First Measurement of a Long-Lived π^{+}π^{-} Atom Lifetime

The adapted DIRAC experiment at the CERN PS accelerator observed for the first time long-lived hydrogenlike π^{+}π^{-} atoms, produced by protons hitting a beryllium target. A part of these atoms crossed the gap of 96 mm between the target and a 2.1  μm thick platinum foil, in which most of them dissociated. Analyzing the observed number of atomic pairs, n_{A}^{L}=436_{-61}^{+157}|_{tot}, the lifetime of the 2p state is found to be τ_{2p}=(0.45_{-0.30}^{+1.08}|_{tot})×10^{-11}  s, not contradicting the corresponding QED 2p state lifetime τ_{2p}^{QED}=1.17×10^{-11}  s. This lifetime value is three orders of magnitude larger than our previously measured value of the π^{+}π^{-} atom ground state lifetime τ=(3.15_{-0.26}^{+0.28}|_{tot})×10^{-15}  s. Further studies of long-lived π^{+}π^{-} atoms will allow us to measure energy differences between p and s atomic states and so to discriminate between the isoscalar and isotensor ππ scattering lengths with the aim to check QCD predictions.

Remyelination of Demyelinated CNS Axons by Transplanted Human Schwann Cells: The Deleterious Effect of Contaminating Fibroblasts

Areas of demyelination can be remyelinated by transplanting myelin-forming cells. Schwann cells are the naturally remyelinating cells of the peripheral nervous system and have a number of features that may make them attractive for cell implantation therapies in multiple sclerosis, in which spontaneous but limited Schwann cell remyelination has been well documented. Schwann cells can be expanded in vitro, potentially affording the opportunity of autologous transplantation; and they might also be spared the demyelinating process in multiple sclerosis. Although rat, cat, and monkey Schwann cells have been transplanted into rodent demyelinating lesions, the behavior of transplanted human Schwann cells has not been evaluated. In this study we examined the consequences of injecting human Schwann cells into areas of acute demyelination in the spinal cords of adult rats. We found that transplants containing significant fibroblast contamination resulted in deposition of large amounts of collagen and extensive axonal degeneration. However, Schwann cell preparations that had been purified by positive immunoselection using antibodies to human low-affinity nerve growth factor receptor containing less than 10% fibroblasts were associated with remyelination. This result indicates that fibroblast contamination of human Schwann cells represents a greater problem than would have been appreciated from previous studies.

Observation of π^{-}K^{+} and π^{+}K^{-} Atoms

The observation of hydrogenlike πK atoms, consisting of π^{-}K^{+} or π^{+}K^{-} mesons, is presented. The atoms are produced by 24  GeV/c protons from the CERN PS accelerator, interacting with platinum or nickel foil targets. The breakup (ionization) of πK atoms in the same targets yields characteristic πK pairs, called "atomic pairs," with small relative momenta Q in the pair center-of-mass system. The upgraded DIRAC experiment observed 349±62 such atomic πK pairs, corresponding to a signal of 5.6 standard deviations. This is the first statistically significant observation of the strange dimesonic πK atom.

Compact permanent magnet H⁺ ECR ion source with pulse gas valve

Compact H(+) ECR ion source using permanent magnets is under development. Switching the hydrogen gas flow in pulse operations can reduce the gas loads to vacuum evacuation systems. A specially designed piezo gas valve chops the gas flow quickly. A 6 GHz ECR ion source equipped with the piezo gas valve is tested. The gas flow was measured by a fast ion gauge and a few ms response time is obtained.

Comparison of graphite materials for targets of laser ion source

To investigate efficient graphite material for carbon ion production in laser ion source, the plasma properties produced from these materials are measured. Comparing acquired current profile and charge state distribution, the distributions of ions in laser induced plasma from isotropic graphite and single crystal of graphite are different. The produced quantity of C(6+) from isotropic materials is larger than that from single crystal.

Interaction of plasmas in laser ion source with double laser system

Multiple laser shots could be used to elongate an ion beam pulse width or to intensify beam current from laser ion sources. In order to confirm the feasibility of the multiple shot scheme, we investigated the properties of plasmas produced by double laser shots. We found that when the interval of the laser shots is shorter than 10 μs, the ion current profile had a prominent peak, which is not observed in single laser experiments. The height of this peak was up to five times larger than that of single laser experiment.

Experimental validation of a novel compact focusing scheme for future energy-frontier linear lepton colliders

A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed in 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This scheme has many advantageous properties over previously studied focusing schemes, including being significantly shorter for a given energy and having a significantly better energy bandwidth. Experimental results from the ATF2 accelerator at KEK are presented that validate the operating principle of such a scheme by demonstrating the demagnification of a 1.3 GeV electron beam down to below 65 nm in height using an energy-scaled version of the compact focusing optics designed for the ILC collider.

Evaluation of a Pyridoxalated-Hemoglobin-Polyoxyethylene Conjugate (PHP) as an Oxygen Carrying Plasma Expander in Lethal Anemia

PHP, mean molecular weight of approximately 90,000 daltons, is produced by chemical modifications of outdated human red cell hemoglobin (Hb). The P50 value of PHP is 22 ± 0.7mmHg. Eleven healthy mongrel dogs were exposed to severe anemia to a hematocrit of 5 ± 2% by normovolemic exchange (ET) with PHP (n=5) or a plasma expander, Hespan (Control, n=6). Hb concentration in the preparation is 6.0 g/dl. All the animals with PHP tolerated the procedure well and have survived for 1 year at sacrifice while five of the controls died within a week (p=0.004). Reductions in hematological and coagulation parameters occurred following ET and these parameters returned to the normal ranges by 4 weeks post ET. Renal function parameters (serum urea and creatinine) remained in the normal range throughout the experimental period. A transient slight increase in the hepatic enzyme SGOT was observed. Open biopsies of major organs at 2 weeks post ET showed vacuolated cells in the liver and kidneys. Normal histology was noted at and after 3 months. Oxygen transport properties as examined by arterial-venous oxygen differences, oxygen delivery and oxygen extraction showed that PHP continued to transport oxygen up to 48 hours studied post ET. PHP functioned as effectively as red blood cells at 6 hours in oxygen delivery to the tissues. PHP effectively supported life at lethal levels of anemia and is physiologically well accepted.

Remote access laparoscopic (REAL) surgery: a novel approach for single-port surgery without a visible scar

INTRODUCTION

Single-port laparoscopic surgery usually uses the transumbilical approach. However, the transumbilical incision may be associated with a high frequency of wound-related complications, including trocar site hernia and infection. Therefore, we developed remote access laparoscopic (REAL) surgery, a new access technique for single-port surgery within the pubic hairline. This study reports on a technique developed at our institution and describes our preliminary results.

MATERIALS AND SURGICAL TECHNIQUE

Ten patients with cholecystolithiasis underwent REAL surgery. A single 2.5-cm transverse incision was made medially within the pubic hairline area, and a SILS Port was inserted. A 5-mm flexible endoscope and an articulating grasper or a long laparoscopic grasper were used. Dissection of the gallbladder was achieved with laparoscopic ultrasonic shears just as in the conventional laparoscopic cholecystectomy. All procedures were successfully performed without conversion to conventional laparoscopic technique. There were no postoperative complications, and outpatient evaluation showed a clean scar within the pubic hair area in all patients.

DISCUSSION

Our early experience shows that REAL surgery is feasible and safe. This novel access technique can preserve the native umbilicus and provides an invisible scar that is concealed within the pubic hair.

Ion spectrometer composed of time-of-flight and Thomson parabola spectrometers for simultaneous characterization of laser-driven ions

An ion spectrometer, composed of a time-of-flight spectrometer (TOFS) and a Thomson parabola spectrometer (TPS), has been developed to measure energy spectra and to analyze species of laser-driven ions. Two spectrometers can be operated simultaneously, thereby facilitate to compare the independently measured data and to combine advantages of each spectrometer. Real-time and shot-to-shot characterizations have been possible with the TOFS, and species of ions can be analyzed with the TPS. The two spectrometers show very good agreement of maximum proton energy even for a single laser shot. The composite ion spectrometer can provide two complementary spectra measured by TOFS with a large solid angle and TPS with a small one for the same ion source, which are useful to estimate precise total ion number and to investigate fine structure of energy spectrum at high energy depending on the detection position and solid angle. Advantage and comparison to other online measurement system, such as the TPS equipped with microchannel plate, are discussed in terms of overlay of ion species, high-repetition rate operation, detection solid angle, and detector characteristics of imaging plate.

A quantitative radiological assessment of outcomes of autogenous bone graft combined with platelet-rich plasma in the alveolar cleft

This longitudinal study evaluated the outcomes of secondary autogenous bone graft combined with platelet-rich plasma (PRP) in the alveolar cleft. Thirty-five alveolar clefts in 30 patients with grafted autogenous bone and PRP (PRP group), and 36 clefts in 30 patients with grafted autogenous bone alone (non-PRP group) were enrolled. PRP was extracted from autogenous blood using a plasma centrifuge system (SmartPReP SMP-1000). The density and resorption of grafted bone were evaluated at 1 week, and 1, 3, 6 and 12 months postoperatively. Bone density was quantitatively assessed as an aluminum-equivalence (Al-Eq) value. Moreover, relationships between bone resorption rate and prognostic factors were discussed. Al-Eq values decreased significantly until 3 months, and then increased up to 12 months in both groups. The Al-Eq rate in the PRP group was significantly smaller than that in the non-PRP group at 3 months. No significant differences were observed in the bone resorption rate between the groups. Regarding prognostic factors, continuous mechanical stress affected bone resorption with or without PRP. The authors suggest that PRP may enhance bone remodeling in the early phase, however, PRP seems to be insufficient as a countermeasure against bone resorption following secondary bone graft in the long term.

Antitumor effects of the MIG and IP-10 genes transferred with poly [D,L-2,4-diaminobutyric acid] on murine neuroblastoma

The number of tumor-infiltrating lymphocytes is known to be related to outcomes in patients with a variety of malignancies. Interferon (IFN) gamma-inducible protein-10 (IP-10) and monokine induced by IFNgamma (MIG) have chemotactic effects on activated T lymphocytes and natural killer (NK) cells. The aim of this study was to evaluate the antitumor effects of exogenous expression of the MIG and IP-10 genes delivered to solid tumors by poly [D,L-2,4-diaminobutyric acid] (PDBA). The murine MIG and IP-10 genes were transfected into mouse neuroblastoma cells with PDBA. MIG and IP-10 levels in supernatants of transfected cells were measured by enzyme-linked immunosorbent assay. The chemotactic activities of MIG and IP-10 in the supernatants of cell cultures were measured by chemotaxis assay. Tumors were injected in vivo with PDBA/pmMIGColon, two colonsIP-10 complexes to evaluate the effects of these genes on tumor volume and survival time of mice. Transfected PDBA/pmMIGColon, two colonsIP-10 complexes produced MIG and IP-10 protein in vitro. MIG and IP-10 proteins secreted into the culture medium showed chemotactic activity. MIG and IP-10 gene therapy with the PDBA system in vivo significantly inhibited tumor growth and prolonged survival time of mice. In conclusion, PDBA-mediated MIG and IP-10 gene therapy may be useful for treatment of solid tumors.

Adenomatoid tumour of the liver

An unusual primary adenomatoid tumour arising in the normal liver is described. Hepatectomy was performed, and the patient is alive and free of disease 1 year postsurgery. Grossly, the tumour showed a haemorrhagic cut surface with numerous microcystic structures. Histological examination revealed cystic or angiomatoid spaces of various sizes lined by cuboidal, low-columnar, or flattened epithelioid cells with vacuolated cytoplasm and round to oval nuclei. The epithelioid cells were entirely supported by proliferated capillaries and arteries together with collagenous stroma. Immunohistochemical studies showed that the epithelioid cells were strongly positive for a broad spectrum of cytokeratins (AE1/AE3, CAM5.2, epithelial membrane antigen and cytokeratin 7) and mesothelial markers (calretinin, Wilms’ tumour 1 and D2-40). These cells were negative for Hep par-1, carcinoembryonic antigen, neural cell adhesion molecule, CD34, CD31 and HMB45. Atypically, abundant capillaries were observed; however, the cystic proliferation of epithelioid cells with vacuoles and immunohistochemical profile of the epithelioid element were consistent with hepatic adenomatoid tumour.

Preoperative transcatheter arterial chemoembolization reduces long-term survival rate after hepatic resection for resectable hepatocellular carcinoma

AIMS

To study the effect of preoperative transcatheter arterial chemoembolization (TACE) on long-term survival after hepatic resection for hepatocellular carcinoma (HCC), we conducted a comparative analysis in 235 HCC patients who underwent hepatic resection with a curative intent.

METHODS

We compared clinicopathologic background, mortality, and survival rates after hepatic resection between those who underwent preoperative TACE (n=109) and those who did not (n=126).

RESULTS

One hundred and two patients in the TACE group (93.6%) received TACE only once. The mean interval between TACE and hepatic resection was 33.1days. Patients in the TACE group were younger than those in the non-TACE group, and liver cirrhosis and non-anatomical hepatic resection were more prevalent in this group. The 5-year overall survival rate after hepatic resection was significantly lower in the TACE group (28.6%) than in the non-TACE group (50.6%), especially in patients without cirrhosis or with stage I or II tumor. There was no difference between the two groups in mortality or disease-free survival after hepatic resection. Multivariate analysis showed preoperative TACE, preoperative aspartate aminotransferase elevation, and microscopic portal invasion to be independent risk factors for a poor outcome after hepatic resection.

CONCLUSIONS

Preoperative TACE should be avoided for patients with resectable HCC, especially for those without cirrhosis or with an early stage tumor.

Irreversible morphological changes in leg bone following chronic gravitational unloading of growing rats

Effects of gravitational unloading or loading on the growth and development of hindlimb bones were studied in rats. Male Wistar rats were hindlimb-unloaded or loaded at 2-G from the postnatal day 4 to month 3. The morphology and mineral content of tibia and fibula, as well as the mobility of ankle joints, were measured at the end of 3-month suspension or loading, and 1, 2, and 3 months after ambulation recovery. Growth-related increases of bone weight and mineral density were inhibited by unloading. But they were gradually recovered toward the control levels, even though they were still less than those in the age-matched controls after 3 months. None of the parameters were influenced by 2-G loading. However, here we report that chronic unloading causes abnormal morphological development in hindlimb bone of growing rats. Irreversible external bend of the shaft and rotation of the distal end of tibia, which limit the dorsiflexion of ankle joints, were induced following chronic gravitational unloading during developing period. It is also suggested that such phenomena are caused by the abnormal mechanical forces imposed by muscle utilization with altered patterns. The activity of ankle dorsiflexor was increased and that of plantarflexor was inhibited during unloading.

Interpretation of scintigraphic findings of oral malignant tumours with a new scanning agent of technetium-99m-hexakis-2-methoxy-isobutyl-isonitrile (Tc-99m-MIBI)

OBJECTIVES

The purpose of this study was to investigate the usefulness of a new scanning agent of technetium-99m-hexakis-2-methoxy-isobutyl-isonitrile (Tc-99m-MIBI) for the diagnosis of malignant tumours of the head and neck.

METHODS

Scintigraphy with Tc-99m-MIBI was performed in 19 patients with malignant tumours of the head and neck. Factors of the early and delayed static scans (hot, warm or cold uptake), the early and delayed retention indexes, the blood flow index and the tumour retention index were obtained from Tc-99m-MIBI scintigraphy. Tumour retention indexes were classified into three grades; slightly (>0.9), moderately (0.9-0.8) and severely (0.8>) decreased. Grade of tissue differentiation of tumour (well, moderately or poorly differentiated) and tumour size (T1 approximately T4) were examined using the excised tumour. Scintigraphic indexes and tumour characteristics were compared.

RESULTS

The early static scan and tumour size showed a correlation with the blood flow index. However, the delayed static scan did not show any relationship with blood flow index and tumour size. The tumour retention index had a tendency to decrease in malignant tumours, and showed a significant correlation with the grade of tissue differentiation of the tumour.

CONCLUSIONS

The tendency of the tumour retention index to decrease in Tc-99m-MIBI scintigraphy showed the malignancy of tumour and would be useful for the diagnosis of malignant tumours of the head and neck.

Expression of permeability-glycoprotein (P-gp) and uptake of technetium-99m-hexakis-2-methoxy-isobutyl-isonitrile (99Tcm-MIBI) in malignant tumour of the head and neck

OBJECTIVES

The purpose of this study is to estimate the role of permeability-glycoprotein (P-gp) in the technetium-99m-hexakis-2-methoxy-isobutyl-isonitrile (99Tc(m)-MIBI) scintigraphy.

METHODS

71 patients with squamous cell carcinoma (39 patients with well differentiated, 19 with moderately differentiated and 13 with poorly differentiated tumour) were examined. Eighteen of these patients underwent 99Tc(m)-MIBI scintigraphy (early and delayed scans). The tumour retention index, obtained from the ratio of the accumulation of the delayed scan to that of the early scan, was divided into three groups. The immunohistochemical evaluation of P-gp expression was performed in all 71 patients. Levels of the P-gp expression were classified into three grades (score 0, 1 and 2). Correlations among the tumour retention index, the P-gp expression and the tumour tissue differentiation were evaluated.

RESULTS

17 of 18 patients showed a decreasing of the tumour retention index ranging from 0.70 to 0.93 (mean+/-SD=0.850+/-0.071). The tumour retention index showed a statistical correlation with the P-gp expression and the tumour tissue differentiation (chi-squared=7.802>7.779, P=0.10 and 16.835>14.860, P=0.005, respectively). Moreover, there was a statistical correlation between the P-gp expression and the tumour tissue differentiation (chi-squared=14.863>14.860, P=0.005).

CONCLUSION

There is a possibility that the P-gp expression is high in the high-grade malignant tumours and P-gp causes the decrease of tumour retention index.

Scintigraphy for interpretation of malignant tumours of the head and neck: comparison of technetium-99m-hexakis-2-methoxyisobutylisonitrile (Tc-MIBI) and thallium-201-chloride (Tl-201)

OBJECTIVES

The purpose of this study was to compare the usefulness of technetium-99m-hexakis-2-methoxyisobutylisonitrile (99Tc(m)-MIBI) and thallium-201-chloride (Tl-201) as scintigraphic agents.

METHODS

Dynamic and static scintigraphic imaging with 99Tc(m)-MIBI and Tl-201 were performed on patients with a variety of malignant and benign tumours. Factors of the grade of the static scan, the blood flow index, the early and delayed retention indexes, and the tumour retention index were obtained from the scintigraphy. In addition to these factors, the grade of tissue differentiation and tumour size were evaluated to clarify the difference between 99Tc(m)-MIBI and Tl-201 for the diagnosis of malignant tumours of the head and neck.

RESULTS

99Tc(m)-MIBI accumulation depended upon the blood flow index in the early static scan, but this accumulation did not correlate with tumour size. The accumulation in most subjects decreased in the delayed static scan, and the tumour retention index had a tendency to decrease with the grade of tissue differentiation. Tl-201 accumulation depended upon the blood flow index in the early static scan similar to 99Tc(m)-MIBI, and the accumulation correlated with tumour size, unlike 99Tc(m)-MIBI. The tumour retention index had a tendency to increase with the grade of tissue differentiation. Thus, the tumour retention indexes showed opposite behaviours between 99Tc(m)-MIBI and Tl-201, but they both accurately determined tumour malignancy.

CONCLUSIONS

There was no major difference between 99Tc(m)-MIBI and Tl-201scintigraphy with respect to accuracy of diagnosis of malignant tumours of the head and neck. However, 99Tc(m)-MIBI was superior to Tl-201 for small-size tumours and Tl-201 was useful for large-size tumours.

Thallium-201 chloride (Tl-201) accumulation and Na+/K+-ATPase expression in tumours of the head and neck

OBJECTIVES

The purpose of this report was to evaluate the relationship between the tumour retention index of thallium-201 chloride (Tl-201) scintigraphy and the Na+/K+-ATPase expression in tumours of the head and neck.

METHODS

Tl-201 scintigraphy was performed in 146 patients (129 with malignant tumours, ten with benign tumours and seven with inflammation). The tumour retention index was obtained from the early and delayed dynamic Tl-201 scans. The Na+/K+-ATPase expression was evaluated immunohistochemically in 61 of 129 patients with malignant tumour. Furthermore, another 22 patients with benign tumour were evaluated immunohistochemically as a benign control. Comparison of the correlations between the grade of histopathological differentiation of tumour, the tumour retention index of Tl-201 scintigraphy and the Na+/K+-ATPase expression was performed.

RESULTS

The grade of histopathological differentiation of tumour, the tumour retention index of Tl-201 scintigraphy and the expression of Na+/K+-ATPase showed a good correlation indicating that Na+/K+-ATPase plays an important role in transportation for Tl-201 to go through the tumour cell membrane.

CONCLUSIONS

Na+/K+-ATPase is one of the most important factors for Tl-201 accumulation in tumour.

A trial for histopathological subclassification of papillary cystadenoma lymphomatosum by 99Tcm-pertechnetate in a patient with multiple bilateral lesions of the parotid glands

OBJECTIVES

The purpose of this report was to evaluate the possibility of subclassification of papillary cystadenoma lymphomatosum (PCL) with 99Tc(m)-pertechnetate.

METHODS

A patient with multiple bilateral PCLs in the parotid glands was examined by using 99Tc(m)-pertechnetate.

RESULTS

All PCLs of the present case, which were diagnosed as the subtype-II histopathologically, showed similar radioactive indexes in scintigraphy (the mean radioactive index = 3.62), although tumours were different in size. The mean radioactive index corresponded well with that from four cases of subtype-II of our previous report (the mean radioactive index = 3.84).

CONCLUSIONS

The results of the present report suggest a possibility of histopathological subclassification of PCLs into subtypes by 99Tc(m)-pertechnetate scintigraphy.

Energetic protons from a few-micron metallic foil evaporated by an intense laser pulse

With detailed experimental studies and hydrodynamics and particle-in-cell simulations we investigate the role of the prepulse in laser proton acceleration. The prepulse or pedestal (amplified spontaneous emission) can completely evaporate the irradiated region of a sufficiently thin foil; therefore, the main part of the laser pulse interacts with an underdense plasma. The multiparametric particle-in-cell simulations demonstrate that the main pulse generates the quasistatic magnetic field, which in its turn produces the long-lived charge separation electrostatic field, accelerating the ions.

Remyelination of demyelinated CNS axons by transplanted human schwann cells: the deleterious effect of contaminating fibroblasts

Areas of demyelination can be remyelinated by transplanting myelin-forming cells. Schwann cells are the naturally remyelinating cells of the peripheral nervous system and have a number of features that may make them attractive for cell implantation therapies in multiple sclerosis, in which spontaneous but limited Schwann cell remyelination has been well documented. Schwann cells can be expanded in vitro, potentially affording the opportunity of autologous transplantation; and they might also be spared the demyelinating process in multiple sclerosis. Although rat, cat, and monkey Schwann cells have been transplanted into rodent demyelinating lesions, the behavior of transplanted human Schwann cells has not been evaluated. In this study we examined the consequences of injecting human Schwann cells into areas of acute demyelination in the spinal cords of adult rats. We found that transplants containing significant fibroblast contamination resulted in deposition of large amounts of collagen and extensive axonal degeneration. However, Schwann cell preparations that had been purified by positive immunoselection using antibodies to human low-affinity nerve growth factor receptor containing less than 10% fibroblasts were associated with remyelination. This result indicates that fibroblast contamination of human Schwann cells represents a greater problem than would have been appreciated from previous studies.

Dynamic scintigraphy with thallium-201 chloride (Tl-201) for the diagnosis of tumors of the head and neck

OBJECTIVE

The purpose of this study was to differentiate between malignant tumors and benign tumors of the head and neck by means of thallium-201 chloride scintigraphy.

STUDY DESIGN

Thallium-201 chloride (Tl-201) scintigraphy and Ga-67 citrate (Ga-67) scintigraphy were performed in 10 patients with a benign tumor and in 90 patients with a malignant tumor. The blood flow index and the tumor retention index were obtained by means of Tl-201 scintigraphy. The blood flow index = the count of tumor/the count of control in the early dynamic scan from 30 to 120 seconds after injection, and the tumor retention index = (the count of tumor/the count of control in the delayed dynamic scan 2.5 hours after injection)/(the count of tumor/the count of control in the early dynamic scan from 4 to 5 minutes after injection).

RESULTS

The early and delayed scans with Tl-201 demonstrated a very high correlation with the blood flow index. The tumor retention index had a tendency to increase in malignant tumors, especially in the poorly differentiated tumors and the severely invasive tumors. Likewise, the tumor retention index decreased in benign tumors. These results proved to be statistically significant, and in turn Tl-201 scintigraphy was deemed superior to Ga-67 scintigraphy. Tl-201 scintigraphy was also useful in detecting small-size tumors.

CONCLUSION

The tumor retention index of Tl-201 was useful for the differentiation of malignant tumors of the head and neck from benign tumors of the same areas.

Assessment of donor fatty livers for liver transplantation

AIM

The effect of fatty liver on graft survival, especially with reference to macrovesicular and microvesicular steatosis, is still uncertain. This preliminarily study was designed to create a noninvasive method for the quantification of the hepatic fat content in vivo and to establish provisional criteria for the assessment of fatty donor livers before liver transplantation among transplant surgeons, radiologists, and pathologists.

METHODS AND MATERIALS

Different degrees of rat fatty liver model were established by feeding rats a diet deficient in choline and methionine for different periods of time. Computed tomography (CT) with test tubes containing variable percentages of fat equivalent substance were used to assess the severity of fatty change of the rat liver. This was then correlated with the histological classification, level of hepatic enzymes, and graft survival.

RESULTS

Linear correlation between the fat volume fraction added to the test tubes and CT density were found. The process of producing a fatty liver via diet alteration peaked at week 3. At this time hepatic enzymes, radiological fat content, and posttransplantation survival were worse (P=0.013), compared with other time points. Radiological assessment of fatty liver correlated well with survival and serum glutamic oxaloacetic transaminase and glutamic pyruvate transaminase levels.

CONCLUSION

Severe microvesicular steatosis does not influence recipient survival, however, macrovesicular steatosis affects graft survival. Caliber CT is a practical and simple method that allows an accurate noninvasive quantitative assessment of hepatic fatty infiltration. It has potential to be a useful parameter for the assessment of donor livers for clinical liver transplantation.

Identification of the indoleamine 2,3-dioxygenase nucleotide sequence in a rat liver transplant model

A tryptophan catabolizer, indoleamine 2,3-dioxygenase (IDO) is highly expressed in the placenta and plays an essential role in maternal tolerance. Recent data have shown that the administration of an IDO inhibitor blocked not only maternal tolerance but also liver allograft tolerance. However, little is known about the induction of IDO in liver allografts, although a gene specific for tryptophan 2,3-dioxygenase (TDO) is believed to be expressed in the liver. In the present study, we investigated whether IDO is induced in liver allografts. Synthetic oligonucleotide primers based on the mouse IDO cDNA sequence were used to amplify RNA derived from livers of donor, syngeneic or allogeneic OLT rats. RNA encoding IDO was induced in the rat allogeneic liver after orthotopic liver transplantation (OLT), but not in syngeneic OLT. The rat nucleotide sequence of the RT-PCR products obtained from OLT livers revealed identities of 89% homology to the mouse IDO and of 68% to the human IDO. This study demonstrated the presence of RNA encoding IDO in allogeneic OLT livers, which may be involved in the immune response after liver transplantation.

Areas of demyelination do not attract significant numbers of schwann cells transplanted into normal white matter

If Schwann cell transplantation is to be used as a therapy for demyelinating disease, it is important to know if the number of transplanted cells and their transplantation site affects the extent of remyelination. Primary Schwann cell cultures were obtained from neonatal rat sciatic nerve, purified, and expanded using bovine pituitary extract and forskolin. Areas of persistent demyelination were created in the dorsal funiculus of the thoracolumbar spinal cord of rats by injecting ethidium bromide into white matter exposed to 40 Gy of X-irradiation, and a high and low number of Schwann cells were transplanted, into either the area of demyelination or the dorsal funiculus cranial to the area of demyelination. Animals were perfused 4 weeks after transplantation. After injection of 4 x 10(4) cells into the area of demyelination, the area of Schwann cell remyelination was 0.88 +/- 0.16 mm(2), while following the injection of 3 x 10(3) cells it was significantly smaller, 0.29 +/- 0.09 mm(2). After implantation of Schwann cells 1-3 mm (mean 2.5 mm) cranial to the area of demyelination, only one of the eight animals (a high-dose animal) showed extensive Schwann cell remyelination. In this animal, the cells were transplanted within 1 mm of the area of demyelination, well within the length of tissue over which cells are passively spread by the injection procedure (1-3 mm). Our results show that significant numbers of transplanted Schwann cells are not attracted through normal tissue to areas of demyelination and when transplanted into areas of demyelination the extent of myelination is related to the number of Schwann cells transplanted.

Schwann cells transplanted into normal and X-irradiated adult white matter do not migrate extensively and show poor long-term survival

Although Schwann cells are able to enter the central nervous system (CNS) when the integrity of the glia limitans is disrupted, their ability to migrate through intact CNS remains unclear. We have addressed this issue by transplanting lacZ-labeled Schwann cells into normal adult spinal cord white matter, and into X-irradiated spinal cord (an environment that, unlike normal spinal cord, permits the migration of transplanted oligodendrocyte progenitors). Schwann cell cultures, obtained from neonatal rat sciatic nerve and expanded using bovine pituitary extract and forskolin, were transfected by repeated exposure to retroviral vectors encoding the Escherichia coli lacZ gene. The normal behavior of the transduced cells was confirmed by transplantation into a nonrepairing area of demyelination in the spinal cord, where they formed myelin sheaths around demyelinated axons. A single microliter containing 4 x 10(4) cells was then transplanted into unlesioned normal and X-irradiated white matter of the spinal cord of adult syngeneic rats. One hour after injection, blue cells were observed as a discrete mass within the dorsal funiculus with a longitudinal distribution of 2-3 mm, indicating the extent of passive spread of the injected cells. At subsequent survival times (1, 2, and 4 weeks posttransplantation) blue cells had a distribution that was no more extensive than that seen 1 h after transplantation. However, the number of Schwann cells declined with time following transplantation such that at 4 weeks there were few surviving Schwann cells in both X-irradiated and nonirradiated spinal cord. These results indicate that transplanted Schwann cells do not migrate extensively and show poor long-term survival when introduced into a normal CNS environment.

Identification of a human olfactory ensheathing cell that can effect transplant-mediated remyelination of demyelinated CNS axons

The olfactory ensheathing cell (OEC) has attracted much interest recently because of its potential for transplantation-based therapy of CNS disease. Rat OECs are able to remyelinate demyelinated axons and support regeneration of damaged axons. Although OECs can be grown readily from the rat, a macrosmatic species, it has been uncertain whether it would be similarly straightforward to obtain these cells from the human, a microsmatic species with a relatively poorly developed olfactory system. In this study, we have identified a human OEC which shares many properties with its rat counterpart, including expression of the low-affinity nerve growth factor receptor (L-NGFr) and similar growth factor requirements. Purified populations of human OECs obtained by selection with L-NGFr antibodies have extremely high viability in tissue culture, and are capable of remyelinating persistently demyelinated CNS axons following transplantation into experimentally induced demyelinating lesions in the rat spinal cord. Thus, the human OEC represents an important new cell for the development of transplant therapy of CNS diseases.

Basic study of the measurement of bone mineral content of cortical and cancellous bone of the mandible by computed tomography

OBJECTIVES

To develop an algorithm for automatic separation of cortical from cancellous bone in the mandible and for measuring mandibular bone mineral content (BMC).

METHODS

A dried mandible was scanned together with a reference phantom by spiral CT. A new algorithm was developed specifically for the mandible and cross-sectional images reconstructed in the buccolingual plane. The cortical bone was extracted with a threshold of 80% of the peak height in the line-scan profile and the cancellous bone extracted separately. The volume and BMC were estimated. Images of cortical and cancellous bone were displayed in a plane approximating the orientation used for dental radiography and BMC expressed as aluminium-equivalents (Al-eqs).

RESULTS

The ratio of cortical to cancellous bone by volume was 22:78, and the ratio of the BMC 60:40. Comparison of BMC from reconstructed CT with Al-eqs showed good correlation but was 1.5 times higher with CT.

CONCLUSIONS

It is possible to separate cancellous from cortical bone automatically from CT images and to measure the BMC.

Redistribution of bisbenzimide Hoechst 33342 from transplanted cells to host cells

Identification of transplanted cells within host tissue is an important component of many transplantation experiments. In this study, Schwann cells labelled with the fluorochrome bisbenzimide (Hoechst 33342, H33342) and transduced with the lac-Z gene were introduced into normal white matter and their distribution was examined 2 h, 24 h and 4 weeks after transplantation. At 2 and 24 h following transplantation, H33342-labelled cells were more widely distributed than lac-Z-labelled cells in both longitudinal and transverse directions. By 4 weeks following transplantation, no lac-Z-labelled cells could be found. However, H33342-labelled cells were observed in and around the glial scar. Therefore, labelling of host cells by transfer of H33342 dye from transplanted cells has to be considered whenever this dye is used as a transplant marker.

Osteoconduction of bioceramics in normal and osteopenic rats: comparison between bioactive and bioinert ceramics

Rats with experimental osteopenia, which was induced by resecting both ovaries and sciatic nerves (OVX + NX), were used to evaluate osteoconduction of an apatite and wollastonite-containing glass-ceramic (designated A-W.GC) and an alumina ceramic. The bone mineral densities (BMDs) of the femurs were measured by dural energy X-ray absorptiometry (DEXA) and determination of the ash weight. Twelve weeks after the first operation, when the BMDs in the OVX + NX groups were about 20% less than that in the sham-treated groups (Sham), the bioceramics were implanted into the proximal tibiae. The bone mineral masses around the implants in the proximal tibiae were evaluated by histological examination of undecalcified specimens and DEXA. Both types of implants in the OVX + NX groups showed less reactive bone than those in the Sham groups. However, a histomorphological study revealed that the direct contact area between bone and implant was larger with bioactive ceramic A-W.GC than with the bioinert alumina ceramic even under osteopenic conditions while two types of ceramic made no difference on the bone at distance from the implant. The direct contact area with A-W.GC did not show any difference between the Sham and the osteopenic OVX + NX groups. The bioactive ceramic A-W.GC appears to have good osteoconductivity solely on its surface even under osteopenic conditions.

Application of cryoprecipitate as a hematostatic glue

BACKGROUND

The effectiveness of cryoprecipitate, harvested from a patient's own fresh frozen plasma, for use in cardiac surgery as a hematostatic glue was studied in 32 randomized elective adult cardiac surgery patients from January 1993 to July 1994.

MATERIALS AND METHODS

Patients from the Toho Sakura Hospital were randomly allocated to two groups: Group 1 (n=11) received conventional fibrin glue presently available in our institution; while Group 2 (n=21) received autologous cryoprecipitate as a hematostatic glue. Surgical procedures broken down by group were as follows: Group 1: 4 CABG, 5 valvular surgeries and 2 other. Group 2: 11 CABG, 6 valvular surgery, 4 other. We preserved the patient's own blood and stored pure red cell and fresh frozen plasma (FFP). Cryoprecipitate was prepared from the FFP and preserved until required.

RESULTS

Cryoprecipitate had a 5-fold increase in fibrinogen activity (1190+/-311 mg/dl vs 238+/-34 mg/dl p<0.001), a 10-fold increase in factor VIII activity (362+/-219% vs 34+/-11%, p=0.001), and 4.5-fold increase in factor XIII activity (538+/-213% vs 119+/-50%, p<0.001), compared to serum. The amount of bleeding postoperatively was slightly lower in the cryoprecipitate glue group compared to the conventional glue group, but this was not significantly different.

CONCLUSIONS

We conclude that autologous samples of human cryoprecipitate prepared from a patient's own FFP had a strong hematostatic effect compared to conventional fibrin glue and was a very valuable hematostatic agent during cardiac surgery.

Vertebral growth disturbance in rapidly growing rats during 14 days of spaceflight

The effect of 14 days of spaceflight on the vertebrae of rapidly growing rats was studied. The hardness of the vertebrae was measured with a Knoop microhardness tester, and bone mineral density was measured from X-ray photographs. Histomorphometric examination was performed with a microcomputer-aided system. No significant difference (P > 0.05) was observed between flight rats and ground controls with regard to mechanical hardness or bone mineral density. However, histological examination revealed irregular thickening of the endosteal surface of cortical bone in the flight rats, whereas it was uniform in the ground controls. The relative area of lamellar bone showed a significant reduction (P < 0.001) in the flight rats. These findings suggest that the structural disturbances were due to retardation of endosteal modeling and remodeling. We conclude that delay of vertebral maturation can occur in rapidly growing rats after even short-term exposure to microgravity.

Intraarterial perfusion of the hindlimb with pyridoxalated hemoglobin polyoxyethylene conjugate solution in anesthetized dogs

To evaluate the potential clinical usefulness of a modified hemoglobin, pyridoxalated hemoglobin polyoxyethylene conjugate (PHP), the hindlimb vascular bed was perfused with PHP solution while monitoring tissue oxygen tension (PtO2) in anesthetized dogs. The hindlimb region was perfused through the external iliac artery with a roller pump at a varying perfusion rate. PtO2 was measured using a PO2-monitoring probe inserted into the gracial muscle. After surgical preparation for perfusion, the iliac arterial flow rate was 19.9 +/- 5.6 ml/min, and baseline PtO2 was 38.4 +/- 1.3 mm Hg. Perfusion with autologous arterial blood with the pump increased PtO2 and perfusion pressure (PP) in a perfusion rate-dependent manner. Perfusion with PHP solution at 20 ml/min decreased PtO2 from the initial baseline level, but an increase in the flow rate to 40-55 ml/min restored or induced an elevation of PtO2. Results demonstrated that PHP solution can deliver oxygen to local tissue and maintain tissue oxygen tension at the same level as autologous arterial blood at a high enough flow rate.

Synthesis and characterization of superoxide dismutase-deferoxamine conjugate via polyoxyethylene: a new molecular device for removal of a variety of reactive oxygen species

A conjugate of Cu,Zn-superoxide dismutase (SOD) with a strong iron chelating agent, deferoxamine (DFO), was synthesized (SOD-POE-DFO) via polyoxyethylene (POE) as a linking agent. N-terminal amino groups of lysine residues in SOD are modified with 1:1 binding products of polyoxyethylene and deferoxamine (POE-DFO) through a covalent amido bond. The mean number of the POE-DFO bound per one SOD molecule is calculated to be 3.3 by determining the C/N ratio after elemental analysis. The half-life of the SOD-POE-DFO is about 1.2 h in rats, whereas that of free SOD is about 5-10 min. POE plays the part not only of the linking agent but also of expanding the lifetime in the circulation. The SOD-POE-DFO possesses both the metal chelating ability (for DFO) and the ability of scavenging superoxide radicals (for SOD). Therefore, the SOD-POE-DFO of the present study can eliminate the superoxide radical and free iron simultaneously and in the same location, and thus, it would be a molecular device with multiple functions which prevents the damage to tissues by scavenging the variety of reactive oxygen species.

Effects of pyridoxalated hemoglobin polyoxyethylene conjugate and other hemoglobin-related substances on arterial blood pressure in anesthetized and conscious rats

The effects of pyridoxalated hemoglobin polyoxyethylene conjugate (PHP) and other hemoglobin-related substances on arterial blood pressure (ABP) and heart rate (HR) were examined. Infusion of PHP and other hemoglobin-related substances elevated ABP and increased HR. The degree of the increase in ABP and HR did not differ among the groups. There were species' differences in responses to PHP. Pretreatment with various blockers did not abolish the elevation of ABP. The pretreatment of NG-monomethyl-L-arginine dose-dependently reduced the elevation of ABP but did not completely abolish it. PHP also elevated ABP in conscious rats. The magnitude of the ABP elevation was significantly smaller than in the anesthetized rats. Results indicate that inhibition of nitric oxide (NO) might be responsible in part for the elevation of ABP, and the degree of the elevation would be dependent on the degree of contribution of NO to the regulation of ABP.

Restoration of function by replacement of spinal cord segments in the rat

Reconstruction of a severed mammalian spinal cord with restoration of function has so far not been achieved, although structural and functional restitution after spinal transection has been successful in some lower vertebrates. In quail-chick and chick-chick chimaeras, spinal cord segments were found to be functional after replacement by isotopic and isochronic grafting of the neural tube. Here we achieve such a replacement in neonatal rats under less restricted topological and temporal conditions than were necessary for the avian chimaeras. The replaced segments united with the host spinal cord and promoted robust growth and regrowth of axons across the graft, enabling neural connections to be reconstructed that were hardly distinguishable from normal. The animals with replaced segments could walk, run and climb with almost normal hind-forelimb coordination. This functional restoration in these animals appeared to be permanent, raising the possibility of therapeutic application in humans.

Effects of indeloxazine HCl on kindled amygdaloid seizures in rats: comparison with the effects of phenytoin, diazepam, ethanol, and imipramine

The anticonvulsant effect of [(+/-)-2-[(inden-7-yloxy)methyl]morpholine (indeloxazine) HCl, a new cerebral activator, was investigated in rats against kindled seizures from the amygdala, an assumed model of secondarily generalized seizures in human. Indeloxazine (0.25-10 mg/kg, IP) dose-dependently depressed the kindled seizure and shortened the evoked amygdaloid afterdischarge. A high dose of indeloxazine (40 mg/kg, IP), however, induced generalized seizures. Comparison of the effects on the kindled seizures of indeloxazine to those of phenytoin, diazepam, ethanol, and imipramine revealed that the anticonvulsant actions of indeloxazine are similar to those of imipramine but not to those of phenytoin, ethanol, and diazepam. The results suggest that indeloxazine may exert its action through the monoaminergic system in the brain.

Relationship between chemical properties and biological properties of pyridoxalated hemoglobin-polyoxyethylene

Pyridoxalated hemoglobin-polyoxyethylene (PHP) is a conjugate of human hemoglobin with alpha-carboxymethyl, omega-carboxymethoxypolyoxyethylene(POE). This conjugate is selected as an oxygen carrier for blood substitute because it can survive for a long time in the circulation and also it can transport the same amount of oxygen as red cell. Optimization of PHP has been done by changing the degree of the modification and reaction procedures in order to adjust viscosity and colloid osmotic pressure to physiological values. The oxygen carrying capacity was physically evaluated by oxygen equilibrium curves and biologically by an ATP content in perfused isolated liver. Structural relationship of PHP to the binding properties to haptoglobin was studied and the effect of the POE modification on the binding properties was observed when the number of POE per one hemoglobin molecule is over six. Based on the comparative study of solubility of met-PHP and met-SFH, the POE modification was suggested to reduce the toxicity of hemoglobin against organs. Finally physical properties of PHP at low temperature was discussed in relation to organ preservation.

Large scale production and characterization of lyophilized pyridoxalated hemoglobin-polyoxyethylene (PHP)

Lyophilized PHP as an oxygen carrier is prepared from outdated red cell and dicarboxymethylated polyoxyethylene. In order to apply PHP for a clinical use, a large scale production of high quality PHP has been studied. We have set up a 20 L scale production flow of PHP88. The product was tested to confirm the quality and lot-to-lot consistency. The blood group specific materials were weakly positive in stroma-free hemoglobin (SFH), however, were found negative in the PHP of this scale. The amount of phosphatidylethanolamine (PE) in purified SFH and PHP88 reconstituted solution was 0.19 +/- 0.04 and 0.03 +/- 0.01 ppm, respectively. Contamination of viruses such as HBV and Non A non B hepatitis virus could not be observed in the final product. Elimination and inactivation of HIV was validated through a spike test. The characterizations of the final products in 20 L scale were done through MW, P50, Hill coefficient, viscosity, and molecular weight distribution by SDS-PAGE and batch to batch consistency was also confirmed. The results show that production process is appropriate to eliminate the blood group materials, PE and virus, and produce PHP of high quality. Lyophilized PHP88 can be produced by addition of maltose and can be stored over 1 year.

Structure and mineral content in weight-bearing bones following hindlimb suspension in young rats

Responses of structure and mineral content in weight-bearing bones to 1-week hindlimb suspension were studied in growing rats. The weight, volume, and length of femur, tibia, and fibula were less in suspended rats than cage controls, although there was no significant difference in the weight/volume ratio. The diameter of mid-shaft, the thickness of cortical bone, and the ratio of cortical bone thickness to femur diameter were significantly less in the suspended rats. The width of marrow space showed no differences, suggesting that the cortical bone was mainly affected. The sum of mineral content and the mineral content per diameter in the cross section of femurs were decreased following suspension, suggesting a change in the internal structure of cortical bone. Data also indicated that the reduction of femur diameter was caused by decreased thickness which is accompanied by the decreased mineral content of the cortical bone. It was suggested that there is a close relationship between the responses of bones and muscles to hindlimb suspension of young rats, although the degree of weight loss was greater in muscles than in bones.

A new type of antiserum to thyrotropin-releasing hormone; detection of new TRH-immunoreactive cell groups in rat hypothalamus

We produced a new type of antiserum to thyrotropin-releasing hormone (TRH) in rabbits. The immunogen is TRH-BSA, the production of which is based on the formation of an amide bond using carbodiimide (EDC). The specificity of the antiserum was assessed by enzyme immunoassay (EIA) and immunohistochemistry. When using the anti-TRH serum for immunohistochemistry in rat hypothalamus, new magnocellular groups were detected in the ventrolateral parts of the posterior hypothalamus and the dorsal parts of the third ventricle. Colchicine treatment was found not to be necessary to visualize perikarya containing TRH.

Characterization of a pyridoxalated hemoglobin-polyoxyethylene conjugate as a physiologic oxygen carrier

A pyridoxalated hemoglobin-polyoxyethylene conjugate (PHP) is an oxygen carrier prepared from outdated human red cells through chemical modifications of hemoglobin (Hb). PHP was evaluated as a physiologic oxygen carrier. PHP was synthesized from a pyridoxalated hemoglobin (PLP-Hb) and an activated diester of polyoxyethylene (POE). The average numbers of molecules of PLP and POE conjugated to a Hb molecule were 3.3 and 6.2, respectively. The p50 of PHP was 20.4 torr, which was much higher than the 14.0 torr of stroma-free Hb. At a Hb concentration of 6 g per dL, PHP had a physiologic colloid osmotic pressure (29 torr) and a lower viscosity (2.6 cP at 37 degrees C) than whole blood (4.2 cP at 37 degrees C). At temperatures below 20 degrees C, the p50 of PHP was higher than that of the red cells. PHP, which had an average molecular weight of 90,000, consisted of 83 percent monomeric PLP-Hb-POE conjugate, 12 percent dimeric PLP-Hb-POE, and 4 percent trimeric PLP-Hb-POE. The consistency of the relative contents of the components was well controlled through seven lots, and each component had sufficient oxygen-carrying capacity. The dimeric and trimeric components contributed to the prolongation of the residence of PHP in the circulation. The results indicate that PHP has favorable properties as an oxygen-carrying blood substitute and perfusate.

A new dopaminergic terminal plexus in the ventral horn of the rat spinal cord. Immunohistochemical studies at the light and electron microscopic levels

It has been thought that the ventral motor column in the rat spinal cord is virtually free of dopaminergic fibers. However, a new dopaminergic terminal plexus was visualized at all spinal levels in the ventral horn using electron as well as light microscopic immunohistochemistry.