]MBP). Studies were also conducted with the butyrophenone [18F]N-methylspiperone (NMSP) for comparison. Tissue-time activity curves of [18F]MABN are similar to those of [18F]NMSP since both compounds displayed approximately the same uptake in the basal ganglia and displayed irreversible binding kinetics in vivo. However, the rapid rate of clearance from the cerebellum and high basal ganglia:cerebellum ratio of [18F]MABN indicate that this compound has a much lower amount of nonspecific binding than [18F]NMSP. [18F]MBP displayed a higher uptake in the basal ganglia relative to [18F]NMSP and [18F]MABN and exhibited reversible binding kinetics in vivo. This property of [18F]MBP is desirable since the uptake of radioactivity in D2-rich ligands is less likely to be influenced by changes in cerebral blood flow. The current data suggest that both [18F]MABN and [18F]MBP are promising ligands for studying dopamine D2 receptors with PET.

Molecular cloning, sequencing, and expression in Escherichia coli of the chalcone synthase gene

Flavonoids form a class of secondary metabolites that are abundant in all higher plants. They serve important functions in flower pigmentation. Chalcone Synthase (CHS) is a key enzyme in the biosynthesis of all classes of flavonoids; therefore, variation of the expression of CHS might change the color of flowers. We cloned CHS-A gene from Petunia hybrida, which has 99% sequence homology with those that have been cloned abroad. The sequence of the coding region is 1170bp and encodes a protein of 39kDa. CHS-A gene is also expressed high-efficiently in E. coli. All this work establishes a sound basis for future research on the impact of the CHS-A gene on flower pigmentation.

Negative binary arithmetic algorithms for digital parallel optical computation

Based on a negative binary number system, an algorithm with weighted-shifted addition, parallel-array multiplication, and a two-stage-array complex operation is proposed to carry out the multiplication of two complex numbers. The complex multiplication is performed without signs, carries, and recoding. The algorithm is suitable for optical implementation, and an optical parallel architecture is suggested. The experimental result is also given.

Concentration recovery for SPECT CNS dopamine-receptor studies for monkeys

Most commercial SPECT scanners do not properly compensate for scattering and partial volume effects, which severely impacts the quantitation of clinical and research SPECT studies, especially in CNS dopamine studies. Hence, in this paper, a brain phantom containing a monkey skull was used to calibrate a Picker Prism 3000 SPECT camera for quantitative studies of 123I and 99mTc-labeled radiopharmaceuticals. In the calibration study, two small vials representing basal ganglia were inserted into a skull phantom. A series of images were taken with different concentration ratios between the basal ganglia and the other brain compartments to simulate the dynamic imaging study of the dopamine D2 receptor in a monkey brain. Based on this calibration, a simple method is proposed for count correction in the region of interest (ROI). This technique is superior to using a single calibration factor from a cylindrical uniform activity phantom since it can compensate for both the partial volume effect and the dynamically changing effect of scattering. A significant difference between the true and measured values was observed in the correction factors (by a factor as much as 3). Furthermore, a cylindrical phantom, approximately the size of a monkey's head and containing the same basal ganglia inserts, was used to investigate the feasibility of using a cylindrical phantom with the proposed correction method. The results indicate that it is feasible to use a cylindrical phantom for the case where the activity inside the brain cavity and the activity in the surrounding tissue are similar.

Triple energy window scatter correction technique in PET

A practical triple energy window technique (TEW) is proposed, which is based on using the information in two lower energy windows and one single calibration, to estimate the scatter within the photopeak window. The technique is basically a conventional dual-window technique plus a modification factor, which can partially compensate object-distribution dependent scatters. The modification factor is a function of two lower scatter windows of both the calibration phantom and the actual object. In order to evaluate the technique, a Monte Carlo simulation program, which simulates the PENN-PET scanner geometry, was used. Different phantom activity distributions and phantom sizes were tested to simulate brain studies, including uniform and nonuniform distributions. The results indicate that the TEW technique works well for a wide range of activity distributions and object sizes. The comparisons between the TEW and dual window techniques show better quantitative accuracy for the TEW, especially for different phantom sizes. The technique is also applied to experimental data from a PENN-PET scanner to test its practicality.

Herpes simplex virus 1 alkaline nuclease is required for efficient egress of capsids from the nucleus

We previously described the isolation of AN-1, a null mutant of the HSV-1 alkaline nuclease gene, which is able to synthesize near wild-type levels of viral DNA and late viral proteins under nonpermissive growth conditions; these results lead us to conclude that the alkaline nuclease is not essential for viral DNA synthesis (Weller, S. K., Seghatoleslami, R. M., Shao, L., Rowse, D., and Carmichael, E. P., 1990, J. Gen. Virol. 71, 2941-2952). AN-1 was found to be deficient in the production of infectious virions suggesting that the nuclease may play a role in processing or packaging of viral DNA into infectious virions. In this report we demonstrate that the defect is distinct from that observed in other late HSV-1 mutants which make but fail to process viral DNA under nonpermissive growth conditions. Following restriction enzyme digestion, specific terminal fragments are observed in DNA from AN-1-infected Vero cells, indicating that specific cleavage has occurred; moreover, the efficiency of cleavage is at near wild-type levels. Also in contrast to cells infected with previously described late mutants, DNase I or staphylococcal nuclease resistant DNA is observed in these cells further indicating that encapsidation has occurred. Three lines of evidence suggest, however, that maturation of DNA-containing AN-1 capsids is defective in some ways. First, in contrast to wild-type, very small amounts of protected DNA is detected in cytoplasmic extracts from AN-1-infected cells. Second, very few if any mature, DNA-containing C capsids are observed in the cytoplasm when analyzed by electron microscopy or sucrose gradient sedimentation. Finally, analysis of nuclei by sucrose gradient sedimentation indicates an elevated ratio of A to B capsids. These data indicate that AN-1 may be defective for the production of capsids competent to mature into the cytoplasm. Possible models for the nature of the defect in AN-1 will be discussed.

The conserved helicase motifs of the herpes simplex virus type 1 origin-binding protein UL9 are important for function

The UL9 gene of herpes simplex virus encodes a protein that specifically recognizes sequences within the viral origins of replication and exhibits helicase and DNA-dependent ATPase activities. The specific DNA binding domain of the UL9 protein was localized to the carboxy-terminal one-third of the molecule (H. M. Weir, J. M. Calder, and N. D. Stow, Nucleic Acids Res. 17:1409-1425, 1989). The N-terminal two-thirds of the UL9 gene contains six sequence motifs found in all members of a superfamily of DNA and RNA helicases, suggesting that this region may be important for helicase activity of UL9. In this report, we examined the functional significance of these six motifs for the UL9 protein through the introduction of site-specific mutations resulting in single amino acid substitutions of the most highly conserved residues within each motif. An in vivo complementation test was used to study the effect of each mutation on the function of the UL9 protein in viral DNA replication. In this assay, a mutant UL9 protein expressed from a transfected plasmid is used to complement a replication-deficient null mutant in the UL9 gene for the amplification of herpes simplex virus origin-containing plasmids. Mutations in five of the six conserved motifs inactivated the function of the UL9 protein in viral DNA replication, providing direct evidence for the importance of these conserved motifs. Insertion mutants resulting in the introduction of two alanines at 100-residue intervals in regions outside the conserved motifs were also constructed. Three of the insertion mutations were tolerated, whereas the other five abolished UL9 function. These data indicate that other regions of the protein, in addition to the helicase motifs, are important for function in vivo. Several mutations result in instability of the mutant products, presumably because of conformational changes in the protein. Taken together, these results suggest that UL9 is very sensitive to mutations with respect to both structure and function, perhaps reflecting its multifunctional character.

Regulation of production of activin A in human marrow stromal cells and monocytes

In studies of the regulation of hematopoiesis, increasing attention has focused on the role of bone marrow stromal cells as rich sources of various cytokines. Present studies indicate that marrow stromal cells and monocytes produce activin A, implicating this new cytokine in the paracrine control of hematopoiesis. Activin A, which was initially recognized as a beta A beta A dimeric gonadal protein, was found to potentiate the proliferation and differentiation of erythroid progenitors; both purified erythroid colony-forming units (CFU-E) and K562 cells possess high affinity receptors specific for activin A. Present studies using Western and Northern blots demonstrate the presence of beta A subunits of activin A in the conditioned medium of monocytes and stromal cells and its RNA transcripts in these cells. The presence of functional and homodimeric beta A beta A activin molecule was confirmed through bioassay with or without a blocking antiserum against activin A or an activin binding protein, follistatin; its presence is further supported by a specific enzyme-linked immunosorbent assay (ELISA) in which a monoclonal antibody reacted only with the beta A beta A dimeric form of this molecule. In other experiments, the production of activin A was found to be regulated by various cytokines and regulators. The production of activin A in monocytes was stimulated more than ninefold by treatment with granulocyte-macrophage colony-stimulating factor (GM-CSF). Activin A expression was also stimulated, albeit less potently, by bacterial lipopolysaccharide (LPS) and gamma-interferon. On the other hand, the expression of activin A in marrow stromal cells was upregulated by incubation with tumor necrosis factor-alpha (TNF-alpha), LPS, and interleukin 1 alpha (IL-1 alpha). Therefore, we propose that the local production of activin A in the microenvironment within bone marrow may fine tune the regulation of steady-state hematopoiesis. In addition, this factor may normally be produced at minimal levels, but under certain situations may be further induced to provide important biological functions.

[Morphometric analysis of gastric dysplasia and malignancy]

One hundred and eleven specimens of dysplasia and carcinoma of gastric mucosa were studied morphometrically with automatic IBAS image analysis system. A total of 12 parameters of histologic and cellular changes were measured. The results showed that index of structural atypism, gland area, gland perimeter, gland maximum diameter, nucleus-gland ratio index and nuclear area increased in the order of intestinal metaplasia, mild dysplasia, moderate dysplasia, severe dysplasia and carcinoma. These data indicate that computer-assisted morphometry can offer objective criteria in the differential diagnosis of gastric dysplasia and carcinoma.

Regulation of globin gene expression in human K562 cells by recombinant activin A

Recent studies indicate that a purified protein, activin A, belongs to the transforming growth factor beta (TGF-beta) superfamily. Similar to TGF-beta, activin A can have different biologic activities, depending on the target tissues. We used recombinant activin A to demonstrate a possible regulatory role of this protein in modulating human erythroid differentiation in the human erythroid cell line, K562. Using genomic probes containing the second exon of alpha, beta, gamma, and epsilon globins, relative abundance of various types of globin transcripts in untreated and activin-treated K562 cells was examined with S1 nuclease analysis. Despite considerable homology amongst various globin sequences, these globin probes were highly specific for their unique mRNA species in the analyses. It was shown that the abundance of specific globin probe fragments for gamma and epsilon globins (209 nucleotides) as well as alpha (180 nucleotides), which were protected from S1 digestion, increased many fold in K562 cells treated with activin A. In contrast, there were no specific transcripts of beta globin detected in either the control or activin-treated cells. The increases in the level of fetal and embryonic beta-like and alpha globin transcripts also confirmed earlier studies of Northern and slot-blot analyses using globin cDNA as probes. In addition, nuclear run-off transcription assay using isolated nuclei indicated that most of the increase in the globin transcripts after activin treatment could be attributed to the stimulation of transcription rate for globin genes. Transient transfection assays also provide evidence that activin A significantly stimulated transcriptional activity of an epsilon globin promoter in K562, but not in the nonerythroid Chinese hamster ovary cells. Therefore, it was concluded that activin A exerts its effects on globin gene expression at the level of transcription in erythroid cells.

Effect of activin A on globin gene expression in purified human erythroid progenitors

The regulatory control of human erythropoiesis through a purified protein, activin A, was examined. Previous studies using mixed populations of bone marrow cells suggested that activin A has an indirect effect on cellular proliferation and DNA synthesis of erythroid progenitors through the mediation of accessory cells. In present studies, the cultures of purified erythroid progenitors were used to examine the effect of activin A on globin gene expression. Human erythroid burst-forming units (BFU-E) were partially purified from peripheral blood, and after 8 days of culture the cells generated consisted mainly of erythroid colony-forming units (CFU-E). It was found that the subsequent 7-day cultures of these purified progenitors yielded similar numbers and size distributions of erythroid colonies, regardless of the presence of activin A in the cultures. In addition, these erythroid progenitor cells were responsive, in terms of stimulation of DNA synthesis, to the addition of erythropoietin, but not to treatment by activin A. Therefore, once the erythroid progenitors are depleted of accessory cells, activin A has little effect on both the proliferation and the DNA synthesis of these progenitors. However, when these purified erythroid progenitors were cultured in the presence of activin A, the levels of all alpha, beta, and epsilon globin transcripts and hemoglobins were significantly increased. In addition, disuccinimidyl suberate was found to chemically cross-link 125I-activin A to cell surface binding proteins (45 to 54 Kd) in both purified erythroid progenitors and K562 cells. The labeling of these binding proteins was specifically inhibited by the presence of unlabeled activin A, but not transforming growth factor-beta. These results suggest that, in addition to its indirect effect on DNA synthesis and cellular proliferation of erythroid progenitors, activin A directly affects the levels of globin mRNAs and hemoglobins in developing human erythroid cells through its specific surface binding receptor(s).

Cross-plane scattering correction-point source deconvolution in PET

The authors propose a new 2-D point source scattering deconvolution method. The cross-plane scattering is incorporated into the algorithm by modeling a scattering point source function. In the model, the scattering dependence on axial and transaxial directions is reflected in the exponential fitting parameters, and these parameters are directly estimated from a limited number of measured point response functions. The results comparing the standard in-plane line source deconvolution to the cross-plane point source deconvolution show that for a small source the former technique overestimates the scatter fraction in the plane of the source and underestimates the scatter fraction in adjacent planes. In addition, the authors also propose a simple approximation technique for deconvolution.

[Morphometrical assessment in classification of different grades of gastric dysplasia and malignancy]

Measurement of cytological features and DNA content was made on epithelial cells from 40 cases of gastric dysplasia and carcinoma graded by subjective scoring with IBAS image analysis system. The measurements were statistically compared with the subjective scores by using discriminant analysis. The result was noticed to provide significant discrimination between the different groups; and nuclear area, nuclear perimeter, nuclear form factor, percentage of 2C cells and percentage of aneuploid cells were all proved to be discriminating variables. Application of classification equation derived from discriminant analysis showed good results for the prediction of different individual cases.

The herpes simplex virus type 1 alkaline nuclease is not essential for viral DNA synthesis: isolation and characterization of a lacZ insertion mutant

Herpes simplex virus type 1 (HSV-1) encodes a novel enzyme activity, the alkaline nuclease, whose precise role in the viral replication cycle remains obscure. The alkaline nuclease gene corresponds to the UL12 open reading frame, which is predicted to encode a protein of 626 amino acid residues. We describe the isolation and characterization of a null mutant of the gene for the viral alkaline nuclease in which 917 bp from the N-terminal half of the gene (corresponding to residues 70 to 375) were deleted and replaced by the insertional mutagen ICP6::lacZ. The resulting mutant virus, AN-1, was propagated in helper cells (S22) which express the wild-type version of the alkaline nuclease gene. Mutant AN-1 growth in Vero cells is severely restricted, although small amounts of infectious virus are produced. On the other hand, wild-type levels of viral DNA and late viral proteins are expressed in virus AN-1-infected Vero cells. These results indicate that the HSV-1 alkaline nuclease gene product is not essential for viral DNA synthesis but may play a role in the processing or packaging of viral DNA into infectious virions. Possible roles in the viral infectious cycle will be discussed.

Information analysis of single photon emission computed tomography with count losses

An analysis is presented of the information transfer from emitter-space to detector-space in single photon emission computed tomography (SPECT) systems. The analysis takes into account the fact that count loss side information is generally not available at the detector. Side information corresponds to the number gamma-rays lost deleted due to lack of interaction with the detector data. It is shown that the information transfer depends on the structure of the likelihood function of the emitter locations associated with the detector data. This likelihood function is the average of a set of ideal-detection likelihood functions, each matched to a particular set of possible deleted gamma-ray paths. A lower bound is derived for the information gain due to incorporating the count loss side information at the detector. This is shown to be significant when the mean emission rate is small or when the gamma-ray deletion probability is strongly dependent on emitter location. Numerical evaluations of the mutual information, with and without side information, associated with information-optimal apertures and uniform parallel-hole collimators are presented.

[Evaluation of DNA content in gastric dysplasia and carcinoma by image cytometry]

In 30 cases of gastric dysplasia and 10 cases of gastric carcinoma, DNA content was studied by IBAS image analysis system. The mean DNA level increased steadily with the advance of histologic gradation, and the highest DNA content was observed in gastric carcinoma. No case of aneuploidy was found in mild dysplasia. In moderate dysplasia, aneuploid cells were occasionally encountered. Severe dysplasia had a lower percentage (4.48%), and gastric carcinoma was characterized by a high percentage of aneuploid cells (14.54%).

[Significance of endothelin in shock pathogenesis]

Endothelin is a recently discovered bioactive peptide produced by vascular endothelial cells. By means of specific radioimmunoassay we found that plasma endothelin level in patients with late septic shock was significantly increased. And a typical shock model in healthy rats was reproduced by continuous infusion of endothelin (endothelin shock). Infusion of endothelin at a small dose to hemorrhagic shocked rats deteriorated the shock process and resulted in an irreversible development. From these results it is suggested that endothelin may be an endogenous injury-inducing factor, acting as one of the important humoral factors involved in shock pathogenesis.

Characterization of the potentiation effect of activin on human erythroid colony formation in vitro

Activin, also named FSH-releasing protein, was previously shown to induce hemoglobin accumulation in K562 cells and potentiate the proliferation and differentiation of CFU-E in human bone marrow cultures. Present studies indicate that the potentiation effect of activin is lineage specific. In addition to CFU-E, activin caused an increase in the colony formation of BFU-E from either bone marrow or peripheral blood. It had little effect on the colony formation of CFU-GM and the mixed colonies from CFU-GEMM. In serum-depleted culture, the effect of activin was shown to be dose-dependent with doses effective at picomolar concentrations. The potentiation effect of activin was exerted indirectly through mediation of both monocytes and T lymphocytes. Activin was also found to increase specifically the proportion of DNA-synthesizing erythroid progenitors from both bone marrow and peripheral blood. It had little effect on DNA synthesis in CFU-GM and in mitogen-stimulated lymphocytes. Addition of the monocytes or T lymphocytes to their respective depleted subpopulations of mononuclear cells reconstituted the enhancing effect of activin on the colony formation and DNA synthesis of erythroid progenitors. These results strongly suggest a specific role of activin in potentiating the proliferation and differentiation of erythroid progenitors in vitro.

The mutual information criterion for SPECT aperture evaluation and design

An aperture performance criterion for single-photon-emission computed tomography (SPECT) that is based on the mutual information (MI) between the source and detector processes is proposed. The MI is a measure of the reduction in uncertainty of the emitter location, given the detector data, and it takes account of the inherent tradeoffs between the effects of sensitivity and resolution on source estimation accuracy. Specific expressions for the MI are derived for one-dimensional linear geometries and two-dimensional, parallel-slice, ring geometries under the assumptions of Poisson emission times, uniform emission angles, no scattering, and a known lost-count correction factor. For one-dimensional geometries a necessary and sufficient condition for an aperture to maximize the mutual information is given. The MI-optimal apertures are derived for various source distributions using an iterative maximization procedure. The MI is then numerically calculated for various ring apertures associated with the parallel-slice SPRINT II system.