Evaluation of Toxoplasma gondii IgG avidity assays through a comparison of IgM serostatus

Primary Toxoplasma gondii (T. gondii) infection during pregnancy could result in congenital disease with severe clinical complications. IgM antibodies are one of the indices of primary infection. The IgG avidity index (AI) is also known to remain low for at least 3 months after primary infection. Here, we evaluated and compared the performance of T. gondii IgG avidity assays as confirmed by T. gondii IgM serostatus and number of days post-exposure. Four assays preferentially used in Japan were employed to measure the T. gondii IgG AI. Results for the T. gondii IgG AI showed good concordance, particularly in cases with a low IgG AI. This study confirms that the combination of T. gondii IgM and IgG AI tests is a reliable and suitable method for identifying T. gondii primary infections. Our study proposes the necessity of measuring the T. gondii IgG AI as an additional indicator of T. gondii primary infection.

The Cytotoxic Effects of Geranylgeranylacetone Are Attenuated in the High-Glucose Condition

Geranylgeranylacetone (GGA) has been used as an antiulcer drug and also is known as inducer of heat shock protein 70 that has cytoprotective effects especially in hyperglycemic condition. In contrast, cytotoxicity of GGA has also been reported. Some studies have reported that GGA suppresses cell growth and induces apoptosis in cell models of human leukemia, ovarian carcinoma, and colon cancer in vitro. Therefore, the aim of this study was to determine whether GGA can have a cytotoxic effect on a human cervical cancer cell line (HeLa), human colorectal adenocarcinoma cells (Caco-2), and human embryonic kidney cells 293 (HEK) in normal-glucose and high-glucose environments (NG and HG, respectively). The results showed that 100 μM GGA inhibited proliferation of HeLa cells only in NG environment despite inhibiting proliferation of Caco-2 and HEK cells regardless of glucose concentration. Cell viability assay revealed that GGA decreased viability of HeLa, Caco-2, and HEK cells only in NG environment. Flow cytometric analyses revealed that the type of cell death was a combination of necrosis and apoptosis. Our study revealed that difference in cytotoxicity of GGA is influenced by glucose condition. The cytotoxic effects of GGA are attenuated in the HG condition. Since both cytotoxic and cytoprotective effects are reported about GGA, further research is needed about the mechanism of the cytotoxic effects.

Evaluation of the indirect and IgM-capture anti-human cytomegalovirus IgM ELISA methods as confirmed by cytomegalovirus IgG avidity

Primary cytomegalovirus (CMV) infection during pregnancy often results in congenital CMV infection with severe clinical complications. IgM antibodies are one of the indices of primary infection. The IgG avidity index (AI) is also known to remain low for 3 months after primary infection. Here, we evaluated and compared the performance of CMV IgM and IgG avidity assays. Because sensitivity and specificity reportedly differ between CMV IgM kits, CMV IgM detection was compared between the two commercially available ELISA kits that are most commonly used in Japan. Sera for CMV IgM were first screened using a traditional indirect ELISA kit. Selected samples were then tested for CMV IgM and CMV AI using a CMV IgM-capture ELISA kit and a CMV IgG avidity assay, respectively. The rate of concordance between the IgM kits was 89% (42/47), indicating the absence of any significant difference. Most of the CMV IgM-positive plasma samples showed high CMV IgG AI; however, 18 commercially available plasma samples with low CMV IgG AI were all CMV IgM-positive. One plausible explanation for this discrepancy is that the duration of low IgG AI is shorter than that of IgM positivity. Alternatively, CMV IgM tests may generate pseudo-positive readouts in cases of congenital infection. Nevertheless, our study confirms that CMV IgG AI can be a reliable indicator of CMV primary infection.

Modification of the HCMV-specific IFN-γ release test (QuantiFERON-CMV) and a novel proposal for its application

Human cytomegalovirus (HCMV) is universally distributed among humans without any adverse effects; however, it induces severe diseases in immunocompromised patients such as organ transplant recipients and AIDS patients. To manage these immunocompromised patients, an easy clinical examination for the monitoring of disease risk is required. In this study, we modified the interferon-γ (IFN-γ) release test (QuantiFERON^®-CMV) using HCMV immediate early-1 (IE-1) or pp65 whole proteins, or UV-inactivated HCMV particles as an antigen. The response of heparinized peripheral blood from healthy volunteers to the pp65 protein showed an obvious dose-dependent sigmoid curve, although no correlation was observed between results of this assay and an ELISPOT assay. The addition of pp65 to the blood samples at a final concentration of 1×10³ to 1×10⁵ pg/ml was found to be optimum. Using this assay, we observed a significant enhancement in cellular immunity in volunteers after the daily ingestion of yogurt for 8 weeks, which suggested a novel application of the assay in addition to monitoring HCMV infection risk. IFN-γ secretion from peripheral blood cells on HCMV-antigen stimulation differed significantly between individuals; therefore, the assay could not be normalized. Nevertheless, it was found to be particularly useful for observing fluctuations in cellular immune activity on an individual level.

Highly reversible capacity at the surface of a lithium-rich manganese oxide: a model study using an epitaxial film system

The surface region of a lithium-rich manganese oxide Li₂MnO₃ is intrinsically active at the electrochemical interface and exhibits a high discharge capacity over 300 mA h g⁻¹ in the fiftieth cycle.

Quantitative MAS NMR characterization of the LiMn(1/2)Ni(1/2)O(2) electrode/electrolyte interphase

The conditions in which degradation processes at the positive electrode/electrolyte interface occur are still incompletely understood and traditional surface analytical techniques struggle to characterize and depict accurately interfacial films. In the present work, information on the growth and evolution of the interphases upon storage and cycling as well as their electrochemical consequences are gathered in the case of LiNi(1/2)Mn(1/2)O(2) with commonly used LiPF(6) (1M in EC/DMC) electrolyte. The use of (7)Li, (19)F and (31)P MAS NMR, made quantitative through the implementation of empirical calibration, is combined with transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) to probe the elements involved in surface species and to unravel the inhomogenous architecture of the interphase. At room temperature, contact with the electrolyte leads to a covering of the oxide surface first by LiF and lithiated organic species are found on the outer part of the interphase. At 55°C, not only the interphase proceeds in further covering of the surface but also thickens resulting in an increase of 240% of lithiated species and the presence of -POF(2) fluorophosphates. The composition gradient within the interphase depth is also strongly affected by the temperature. In agreement with the electrochemical performance, quantitative NMR surface analyses show that the use of LiBOB-modified electrolyte results in a Li-enriched interphase, intrinsically less resistive than the standard LiPF(6)-based interphase, comprised of a mixture of resistive LiF with non lithiated species.

Neoclassical toroidal viscosity calculations in tokamaks using a δf Monte Carlo simulation and their verifications

Neoclassical toroidal viscosities (NTVs) in tokamaks are investigated using a δf Monte Carlo simulation, and are successfully verified with a combined analytic theory over a wide range of collisionality. A Monte Carlo simulation has been required in the study of NTV since the complexities in guiding-center orbits of particles and their collisions cannot be fully investigated by any means of analytic theories alone. Results yielded the details of the complex NTV dependency on particle precessions and collisions, which were predicted roughly in a combined analytic theory. Both numerical and analytic methods can be utilized and extended based on these successful verifications.

Dose-dependent requirement of patched homologue 1 in mouse pancreatic beta cell mass

AIMS/HYPOTHESIS

Ectopic activation of hedgehog (HH) signalling in pancreas induces various abnormal morphogenetic events in the pancreas. This study analysed the dose-dependent requirement of patched homologue 1 (PTCH1), a negative regulator of HH signalling on pancreatic development.

METHODS

We used a recessive spontaneous mutant mouse denoted as mes which carries a mutated Ptch1 resulting in deletion of the most carboxy-terminal cytoplasmic domain of the PTCH1 protein. In this study, we analysed pancreatic morphology in Ptch1 ( +/+ ), Ptch1 ( +/mes ), Ptch1 (+/-), Ptch1 ( mes/me ) (s) and Ptch1 (-/mes ) mouse embryos, as well as the islet mass in adult Ptch1 (+/+), Ptch1 (+/mes ) and Ptch1 (+/-) mice.

RESULTS

Until embryonic day (E) 12.5, no obvious abnormality of pancreas was observed in any of the Ptch1 mutants. The levels of PDX1 and glucagon were also not evidently different among the mice genotypes studied. Thereafter, morphological abnormalities appeared in the Ptch1 mutant mice. The beta, alpha and exocrine cell masses decreased at E18.5 in parallel with increased HH signalling, with beta cell mass showing the highest sensitivity to HH signalling with a significant decrease even in Ptch1 (+/mes ) mice. Adult Ptch1 (+/-) mice also showed a significant decrease in beta cell mass compared with wild-type mice.

CONCLUSIONS/INTERPRETATION

Our findings indicate that the carboxy-terminal domain of Ptch1 is essential for pancreatic development. In addition, the loss of Ptch1 function decreases both the endocrine and exocrine cell mass in a dose-dependent manner, with beta cells particularly sensitive to changes in HH signalling.

Spin gap in Tl2Ru2O7 and the possible formation of Haldane chains in three-dimensional crystals

Dimensionality is one of the most important parameters of physical phenomena. Only two things determine the universality class of a phase transition: the dimensionality of a given system and the symmetry of the order parameter. In most cases, the dimensionality of a substance is predetermined by its crystal structure. Examples in which the effective dimensionality is reduced are quite rare. Here we show that the three-dimensional cubic system of Tl(2)Ru(2)O(7) most probably evolves into a one-dimensional spin-one Haldane system with a spin gap below 120 K, accompanied by anomalies in the structure, resistivity and susceptibility. We argue that these anomalies are due to an orbital ordering of Ru 4d electrons, with a strong coupling among three degrees of freedom: orbital, spin and lattice. Our work provides a unique example of the spontaneous formation of Haldane system with an insight into the intriguing interplay of different degrees of freedom.

Structure, backbone dynamics and interactions with RNA of the C-terminal RNA-binding domain of a mouse neural RNA-binding protein, Musashi1

Musashi1 is an RNA-binding protein abundantly expressed in the developing mouse central nervous system. Its restricted expression in neural precursor cells suggests that it is involved in the regulation of asymmetric cell division. Musashi1 contains two ribonucleoprotein (RNP)-type RNA-binding domains (RBDs), RBD1 and RBD2. Our previous studies showed that RBD1 alone binds to RNA, while the binding of RBD2 is not detected under the same conditions. Joining of RBD2 to RBD1, however, increases the affinity to greater than that of RBD1 alone, indicating that RBD2 contributes to RNA-binding. We have determined the three-dimensional solution structure of the C-terminal RBD (RBD2) of Musashi1 by NMR. It folds into a compact alpha beta structure comprising a four-stranded antiparallel beta-sheet packed against two alpha-helices, which is characteristic of RNP-type RBDs. Special structural features of RBD2 include a beta-bulge in beta2 and a shallow twist of the beta-sheet. The smaller 1H-15N nuclear Overhauser enhancement values for the residues of loop 3 between beta2 and beta3 suggest that this loop is flexible in the time-scale of nano- to picosecond order. The smaller 15N T2 values for the residues around the border between alpha2 and the following loop (loop 5) suggest this region undergoes conformational exchange in the milli- to microsecond time-scale. Chemical shift perturbation analysis indicated that RBD2 binds to an RNA oligomer obtained by in vitro selection under the conditions for NMR measurements, and thus the nature of the weak RNA-binding of RBD2 was successfully characterized by NMR, which is otherwise difficult to assess. Mainly the residues of the surface composed of the four-stranded beta-sheet, loops and C-terminal region are involved in the interaction. The appearance of side-chain NH proton resonances of arginine residues of loop 3 and imino proton resonances of RNA bases upon complex formation suggests the formation of intermolecular hydrogen bonds. The structural arrangement of the rings of the conserved aromatic residues of beta2 and beta3 is suitable for stacking interaction with RNA bases, known to be one of the major protein-RNA interactions, but a survey of the perturbation data suggested that the stacking interaction is not ideally achieved in the complex, which may be related to the weaker RNA-binding of RBD2.

mel-18 negatively regulates cell cycle progression upon B cell antigen receptor stimulation through a cascade leading to c-myc/cdc25

mel-18 is a mammalian Polycomb group gene encoding a transcriptional repressor with tumor suppressive activity. Overexpression of mel-18 in mice results in cell cycle arrest of B cells upon B cell receptor stimulation with downregulation of c-myc. This phenotype is rescued in mel-18/c-myc double-transgenic mice, suggesting that c-myc locates downstream of mel-18. In mel-18 transgenic mice, the downregulation of cyclins D2 and E; CDK4, -6, and -7; and CDC25A causes the impairment in the activities of cyclin-dependent kinases, resulting in hypophosphorylation of the retinoblastoma protein. In contrast, the upregulation of c-Myc, CDC25, and CDC2/CDK2 kinase activities results in the augmentation of B cell proliferation in mel-18-deficient mice. We therefore propose that mel-18 negatively regulates the cell cycle through a c-myc/cdc25 cascade.

Mammalian Polycomb group genes are categorized as a new type of early response gene induced by B-cell receptor cross-linking

Polycomb group (PcG) genes were initially described in Drosophila melanogaster as regulators of the homeobox gene. Four mammalian homologues, mel-18, bmi-1, M33 and rae-28, are analyzed in this study. They not only regulate mammalian homeotic genes by analogy with their Drosophila counterparts, but also have some influence on the growth and differentiation of B lymphocytes. Here we report that these four mammalian PcG genes are rapidly induced after antigen-receptor cross-linking in B cells. Thus we would like to propose that mammalian PcG genes can be categorized as a new type of immediate early gene.

Clinicopathologic features of local and metastatic recurrences in primary lung adenocarcinoma

We attempted to construct the contour of recurrence in primary lung adenocarcinoma with clinicopathologic variables based on data of 131 patients with completely resected primary lung adenocarcinoma. In univariate analysis, tumor size (more or less 3 cm in diameter), p-T, p-N, pathological stage, differentiation, ly factor and v factor were chosen for prognostic predictors. In multivariate analysis, v factor and p-N were independent variables of local recurrence and metastatic recurrence, respectively. The examination of significant correlation among clinicopathologic variables in terms of 5-year survival rates of patients showed that tumor size, p-T, ly factor and v factor were profoundly related to local recurrence, whereas ly factor, differentiation and p-N were linked to distant metastasis. We therefore examined an additive effect of tumor size, differentiation and vascular invasion on recurrence. The results demonstrated that neither local nor metastatic recurrences were found in patients with well differentiated adenocarcinoma less than 3 cm in diameter if vascular invasion was negative. We conclude that vascular (ly factor and v factor) is central to lung adenocarcinoma recurrence. The vascular invasion is a powerful predictor of recurrence in less than 3 cm diameter, well differentiated adenocarcinoma of the lung.

On the linearization of eruption series of the permanent teeth

In order to confirm the linearization of permanent eruption, Masuyama's linearization method was applied to the data of Kitamura's study. At first, we considered the eruption age t alpha i of permanent teeth T alpha, where alpha corresponds a tooth of every description, and examined the linear regression of Y alpha i = log10 t alpha i on m(y) alpha (the mean of Y alpha i with respect to i), but the result was not good. For the correlation coefficient r between two variables in linear regression, the percentage of subjects with r > or = 0.970 was only 10.3% in males and 28.8% in females in Kitamura's study. Next we took notice of the eruption age u beta i of each tooth, which is the beta-th in order of eruption. The fitness of the linear regression of Z beta i = log10 u beta i on mz beta (the mean of Z beta i) was very good. The percentage of subjects with r > or = 0.970 increased to 80.0% in males and 86.0% in females. Then we used m(y) (beta) (rearranged m(y) alpha in order of increasing size) instead of mz beta as an independent variable in the linear regression. The degree of the linearization was slightly inferior to that using mz beta. In every linearization, a quasi-fixed point with coordinates (C, C) existed on the linearized dentition plot, where the value of C was almost equal in each way, i.e., C = 10.23 (years) for males and C = 8.91 (years) for females in Kitamura's data. This linearized dentition plot will be useful in detecting certain growth disturbances. The existence of a quasi-fixed point may be useful in forecasting the age of the eruption of subsequent teeth, once the first eruption is observed.

[Recurrent thymic carcinoid tumor with multiple endocrine neoplasia syndrome--a case report]

A 55-year-old male with multiple endocrine neoplasia syndrome accompanied by hyperparathyroidism and hypergastrinemia was admitted because of local recurrence of thymic carcinoid tumor and a parathyroid adenoma. The recurrent thymic carcinoid tumor replaced anterior mediastinum, invaded brachiocephalic vein and superior vena cava, a disseminated nodule was found at pericardium. After induction chemotherapy using carboplatin and etoposide the operation was performed. The parathyroid tumor and recurrent thymic carcinoid tumor were removed completely together with brachiocephalic vein, superior vena cava, pericardium and anterior chest wall. Superior vena cava was replaced with synthetic graft and chest wall was reconstructed. The patient is alive and well 22 months after surgery without recurrence. Immunohistochemistry of removed specimens revealed parathormone and gastrin secreted from the parathyroid adenoma but not from the carcinoid tumor. Careful survey of systemic endocrine organs is necessary in case of thymic carcinoid tumor. Aggressive surgery in locally recurrent thymic carcinoid without distant metastasis must be considered.

Development of Valpha4+ NK T cells in the early stages of embryogenesis

The majority of T lymphocytes start to develop at around day 15 of gestation (d15)-d17 in the thymus and comprise the peripheral repertoire characterized by the expression of polymorphic T-cell antigen receptors (TCRs). Contrary to these conventional T cells, a subset of T cells, called natural killer (NK) T cells (most of them expressing an invariant TCR encoded by the Valpha14Jalpha281 gene with a 1-nt N-region), preferentially differentiates extrathymically and dominates the peripheral T-cell population at a high frequency (5% in splenic T cells and 40% in bone marrow T cells). Here, we investigated the development of NK T cells and found that the invariant Valpha14+ TCR transcripts and the circular DNA created by Valpha14 and Jalpha281 gene rearrangements can be detected in the embryo body at d9.5 of gestation and in the yolk sac and the fetal liver at d11.5-d13.5 of gestation, but not in the thymus, whereas T cells with Valpha1+ TCR expression, a major population in the thymus, were not observed at these early stages of gestation. Fluorescence-activated cell sorter analysis also demonstrated that there exist CD3+ alpha beta+ T cells, almost all of which are Valpha14/Vbeta8+ NK+ T cells, during early embryogenesis. To our knowledge, this demonstrates for the first time that a T lymphocyte subset develops in extrathymic tissues during the early stages of embryogenesis.

Cloning and characterization of two transcripts generated from the mel-13 gene positioned adjacent to the mammalian Polycomb group-related gene mel-18

We previously isolated the mel-18 gene, a mammalian Polycomb group (PcG)-related gene with homology to bmi-1 oncogene. We show in this paper the existence of a new gene, mel-13, which overlapped with the mel-18 anti-oncogene. We discuss the relationships between mel-13 and the mel-18, bup, and Su(z)2 genes.

Dental health indicator based on a questionnaire

Dentistry has lacked an effective indicator of the impact of dental problems on a person's daily life. Subjective factors in dental health need to be included in order to improve current indicators. The purpose of this research was to develop a new type of indicator recorded from a questionnaire which takes account of subjective factors in dental health. The indicator we constructed has the following advantages. 1. Calculation process is simple in practice. 2. The indicator values range from 0 to 100, with values closer to 100 indicating a more favorable condition for the individual. 3. The distribution of indicator values is similar to the normal distribution. 4. The score of each item is reflected on the indicator, suggesting the individual's characteristics in terms of dental health. 5. Although it is principally an indicator for individuals, it can also be applied to groups. This study will also provide a model for the preparation of a dental health indicator.

Predominant expression of invariant V alpha 14+ TCR alpha chain in NK1.1+ T cell populations

A novel T cell subset characterized by cell surface NK1.1+ TCR alpha beta+ expression was investigated for its TCR alpha usage, particularly that of invariant V alpha 14 TCR, which was found to be preferentially used in peripheral CD4-CD8- T cells developed at extrathymic sites. We found that NK+ alpha beta T cell subsets account for 0.4% in thymocytes, 5% in the splenic T cells and 40.5% in the bone marrow T cells. Among these NK+ alpha beta T cells, two distinct subsets were detected; cell surface TCR V alpha 14+ and V alpha 14- subpopulations. Almost all of NK+ alpha beta thymocytes express V alpha 14 mRNA; however, only < 20% were positive, while > 80% were negative or undetectable for V alpha 14 TCR expression on the cell surface in the thymus. Similarly, approximately 50% of NK+ alpha beta T cells in spleen and bone marrow are V alpha 14+ as revealed by FACS. TCR repertoire analysis by nucleotide sequences on inverse PCR products demonstrated that most NK+ alpha beta T cells express an invariant TCR encoded by the V alpha 14J alpha 281 gene with a 1 base N-region in all tissues. Thus, invariant V alpha 14 TCR is uniquely expressed on NK T cells, and can be a marker to distinguish NK, NK T and T cells.

Extrathymic development of V alpha 14-positive T cells

It is known that rearrangement of the T cell antigen receptor (TCR) gene occurs in the thymus during T cell development and consequently results both in the deletion of DNA between the variable (V) and diversity/joining segments and in the formation of a circular DNA with recombination signal sequences. Here, we provide evidence that V alpha 14+ TCR gene rearrangements take place in extrathymic sites, such as bone marrow, liver, and intestine, but not in spleen, because we were able to detect frequent productive and nonproductive V alpha 14+ coding and signal sequences as a result of TCR rearrangements in extrathymic sites. Similar findings were also detected in athymic mice. Quantitative analysis shows that the relative amounts of V alpha 14 gene-mediated signal sequences in extrathymic tissues are higher than those in thymus. On the contrary, TCR rearrangements of V alpha 1.1 T cells, which are known to develop in the thymus, were mainly detected in the thymus, Peyer's patch, and spleen, but not in other extrathymic tissues, showing patterns distinct from V alpha 14 TCR rearrangements. These findings are evidence of extrathymic development of V alpha 14+ T cells. Differential characteristic TCR rearrangement patterns also indicate that distinct TCR repertoires are generated in different lymphoid tissues.

[A study of the right ventricular load at the unilateral pulmonary artery occlusion test after pneumonectomy]

After pneumonectomy, it is recognized that the absolute reduction of the pulmonary vascular bed makes the right ventricular afterload increase and can cause right heart failure in patients with low cardiopulmonary reserve. Therefore, we investigated how the right ventricular load was predicted by UPAO test, comparing hemodynamics at the time of the test with those after pneumonectomy in patients with lung cancer. At the test, the absolute reduction of the pulmonary vascular bed made the right ventricular afterload increase but the right ventricular pump function was maintained at the preoperative level by the increase of the right ventricular work load, namely, by the contraction of the right ventricle. After pneumonectomy, the absolute reduction of the vascular bed did not always make the afterload increase and in spite of the decreased preload the pump function was maintained at the preoperative level by increased heart rate. Additionally, the increase of the right ventricular work load improved during early postoperative days. It was concluded that UPAO test was apt to overestimate the right ventricular load of the postoperative day because it was done under the condition of the different compensatory function from the postoperative hypovolemic change.

[Reevaluation of the unilateral pulmonary artery occlusion test--hemodynamics after lobectomy and pneumonectomy for lung cancer]

After lobectomy, it is recognized that functional as well as absolute reduction occurs in residual lobes of the operated side. So whether lobectomy is indicated or not is determined by the same criteria as those for pneumonectomy, namely, by the unilateral pulmonary artery occlusion (UPAO) test. However, is it really appropriate to use the same criteria for both lobectomy and pneumonectomy? To answer to this question, in patients with lung cancer we compared the hemodynamics after lobectomy (13 cases) and pneumonectomy (14 cases) with that at the UPAO test. After pneumonectomy, the mean pulmonary arterial wedge pressure (mPWP) was significantly lower than that on the preoperative day and at the test. It seemed that hypovolemic change occurred in the hemodynamics after pneumonectomy. After pneumonectomy, the pulmonary arteriolar resistance index (PARI) was significantly higher than the preoperative value. It was the same as that as at the time of the UPAO test. The total pulmonary vascular resistance index (TPVRI) at the time of the test was significantly higher than the preoperative value, but the TPVRI after pneumonectomy was not significantly higher. The TPVRI tended to decrease after pneumonectomy, compared to the value predicated by the test. These results indicated that some of the cases judged inoperable on the basis of the UPAO test might be operable. On the day of lobectomy, the PARI was significantly higher than the preoperative value, but significantly lower than that at the time of the test. The cardiac index (CI) was significantly higher and the mPWP was significantly lower than each preoperative value.(ABSTRACT TRUNCATED AT 250 WORDS)

[Hypercoagulability after surgery of esophageal carcinoma]

The purpose of this study was to determine hypercoagulability in patients surgically treated for thoracic esophageal cancer. Twenty-four patients were evaluated; 19 subjected to open chest esophagectomy and 5 closed chest blunt dissection. Six patients subjected to gastrectomy served as controls. In all test patients, preoperative coagulability was within the normal range. Immediately after surgery, however, they were in a hypercoagulable state, showing a marked decrease in platelet count, prothrombin time, antithrombin III level and plasminogen level and an increase in activated partial thromboplastin time and fibrinopeptide B beta 15-42. The controls showed almost no change. There was a close correlation between hypercoagulability on one hand and the time needed for surgery and hemorrhage during 3rd to 7th postoperative day except those with multiple organ failure whose recovery was delayed and those with leakage of anastomosis whose condition did not improve even on the 10th postoperative day.

The quasi-fixed point for the linearised deciduous dentition plot

As Masuyama has indicated, the existence of a quasi-fixed point on the linearised dentition plot is useful in forecasting the age at which subsequent teeth will erupt, once the first eruption was observed. He proposed two methods (direct and indirect) for finding this quasi-fixed point. The direct method is based on individual data obtained by longitudinal research, and the indirect method is to estimate it from the mean and standard deviation of the age of eruption. We first examined whether the two methods give the same result with Kitamura's data, which lists the ages of eruption for individuals. When we used the indirect method, the estimates in both sexes were not valid and did not coincide with those from the direct method. However, when we considered a selected group of subjects with good linearization of dentition, the results obtained from the two methods were sufficiently close. Secondly, we attempted to determine the quasi-fixed point (C, C) in many other reports published in the past. Since almost all papers on dentition have not published individual data, we could only use the indirect method. The estimates of C differed considerably, but all of the quasi-fixed points occurred in the late stages of dentition. When we excluded deciduous central incisor from the data, the range of C narrowed and the value varied from about 1.3 (20 months) to about 1.5 (31.6 months).

Physical and functional map of an amikacin-resistance plasmid isolated from a multiresistant strain of Serratia marcescens

pTK159, a multiresistance 40-kilobase (kb) plasmid, was isolated from a clinical strain of Serratia marcescens. pTK159 was nonconjugative and carried determinants for resistance to amikacin, streptomycin/spectinomycin, sulfamethoxazole and ampicillin. A physical and functional map of pTK159 was constructed. By cloning various fragments of pTK159 in pACYC184 or pBR322, genes for resistance to amikacin, streptomycin/spectinomycin, and sulfamethoxazole were found to be located on a 2.0-kb BamHI-HindIII fragment, a 1.4-kb HindIII fragment and a 2.1-kb HindIII fragment, respectively. The map of pTK159 was compared with published maps of amikacin-resistance determinants and transposons.