Adsorption and purification of biogas inside graphitic nanopores: molecular dynamics simulation approach

Biogas is one of the most common sources of biomass energy. Due to the associated environmental pollution and costs, desulfurization, and purification are the most important challenges of biogas power generation. Using all-atom molecular dynamics (MD), we systematically simulated the isothermal adsorption behavior of biogas (comprising CH₄, CO₂, H₂O, H₂S, and H₂) in graphite (Gr) slit nanopores. The impact of slit width, system temperature, and moisture content on the adsorption energy, adsorption ratio, and diffusion coefficient of biogas molecules was investigated. Simulation results revealed that due to strong interactions between graphite and H₂S, graphite slits of width d = 48 ~ 80 Å displayed significant selective adsorption of H₂S molecules. At temperatures between 300 and 500 K, Gr slits can effectively separate H₂S in biogas. Moreover, as the moisture content of biogas (vol%) increases from 0 to 20%, the formation and interactions of hydrogen bonds between water molecules create H₂O films accumulating on the Gr surface and taking up the adsorption sites, which reduces the amount of hydrogen sulfide that can be adsorbed. Our findings provide important insights into the material design for biogas purification. A schematic representation of molecular interactions between adsorbates and the wall for biogas mixtures (comprising CH₄, CO₂, H₂O, H₂S, and H₂) inside graphitic nanopores.

Systemic treatment of advanced clear cell sarcoma: results from a retrospective international series from the World Sarcoma Network

Background

Clear cell sarcoma (CCS) is a translocated aggressive malignancy with a high incidence of metastases and poor prognosis. There are few studies describing the activity of systemic therapy in CCS. We report a multi-institutional retrospective study of the outcomes of patients with advanced CCS treated with systemic therapy within the World Sarcoma Network (WSN).

Materials and methods

Patients with molecularly confirmed locally advanced or metastatic CCS treated with systemic therapy from June 1985 to May 2021 were included. Baseline demographic and treatment information, including response by Response Evaluation Criteria in Solid Tumours (RECIST) 1.1, was retrospectively collected by local investigators. Descriptive statistics were carried out.

Results

Fifty-five patients from 10 institutions were included. At diagnosis, the median age was 30 (15-73) years and 24% (n = 13/55) had metastatic disease. The median age at diagnosis was 30 (15-73) years. Most primary tumours were at aponeurosis (n = 9/55, 16%) or non-aponeurosis limb sites (n = 17/55, 31%). The most common fusion was EWSR1–ATF1 (n = 24/55, 44%). The median number of systemic therapies was 1 (range 1-7). The best response rate was seen for patients treated with sunitinib (30%, n = 3/10), with a median progression-free survival of 4 [95% confidence interval (CI) 1-7] months. The median overall survival for patients with advanced/metastatic disease was 15 months (95% CI 3-27 months).

Conclusions

Soft tissue sarcoma-type systemic therapies have limited benefit in advanced CCS and response rate was poor. International, multicentre prospective translational studies are required to identify new treatments for this ultra-rare subtype, and access to early clinical trial enrolment remains key for patients with CCS.

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This is the largest reported series of advanced CCS patients treated with systemic therapy.

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The activity of sarcoma-type systemic therapy is poor and modest responses were seen only with sunitinib.

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Effective therapies are needed to improve outcomes for patients with this ultra-rare sarcoma type.

The adequacy of tissue microarrays in the assessment of inter- and intra-tumoural heterogeneity of infiltrating lymphocyte burden in leiomyosarcoma

The characterisation and clinical relevance of tumour-infiltrating lymphocytes (TILs) in leiomyosarcoma (LMS), a subtype of soft tissue sarcoma that exhibits histological heterogeneity, is not established. The use of tissue microarrays (TMA) in studies that profile TIL burden is attractive but given the potential for intra-tumoural heterogeneity to introduce sampling errors, the adequacy of this approach is undetermined. In this study, we assessed the histological inter- and intra-tumoural heterogeneity in TIL burden within a retrospective cohort of primary LMS specimens. Using a virtual TMA approach, we also analysed the optimal number of TMA cores required to provide an accurate representation of TIL burden in a full tissue section. We establish that LMS have generally low and spatially homogenous TIL burdens, although a small proportion exhibit higher levels and more heterogeneous distribution of TILs. We show that a conventional and practical number (e.g. ≤3) of TMA cores is adequate for correct ordinal categorisation of tumours with high or low TIL burden, but that many more cores (≥11) are required to accurately estimate absolute TIL numbers. Our findings provide a benchmark for the design of future studies aiming to define the clinical relevance of the immune microenvironments of LMS and other sarcoma subtypes.

P1585Increased circulating galectin 1 level is associated with progression of kidney function decline in patients with suspected coronary artery disease, independent of diabetes

Background

Galectin-1 modulates acute and chronic inflammation, and is associated with glucose homeostasis and chronic renal disease. Whether serum Galectin-1 levels could predict the short-term and long-term renal outcomes after contrast exposure in patients with suspected coronary artery disease remains uncertain.

Purpose

This study aimed to evaluate the relationship between serum Galectin-1 levels and the incidence of contrast-induced nephropathy and to investigate the predictive role of circulating galectin-1 levels in renal function decline in patients undergoing coronary angiography.

Methods

In total, 798 patients who had received coronary angiography were enrolled. Serum galectin-1 levels were determined before administration of contrast media. Contrast-induced nephropathy was defined as a rise in serum creatinine of 0.5 mg/dL or a 25% increase from baseline within 48 h after the procedure. Progressive renal function decline was defined as >30% decrease in estimated glomerular filtration rate after discharge. All patients were followed up for at least one year or until the occurrence of death after coronary angiography.

Results

Overall, contrast-induced nephropathy occurred in 41 (5.1%) patients. During a median follow-up of 1.4±1.1 years, 80 (10.0%) cases had subsequent decline in renal function. After adjustment for demographic characteristics, kidney function, traditional risk factors, and medications, higher galectin-1 level was found to be independently associated with a higher risk for mortality and renal function decline (tertile 2, HR=3.12 95% CI,1.25–7.78; tertile 3, HR=3.25, 95% CI,1.42–7.41) but not for contrast-induced nephropathy, regardless of the presence of diabetes.

Conclusions

Higher baseline serum galectin-1 levels were associated with a higher risk of mortality and renal function decline in patients undergoing coronary angiography. Galectin-1 may play a pivotal role in progressive renal dysfunction, but further studies are needed to verify these results.

Acknowledgement/Funding

Ministry of Science and Technology of Taiwan (MOST 104-2314-B-075-047), Taipei Veterans General Hospital (V105C-0207, V106C-045, V108C-195)

Mice Deficient in Hepsin, a Serine Protease, Exhibit Normal Embryogenesis and Unchanged Hepatocyte Regeneration Ability

Hepsin, a liver-enriched novel serine protease, has been implicated in participating with normal cell growth, embryogenesis, and blood coagulation pathway. To study its function in vivo, we have disrupted the mouse hepsin gene by homologous recombination. Targeted disruption of the hepsin gene and ablation of hepsin message were demonstrated by Southern blotting, Northern blotting and RT-PCR analysis. Homozygous hepsin −/− mice were viable, fertile, and exhibited no gross abnormalities, as judged by the size, weight and blood coagulation (PT) assays. However, the serum concentration of the bone form of alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase of the hepsin −/− mice was mildly elevated, in spite of no obvious pathological change of hepatocytes. To examine whether hepsin is involved in controlling cell growth in adult tissues, 70% hepatectomy was applied to the hepsin −/− mice. Liver regeneration proceeded normally in the hepsin −/− mice as judged by the liver mass restoration rate. These results suggest that loss of hepsin function causes no effect in cell growth and embryogenesis in vivo, which is in contradiction to the studies using in vitro cell culturing system. Moreover, gross mass regeneration of liver after damage proceeds normally in the absence of functional hepsin.

Accuracy and Trending of Continuous Noninvasive Hemoglobin Monitoring in Patients Undergoing Liver Transplantation

BACKGROUND

Shift in large fluid volumes and massive blood loss during liver transplantation frequently leads to rapid changes in hemoglobin (Hb) concentration; thus, to ensure adequate tissue oxygenation, accurate and rapid determination of Hb concentration is essential in transplant recipients. The Radical-7 Pulse CO-Oximeter provides a noninvasive and continuous way to monitor Hb concentration (SpHb) in real time and is an ideal candidate for use during liver transplantation. In this study, we assessed the relationship between SpHb and total Hb (tHb) obtained from arterial blood samples during surgery.

METHODS

Forty patients undergoing liver transplantation were enrolled in this study. tHb and time-matched SpHb were measured at 5 different phases throughout surgery. Paired SpHb and tHb levels were assessed using linear regression, Bland-Altman analysis, and the Critchley polar plot method.

RESULTS

A total of 161 paired measurements with sufficient signal quality were analyzed. The correlation between SpHb and tHb was 0.59 (P < .001). Bland-Altman analysis revealed that a bias between SpHb and tHb was 2.28 g/dL, and limits of agreement (LoA) were from -0.78 to 5.34 g/dL. Trending analysis showed that 87% of data were located within the acceptable trending area, indicating that the trending ability was not satisfied.

CONCLUSIONS

The Radical-7 Pulse CO-Oximeter was not sufficient to monitor Hb levels and trends during liver transplantation surgery in our cohort. In particular, in critical patients and in those with low Hb levels, invasive Hb measurement should be used for assessment.

Mitochondrial DNA variants as genetic risk factors for Parkinson disease

BACKGROUND AND PURPOSE

Investigation of the relationship between mitochondrial DNA (mtDNA) variants and Parkinson disease (PD) remains an issue awaiting more supportive evidence. Moreover, an affirming cellular model study is also lacking.

METHODS

The index mtDNA variants and their defining mitochondrial haplogroup were determined in 725 PD patients and 744 non-PD controls. Full-length mtDNA sequences were also conducted in 110 cases harboring various haplogroups. Cybrid cellular models, composed by fusion of mitochondria-depleted rho-zero cells and donor mitochondria, were used for a rotenone-induced PD simulation study.

RESULTS

Multivariate logistic regression analysis revealed that subjects harboring the mitochondrial haplogroup B5 have resistance against PD (odds ratio 0.50, 95% confidence interval 0.32-0.78; P = 0.002). Furthermore, a composite mtDNA variant group consisting of A10398G and G8584A at the coding region was found to have resistance against PD (odds ratio 0.50, 95% confidence interval 0.33-0.78; P = 0.001). In cellular studies, B4 and B5 cybrids were selected according to their higher resistance to rotenone, in comparison with cybrids harboring other haplogroups. The B5 cybrid, containing G8584A/A10398G variants, showed more resistance to rotenone than the B4 cybrid not harboring these variants. This is supported by findings of low reactive oxygen species generation and a low apoptosis rate in the B5 cybrid, whereas a higher expression of autophagy was observed in the B4 cybrid particularly under medium dosage and longer treatment time with rotenone.

CONCLUSIONS

Our studies, offering positive results from clinical investigations and cybrid experiments, provide data supporting the role of variant mtDNA in the risk of PD.

Phosphoproteomics in translational research: a sarcoma perspective

Phosphoproteomics has been extensively used as a preclinical research tool to characterize the phosphorylated components of the cancer proteome. Advances in the field have yielded insights into new drug targets, mechanisms of disease progression and drug resistance, and biomarker discovery. However, application of this technology to clinical research has been challenging because of practical issues relating to specimen integrity and tumour heterogeneity. Beyond these limitations, phosphoproteomics has the potential to play a pivotal role in translational studies and contribute to advances in different tumour groups, including rare disease sites like sarcoma. In this review, we propose that deploying phosphoproteomic technologies in translational research may facilitate the identification of better defined predictive biomarkers for patient stratification, inform drug selection in umbrella trials and identify new combinations to overcome drug resistance. We provide an overview of current phosphoproteomic technologies, such as affinity-based assays and mass spectrometry-based approaches, and discuss their advantages and limitations. We use sarcoma as an example to illustrate the current challenges in evaluating targeted kinase therapies in clinical trials. We then highlight useful lessons from preclinical studies in sarcoma biology to demonstrate how phosphoproteomics may address some of these challenges. Finally, we conclude by offering a perspective and list the key measures required to translate and benchmark a largely preclinical technology into a useful tool for translational research.

Molecular dynamics investigation of separation of hydrogen sulfide from acidic gas mixtures inside metal-doped graphite micropores

Separation of hydrogen sulfide from acidic gas mixtures is demonstrated using metal-doped graphene micropores via a prototype model.

Molecular dynamics investigations of liquid–vapor interaction and adsorption of formaldehyde, oxocarbons, and water in graphitic slit pores

We report a multi-component liquid–vapor adsorption study that allowed us to predict the ideal adsorption conditions and to explore the fundamental interaction and adsorption behaviors for formaldehyde, carbon dioxide, carbon monoxide, and water mixtures in GR slit pores.

Using mass spectrometry to detect buffalo salivary odorant-binding protein and its post-translational modifications

A large number of mammalian odorant-binding proteins, which are lipocalins, have been studied. These proteins participate in peri-receptor events by selecting and carrying odorant molecules. The present study aimed at identifying the buffalo salivary odorant-binding protein (sOBP), and to determine its post-translational modification using mass spectrometry. The buffalo salivary 21  kDa protein was initially separated adopting sodium dodecyl sulfate-polyacrylamide gel electrophoresis and it was identified as sOBP with high statistical reliability using liquid chromatography/tandem mass spectrometry (LC/MS/MS) and SEQUEST, for the first time. Further, the post-translationally modified peptides were screened adopting MS/MS. A total of four post-translational modifications, namely glycation at lysine-(59), hydroxylation at lysine-(134), ubiquitination at lysine-(121), and dihydroxylation in lysine-(108), were recorded. Moreover, these modifications have not been identified in buffalo salivary odorant-binding protein.

Pressure-induced solid-state lattice mending of nanopores by pulse laser annealing

This paper presents the pressure-induced solid-state lattice mending of nanopores in single-crystal copper by femtosecond laser annealing processes. The microscopic mechanism of lattice mending is investigated by a modified continuum-atomistic modeling approach. Three typical lattice mending phases, including (i) the incubation of dislocation nucleation, (ii) plastic deformation under the combined effect of pressure and atomic thermal diffusion, and (iii) lattice recovery and reconstruction, are characterized via the microscopic structure changes and transient thermodynamic trajectories. The simulation results reveal that the structural mending of a pore is originated in heterogeneous nucleation of dislocations from the pore surface. The shear-induced multiple lattice glides are found to significantly contribute to the mending of a nanopore in the process of solid-state structural mending. The mending rates of two different modes, the pressure-induced and the classical unsteady-state atomic diffusion, are estimated and found to be very different from each other, by an order of 10(4). In addition, the location of the pore is also found to significantly influence the annealing threshold. Since the largest amplitude of the pressure wave is built up at a characteristic depth of approximately 45 nm below the irradiated surface, the shock wave will directly impinge on the pore and induce a fast solid-state lattice mending if the pore is located within the lower limit of the range of the characteristic depth. Furthermore, it is also interesting to note that the mending of a nanopore close to the characteristic depth by annealing fluence is generally lower than that of a pore near the surface. These results provide vital insights of photomechanical interactions with the microstructure of metallic solid, and the proposed approach can be further considered and enhanced to predict the mending depth for various defects in the future.

Kondo interactions and magnetic correlations in CePt2 nanocrystals

The evolution of the Kondo effect and antiferromagnetic (AF) correlations with size reduction in CePt2 nanoparticles (3.1-26 nm) is studied by analysis of the temperature-dependent specific heat and magnetic susceptibility. The AF correlations diminish with size reduction. The Kondo effect predominates at small particle size with trivalent, small Kondo temperature (TK) magnetic regions coexisting with strongly mixed-valent, large TK nonmagnetic regions. We discuss the role of structural disorder, background density of states and the electronic quantum size effect on the results.

Mice deficient in collapsin response mediator protein-1 exhibit impaired long-term potentiation and impaired spatial learning and memory

Collapsing response mediator protein-1 (CRMP-1) was initially identified in brain and has been implicated in plexin-dependent neuronal function. The high amino acid sequence identity among the five CRMPs has hindered determination of the functions of each individual CRMP. We generated viable and fertile CRMP-1 knock-out (CRMP-1(-/-)) mice with no evidence of gross abnormality in the major organs. CRMP-1(-/-) mice exhibited intense microtubule-associated protein 2 (MAP2) staining in the proximal portion of the dendrites, but reduced and disorganized MAP2 staining in the distal dendrites of hippocampal CA1 pyramidal cells. Immunoreactivity to GAP-43 (growth-associated protein-43) and PSD95 (postsynaptic density-95) (a postsynaptic membrane adherent cytoskeletal protein) was also decreased in the CA1 region of the knock-out mice. These changes were consistent with the mutant mice showing a reduction in long-term potentiation (LTP) in the CA1 region and impaired performance in hippocampal-dependent spatial learning and memory tests. CRMP-1(-/-) mice showed a normal synapsin I labeling pattern in CA1 and normal paired-pulse facilitation. These findings provide the first evidence suggesting that CRMP-1 may be involved in proper neurite outgrowth in the adult hippocampus and that loss of CRMP-1 may affect LTP maintenance and spatial learning and memory.

Lattice disorder and size-induced kondo behavior in CeAl2 and CePt(2+x)

When the size of CeAl2 and CePt(2+x) particles is reduced to the nanometer scale, antiferromagnetism is suppressed and Kondo behavior predominates, with the Kondo temperature T(K) either decreasing (CeAl2) or increasing (CePt(2+x)) relative to the bulk. Local structure measurements show that these nanoparticles are significantly distorted. While such distortions should strongly affect magnetic and electronic properties, we find they cannot explain the observed changes in T(K). Other size-induced changes to the electronic structure must, therefore, play a significant role.

The juvenile variant of papular-purpuric gloves and socks syndrome and its association with viral infections

BACKGROUND

Papular-purpuric gloves and socks syndrome (PPGSS) occurs mostly in adults and has been shown to be related to several possible viral infections. However, childhood-onset PPGSS seems to be not so rare as previously thought in our clinical experience.

OBJECTIVES

To survey the general characteristics of childhood-onset PPGSS and to determine the possible association between this juvenile variant of PPGSS and various viral infections.

PATIENTS AND METHODS

Thirty-three children with erythematopurpuric papular eruptions on the hands and/or feet were enrolled. Detailed history-taking and physical examination were performed on all of them. Blood samples were obtained from 25 patients about 1-5 weeks after the appearance of cutaneous eruptions to check complete blood counts, differential white blood cell counts, and IgM and IgG antibodies to parvovirus B19, cytomegalovirus (CMV), viral capsid antigen of Epstein-Barr virus (EBV) and measles.

RESULTS

The median age of these 33 patients was 23 months. The mean duration of the skin eruption was 4.8 weeks (SD 2.7, 95% CI 3.9-5.0). Lymphocytosis was present in 13 patients (52%) while mild eosinophilia occurred in only three patients (12%). Five patients (20%) were positive for IgM antibodies against CMV and seven (28%) were positive for IgM antibodies against EBV. Only one patient (4%) was detected to have IgM antibodies against parvovirus B19.

CONCLUSIONS

Childhood-onset PPGSS shows somewhat different clinical features from the adult type. It may represent a nonspecific manifestation of several viral infections, including CMV, EBV and parvovirus B19 infections.

TXAS-deleted mice exhibit normal thrombopoiesis, defective hemostasis, and resistance to arachidonate-induced death

Besides its well-recognized role in hemostasis and thrombosis, thromboxane A(2) synthase (TXAS) is proposed to be involved in thrombopoiesis and lymphocyte differentiation. To evaluate its various physiologic roles, we generated TXAS-deleted mice by gene targeting. TXAS(-/-) mice had normal bone marrow megakaryocytes, normal blood platelet counts, and normal CD4 and CD8 lymphocyte counts in thymus and spleen. Platelets from TXAS(-/-) mice failed to aggregate or generate thromboxane B(2) in response to arachidonic acid (AA) but produced increased prostaglandin-E(2) (PGE(2)), PGD(2), and PGF(2 alpha). AA infusion caused a progressive drop of mean arterial pressure (MAP), cardiac arrest, and death in wild-type (WT) mice but did not induce shock in TXAS(-/-) mice or in WT and TXAS(-/-) mice treated with antagonist to the thromboxane-prostanoid (TP) receptor. The TXAS(-/-) mice were able to maintain normal MAP upon AA insult when TP was present but were unable to do so when TP was blocked by an antagonist, suggesting a role of endoperoxide accumulation in influencing MAP. We conclude that TXAS is not essential for thrombopoiesis and lymphocyte differentiation. Its deficiency causes a mild hemostatic defect and protects mice against arachidonate-induced shock and death. The TXAS-deleted mice will be valuable for investigating the roles of arachidonate metabolic shunt in various pathophysiologic processes.

Herd behavior in designer genes

The ability of individuals to choose their children's genes has increased over time and may ultimately culminate in a world involving free market reprogenetic technologies. Reprogenetic technologies combine advances in reproductive biology and genetics to provide humans increased control over their children's genes. This Article offers economic perspectives that are helpful in understanding the possibly unexpected ethical, legal, and social issues at stake in using reprogenetic technologies for trait enhancement selection. The Appendix analyzes two competitive games that might arise in such a biotechnological society. Specifically, the Article focuses on herd behavior, caused by either a popularity contest or positional competition, in the choice of genetic traits. The analytical game-theoretic models in the Appendix can have several equilibrium outcomes in terms of individual reprogenetic technological choices and corresponding beliefs about such choices by others. This multiplicity of potential social outcomes suggests that a society can attain efficiency if the state or some private organization transforms individual parents' beliefs over the choices of other parents regarding their children's traits and, thus, coordinates parental reprogenetic decisions by selecting, as focal, certain beliefs over parents' reprogenetic decisions.

Co-expression of VEGF-C and its receptors, VEGFR-2 and VEGFR-3, in endothelial cells of lymphangioma. Implication in autocrine or paracrine regulation of lymphangioma

Lymphangioma has long been thought of as congenital malformations resulting from the failure of lymphatic vessels communicating with the venous system in the fetal period. Alternatively, it is proposed to be true neoplasm originated from the transformation of lymphatic endothelia. To extend the molecular basis of the pathogenesis of lymphangioma, we have characterized the expression of vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFR) in 29 cases of lymphangioma by RNA in situ hybridization. Endothelial cells of lymphangioma co-express transcripts of VEGF-C and its receptors VEGFR-3 (Flt4) and VEGFR-2 (Flk1), which are not detectable in the adjacent connective tissue. In contrast, there is little or no expression of VEGF-C, VEGFR-3, and VEGFR-2 mRNA in endothelial cells of hemangiomas, angiosarcomas, or normal lymphatic vessels of the small or large intestines. The results suggest that VEGF-C and its receptors may take active parts in the formation of lymphangioma by autocrine or paracrine regulation.

Sequence and phylogenetic analysis of the sigmaA-encoding gene of avian reovirus

The full-length sigmaA-encoding gene nucleotide sequences (1251 bp) of ten avian reovirus (ARV) field-isolates and three vaccine strains were determined and analyzed to study the degree of genetic divergence and evolution. Strains were isolated over a 23-year period from different hosts, pathotypes, and geographic locations. A phylogenetic tree constructed from variation in the sigmaA nucleotide sequences among ARV isolates showed that Taiwanese isolates from different dates of isolation were grouped into two distant groups, indicating that they have evolved in nature. In paired identity analysis, there was over 97.3% nucleotide sequence identity in the sigmaA-encoding genes between group I Taiwanese isolates (T6, 750505, 919, and 918) and Japanese isolate OS161 as well as three US vaccine strains, suggesting that they might have descended from a common ancestor. However, the nucleotide sequences of these sigmaA-encoding genes varied extensively from those of group II Taiwanese isolates (601SI, R2/TW, 1017-1, 916, and 601G), displaying only 86% identity. These results revealed that the genetic diversity in the sigmaA-encoding gene of ARV correlated with the date of isolation and geographic locations.

Electromyographic evaluation in children with spina bifida

BACKGROUND

It is controversial to predict ambulation potential using neurological level or specific pattern of muscle strength in patients with spina bifida. We attempted to analyze the relationship between the mobility outcome and its influencing factors utilizing electromyography to study motor unit activity in lower limbs. A subsidiary aim was to evaluate the external anal sphincter with electromyography and to determine the relevant factors of bowel and bladder functions.

METHODS

Among 156 patients with spina bifida who had received electromyographic examination and were followed at the out-patient clinic between 1998 and 2000, functional assessment with Pediatric Evaluation of Disability Inventory (PEDI) was applied in 47 randomly selected patients. Other assessments included clinical neurological examination, bowel and bladder function survey, and ambulation evaluation. We correlated the parameters of electromyography with the ambulatory ability and PEDI scores. The innervation of external sphincter was compared between groups with or without neurogenic bowel or bladder dysfunction.

RESULTS

The innervations of hip adductor and quadriceps were found to correlate with walking ability (p < 0.01); above muscles as well as anterior tibialis, and gastrocnemius were related to PEDI scores (p < 0.01). The neurological level still manifested correlation with walking ability (p < 0.05) and PEDI scores (p < 0.01). Both denervation potentials and recruitment pattern were important parameters for ambulation and mobility prediction. Significant difference was obtained in denervation patentials of sphincter within bowel groups (p = 0.036) and bladder groups (p = 0.016).

CONCLUSIONS

Both traditional neurological level and specific muscle innervation exert crucial influence on walking and mobility functions. Electromyographic assessment demonstrates its contribution in prediction of functional outcome in spina bifida.

Molecular characterisation of very virulent infectious bursal disease viruses in Taiwan

The very virulent infectious bursal disease virus (vv IBDV) RNA in the bursa of Fabricius and spleen from experimentally infected chickens or field samples was detected by in situ hybridisation (ISH) with subsequent reverse transcription (RT)-polymerase chain reaction (PCR) and sequence analysis. The VP 2 gene of vv IBDV was detected by ISH in infected chicken tissues with a cloned digoxigenin (DIG)-labelled cDNA probe. To verify ISH, RT - PCR was used to amplify two 643- and 500-base pair fragments on the VP 2 gene of IBDV in the bursa of Fabricius. With all isolates, two c DNA fragments of 643 and 500 bp long, respectively, were generated as expected and further confirmed the specificity of ISH. Analysis of the hypervariable region (HVR) of the VP 2 gene revealed that a serine-rich heptapeptide SWSASGS located at amino acids 326-332 was conserved in recent Taiwanese strains, and two amino acid substitutions were found in the classical Taiwanese strains at positions 330M and 331W. Three amino acids were unique to the vv strains at positions 222A, 256I and 294I, compared with classical and variant strains. Sequence and phylogenetic analysis showed that the recent Taiwanese strains were closely related, very similar to vv IBDV s from Europe, China, Japan, and Africa, and distantly related to the Taiwanese classical strains.

The association of heterotrimeric GTP-binding protein (Go) with microtubules

The heterotrimeric GTP-binding regulatory proteins (G proteins) play an important role in the regulation of membrane signal transduction. Recently, we identified the association of Go protein with mitotic spindles. Here we have investigated the relationship between Go protein and microtubules. We used temperature-dependent reversible assembly and taxol methods to purify microtubules from bovine brains. Goalpha and Gbeta proteins were identified in the microtubular fraction by both methods. The Goalpha subunit in the microtubular fraction could be ADP ribosylated by pertussis toxin. Co-immunoprecipitation data also revealed that Go protein can interact with microtubules. Exogenous Go protein could be incorporated into the assembled microtubular fraction, and 5 microg/ml (60 nM) of Go protein inhibited 40% of microtubule assembly. Western blot analysis of Goalpha-1 and Goalpha-2 in microtubular fractions showed that only Goalpha-1 is associated with microtubules. We conclude that the Goalpha-1betagamma proteins are associated with microtubules and may play some role in regulating the assembly and disassembly of microtubules.

G protein beta2 subunit antisense oligonucleotides inhibit cell proliferation and disorganize microtubule and mitotic spindle organization

The association of G protein beta2 subunit (Gbeta2) with mitotic spindles in various mammalian cells has been demonstrated previously. Recently, we have identified the association of Gbeta2 protein with microtubules (Wu et al., [1998] J. Cell. Biochem. 70: 552-562). In the present experiment we have demonstrated the possible functional role of Gbeta2 in microtubule and mitotic spindle organization in mammalian cells. When Gbeta2 antisense phosphorothioate oligonucleotides were transfected into mammalian cells, inhibition of cell proliferation with cell death after a 4-day treatment was observed. If the transfected cells were incubated for two days and their Gbeta2 and microtubules were examined by Western blotting and immunofluorescence localization, marked reduction of the Gbeta2 protein, fragmentation and disassembly of cytoplasmic microtubules, and disorganized mitotic spindles were found. We conclude that the Gbeta2 protein is closely associated with microtubule assembly and may play a potential role in the regulation of cell proliferation and microtubule and mitotic spindle organization in mammalian cells.

ARL4, an ARF-like protein that is developmentally regulated and localized to nuclei and nucleoli

ADP-ribosylation factors (ARFs) are highly conserved approximately 20-kDa guanine nucleotide-binding proteins that participate in both exocytic and endocytic vesicular transport pathways via mechanisms that are only partially understood. Although several ARF-like proteins (ARLs) are known, their biological functions remain unclear. To characterize its molecular properties, we cloned mouse and human ARL4 (mARL4 and hARL4) cDNA. The appearance of mouse ARL4 mRNA during embryonic development coincided temporally with the sequential formation of somites and the establishment of brain compartmentation. Using ARL4-specific antibody for immunofluorescence microscopy, we observed that endogenous mARL4 in cultured Sertoli and neuroblastoma cells was mainly concentrated in nuclei. When expressed in COS7 cells, ARL4-T34N mutant, predicted to exist with GDP bound, was concentrated in nucleoli. Yeast two-hybrid screening and in vitro protein-interaction assays showed that hARL4 interacted with importin-alpha through its C-terminal NLS region and that the interaction was not nucleotide-dependent. Like ARL2 and -3, recombinant hARL4 did not enhance cholera toxin-catalyzed auto-ADP-ribosylation. Its binding of guanosine 5'-O-(thiotriphosphate) was modified by phospholipid and detergent, and the N terminus of hARL4, like that of ARF, was myristoylated. Our findings suggest that ARL4, with its distinctive nuclear/nucleolar localization and pattern of developmental expression, may play a unique role(s) in neurogenesis and somitogenesis during embryonic development and in the early stages of spermatogenesis in adults.

Mice deficient in hepsin, a serine protease, exhibit normal embryogenesis and unchanged hepatocyte regeneration ability

Hepsin, a liver-enriched novel serine protease, has been implicated in participating with normal cell growth, embryogenesis, and blood coagulation pathway. To study its function in vivo, we have disrupted the mouse hepsin gene by homologous recombination. Targeted disruption of the hepsin gene and ablation of hepsin message were demonstrated by Southern blotting, Northern blotting and RT-PCR analysis. Homozygous hepsin -/- mice were viable, fertile, and exhibited no gross abnormalities, as judged by the size, weight and blood coagulation (PT) assays. However, the serum concentration of the bone form of alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase of the hepsin -/- mice was mildly elevated, in spite of no obvious pathological change of hepatocytes. To examine whether hepsin is involved in controlling cell growth in adult tissues, 70% hepatectomy was applied to the hepsin -/- mice. Liver regeneration proceeded normally in the hepsin -/- mice as judged by the liver mass restoration rate. These results suggest that loss of hepsin function causes no effect in cell growth and embryogenesis in vivo, which is in contradiction to the studies using in vitro cell culturing system. Moreover, gross mass regeneration of liver after damage proceeds normally in the absence of functional hepsin.

Chimaeric mice with disruption of the gene coding for phosphatidylinositol glycan class A (Pig-a) were defective in embryogenesis and spermatogenesis

Mutations in the gene encoding PIG-A (phosphatidylinositol glycan class A) are found in patients with paroxysmal nocturnal haemoglobinuria (PNH), an acquired haematopoietic stem cell disorder. Individuals with hereditary PIG-A mutations have never been identified, which is also manifested by the difficulties in generating Pig-a knockout (KO) mice. This study investigated the effect of Pig-a mutations on the development of visceral and genital organs in addition to the haematopoietic system by the generation of Pig-a KO chimaeric mice. Of a total of 54 live births out of 1684 blastocysts injected, chimaerism for Pig-a knockout was detected in 29 mice, suggesting the importance of Pig-a in embryogenesis and in live birth. Quantification of the degree of chimaerism in different organs of the surviving chimaeric mice revealed extremely low levels of Pig-a KO cells in the liver and spleen. In contrast, high levels of KO signals were usually detected in the brain, heart, lung and kidney. Haematopoiesis proceeded normally in these chimaeric mice (as measured by 'complete blood cell counting') and the Pig-a KO cells were present at low levels in red blood cells and B lymphocytes but at high levels in T lymphocytes, although these KO cells did not gain any growth advantage. The effect of Pig-a knockout was also prominent in the reproductive system, another organ with high mitotic activity. Breeding the male chimaeras revealed a high rate of infertility and abnormality in the male genital organs, including abnormally shaped testes, epididymis and seminal vesicles. Even in the absence of gross abnormalities of the genital organs, low counts of motile sperm were also discernible. Pig-a KO sperm was detected in these organs; however, no transmission of the KO allele was observed. The results suggest a possible mechanism underlying the non-transmission of the Pig-a KO gene in germlines.

Interaction of [glutarimide-2-14C]-thalidomide with rat embryonic DNA in vivo

We have investigated the possibility of [phthalimide carbonyl-14C]thalidomide and [glutarimide-2-14C]thalidomide interaction with DNA. In each experiment, groups of pregnant Wistar rats were treated with a labeled compound on day 12 of gestation. The embryos were harvested 24 h later, and dimethlformamide-treated control groups and groups treated with the same labeled compound and with the same radioactive doses were pooled respectively and analyzed. The DNA from each group was purified and monitored for 14C radioactivity. Low but statistically significant radioactivity was detected in only the DNA samples prepared from the [glutarimide-2-14C]thalidomide-treated embryos. This result demonstrates the binding of the glutarimide moiety, or its reactive intermediates, with rat embryonic DNA in vivo.

Itraconazole pulse therapy for dermatophyte onychomycosis in children

BACKGROUND

Onychomycosis, or fungal infection of the nail, can occur in prepubertal children. However, its diagnosis is often missed or the condition is inappropriately treated with topical medication. Griseofulvin has been the therapy of choice, but even long-term treatment is associated with a poor cure rate and high rate of relapse. Trials with adult patients have shown that itraconazole pulse therapy for onychomycosis requires a shorter duration of total therapy than griseofulvin treatment and is rarely associated with adverse reactions, suggesting that it may be the treatment of choice for pediatric patients with onychomycosis.

DESIGN

We retrospectively reviewed the courses of prepubertal patients with dermatophyte onychomycosis who initiated treatment with itraconazole pulse therapy between January 1995 and June 1998.

SETTING

Urban and suburban pediatric dermatology clinics of a children's hospital.

PATIENTS

Seventeen prepubertal patients met the enrollment and follow-up criteria. These included fungal infection of the nail(s), documented by fungal culture and/or positive potassium hydroxide mounts of nail scrapings; at least 1 follow-up visit; and contact by telephone or clinic visit within 2 months prior to compilation of data. In 59% of patients, a relative living at the home had onychomycosis at the time of diagnosis.

INTERVENTION

Patients were treated with daily to twice-daily pulses of itraconazole, administered for 1 week of each of 3 to 5 months.

MAIN OUTCOME MEASURES

Clinical cure after itraconazole therapy in patients with documented onychomycosis and clinical and mycologic relapse after initial cure. Fungal cultures were not repeated if clinical cure was noted.

RESULTS

All but 1 patient responded fully to therapy, showing improvement within a few months and subsequently clearance (94% clinical cure rate). No patients experienced any clinical adverse reactions. No relapses occurred after clinical cure during a follow-up period of 1 to 4.25 years after initiation of therapy.

CONCLUSIONS

Itraconazole pulse therapy is effective and safe for the treatment of onychomycosis in children. The relapse rate in pediatric patients is lower than in adults, although the high frequency of onychomycosis in non-pediatric family members suggests that the recurrence risk is increased if other family members are not treated concomitantly.

Expression of cyclin-dependent kinase 6 (cdk6) and frequent loss of CD44 in nasal-nasopharyngeal NK/T-cell lymphomas: comparison with CD56-negative peripheral T-cell lymphomas

Lymphomas involving the nasal and nasopharyngeal region mainly include CD56-positive natural killer (NK)/T-cell lymphomas, CD56-negative peripheral T-cell lymphomas (PTL), and B-cell lymphomas. Among these, the CD56-positive lymphoma, presumably of an NK/T-cell nature, is frequently seen in Asian, Mexican, and South American patients. NK cells are proposed to be closer developmentally to T cells than to other lymphoid cells, because bipotential common progenitor cells of NK/T-cell lineage have been isolated. In this study, we collected 47 cases of nasal lymphoma and investigated the phenotypic difference between NK/T-cell lymphoma and PTL by examining the pattern of the developmentally differentially expressed molecules cdk6 (cyclin-dependent kinase 6), CD44, CD117, and by examining the rearrangement of the T-cell receptor gene (TcR-GR). cdk6, an essential regulator of the cell cycle in G1 progression, was over-expressed in a subset of cortical thymocytes, but absent in mature thymocytes. In contrast, CD44, a glycosylated adhesion molecule, was absent in cortical thymocytes, but present in mature thymocytes and peripheral activated T cells. We found both over-expression of nuclear cdk6 (n-cdk6) and frequent absence of CD44 in nasal CD56-positive NK/T-cell lymphomas, in contrast to most nasal CD56-negative PTL, which were CD44-immunoreactive with weak or no expression of n-cdk6. Almost all tested cases of NK/T-cell lymphoma displayed a germ-line configuration of TcR, without evidence of gene rearrangement. Thus, there seems to be a useful distinction between the classical NK/T type of nasal lymphoma (CD56+/n-cdk6+/CD44-/TcR-GR-) and PTL (CD56-/n-cdk6-/CD44+/TcR-GR+) involving the nasal region. The presence of Epstein-Barr virus does not seem to be a good marker for distinguishing between NK/T lymphoma and PTL involving the nasal region.

[Experimental safety study using rats and mice irradiated with the complex field cure instrument]

The complex field cure instrument is a new medical instrument. The complex field is composed of several sorts of physical quantum fields. Mice and rats are continuously irradiated by the complex field for 20 days to 90 days. The result shows that WBC, Hb and PLT value of the animals irradiated with the instrument are more than the control group, and their biochemical index is normal. The internal organs of the experimental animals show no toxicity. The visceval coefficient (liver, spleen) of the experimental animals is more than the control group. The marrow micronucleas test is negative. The chromosome test show no distortion. All of the results have proved that the instrument produces no toxicity side effect. Application of the instrument is safe and reliable and it may increase immune function of the body.

Kikuchi's disease (histiocytic necrotizing lymphadenitis): report of one case

Kikuchi's disease (histiocytic necrotizing lymphadenitis) is a self-limited disease of unknown cause. The disease often presents with persistently intermittent fever and enlarged cervical lymph nodes. It usually occurs in adult group and is unresponsive to antibiotic therapy. The diagnosis can be confirmed by histopathological findings of lymph node in open biopsy. We report a pediatric case of Kikuchi's disease in an 8-year-8-month-old school-age boy with generalized lymphadenopathy. He was hospitalized under the impression of fever of unknown origin. A diagnosis of Kikuchi's disease was made by cervical lymph node histology. Reviewing the literature of Kikuchi's disease, we found very few reports in young pediatric group. We conclude that Kikuchi's disease should be considered in the differential diagnosis of fever of unknown origin in children, even in the absence of cervical lymphadenopathy.

Observed differences in virulence-associated phenotypes between a human clinical isolate and a veterinary isolate of Mycobacterium avium

Mycobacterium avium, the most common opportunistic pathogen in patients with AIDS, is frequently isolated from a variety of environmental sources, but rarely can these environmental isolates be epidemiologically linked with isolates known to cause human disease. Using a number of in vitro tissue culture assays, we found significant pathogenic differences between a serotype 4 human clinical M. avium isolate and a serotype 2 veterinary isolate. Cell association of the patient strain with a human intestinal cell line was 1.7 times that of the veterinary strain. Growth of this clinical strain in human peripheral blood mononuclear cell-derived macrophages increased from 12-fold higher than that of the veterinary isolate after 2 days to 200-fold higher after 4 days. By the conclusion of each experiment, lysis of all examined host cell types and accumulation of cell debris were observed in infections with the human isolate, but monolayers remained relatively intact in the presence of the animal isolate. The two strains also differed in the ability to stimulate human immunodeficiency virus replication in coinfected host cells, with p24 antigen levels after 6 days threefold higher in the cells coinfected with the clinical strain than in those infected with the veterinary strain. If the genetic differences responsible for the phenotypes observed in these assays can be identified and characterized, it may be possible to determine which M. avium strains in the environment are potential human pathogens.

Interaction of thalidomide with DNA of rabbit embryos: a possible explanation for its immunosuppressant and teratogenic effects

Although thalidomide (alpha-phthalimidoglutarimide) is a potent teratogen, in recent years it has become widely used in the treatment of a variety of diseases. Despite many studies, the mechanism of its teratogenic action is still not clear. Recently we reported that only the glutarimide moiety bound to rat embryonic DNA. This result could explain our earlier observation, that thalidomide induced alteration in the secondary structure of rat embryonic DNA. In this study it was shown that [glutarimide-2-14C]-thalidomide also interacts with the DNA of rabbit embryos. This interaction is a possible explanation for the diverse types of malformations caused by thalidomide and may also account for its immunosuppressant action which makes it useful in the treatment of graft-versus-host disease.

Suspected nasopharyngeal carcinoma in three workers with long-term exposure to sulphuric acid vapour

Sulphuric acid vapour has been suspected of being an industrial carcinogen. In this study, a cluster is presented of three patients with nasopharyngeal carcinoma (NPC) who worked in the same building of a telecommunications conveyance station in southern Taiwan with long term exposure to sulphuric acid vapour concentrations as high as 0.18 mg/m3. All three workers were diagnosed with NPC within a 5 month period between September 1992, and March 1993. Compared with 19 other healthy workers from the same building, these three workers with NPC had worked significantly longer in this building than had the others (mean (SD) (years): 12.7 (0.6) v 7.4 (4.4); p = 0.01). With an in situ nucleic acid hybridisation and immunostaining method for colocalised Epstein-Barr virus (EBV) and secretory component (SC) protein among biopsy specimens of these three patients with NPCs, it was found that some tumour cells did not contain EBV and SC protein staining signals. These results indicate that EBV infection is not the only risk factor for NPC and long term exposure to relatively low concentrations of sulphuric acid vapour may be associated with the development of NPC.

Interdigitating reticulum cell tumor of lymph node: a case report and literature review

Interdigitating reticulum cell (IRC) tumor is a rare tumor arising from the antigen-presenting cell - interdigitating reticulum cell. A 41-year-old male presented with lumps in the left neck and bone pain. Further investigations revealed multiple left neck and para-aortic lymphadenopathy, and multiple bony lesions. Histological examination of the lymph node showed proliferation of unusual, large, round neoplastic cells mimicking large cell lymphoma. Immunophenotypic and ultrastructural studies confirmed this tumor to be arising from an interdigitating reticulum cell. A review of reported IRC tumors illustrates the variability of this tumor in clinical and pathological features, which differ from other dendritic reticulum cell tumors.

Calculus-like deposit at apex of tooth with refractory apical periodontitis

It is generally accepted that bacteria in or outside the root canal are the reason for apical periodontitis and endodontic failures. This case report presents a 60-year-old woman with a periapical lesion and a fistulous tract which did not respond to conventional root canal treatment. During periapical surgery, granulomatous tissue was removed and a calculus-like deposit was observed on the root surface. A radicular cyst was diagnosed. Nine months after this calculus-like deposit had been removed and the cyst enucleated, complete recovery of the bone had occurred. It is suggested that the presence of the calculus-like deposit at the apex of the tooth or its effects may in part have delayed the healing of the periapical inflammation in spite of apparently adequate endodontic treatment.

G protein beta subunit is closely associated with microtubules

Previously, we have identified the association of G protein beta subunit (Gbeta) with mitotic spindles in various mammalian cells. Since microtubules are the main component of mitotic spindles, here we have isolated bovine brain microtubules and purified Gbeta subunit to identify the close association of Gbeta subunit with purified brain microtubules and have shown the direct incorporation of Gbeta subunit into the microtubules both in vitro and in vivo. It was found that: (1) microtubular fraction isolated from bovine brain contained Gbeta subunit, (2) coimmunoprecipitation demonstrated that Gbeta subunit could be coprecipitated with tubulin, (3) addition of purified Gbeta subunit into cytosolic extract for microtubule assembly caused direct incorporation of Gbeta subunit into assembled microtubules and increased the association of microtubule-associated proteins with microtubules, and (4) incubation of exogenous Gbeta subunit with detergent-permeabilized cells resulted in direct incorporation of Gbeta subunit into microtubule fibers and depolymerized tubulin molecules. We conclude that G protein beta subunit is closely associated with microtubules and may play an important role in the regulation of microtubule formation in addition to its regulatory role in cellular signal transduction.

ESR and U-series analyses of teeth from the palaeoanthropological site of Hexian, Anhui Province, China

ESR and U-series analyses of teeth from the palaeoanthropological site of Hexian which contained Homo erectus remains, illustrate the limited effectiveness of stand-alone ESR and U-series age estimates on faunal materials. The problem lies in the unknown U-uptake history causing very large uncertainties in the age results of both techniques. This study demonstrates the particular strength that lies in the integration of ESR and U-series dating analyses allowing the estimation of the U-uptake history. We obtained a combined ESR/U-series age estimate of 412 +/- 25 ka (average of six analyses on two teeth). This pinpoints the deposition of the faunal remains to the time of the transition between oxygen isotope stages 12 and 11. This is in agreement with the faunal composition which show a mixture of cold adapted northern mammals and more subtropical-tropical southern elements. The age also implies that the advanced Hexian Homo erectus occurred at a similar time as the less advanced Homo erectus specimens at Locality 1 at Zhoukoudian (LI-LIII).

Total skin electron beam irradiation in scleromyxoedema

We report a 44-year-old male with generalized progressive scleromyxoedema treated by total skin electron beam therapy (TSEBT) which produced a marked improvement in the skin lesion. TSEBT can provide effective treatment for patients with widespread skin involvement in scleromyxoedema.

Identification of novel vesicles in the cytosol to vacuole protein degradation pathway

The key gluconeogenic enzyme, fructose-1,6-bisphosphatase (FBPase), is induced when Saccharomyces cerevisiae are starved of glucose. FBPase is targeted from the cytosol to the yeast vacuole for degradation when glucose-starved cells are replenished with fresh glucose. Several vid mutants defective in the glucose-induced degradation of FBPase in the vacuole have been isolated. In some vid mutants, FBPase is found in punctate structures in the cytoplasm. When extracts from these cells are fractionated, a substantial amount of FBPase is sedimentable in the high speed pellet, suggesting that FBPase is associated with intracellular structures in these vid mutants. In this paper we investigated whether FBPase association with intracellular structures also existed in wild-type cells. We report the purification of novel FBPase-associated vesicles from wild-type cells to near homogeneity. Kinetic studies indicate that FBPase association with these vesicles is stimulated by glucose and occurs only transiently, suggesting that these vesicles are intermediate in the FBPase degradation pathway. Fractionation analysis demonstrates that these vesicles are distinct from known organelles such as the vacuole, ER, Golgi, mitochondria, peroxisomes, endosomes, COPI, or COPII vesicles. Under EM, these vesicles are 30-40 nm in diam. Proteinase K experiments indicate that the majority of FBPase is sequestered inside the vesicles. We propose that FBPase is imported into these vesicles before entering the vacuole.

ESR analysis of teeth from the palaeoanthropological site of Zhoukoudian, China

An ESR dating study on teeth collected from layers 3, 6/7 and 10 at Locality 1, Zhoukoudian provides results that are in general agreement with an earlier multi-dating study and confirm an age range of 300-550 ka for the Homo erectus remains in the Peking Man Cave. Uncertainties due to U-uptake and the external gamma dose rates do not allow very precise age estimates for the respective layers.

A new approach to the treatment of true-combined endodontic-periodontic lesions by the guided tissue regeneration technique

Clinicians often have difficulty in the diagnosis and treatment of the combined endodontal and periodontal (endo-perio) lesion. A case of an endo-perio true-combined lesion on a maxillary premolar was first treated with conventional endodontic therapy. Periodontal surgery was then completed, which included scaling and root planing and apical curettage on the tooth. The facial bony defect was then filled with a decalcified freeze-dried bone allograft mixed with tetracycline powder. A non-resorbable Teflon membrane was then used to cover the bone material and the periodontal flap sutured over this. This combined treatment resulted in minimal probing depth (2 mm), maximal clinical attachment gain (8 mm), as well as radiographic evidence of alveolar bone gain. This case report demonstrates that proper diagnosis, followed by removal of etiological factors and utilizing the guided tissue regeneration technique combined with osseous grafting, will restore health and function to a tooth with severe attachment loss caused by an endo-perio lesion.

Biliary tree rhabdomyosarcoma: report of one case

A four-year-old boy was admitted due to abdominal distention for two years and jaundice of a few days duration. Abdominal ultrasound and CT scan of the abdomen showed marked dilatation of the common bile duct with two masses noted and a tumor extended to the left hepatic duct. Left hepatic lobectomy with Roux-en-Y right hepaticojejunostomy was performed which was histologically proved to be a embryonal type rhabdomyosarcoma. Chemotherapy was given postoperatively. The patient has had frequent follow-up for two years.

Changes in secondary structure of DNA of rat embryos following treatment with 1,2-diethylhydrazine and dimethylnitrosamine in vivo

1,2-Diethylhydrazine (DEH) and dimethylnitrosamine (DMN) are indirect acting carcinogens that require metabolic activation to exert their potency. DEH is a transplacental carcinogen and teratogen in Wistar rats when administered by i.p. injection on day 12 of gestation. DMN is embryotoxic during this period. In this study, gravid Wistar rats were injected i.v. with DEH (10, 15, or 20 mg/kg) or i.p. with DMN (10 or 30 mg/kg) and the effects on the embryos 24 hours later were observed. Controls were similarly injected with saline vehicle. The incidence of resorptions increased after treatment with 20 mg DEH/kg. DEH treatment also resulted in decreases in embryo wet weights and total DNA that were not dose dependent. Treatment with DMN did not affect embryonic wet weights and total embryonic DNA amount when compared to the saline-treated controls. The effects of DEH and DMN on DNA synthesis in vivo were monitored by injecting [methyl-14C]-thymidine 1 hour prior to embryo death. DEH induced significant increases in thymidine incorporation into embryo DNA but the increases were not proportional to the doses administered. DNA synthesis was significantly decreased in embryos treated with 30 mg DMN/kg. The DNA of treated and control embryos was fractionated by benzoylated DEAE-cellulose (BD-cellulose) chromatography to determine differences in DNA secondary structure following treatment. BD-cellulose chromatography separates double-stranded DNA from DNA containing single-stranded regions by step elution with 1 M NaCl solution and caffeine solution, respectively. Embryonic DNA was monitored by in vivo labelling with [methyl-3H]-thymidine on days 6 and 7 of gestation. Significant dose dependent increases in percentages of caffeine-eluted DNA (%CE-DNA) compared to controls were detected after treatment with 10, 15, and 20 mg DEH/kg and 10 and 30 mg DMN/kg. The relative %CE-DNA is expressed as the ratio of %CE-14C-labeled DNA to %CE-3H-labeled DNA. Litters treated with 10, 15, and 20 mg DEH/kg had relative %CE-DNA values significantly lower than controls. The results support the hypothesis that initiation mechanisms of transplacental carcinogenesis and teratogenesis are different. The pertinence of %CE-DNA and relative %CE-DNA values to the study of transplacental carcinogenesis and teratogenesis is discussed.