Reduction of the gamma-ray component from 252Cf fission neutron source--optimization for biological irradiations and comparison with MCNP code

Gamma-rays contribute 33% of the absorbed dose from an unfiltered 252Cf fission neutron source. To reduce this gamma-ray component and to enable radiobiological experiments at as high a dose rate as possible, Monte Carlo calculations for several filter materials (Al, Fe, Pb and concrete) have been made using MCNP neutron and photon transport code version 4a. A lead filter of thickness 4 cm was found to reduce the gamma-ray component to 6.7% of the total dose whilst reducing the neutron dose by only about 10%. Such a filter was installed at the MRC 252Cf neutron irradiation facility and dosimetric measurements were made using a TE-TE chamber and a 7LiF(Mg, Cu, P) TLD. Monte Carlo simulations agree with experimental measurements of neutron and gamma-ray doses within 6%. V79-4 Chinese hamster cells were irradiated with lead-filtered and unfiltered neutrons and also with 60Co gamma-rays at two dose rates. The survival fraction obtained for each radiation was consistent with the reduced gamma-ray dose. The relative biological effectiveness for neutrons alone, corrected for gamma-ray effects, was found to be 9.2 +/- 3.4 from the initial slopes and 3.1 +/- 0.5 at 10% survival, both relative to the acute gamma-rays.

The Fanconi anemia group E gene, FANCE, maps to chromosome 6p

Fanconi anemia (FA) is a genetically heterogeneous autosomal recessive disease with bone marrow failure and predisposition to cancer as major features, often accompanied by developmental anomalies. The cells of patients with FA are hypersensitive to DNA cross-linking agents in terms of cell survival and chromosomal breakage. Of the eight complementation groups (FA-A to FA-H) distinguished thus far by cell fusion studies, the genes for three-FANCA, FANCC, and FANCG-have been identified, and the FANCD gene has been localized to chromosome 3p22-26. We report here the use of homozygosity mapping and genetic linkage analysis to map a fifth distinct genetic locus for FA. DNA from three families was assigned to group FA-E by cell fusion and complementation analysis and was then used to localize the FANCE gene to chromosome 6p21-22 in an 18.2-cM region flanked by markers D6S422 and D6S1610. This study shows that data from even a small number of families can be successfully used to map a gene for a genetically heterogeneous disorder.

[The anesthetic management of tracheal T-tube exchange using Patil-Syracuse mask]

We exchanged the tracheal T-tube inserted to a 17-year-old female, who wanted to be able to enunciate again, with relapsing polychondritis and difficulty in enunciation which the proximal end of tracheal T-tube above the false vocal cords was causing. The procedure was performed using Patil-Syracuse mask, without tracheal intubation, under-general anesthesia. This method will ensure precise length adjustment and correct placement of the T-tube under fiberoptic bronchoscope.

The effect of various doses of lazaroid U74389G on lung ischemia reperfusion injury

BACKGROUND

We investigated the effect of lazaroid U74389G, a potent inhibitor of lipid peroxidation, on ischemia-reperfusion injury at three different doses in the rat orthotopic left lung transplantation model.

METHODS

Four groups of reperfused lungs were studied. In group I (control) donor lungs were transplanted after 12 hours of preservation in University of Wisconsin (UW) solution at 4 degrees C. In groups II, III, and IV, lazaroid was used as an additive to UW solution at concentrations of 30 micromol/L, 50 micromol/L, and 100 micromol/L, respectively, and was also administered intravenously to the recipients 30 minutes before reperfusion after 12 hours of storage in the UW solution at 4 degrees C.

RESULTS

After 1 hour of reperfusion, gas exchange function (p < 0.01), tissue lipid peroxide levels (p < 0.05) and histologic damage in reperfused lung allografts (p< 0.05) were significantly improved in lazaroid-treated group IV compared with control group I.

CONCLUSIONS

These findings suggest that lazaroid U74389G ameliorates ischemia-reperfusion injury in rat lung transplants by inhibiting lipid peroxidation.

Cerebellar clear cell ependymoma mimicking hemangioblastoma: its clinical and pathological features

BACKGROUND

As the clinical and pathological significance of cerebellar clear cell ependymoma (CCE) has not been recognized in the past, eight cases of cerebellar CCEs were studied.

METHODS

Subjects were six men and two women, and their ages ranged from 23 to 64 years old. Their neuroradiological, operative, and pathological features were reviewed.

RESULTS

The tumors frequently showed high vascularity on angiography and marked enhancement on computerized tomography. Grossly, six tumors exhibited a "cyst with mural nodule" and two were mostly solid containing small cysts. At operation, the tumor nodules were dark red in color and the cysts contained xanthochromic fluid. Microscopically, all tumors displayed mostly clear round cells and abundant blood vessels. Although they commonly lacked the characteristic features of ependymomas, immunostaining and electron microscopy confirmed their ependymal origin.

CONCLUSIONS

The results indicate that cerebellar CCEs closely mimic hemangioblastoma both clinically and pathologically, which suggests CCE should be considered in the differential diagnosis of vascular tumors of the cerebellum. Some diagnostic clues to differentiate CCE from hemangioblastoma are discussed.

[Fiberoptic bronchoscopy-aided tracheal intubation using a patil-syracuse mask in a "can ventilate/cannot intubate" situation]

We could perform endotracheal intubation in three patients whose ventilation had been anticipated possible preoperatively but endotracheal intubation impossible, using a fiberoptic bronchoscope while ventilating via Patil-Syracuse mask. This method is an alternative in a "can ventilate/cannot intubate" situation.

Lazaroid U74389G ameliorates ischemia-reperfusion injury in the rat lung transplant model

We investigated the effect of Lazaroid U74389G on ischemia-reperfusion injury in the rat orthotopic left lung transplantation model. Five groups of reperfused lungs were studied. In group I, donor lungs were transplanted after 12 hours of preservation in University of Wisconsin (UW) solution at 4C. In groups II, III, and IV, Lazaroid was intravenously administrated at a dose of 1 mg/kg, 8 mg/kg, and 15 mg/kg, respectively, to the donors 30 minutes before preservation and also to the recipients 30 minutes before reperfusion after 12 hours of storage in UW solution at 4C. In group V, Lazaroid was added to the UW solution (80 micromol/l), and also was administered intravenously (6 mg/kg) 30 minutes before reperfusion. After 1 hour of reperfusion, gas exchange function and tissue lipid peroxide levels were significantly improved in Lazaroid-treated groups III, and V compared with no treatment group I. Histologic damage was less severe in groups III, IV, and V than in group I. These findings suggest that Lazaroid U74389G ameliorates ischemia-reperfusion injury in the rat lung transplants by inhibiting lipid peroxidation, regardless of whether it is administrated intravenously or given as an additive to the preservation solution.

Pharmacological properties of traditional medicines. XXV. Effects of ephedrine, amygdalin, glycyrrhizin, gypsum and their combinations on body temperature and body fluid

Effects of ephedrine, amygdalin, glycyrrhizin, gypsum and their combinations on body temperature and body fluid were studied in rats using the method developed in our previous reports. Ephedrine significantly increased respiratory evaporative water loss and heat loss in response to a marked elevation of body temperature. There was a small but significant increase in body temperature when amygdalin was orally given rats at a dose of 46.32 mg/kg. Glycyrrhizin and gypsum were unable to affect body temperature. However, gypsum was able to prevent the increased action of ephedrine on body temperature, amygdalin exhibited a preventive tendency to it, and glycyrrhizin did not affect it. The results are in good agreement with classical claims of Makyo-kanseki-to and the related crude drugs in traditional medicine. Moreover, a combination of the four components reproduced the effects of Makyo-kanseki-to on body temperature and body fluid. This report suggests that the co-administration of ephedrine and gypsum is physiologically more desirable than ephedrine alone for dry-type asthmatic patients with a fever. Also, it experimentally supports the clinical efficacy of Makyo-kanseki-to.

Complement activation accelerates glomerular injury in diabetic rats

A known inhibitor of the complement cascade (K-76 COONa) was administered to an inbred diabetic rat model to investigate whether the complement system may play a role in the progression of diabetic glomerulosclerosis. Drinking water containing K-76 COONa was available continuously to inbred diabetic rats (Otsuka Long-Evans Tokushima Fatty, OLETF) from the age of 25 to 55 weeks (Group L). Drinking water without K-76 COONa was similarly available to OLETF rats (Group H) and nondiabetic control rats (Long-Evans Tokushima Otsuka, LETO) (Group C). The levels of plasma glucose (mg/dl) at the 55th week were 156 +/- 16 in Group C, 252 +/- 18 in Group L and 349 +/- 93 in Group H. There was no significant difference in the degree of diabetes between Group L and Group H. The levels of urinary protein at 55 weeks of age (mg/day) were 2.1 +/- 0.4 in Group C, 11. 6 +/- 1.5 in Group L and 18.0 +/- 2.8 in Group H. The level of urinary protein was significantly decreased by the administration of K-76 COONa. Histological examination of renal specimens from the sacrificed rats at 55 weeks of age revealed diffuse mesangial expansion in almost all glomeruli in Group H, exudative lesions in 30% of glomeruli in Group H, and only mild mesangial expansion was recognized in Group L. Immunofluorescence study revealed brilliant staining of C3 and immunoglobulins (Ig) in Group H; trace staining of Ig and no staining of C3 were recognized in Group L. The incubation study with guinea pig serum and glomeruli from rats revealed that Ig and complement components also bound to injured glomeruli in vitro. These data indicate that the complement cascade is activated by injured glomeruli and this activation exacerbates diabetic glomerulosclerosis.

A new flavanone isolated from rhizoma smilacis glabrae and the structural requirements of its derivatives for preventing immunological hepatocyte damage

From the rhizome of Smilax glabra Roxb., a new flavanone was isolated and named as smitilbin (1), together with 6 known compounds, engeletin (2), astilbin (3), dihydroquercetin (4), eurryphin (5), resveratrol (6), and 5-O-caffeoylshikimic acid (7). These compounds were applied to the assay of liver nonparenchymal cells (NPC) against hepatocytes (HC) isolated from mice with an immunological liver injury. Against the NPC-caused elevation of ALT (alanine transminase) in culture supernatant from HC, the pretreatment of NPC with flavanoids (1-3) dose-dependently blocked the ALT release while 4, the aglycone of 3, did not. The chromone 5 showed a much stronger inhibition. Compound 6 also showed the activity. However, 1-7 did not show any suppression of NPC or CCl4-induced ALT release when they were used to pretreat HC. These results suggest that compounds 1-3, 5, and 6 could protect the hepatocyte damage from NPC through selectively producing the dysfunction of NPC with an essential requirement of rhamnose, and the chromone part in their structures may be critical for exhibiting the activity rather than through protecting the hepatocyte membranes.

Prolyl endopeptidase inhibitors from the underground part of Rhodiola sacra S. H. Fu

Prolyl endopeptidase (PEP, EC 3.4.21.26) is an enzyme which plays a role in the metabolism of proline-containing neuropeptides, e.g., vasopressin, substance P and thyrotropin-releasing hormone (TRH), which have been suggested to be involved in learning and memory processes. In our systematic screening for PEP inhibitors from traditional Chinese medicines, we found that MeOH extract from the underground part of Rhodiola sacra S. H. Fu shows significant inhibitory activity against PEP from Flavobacterium meningosepticum. Examination of the constituents of the extract resulted in the isolation of nineteen known compounds, identified as hydroquinone (1), 4-hydroxybenzoic acid (2), caffeic acid (3), 4-hydroxycinnamic acid (4), suberic acid (5), protocatechuic acid (6), gallic acid (7), (-)-epigallocatechin 3-O-gallate (8), 2-phenylethyl beta-D-glucopyranoside (9), 3-O-galloylepigallocatechin-(4beta-->8)-epigallocatechin+ ++ 3-O-gallate (10), 2-phenylethyl alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranoside (11), sacranoside A (12), beta-D-glucopyranosyl 4-hydroxybenzoate (13), rhodiocyanoside A (14), rhodiooctanoside (15), sarmentosin (16), heterodendrin (17), arbutin (18) and 4-O-(beta-D-glucopyranosyl)-gallic acid (19). Among these, 1, 2, 5, 8-10, 13, 16, 18 and 19 have been isolated for the first time from R. sacra, among which 5, 9, 10, 13, 16, 18 and 19 have been isolated from Rhodiola plants for the first time. On the PEP inhibition, seven compounds (6-8, 10, 12, 18, 19) showed inhibition with an 1C50 of 27.8, 487, 1.47, 0.437, 348, 391 and 215 microM, respectively. The kinetic study of these inhibitors indicated that they are noncompetitive inhibitors, except for 6 which is a competitive inhibitor.

Heat sensitivity of double-stranded DNA-dependent protein kinase (DNA-PK) activity

PURPOSE

The heat sensitivity of DNA-PK activity in hybrid cells and the possible restoration of this activity with extracts from scid cells (defective in DNA-PKcs), sxi-3 cells (defective in Ku80) and V794 (sxi-3 parental wild-type cells) was analysed.

MATERIALS AND METHODS

Heat treatment of cells was performed in a water bath at 44 degrees C. The cell extract from scid cells or sxi-3 cells was added to heat-treated hybrid cell extracts, and the DNA-PK activity was assayed.

RESULTS

When hybrid cells were heated at 44 degrees C for 15 min, DNA-PK activity was reduced to undetectable levels. The decreased DNA-PK activity could be restored in a concentration-dependent manner with the addition of scid cell extract. The sxi-3 cell extract could not restore heat-inactivated DNA-PK activity.

CONCLUSIONS

DNA-PK was inactivated by heat treatment at 44 degrees C. Ku70/Ku80, but not Ku70 alone, could restore heat-inactivated DNA-PK.

Sequence analysis of an 800-kb genomic DNA region on chromosome 8q21 that contains the Nijmegen breakage syndrome gene, NBS1

An 800-kb region on chromosome 8q21, which complements the phenotype of cells from Nijmegen breakage syndrome patients, is a candidate for the locus of the underlying gene, termed NBS1. The sequence of this 800-kb region of DNA indicated that the size of this segment is 755,832 bp with an additional 36-kb gap. From this region, we identified four genes including NBS1, a gene coding for a 27-kDa vitamin D-dependent calcium-binding protein (27-kDa calbindin), the mitochondrial 2,4-dienoyl-CoA reductase gene, and a novel gene, C8orf1/hT41. All four genes were aligned in a 250-kb centromeric portion of the region, and no gene was found in the remaining telomeric portion containing 500 kb. The genomic organization of the C8orf1/hT41 and NBS1 genes has been analyzed using the computer programs GRAIL 2 and GENSCAN. They predicted and successfully found more than 93% of the exons, even a small 54-bp exon, indicating that one or more exons in any gene can be identified by these programs. GENSCAN was more efficient at locating the four genes than GRAIL 2 and identified 15 of the 16 exons of the NBS1 gene. This 800-kb region contained repetitive sequences, including 179 copies of the Alu sequence (1 copy/4.2 kb), 123 copies of the L1 sequence (1 copy/6.1 kb), 107 copies of the LTR sequence (1 copy/7.1 kb), and 63 copies of the MER sequence (1 copy/12 kb). There was a slight but not significant difference in the repetitive content of the gene-rich region and the remaining noncoding region. Our results indicate that computer-assisted methods are useful and powerful for identifying exons of both known and novel genes.

Direct preparation of radioactive fullerenes as a tracer for applications

The C60 and C70 fullerenes were irradiated by high-energy gamma-rays and charged particles. The irradiated samples were dissolved in CS2 and/or toluene and filtered to remove insoluble by-products. Finally, radioactive fullerenes and products labeled with 11C or 13N were isolated and detected in the liquid phase by radiochromatography. It was found that (1) not only 11C or 13N radioactive monomer fullerenes but also their dimers (trimers and, possibly, tetramers) were produced by recoil implantation process following nuclear reaction and (2) the radioactive fullerene labeled with 11C yields has led to high yields.

Coccidioidomycosis in Arizona: increase in incidence from 1990 to 1995

The number of cases of coccidioidomycosis (incidence) reported to the Arizona Department of Health Services increased from 255 (7.0 per 100,000 population) in 1990 to 623 (14.9 per 100,000 population) in 1995 (P < .001). Four counties in the south central region of the state, which contained 80% of the state's population, had the largest increase and accounted for 95% of all cases in 1995. Cases in persons aged 65 years or older and men were reported more frequently (for both, P < .001). During 1995, 890 patients were discharged from Arizona hospitals with a diagnosis of coccidioidomycosis. Rates of hospitalization were greater among persons aged 55 years or older, men, and African-American (for all three, P < .01). Of the hospitalized patients, 48 died, and 12 (25%) of these patients had a concurrent diagnosis of human immunodeficiency virus infection. These data demonstrate that coccidioidomycosis is a growing health problem in Arizona.

The phosphatidylinositol 3-kinase inhibitor wortmannin sensitizes quiescent but not proliferating MG-63 human osteosarcoma cells to radiation

Recent genetic and biochemical studies indicate that DNA-dependent protein kinase (DNA-PK) plays an important role in DNA double-strand break (dsb) repair and V(D)J recombination. Since the catalytic subunit of DNA-PK (DNA-PKcs) has high sequence homology with phosphatidylinositol 3-kinase (PI 3-kinase), we examined the effect of wortmannin, a specific inhibitor of PI 3-kinase, on the survival of human tumor cells after X-irradiation. The present study demonstrates that wortmannin at 20 microM is an effective radiosensitizer of quiescent (Q), but not proliferating (P) cells. In addition, the rejoining of DNA dsb is significantly inhibited in Q, but not in P cells. Finally, we found that Q cell extracts have approximately five-fold less DNA-PK activity than those of P cells. After a 2 h exposure to wortmannin, the DNA-PK activity of Q cell extracts was considerably lower than that of P cells. This can explain why wortmannin sensitizes Q, but not P cells to radiation.

[Aortic valvular vegetation in annuloaortic ectasia due to idiopathic cystic medial necrosis: a case report]

Annuloaortic ectasia is often accompanied by Marfan syndrome and associated with infective endocarditis usually involving the mitral valves. We treated a patient with annuloaortic ectasia due to idiopathic cystic medial necrosis who developed congestive heart failure with aortic valvular vegetation. A 56-year-old man had dyspnea on effort since the beginning of January, 1997 and was admitted to our hospital on April 6, 1997 because of orthopnea. The diagnosis was congestive heart failure due to severe aortic regurgitation with annuloaortic ectasia detected by echocardiography. Medication and rest after hospitalization relieved his symptoms but congestive heart failure deteriorated after he had a high fever. At this time, a vegetation attached to the noncoronary cusp of the aortic valve was found which had not been detected on admission. Blood culture yielded Streptococcus sanguis. The diagnosis was infective endocarditis involving the aortic valve. Surgical correction (Bentall method) improved congestive heart failure and he was discharged on August 4, 1997 without recurrence of endocarditis. Infective endocarditis involving the aortic valves is a possible cause of development or deterioration of congestive heart failure in patients with annuloaortic ectasia.

[Effects of cardiac output on blood and tissue pH during general anesthesia with constant ventilation]

We investigated the effects of cardiac output on blood and tissue pH in 106 adult patients undergoing cardiac or non-cardiac surgery under general anesthesia. After anesthetic induction, the minute ventilation volume was kept constant at 10 ml.kg-1 x 10 cycles.min-1. A pulmonary artery catheter and a nasogastric tube incorporating a tonometer were inserted. During surgery, cardiac index (CI), pH, Pco2, BE, So2 and Hb of arterial and mixed venous blood as well as gastric intramucosal pH (pHi) were measured simultaneously. Oxygen uptake index (Vo2I) and blood CO2 contents were calculated. The measurements were repeated every 10 to 20 minutes during surgery or during the prebypass period. Two patients with preoperative cardiogenic shock were excluded from data analysis because of development of severe acidosis and 624 sets of data from 104 patients were analyzed. Arterial and mixed venous pH correlated negatively with CI. Blood Pco2 and base excess (BE) correlated positively and negatively, respectively, with CI. Blood lactate concentration measured 142 times in the last 30 patients correlated positively with CI. Vo2I correlated positively with CI and Paco2 correlated positively with Vo2I. Veno-arterial differences in Pco2 and Cco2 correlated negatively with CI. Due to the difference, Caco2 correlated positively with CI, while Cvco2 did not correlate with CI. pHi correlated negatively with CI but only marginally. By multiple regression analysis, pHi was not affected significantly by CI, while it showed positive correlation with pHa, Hb, Sao2 and negative correlation with blood temperature. When cardiac output increased, blood pH decreased due to increased Pco2 and decreased BE. An increase in Paco2 might result from both an increase in Vo2 or Vco2 and decreased ventilation-to-perfusion ratio. A decrease in BE might result from increased washout of acids (e.g. lactate) from the tissue to the central circulation. In contrast to blood pH, pHi or tissue pH was not affected significantly by cardiac output unless patients were in cardiogenic shock.

[A case of leiomyosarcoma of the jejunum with postoperative hepatic encephalopathy]

We report a case of leiomyosarcoma of the jejunum with postoperative hepatic encephalopathy. A 60-year-old man was operated for tumor of the abdomen. He was diagnosed as leiomyosarcoma of the jejunum with disseminated peritoneal metastasis, but no liver metastasis and cirrhosis. A palliative resection of the jejunum was performed. After operation, disturbance of orientation and apraxia with electroencepharographic abnormality and hyperammonemia developed. He was diagnosed as hepatic encephalopathy without lesion of the liver, and died 11 months after surgery. We consider that the portosystemic shunt and bleeding from the digestive tract due to invasion of metastatic lesions caused hepatic encephalopathy.

Pharmacological properties of traditional medicines. XXIV. Classification of antiasthmatics based on constitutional predispositions

It is commonly accepted that bronchial asthma or rhinitis accompanies disorders in body fluids and body temperature. The effects of ephedrine and the traditional antiasthmatics "Makyo-kanseki-to" and "Goko-to" were therefore studied on such constitutional predispositions as insensible perspiration and body temperature. Ephedrine markedly increased body temperature and exhibited a strong increased action on respiratory insensible perspiration, whereas Makyo-kanseki-to and Goko-to not only prevented the elevation of body temperature, but also increased respiratory insensible perspiration following the reduction of non-evaporative heat loss from the body surface. Thus, the diagnostic criteria of these two medicines used to treat hot-type asthma or dry cough were experimentally determined. The results also suggest that there is a great possibility that the administration of antiasthmatics may elicit side effects or make diseases worse unless their actions on constitutional predispositions are taken into account, such as body temperature and body fluids.

Purification and characterization of cannabichromenic acid synthase from Cannabis sativa

Cannabichromenic acid synthase was purified to apparent homogeneity by sequential column chromatography including DEAE-cellulose, phenyl-Sepharose CL-4B, and hydroxylapatite. The enzyme catalysed the oxidocyclization of cannabigerolic acid and cannabinerolic acid to cannabichromenic acid. The K(m) values for both substrates were in the same order of magnitude although the Vmax value for the former was higher than that for the latter. These results suggested that cannabichromenic acid is predominantly formed from cannabigerolic acid rather than cannabinerolic acid. The enzyme required neither molecular oxygen nor hydrogen peroxide, indicating that the cannabichromenic acid synthase reaction proceeds through direct dehydrogenation without hydroxylation.