Reaction Mechanism and Selectivity Control of Si Compound ALE Based on Plasma Modification and F-Radical Exposure

In this work, atomic layer etching (ALE) of Si compounds using H₂ or N₂ plasma modification followed by fluorine radical exposure is discussed. It is shown that the H₂ plasma modification process promotes the selective etching of SiN, SiC, and SiCO versus SiO₂. The N₂ plasma modification, on the other hand, enables the selective etching of SiC and SiCO versus SiN and SiO₂. The origin of the etching selectivity between different Si compounds is investigated using a combination of in situ SE and FTIR supported by several ex situ analysis techniques. It is shown that the formation of a hydrogen-rich layer after plasma modification is essential to enable the ALE process. The hydrogen-rich layer can be formed due to ion and radicals of the modification plasma (H₂ plasma modification) or be a result of the reconfiguration of hydrogen that is already present in the film (N₂ plasma modification). The obtained insights are expected to further enhance the etching selectivity of Si compound ALE processes. Furthermore, it is anticipated that the process can be extended to many other compound materials such as Ti and Hf, as well as enable selective etching between their oxides, carbides, and nitrides.

Thoroughly mesoporous TiO2 nanotubes prepared by a foaming agent-assisted electrospun template for photocatalytic applications

A thoroughly mesoporous long TiO₂ nanotube with intact morphology was firstly prepared using a foaming agent-assisted electrospun template method for photocatalytic applications.

Assessment of the loop-mediated isothermal amplification assay for rapid diagnosis of Mycoplasma pneumoniae in pediatric community-acquired pneumonia

Rapid diagnosis of Mycoplasma pneumoniae pneumonia is required for timely treatment with effective antibiotics; however, PCR-based methods are often too expensive and technologically intensive for general use in clinical practice. In this study, the efficacy of the loop-mediated isothermal amplification (LAMP) assay for diagnosis of M. pneumoniae pneumonia in clinical practice was prospectively evaluated. From July 2011 to March 2012, 531 children hospitalized for community-acquired pneumonia were enrolled. In all patients, throat swabs were obtained on admission for the detection of M. pneumoniae DNA, and paired serum samples were obtained to assay M. pneumoniae particle agglutination (PA) antibody titers. M. pneumoniae pneumonia was diagnosed by either a positive LAMP assay or an increase of 4-fold or greater in the PA titer. Overall, 271 children (51.0% of the patients with pneumonia) were diagnosed with M. pneumoniae pneumonia. Among these, 258 (95.2%) and 248 (91.5%) were identified by the LAMP assay and serological tests, respectively. When the results of serological tests were considered as standard, the sensitivity, specificity, and positive and negative predictive values of the LAMP assay were 94.8%, 91.9%, and 91.1% and 95.2%, respectively. The median duration of pharyngeal carriage, as measured by the LAMP assay, was 9.5 days. Thus, the LAMP assay is useful in the rapid diagnosis of M. pneumoniae pneumonia.

Bone augmentation using a highly porous PLGA/β-TCP scaffold containing fibroblast growth factor-2

BACKGROUND AND OBJECTIVE

Beta-tricalcium phosphate (β-TCP), a bio-absorbable ceramic, facilitates bone conductivity. We constructed a highly porous three-dimensional scaffold, using β-TCP, for bone tissue engineering and coated it with co-poly lactic acid/glycolic acid (PLGA) to improve the mechanical strength and biological performance. The aim of this study was to examine the effect of implantation of the PLGA/β-TCP scaffold loaded with fibroblast growth factor-2 (FGF-2) on bone augmentation.

MATERIAL AND METHODS

The β-TCP scaffold was fabricated by the replica method using polyurethane foam, then coated with PLGA. The PLGA/β-TCP scaffold was characterized by scanning electron miscroscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, compressive testing, cell culture and a subcutaneous implant test. Subsequently, a bone-forming test was performed using 52 rats. The β-TCP scaffold, PLGA-coated scaffold, and β-TCP and PLGA-coated scaffolds loaded with FGF-2, were implanted into rat cranial bone. Histological observations were made at 10 and 35 d postsurgery.

RESULTS

SEM and TEM observations showed a thin PLGA layer on the β-TCP particles after coating. High porosity (> 90%) of the scaffold was exhibited after PLGA coating, and the compressive strength of the PLGA/β-TCP scaffold was six-fold greater than that of the noncoated scaffold. Good biocompatibility of the PLGA/β-TCP scaffold was found in the culture and implant tests. Histological samples obtained following implantation of PLGA/β-TCP scaffold loaded with FGF-2 showed significant bone augmentation.

CONCLUSION

The PLGA coating improved the mechanical strength of β-TCP scaffolds while maintaining high porosity and tissue compatibility. PLGA/β-TCP scaffolds, in combination with FGF-2, are bioeffective for bone augmentation.

A new heating method with dielectric bolus using resonant cavity applicator for brain tumors

In this paper, we discuss a new method of controlling heating location in the proposed resonant cavity applicator. A dielectric bolus was used to non-invasively treat brain tumors. We have already confirmed that our heating system using resonant cavity is useful to non-invasively heat brain tumors. In order to heat tumors occurring at various locations, it is necessary to control the heating area with our heating system. First, we presented the proposed heating method and a phantom model to calculate temperature distributions. The results of temperature distributions were discussed. Second, a 3-D human head model constructed from 2-D MRI images was presented. The results of specific absorption rate distributions were discussed. From these results, it was found that the proposed heating method was useful to non-invasively treat brain tumors.

Heating properties of coaxial needle applicator made of SMA for hyperthermia treatments

This paper describes heating properties of the developed coaxial needle applicator made of a shape memory alloy (SMA) for brain tumor hyperthermia treatments to avoid undesirable hotspots. We estimated the temperature distribution inside an agar phantom by the finite element method (FEM) and heated the agar phantom with the developed needle applicator.

T serotypes and antimicrobial susceptibilities of group A streptococcus isolates from pediatric pharyngotonsillitis

Group A streptococcus (GAS) is a major cause of pediatric pharyngotonsillitis. In this study we determined the T serotype and antimicrobial susceptibility of GAS isolates from Japanese children. From January to December 2006, a total of 438 isolates of GAS were obtained from pharyngeal swabs of 438 children with pharyngotonsillitis. The commonest T serotype was type 1 (110 strains, 25.1%), followed by type 12 (107, 24.4%) and type 4 (77, 17.6%). All GAS isolated from pharyngeal swabs were susceptible to beta-lactams (benzylpenicillin, amoxicillin, cefotaxime, ceftriaxone, imipenem, panipenem, and cefditoren) and vancomycin, but 19.6, 19.6, 3.2, 11.6, and 27.6% were resistant to erythromycin, clarithromycin, clindamycin, minocycline, and norfloxacin, respectively. Resistance varied considerably with the T serotype. In particular, type 4 isolates had the highest resistance (67.5, 67.5, 26.0, and 53.2% were resistant to erythromycin, clarithromycin, minocycline, and norfloxacin, respectively).

DNA sequence analysis of varicella-zoster virus gene 62 from subclinical infections in healthy children immunized with the Oka varicella vaccine

A live attenuated varicella vaccine, the Oka vaccine strain (vOka), is routinely administered to children in Japan and other countries, including the United States. vOka consists of a mixture of genotypically distinct variants, but little is known about the growth potential of each variants in vivo. We isolated varicella-zoster virus (VZV) DNA sequences from the peripheral blood mononuclear cells (PBMCs) of asymptomatic healthy children immunized with the Oka varicella vaccine. VZV gene 62 DNA fragments were detected in 5 of 166 (3.0%) PBMC samples by nested PCR within 5 weeks of the vaccination. Sequence analysis of VZV DNA from these five PBMC samples indicated that multiple viral clones in the vaccine could infect vaccinees and replicate in vivo. We also provide evidence that a nonsynonymous substitution at position 105356 may affect viral replication in vivo.

Utility of a rapid diagnosis kit for Mycoplasma pneumoniae pneumonia in children, and the antimicrobial susceptibility of the isolates

We evaluated a kit for the rapid diagnosis of Mycoplasma pneumoniae infection and investigated the antimicrobial susceptibility of the isolates. A total of 194 otherwise healthy children, aged 0.3-14.9 years, were diagnosed as having pneumonia by chest X-ray findings between December 2003 and November 2004, and were admitted to Showa Hospital. Isolation of M. pneumoniae was attempted from a throat swab obtained on admission, and the complement fixation titer was measured in paired serum samples obtained at admission and at the convalescent stage. We also used a rapid diagnosis kit (ImmunoCard Mycoplasma) for the detection of specific immunoglobulin M antibody in paired sera. Pneumonia due to M. pneumoniae was defined by isolation of this microorganism, or by seroconversion, or a >or=4-fold increase in the antibody titer. Using each isolate, we determined the minimum inhibitory concentrations for five antimicrobial agents by the broth dilution method. M. pneumoniae pneumonia was diagnosed in 45 children (23.2%). The ImmunoCard had a sensitivity of 31.8% using admission serum and 88.6% using paired sera, while the specificity was 78.1% and 70.5%, respectively. M. pneumoniae was isolated from 14 of the 45 patients (31.1%). The 50%/90% minimum inhibitory concentration (microg/ml) of erythromycin, clarithromycin, azithromycin, minocycline, and levofloxacin was 0.006/0.012, <or=0.003/<or=0.003, <or=0.003/<or=0.003, 0.78/1.56, and 0.39/0.78, respectively. For a rapid diagnosis of M. pneumoniae pneumonia, the ImmunoCard was not effective. Macrolides showed superior in vitro antimicrobial activity against M. pneumoniae isolates causing pediatric pneumonia.

Variation in CO2 assimilation rate induced by simulated dew waters with different sources of hydroxyl radical (*OH) on the needle surfaces of Japanese red pine (Pinus densifora Sieb. et Zucc.)

The hydroxyl radical (*OH) is generated in polluted dew on the needle surfaces of Japanese red pine (Pinus densiflora Sieb. et Zucc.). This free radical, which is a potent oxidant, is assumed to be a cause of ecophysiological disorders of declining trees on the urban-facing side of Mt. Gokurakuji, western Japan. Mists of *OH-generating N(III) (HNO2 and NO2-) and HOOH + Fe + oxalate solutions (50 and 100 microM, pH 5.1-5.4) simulating the dew water were applied to the foliage of pine seedlings grown in open-top chambers in the early morning. Needles treated with 100 microM N(III) tended to have a greater maximum CO2 assimilation rate (Amax), a greater stomatal conductance (g(s)) and a greater needle nitrogen content (Nneedle), suggesting that N(III) mist acts as a fertilizer rather than as a phytotoxin. On the other hand, needles treated with 100 microM HOOH + Fe + oxalate solution showed the smallest Amax, g(s), and Nneedle, suggesting that the combination of HOOH + Fe + oxalate caused a decrease in needle productivity. The effects of HOOH + Fe + oxalate mist on pine needles were very similar to the symptoms of declining trees at Mt. Gokurakuji.

Peripheral bone metastasis from hepatocellular carcinoma: sonographic findings

BACKGROUND AND METHODS

We reviewed medical and radiologic records of five patients with bone metastasis from hepatocellular carcinoma (HCC) to evaluate the role of sonography (US) in the diagnosis of this bone metastasis.

RESULTS

The metastatic lesions were clearly visualized by US as expansive, homogeneous, soft tissue masses with bony destruction, and color Doppler US showed fine vessels within the lesions. After treatment, US showed a decrease in tumor size with an increase in echogenicity and a decrease in blood flow. Hepatic US at the time of bone metastasis showed a portal tumor thrombus in all cases.

CONCLUSION

When US detects a portal venous tumor thrombus in HCC patients, attention should be directed not only to the liver but also to bone to improve patient care. US is useful not only in detecting the metastatic lesion but also in evaluating the treatment effect.

Macronodular deformity of the spleen

BACKGROUND AND METHODS

Macronodular splenic deformity without a focal lesion has rarely been reported. We present three such cases and discuss the possible pathomechanism.

RESULTS

There was one case of macronodular deformity of unknown cause. In this case, the liver was elongated anteriorly over the dome of the spleen, and the markedly deformed spleen mimicked a round lesion in the left lobe of the liver. Color Doppler ultrasonography showed the major intra- and perisplenic vessels to be patent. There were two cases of macronodular deformity associated with extended portal thrombosis. In both cases, portal thrombosis extended throughout the intrahepatic and extrahepatic portal systems, and this portal flow disturbance was presumed to be the cause of the splenic deformity.

CONCLUSION

Although very rare, thrombosis should be sought throughout the portal system when ultrasonography shows a markedly deformed spleen. Marked splenic deformity, especially in cases with an elongated liver, may mimic a liver tumor. A good understanding of its sonographic appearance may help sonographers prevent a hazardous misdiagnosis.

Clinical significance of TT virus in chronic hepatitis C

BACKGROUND AND AIMS

Much is still unknown about the clinical significance of TT virus (TTV), which has been reported as a candidate for non A-G hepatitis virus. The aim of this study was to clarify the clinical significance of TTV in patients coinfected with TTV and hepatitis C virus (HCV).

METHODS

The 95 subjects studied had chronic hepatitis C (CHC), and underwent interferon (IFN) therapy. TT Virus DNA was detected by using polymerase chain reaction. The nucleotide sequences were determined by using a dideoxy chain termination method. A phylogenetic tree was drawn up by using the neighbor-joining method.

RESULTS

TT Virus DNA was detected in 37.9% of patients with the use of an open reading frame 1 (ORF1) primer, and in 88.4% of patients by using a 5' untranslated region (5' UTR) primer. Using both sets of primers, no differences were found between TTV-DNA-positive and -negative subjects with CHC in the clinical findings. Serum TTV DNA was eradicated in 30.6% of patients with the ORF1 primer, and in 19.1% of patients with the 5' UTR primer at 6 months after the cessation of IFN therapy. The levels of TTV DNA before IFN therapy were significantly lower in the viral eradication group than in non-eradication group. The changes in alanine aminotransferase (ALT) concentrations were significantly correlated with changes in HCV-RNA in CHC patients with TTV. Moreover, there was no correlation between the changes in TTV DNA and the course of ALT.

CONCLUSION

Hepatocellular injury in patients with chronic hepatitis who are coinfected with HCV and TTV appears to primarily be caused by HCV and is less attributable to TTV.

Measurement of ethylene emission from Japanese red pine (Pinus densiflora) under field conditions in NOx-polluted areas

Emission of ethylene from the needles of Japanese red pine, Pinus densiflora, was measured in air-polluted areas in Hiroshima, Japan. We applied a suitable protocol to determine the rate of ethylene emission from the excised needles. The influence of excision of needles on ethylene emission was not detected during the first 4 h of incubation at 20 degrees C. Ethylene emissions were low in the unpolluted (clean) areas regardless of the altitude or season. The emission of stress ethylene increased with the atmospheric NO2 concentration, suggesting that atmospheric NOx or related substances induced the higher ethylene emission in the polluted areas (near urban and industrial areas). In all cases, 1-year-old needles emitted significantly larger amounts of ethylene than the current needles. Ethylene emission did not increase evenly in the polluted areas, but the frequency of trees emitting high ethylene increased. Therefore, threshold rates for the baseline ethylene emission were proposed.

Iatrogenic GB virus C/hepatitis G virus infection in an area endemic for hepatitis C virus

GB virus C/hepatitis G virus (GBV-C/HGV) is reported to be transmitted by blood products. This study reports infection with GBV-C/HGV from Area-O of town T, an area of high prevalence of antibody to hepatitis C virus (anti-HCV). Four hundred and thirty-five inhabitants of Area-O in town T were examined. Three hundred and forty-three inhabitants of Area-H in town T (where differences of age or sex are not markedly different to Area-O) were studied as controls. We investigated the virus markers and conducted a survey of life history in both areas. The seroprevalence of anti-HCV and GBV-C/HGV markers in Area-O was 17.7% and 11.7%, significantly higher than in Area-H (1.5% and 4.4%). The prevalence of GBV-C/HGV markers was significantly higher in the anti-HCV-positive group than in the sero-negative group. Anti-HCV- or GBV-C/HGV positive subjects tended to have a history of intravenous medications at hospital C in town T, suggesting iatrogenic infection through insufficient sterilization of needles and/or syringes.

GB virus C infection: clinical significance

GB virus C (GBV-C) RNA positivity rates were examined in serum specimens from 231 patients with liver disease (23 patients with hepatitis B, 175 patients with hepatitis C, five patients with hepatitis B virus plus hepatitis C virus coinfection, and 28 patients with non-A, non-B, non-C hepatitis) to clarify the clinical significance of this virus. GBV-C RNA was detected in none of 12 patients with fulminant hepatitis, one of two patients with acute hepatitis positive for hepatitis B surface antigen and one of four patients with acute non-A, non-B, non-C hepatitis. Pathogenetic involvement of GBV-C was suspected in some patients in the latter group. Among patients with the non-B, non-C type of chronic disease, one of seven with cirrhosis (14%) and none with chronic hepatitis or hepatocellular carcinoma were GBV-C-positive. In chronic hepatitis C patients who had received interferon treatment, no difference was found in clinical findings, alanine aminotransferase (ALT) concentrations, histology or response to interferon between 11 patients who were GBV-C RNA-positive and 101 patients who were GBV-C RNA-negative. Moreover, changes in ALT after interferon therapy showed no relation to positivity for GBV-C RNA. On the basis of these findings, GBV-C appears to be an unlikely cause of initiation or progression of chronic hepatic diseases.

Primary biliary cirrhosis associated with membranous glomerulonephritis

A 33-year-old woman was admitted to our department for evaluation of liver dysfunction and proteinuria. A liver biopsy specimen showed ductular proliferation and moderate portal fibrosis indicating stage II primary biliary cirrhosis. A renal biopsy specimen showed mild to moderate mesangial cell proliferation without crescent formation or interstitial nephritis. Immunofluorescent staining revealed deposition of immunoglobulin G (IgG), third component of complement (C3), and Clq on glomerular basement membranes. The findings indicated stage I membranous glomerulonephritis. Administration of ursodesoxycholic acid together with prednisolone, azathioprine, and dipyridamole decreased proteinuria and improved cholestatic liver dysfunction.

Giant hepatic biloma following transcatheter oily chemoembolization in a patient with hepatic metastases from malignant pheochromocytoma

A 48-year-old woman developed hepatic metastases from malignant pheochromocytoma resected 8 years previously. Angiography revealed multiple tumor stains in the liver. Transcatheter oily chemoembolization using styrenomaleic acid neocarzinostatin and iodized oil was performed. The patient complained of severe right upper quadrant pain immediately following the transcatheter oily chemoembolization. Necrotizing cholecystitis developed on the 4th day post-transcatheter oily chemoembolization, hepatic infarction on the 12th day, and a biloma on the 19th day. Despite the administration of antibiotics and percutaneous transhepatic drainage, neither the volume of drainage nor the size of the biloma decreased. Biliary reconstruction was performed using a metallic stent, which decreased the size of the biloma.

Kinetic assay of serum and urine for urea with use of urease and leucine dehydrogenase

We describe a new kinetic assay for determining urea in serum or urine with use of urease (EC 3.5.1.5) and leucine dehydrogenase (EC 1.4.1.9). The latter enzyme is suitable for the kinetic assay of NH4+ because its Km value for NH4+ at pH 8.75 is large (approximately 500 mmol/L). Interference from endogenous NH4+ in serum or urine is obviated by subtraction of the assayed endogenous NH4+ value in a sample blank. For serum, within-assay CVs (n = 10) were 0.39-0.58%; day-to-day CVs (n = 10) were 1.56-2.30%. In urine, within-assay CVs (n = 10) were 0.86-1.15%. Analytical recovery of urea (0.893-71.4 mmol/L) added to patients' sera (urea 6.14 mmol/L) was 99.2-105.2%. The calibration curve for serum was linear through zero for urea concentrations up to 142.9 mmol/L and for urine up to 714.3 mmol/L. No influences of added ammonium ion, bilirubin, hemoglobin, ascorbic acid, or Intralipid were observed. The regression equations for this method (y) and conventional methods (x = Determiner-LUN for serum assays, Serotec UUR-R for urine) were: y = 1.016x - 0.12 mmol/L (r = 0.999, S(y/x) = 0.34 mmol/L, n = 100) for sera, and y = 1.070x - 12.6 mmol/L (r = 0.998, S(y/x) = 7.41 mmol/L, n = 100) for urine.

[A case of sarcoidosis with cranial mononeuritis multiplex and peripheral polyneuropathy]

A 67-year-old woman with sarcoidosis, cranial mononeuritis multiplex and peripheral neuropathy was reported. The initial presentation of her sarcoidosis was a subcutaneous nodule of left knee joint on June, 1990. The number of subcutaneous nodules increased. Sarcoidosis was diagnosed by biopsy of the subcutaneous nodule. Paresthesia of the face and limbs appeared from November, 1991 and one month later, left abducens palsy and hearing disturbances were added. Alternate day therapy of 20mg prednisolone was effective in improvement of symptoms. The case of sarcoidosis with cranial mononeuritis multiplex and peripheral polyneuropathy was rarely found in 6 to 25% of patients with sarcoid neuropathy in the previous reports. Angiotensin-converting enzyme (ACE) in cerebro-spinal fluid not only raised on exacerbation also lowered with improvement of symptoms after steroid therapy. The ACE, which had a selective activity in the central nervous system, seemed to contribute to the index of treatment for sarcoidosis.

Relationship between susceptibility to apoptosis and Fas expression in peripheral blood T cells from uremic patients: a possible mechanism for lymphopenia in chronic renal failure

Chronic renal failure (CRF) is often complicated by lymphopenia, which may be partly responsible for immune deficiency. We hypothesized that lymphopenia in CRF might result from apoptosis of T cells in vivo. To elucidate the involvement of Fas antigen which mediates apoptosis, we analyzed Fas expression on peripheral blood T cells in uremic non-dialyzed (non-HD) patients and hemodialysis (HD) patients. T cells from both uremic groups expressed Fas with higher intensity than control T cells. When two uremic groups were compared, Fas intensity on T cells was significantly higher in non-HD patients than in patients on HD. Moreover, uremic T cells were shown to undergo accelerated apoptosis when cultured in vitro, in correlation with Fas expression. Our results suggest that T cells in CRF may undergo apoptosis by the Fas system and that hemodialysis treatment has beneficial effects in the light of the inhibition of T cell apoptosis.

[Early detection of hepatocellular carcinoma with lectin reactive alpha-fetoprotein]

Lens culimaris agglutinin A-reactive alpha-fetoprotein (AFP L3) and erythroagglutinating phytohemagglutin-reactive alpha-fetoprotein (AFP P4 + P5) were determined by a sensitive method using lectin-affinity electrophoresis coupled with antibody-affinity blotting, and the usefulness of this method for early detection of hepatocellular carcinoma (HCC) was examined. For 72 operated cases of the HCC group including 28 cases of small liver cancer, the AFP value was 124 +/- 198ng/ml (Mean +/- SD); the lectin fraction values for L3 and P4 + P5 were 12.2 +/- 17.9 and 17.9 +/- 17.9%, respectively, which were significantly higher compared with the chronic hepatitis (CH).cirrhosis (LC) group and showed an increasing tendency with an increase in tumor diameter. The cut-off values for distinguishing HCC from CH.LC, determined with the receiver-operating characteristic (ROC) plots, were 10.0 and 15.0% for the L3 and P4 + P5 fractions, respectively, and the positive rates in the patient with HCC were 33.3 and 48.6% for AFP L3 and AFP P4 + P5, respectively, and 59.7% with a combination assay. For small liver cancer, the positive rate was 17.9% with protein induced by vitamin K absence-II (PIVKA-II) and 46.4% with combination assay of AFP L3 and AFP P4 + P5. Also, for HCC below AFP 50ng/ml, a positive rate of 45.0% was obtained. In the CH.LC group, all cases were negative for AFP L3 and 2 of 44 cases (4.5%) were false-positive for AFP P4 + P5.

Evaluation of regional cerebral blood flow changes on perifocal brain tissue SPECT before and after removal of arteriovenous malformations

In fifteen cases of arteriovenous malformation (AVM), serial examinations of regional cerebral blood flow (rCBF) using single photon emission computed tomography (SPECT) and N-isopropyl-(123I)p-iodoamphetamine were performed. On SPECT images, the nidus was visualized as a focal rCBF defect in all cases preoperatively and seven of these cases had abnormal decreased perfusion areas in the tissues adjacent to the nidus. In five cases, the postoperative SPECT images on the day after surgery revealed an abnormal increased perfusion area adjacent to the nidus and in one case the increased perfusion was accompanied by a massive intracerebral haemorrhage detected by brain computed tomography (CT). In seven cases, postoperative SPECT images showed widespread abnormal decreased perfusion areas in the surrounding tissues and brain CT revealed either intracerebral haemorrhage or significant cerebral oedema. In the other three cases, no remarkable rCBF changes were found in comparison with the pre-operative study. There was a tendency for the preoperative abnormal decreased perfusion area adjacent to the nidus to correlate with the postoperative hyperperfusion and for the postoperative abnormal decreased perfusion area to reflect brain damage.

Determination of Kt/V and protein catabolic rate using pre- and postdialysis blood urea nitrogen concentrations

We developed a new urea kinetic method for simultaneous determination of the Kt/V and protein catabolic rate (PCR) only from blood urea nitrogen (BUN) concentrations before and after a single dialysis session. Using this method, the parameters were calculated within 1.5 s even when a hand-held computer with a low central processing capacity is used. The total amount of urea eliminated during three dialysis sessions in 1 week is assumed to be equal to urea volume (Gw) generated over a 1-week period (Tw): [formula: see text]. Here, G is the generation rate, K is the dialyzer urea clearance, T is the dialysis time and C1, C2 and C3 are BUN during the respective dialysis session. If this equation and the equation expressing the urea kinetics during a single dialysis session are solved together, we have a solution for Kt/V and G. The thus-obtained Kt/V and G are corrected using the change in body weight. The corrected Kt/V showed a good correspondence with the parameter calculated with the classical method, and the midweek PCR derived from G determined by the present method being equivalent to the PCR averaged for a 1-week period determined by the classical methods.

[Myocardial metabolism during dynamic exercise]

The development of Webster catheterization has enabled us to make clinical measurement of coronary sinus blood flow and to estimate the kinetics in myocardial substrate uptake. In this study, exercise tolerance test using supine multistage bicycle ergometer test was performed and exercise-induced hemodynamic alteration was evaluated in 18 patients with ischemic heart disease (16 males and 2 females, average age 56.3 years). The change in substrate kinetics in myocardial metabolism was also examined in terms of two indexes; myocardial uptake rate and myocardial uptake. The following results were obtained. 1) The myocardial uptake rates of glutamate and free fatty acid were significantly decreased by exercise, while those of glucose and lactate showed no significant change. 2) The myocardial uptakes of glutamate, glucose and lactate were significantly increased by exercise, but that of free fatty acid did not change significantly. 3) A significant negative correlation (r = -0.52, p < 0.05) was observed between the change in myocardial glutamate uptake and the change in pulmonary artery wedge pressure induced by exercise, suggesting that patients with ischemic heart disease might fail in glutamate uptake induced by exercise. The difference in the kinetics of myocardial uptake rate and myocardial uptake for glutamate, alanine, glucose, free fatty acid and lactate is observed. This difference occurs from the decrease in uptake rate due to the increase in coronary sinus blood flow. Myocardial uptake, which directly reflects myocardial energy metabolism is regarded as a more useful index of myocardial metabolism than myocardial uptake rate.

[The administered activity of radionuclides in nuclear medicine--rational reduction of medical radiation exposure]

A survey of 104 hospitals was conducted to determine the administered activity of radionuclides. Eighty-five hospitals responded, and reported a total of 119,614 examinations in one year. The examinations included: bone scintigraphy, 26.4%; Thallium-201 (201Tl) myocardial scintigraphy, 15.5%; Gallium-67 (67Ga) scintigraphy, 13.3%; N-isopropyl-p-[123I]iodoamphetamine (IMP) brain perfusion scintigraphy, 7.0%. The administered activity was corrected by body weight only for children at more than 80% of the responding hospitals. The number of hospitals that reported over-administration of radionuclide varied according to the type of scintigraphy performed: bone, 76%; inflammatory (67Ga), 93%; myocardial (201Tl), 89.2%; brain (IMP), 8.5%. The administered activity of IMP was closer to the upper limits specified in the Recommendations on Standardization of Radionuclide Imaging by the Japan Radioisotope Association (1987), because IMP is very expensive and is supplied as single vials. The highest average effective dose was for myocardial scintigraphy, the second-highest for inflammatory scintigraphy, and the third-highest for bone scintigraphy. In 201Tl and 67Ga scintigraphy, the entire contents of the vial may be administered two days before the expiration date, because the ratio of (true patient administered activity) to (declared patient administered activity) is similar to the ratio of (radioactivity on the day of supply) to (radioactivity on the day of expiration). The factors that influence administered activity are throughput, price of the radionuclide, and whether the radionuclide is sold as a single vial. In order to decrease the effective dose, it is necessary to establish a close cooperation between medical personnel, the makers of radiopharmaceuticals, and manufacturers of gammacameras.

Quantitative measurement of regional cerebral blood flow using N-isopropyl-(iodine-123)p-iodoamphetamine and single-photon emission computed tomography

We have developed a quantitative method of measuring regional cerebral blood flow (rCBF) by using N-isopropyl-(iodine-123)p-iodoamphetamine and single-photon emission computed tomography (SPECT). Twenty-five dynamic SPECT images (24 sec/scan) were collected immediately after tracer injection using a ring-type SPECT system and the accumulation curve (C(t)) was obtained. The time-activity curve corresponding to the arterial blood activity curve was used as B(t). The latter curve was calculated from the lung time-activity curve monitored during scanning and corrected by the actual activity obtained by one-point blood sampling 5 min after tracer injection. The octanol extraction ratio during scanning was considered to be constant and taken as the value measured 5 min after tracer injection (E). The uptake constant (K) per pixel was calculated by the least squares fitting method as the slope of the linear relationship in which C(t)/E x B(t) was plotted against E x integral of t(o)B(tau)d tau/E x B(t). Functional maps of rCBF values were obtained on a 64 x 64 matrix by calculating the uptake constant per pixel and the cross calibration factor (CF) between the SPECT system and a well counter (rCBF = K.CF x 100).

Relationship between dialysis induced hypotension and adenosine released by ischemic tissue

Two types of dialysis induced hypotension apparently exist. One type presents as gradually decreasing blood pressure with eventual symptoms (gradual hypotension), whereas the other presents as abruptly and sharply decreasing blood pressure, along with symptoms (abrupt hypotension). In the current study, the authors found that the plasma hypoxanthine concentration during abrupt hypotension was significantly higher than before the hypotension occurred (20 min after saline was administered or at the beginning of dialysis), whereas comparison of the plasma hypoxanthine concentration during gradual hypotension and that before the hypotension occurred (20 min after saline was administered or at the beginning of dialysis) revealed no significant difference. The current results indicate that abnormally increased adenosine triphosphate (ATP) degradation associated with tissue ischemia occurred during abrupt hypotension but not during gradual hypotension. It can be speculated that the increased release of adenosine due to abnormally increased ATP degradation caused the abrupt hypotension. This conclusion seems reasonable given that adenosine directly decreases small vessel tone and inhibits prejunctional release of norepinephrine.

A DNA hybridization assay for use in drug sensitivity tests in vitro for Plasmodium falciparum under field conditions

A deoxyribonucleic acid (DNA) hybridization technique was applied to in vitro drug sensitivity testing of P. falciparum using a synthetic 21-mer oligonucleotide coupled to alkaline phosphatase (PFR1-AP) to monitor development of parasite stages in culture. The density of the coloured spot clearly distinguished schizonts from ring forms. This assay system was applied in the field on Hainan Island, China. Blood samples obtained from patients were cultivated in the presence of antimalarial drugs and the minimum drug concentration required to inhibit development of parasites was determined by the DNA hybridization assay and by microscopical observation of Giemsa-stained blood smears. The 2 methods yielded identical results, indicating that the DNA hybridization assay can be used for in vitro drug sensitivity testing under field conditions.

[Utilization of an enzyme-sensor in clinical medicine]

The utilization and merit of an enzyme-sensor for measuring serum- or urine-components were reported. The enzyme sensor (enzyme-electrode) is an H2O2-electrode, O2-electrode or ion selective electrode connected with an enzyme-immobilized nylon tube. First, the principle of measurements with an enzyme sensor was reported. Secondly, and H2O2 electrode which had been planned and developed in our laboratory was introduced. The outline of our apparatus and the procedure of enzyme-immobilization onto a nylon tube wall were explained. Then the results obtained from quantitative analysis of serum- and urine-components were shown. For the analysis by our apparatus, 3-60 microliters of serum or urine was used and incubation time was approximately 5 min. The results obtained by our apparatus coincided with those obtained by other methods (r = 0.981-0.997). Thirdly, the usefulness of commercial instruments with an enzyme-sensor for determining glucose- or lactic acid-content was described. The results (glucose and lactic acid-contents) measured by desktop-size instruments showed a high lineality and good reproducibility (CV = 0.6-1.5% in glucose and 0-0.7% in lactic acid). A good correlation was observed among each instrument (r = 0.999). The results by card-size instruments, GLUTEST E or ExacTech, showed a lower reproducibility (CV = 4.1-6.5%) and correlation (r = 0.95-0.98) than those by desktop-size instruments.

[In vivo effects on human neutrophils by administration of rhG-CSF and clinical significance]

To evaluate the clinical effect by administration of recombinant human granulocyte-stimulating factor (rhG-CSF) post chemotherapy in non-Hodgkin malignant lymphoma (NHL), 17 patients with NHL were subjected to this study. Administration of rhG-CSF ameliorated the decrease in absolute neutrophil counts after the cytotoxic chemotherapies and activated neutrophil functions in active oxygen product and expressions of adhesion proteins. To consistent with these results, rhG-CSF administrations post cytotoxic chemotherapy were effective for reducing infection complications associated with neutropenia. Furthermore, administration of rhG-CSF increased peripheral hematopoietic progenitor cells, thus suggesting promising therapeutic potential for autografting. Recently, it has been reported that blood neutrophils may synthesize mRNA and proteins important in inflammation including various cytokines such as IL-1, IL-6, TNF-alpha and IFN-alpha, but, administration of rhG-CSF showed no obvious effect on the level of either IL-1, IL-6, TNF-alpha or IFN-alpha in sera, and furthermore, the in vitro stimulation by rhG-CSF induced no significant production of these cytokines and expressions of TNF-alpha and IFN-alpha mRNAs. Finally, we studied on anti-tumor effect of administration of rhG-CSF in CDF1 mice inoculated with syngeneic lymphoma cells. rhG-CSF infusion suppressed the liver metastasis and prolonged the overall survival, thus suggesting the hypothesis that use of rhG-CSF in some patients with NHL might control the disease through stimulating both production and functional activation of neutrophils.

Quantitative measurement of regional cerebral blood flow with I-123 IMP SPECT: a correction of the microsphere model by global extraction between artery and internal jugular vein

Quantitative measurements of regional cerebral blood flow with N-isopropyl-(Iodine 123)p-iodoamphetamine (I-123 IMP) as a microsphere model were performed in forty cases. The regional cerebral blood flow values obtained with I-123 IMP were slightly underestimated compared with those of Xe-133 inhalation methods (y = 0.90x-2.1, r = 0.85, p less than 0.01). After correction by global extraction (87%) between the artery and internal jugular vein, which was measured in four patients by means of a catheter technique, the underestimation of the values obtained with I-123 IMP was improved (y = 1.0x-2.4, r = 0.85, p less than 0.01). Several problems in the accurate quantitative measurement of regional cerebral blood flow with I-123 IMP are discussed.

Minor changes in regional cerebral blood flow revealed by the early distribution of I-123 IMP in brain

To evaluate the early distribution of I-123 IMP in the brain, 10 dynamic images were obtained in the first 10 minutes after injection using a ring-type SPECT system with a high-sensitivity collimator. In cases of chronic carotid occlusion without brain CT abnormalities, areas of low perfusion were more clearly demonstrated in dynamic images than in static images obtained beginning 20 minutes after injection and continuing for 15 minutes using a high-resolution collimator. In cases of hyperperfusion following infarct or surgery, there was a difference between dynamic and static images in the visualization of hyperemic lesions. The distribution of I-123 IMP in the brain changes gradually, even in the early period after injection, and evaluation of early accumulation is useful for the detection of minor changes in regional cerebral blood flow.

Continuous measurement of pressure in internal arteriovenous fistulae and prevention of symptomatic hypotension during hemodialysis

To continuously monitor the blood pressure (BP) in an internal arteriovenous fistula, the blood tubing wall was punctured with a long, fine needle (25 gauge), and the needle tip was advanced into the fistula vein through the lumen of the outflow blood access puncture needle. It was found that the intrafistula BP thus measured varied in parallel with the systemic arterial BP during hemodialysis (HD). When the intrafistula BP fell to 60% of the level at the start of HD, 50 ml of saline was administered. As a result, hypotension was prevented completely in 60 HD in five patients who often showed symptomatic hypotension during HD.

Morphological Features of Blood Access Stenosis and Results of Noninvasive Angioplasty

We investigated a connection between the results of noninvasive angioplasty for the blood access stenosis and its morphological features in 37 dialysis cases. In 3 cases presenting stenosis in the original artery, the area could not be dilated by noninvasive techniques. In 4 cases with stenosis in the arterialized vein downstream of the needle insertion points for extracorporeal circulation, 3 showed longterm dilatation by the procedures. In 30 cases having stenosis upstream of the points, 16 showed longterm dilatation. In the unsuccessful cases, the angle formed between the axes of the stenosed portion and the normal vessel was over 39 degrees, and the distance between the anastomosis and the stenosed portion was less than 11 mm.

Morphological features of blood access stenosis and results of noninvasive angioplasty

We investigated a connection between the results of noninvasive angioplasty for the blood access stenosis and its morphological features in 37 dialysis cases. In 3 cases presenting stenosis in the original artery, the area could not be dilated by noninvasive techniques. In 4 cases with stenosis in the arterialized vein downstream of the needle insertion points for extracorporeal circulation, 3 showed long-term dilatation by the procedures. In 30 cases having stenosis upstream of the points, 16 showed long-term dilatation. In the unsuccessful cases, the angle formed between the axes of the stenosed portion and the normal vessel was over 39 degrees, and the distance between the anastomosis and the stenosed portion was less than 11 mm.

Change in sympathetic activity before, during, and after dialysis-induced hypotension

During the hemodialyses of eight patients with end-stage renal failure, who often had sudden-onset dialysis-induced hypotension, catecholamine (CA) levels were measured in the ultrafiltrate obtained by a mini-filter placed in series upstream of the dialyzer. The water evaporation rate from the skin (reflecting the perspiration rate) was also monitored. Results showed a temporary elevation in CA levels in the ultrafiltrate before hypotension occurred. This rise did not continue for long, returning to baseline when hypotension actually occurred. The temporary elevation may reflect transient compensation by the sympathetic nervous system for the decrease in vascular wall tension. It was also found that there was considerable water evaporation from the skin during hypotension. Because sweat gland activity is reflexively modulated by the baroreceptor, perspiration after a drop in blood pressure may reflect the normal diminiution in baroreceptor activity.

Occurrence and character of a putative causative virus of enterically-transmitted non-A, non-B hepatitis in bile

The present investigation confirms the possibility that the etiological agent of enterically-transmitted non-A, non-B (ET-NANB) hepatitis (type E hepatitis), multiplied in hepatocytes, is excreted into the feces via bile. The fecal extract was inoculated into 7 cynomolgus monkeys. Bile juice was collected directly from the gallbladder by needle puncture after abdominal operation 3 to 6 times during the experimental course. All 7 monkeys developed elevated serum aminotransferases, which began gradually approximately 2 weeks postinoculation and reached a peak at 3 to 5 weeks. In parallel with this elevation, both in time and magnitude, necroinflammation was observed in the livers. The virus-like particles (VLPs) were found in the bile juice of all 7 monkeys and the serial occurrence of VLPs was typified as follows: the VLPs were negative on day 7, appeared on day 10 after inoculation, and were present until the 3rd week when the subjects were sacrificed. While the particles were individually dispersed on day 10, they started to exhibit spontaneous aggregation on and after week 2. Also, empty particles were very rare at first, but increased in ratio compared to full ones over time. Thus, the putative causative virus of ET-NANB hepatitis was demonstrated to be excreted through bile. The spontaneous aggregation of VLPs might be due to the specific antibody secreted into the bile juice and was closely correlated with hepatitis activity. The increase in empty particles might indicate an increase in disorganized assembly of the nucleic acid and protein during virus proliferation.

Myelopathy due to osteochondroma: MR and CT studies

A 9-year-old boy with multiple osteochondromas developed progressive transverse myelopathy. Magnetic resonance imaging and CT demonstrated an exostosis at C7-T1 with cord compression.

Enzymatic determination of bilirubin fractions in serum

Novel enzymatic methods using bilirubin oxidase from Myrothecium verrucaria are described for the determination of bilirubin fractions in serum. These fractions include an unconjugated form (Bu), a conjugated form (Bc), and a delta fraction of bilirubin that reacts with direct diazo reagent and is irreversibly bound to serum albumin (B delta). The determination is based on the different reactivities of the enzyme to bilirubin fractions at different pH in the presence or absence of anionic detergent such as sodium dodecyl sulfate (SDS) or sodium cholate. Thus, in the absence of detergents, Bc and B delta are oxidized at acidic pH, while Bc is oxidized at alkaline pH; Bu is not oxidized at either acidic or alkaline pH. The first approach is based on measuring the decreased absorbance of bilirubin colour at 450 nm caused by the enzymatic oxidation. Total bilirubin is measured at pH 8.0 in the presence of SDS. Direct bilirubin is measured at pH 3.7 and Bc is measured at pH 10.0 in the absence of SDS, respectively. The second approach is made by coupling the diazo reaction with the enzyme reaction. Total and direct bilirubin are determined by a conventional diazo method without prior treatment by the enzyme. B delta is determined with a direct diazo method after the serum sample is treated at pH 10.0 by the enzyme to oxidize the Bc fraction. The precision and the accuracy of these methods were compared with a diazo method, an HPLC method and a slide method, and good results were obtained.