Genghis Khan (Gek) as a putative effector for Drosophila Cdc42 and regulator of actin polymerization

The small GTPases Cdc42 and Rac regulate a variety of biological processes, including actin polymerization, cell proliferation, and JNK/mitogen-activated protein kinase activation, conceivably via distinct effectors. Whereas the effector for mitogen-activated protein kinase activation appears to be p65PAK, the identity of effector(s) for actin polymerization remains unclear. We have found a putative effector for Drosophila Cdc42, Genghis Khan (Gek), which binds to Dcdc42 in a GTP-dependent and effector domain-dependent manner. Gek contains a predicted serine/threonine kinase catalytic domain that is 63% identical to human myotonic dystrophy protein kinase and has protein kinase activities. It also possesses a large coiled-coil domain, a putative phorbol ester binding domain, a pleckstrin homology domain, and a Cdc42 binding consensus sequence that is required for its binding to Dcdc42. To study the in vivo function of gek, we generated mutations in the Drosophila gek locus. Egg chambers homozygous for gek mutations exhibit abnormal accumulation of F-actin and are defective in producing fertilized eggs. These phenotypes can be rescued by a wild-type gek transgene. Our results suggest that this multidomain protein kinase is an effector for the regulation of actin polymerization by Cdc42.

[Cytotoxicity and genotoxicity of methyl tert-butyl ether and its metabolite to human leukemia cells]

DNA damage of human leukemia (HL-60) cells caused by methyl tert-butyl ether (MTBE), a new gasoline additive, and its metabolites tert-butyl alcohol (TBA), a-hydroxyisobutyric acid (HIBA) and formaldehyde was determined by single cell gel electrophoresis (SCGE), with release of lactate dehydrogenase as an indicator for evaluating its cytotoxicity. Results showed that MTBE, TBA and HUBA at levels of 1 to 30 mmol/L could cause DNA damage in a dose-dependent pattern. Formaldehyde at level of 5 mumol/L could cause DNA damage, but at a higher level could decrease DNA migration. It suggested that MTBE and its metabolites could have genotoxicity, however, with doses causing genotoxic effects, no cytotoxic effect by MTBE, TBA and HIBA was observed, but formaldehyde presented obvious cytotoxic effect.

[Studies on the regulation of glucoamylase gene (glaA) expression in A. niger I. The overall analysis and comparison of the expression of glucoamylase in the overproducing strain A. niger T21 and its original strain A. niger 3.795]

Expression of the A. niger T21 and 3.795 glaA gene was investigated with respect to the growth of mycelia, producing of glucoamylase, copy number of glaA gene as well as glucoamylase mRNA level and its stability. Both A. niger T21 and 3.795 produced substantial glucoamylase at the stable phase when their biomass were the same. After incubating for 72 hours, while the biomass remained the same, the glucoamylase produced by T21 was 10-17 times higher than that by 3.795. Northern analysis showed that in the total RNA from T21 4.3-4.4 fold as much glucoamylase mRNA as from 3.795 was determined. This result along with results with regard to copy number of glaA gene and stability of glucoamylase mRNA supported the suggestion that the increased mRNA level of glucoamylase was contributed by the increasing at transcription level. The inconsistancy between the difference of enzyme production (10-17 fold) and that of the mRNA level (4.3-4.4 fold) revealed that some difference at translation exist probably. Furthermore, expression of both T21 and 3.795 glaA gene was regulated by carbon sources, this regulation occurred at transcription level in the same manner and also probably occurred at translation level.

Gene transfer and delivery in central nervous system disease

Gene transfer offers the potential to explore basic physiological processes and to intervene in human disease. The central nervous system (CNS) presents a fertile field in which to develop novel therapeutic modalities to treat intractable and pervasive malignant tumors and neurodegenerative disease. The extension of gene therapy to the CNS, however, faces the delivery obstacles of a target population that is postmitotic and isolated behind a blood-brain barrier (BBB). Approaches to this problem have included grafting of genetically modified cells to deliver novel proteins or introducing genes by viral or synthetic vectors geared toward the CNS cell population. Direct inoculation and bulk flow, as well as osmotic and pharmacological disruption, have been used to circumvent the BBB's exclusionary role. Once the gene is delivered, myriad strategies have been used to affect a therapeutic result. Genes activating prodrugs are the most common antitumor approach. Other approaches focus on activating immune responses, targeting angiogenesis, and influencing apoptosis and tumor suppression. At this time, therapy directed at neurodegenerative diseases has centered on ex vivo gene therapy for supply of trophic factors to promote neuronal survival, axonal outgrowth, and target tissue function. Despite early promise, gene therapy for CNS disorders will require advancements in methods for delivery and long-term expression before becoming feasible for human disease.

Measurement of retinoids and carotenoids in breast adipose tissue and a comparison of concentrations in breast cancer cases and control subjects

A case-control study of the associations of retinoids and specific carotenoids with breast cancer using concentrations of these nutrients in breast adipose tissue was conducted among women attending a breast clinic in the Boston area in 1989-1992. Breast adipose tissue was collected during breast biopsy. Cases (n = 46) were women whose biopsies revealed invasive or in situ breast cancer; control subjects (n = 63) were women whose biopsies revealed benign disease. We observed inverse associations between breast adipose concentrations of retinoids and carotenoids and risk of breast cancer, although not all were statistically significant. The multivariate-adjusted odds ratio comparing women above the median value of the control group for retinol with those below or equal to the median was 0.71 (95% CI: 0.26, 1.93; NS); corresponding odds ratios were 0.61 (95% CI: 0.23, 1.64; NS) for retinyl palmitate, 0.30 (95% CI: 0.11, 0.85) for beta-carotene, 0.32 (95% CI: 0.11, 0.94) for lycopene, and 0.68 (95% CI: 0.27, 1.73; NS) for lutein/zeaxanthin. There was a nonsignificant positive correlation (r = 0.23, P = 0.15) between breast adipose tissue concentrations of retinol and dietary intake of preformed vitamin A, including supplements measured by using a food-frequency questionnaire. No correlation was found between breast adipose concentrations of carotenoids and intake of dietary carotenoids. These data suggest that higher breast adipose concentrations of retinoids and some carotenoids may be associated with decreased risk of breast cancer and that further examination of these relations is warranted.

Regulation of lysine catabolism through lysine-ketoglutarate reductase and saccharopine dehydrogenase in Arabidopsis

In plant and mammalian cells, excess lysine is catabolized by a pathway that is initiated by two enzymes, namely, lysine-ketoglutarate reductase and saccharopine dehydrogenase. In this study, we report the cloning of an Arabidopsis cDNA encoding a bifunctional polypeptide that contains both of these enzyme activities linked to each other. RNA gel blot analysis identified two mRNA bands-a large mRNA containing both lysine-ketoglutarate reductase and saccharopine dehydrogenase sequences and a smaller mRNA containing only the saccharopine dehydrogenase sequence. However, DNA gel blot hybridization using either the lysine-ketoglutarate reductase or the saccharopine dehydrogenase cDNA sequence as a probe suggested that the two mRNA populations apparently are encoded by the same gene. To test whether these two mRNAs are functional, protein extracts from Arabidopsis cells were fractionated by anion exchange chromatography. This fractionation revealed two separate peaks-one containing both coeluted lysine-ketoglutarate reductase and saccharopine dehydrogenase activities and the second containing only saccharopine dehydrogenase activity. RNA gel blot analysis and in situ hybridization showed that the gene encoding lysine-ketoglutarate reductase and saccharopine dehydrogenase is significantly upregulated in floral organs and in embryonic tissues of developing seeds. Our results suggest that lysine catabolism is subject to complex developmental and physiological regulation, which may operate at gene expression as well as post-translational levels.

[Synthesis and characterization of biodegradable alpha,beta-poly (3-hydroxypropyl, propyl)-DL-asparamide]

A biodegradable condensation polymer alpha,beta-poly (3-hydroxypropyl, propyl)-DL-asparamide has been synthesized. Its monomer is DL-aspartic-acid and its spacers are mixture of 3-amino-propanol-1 and propylamine. The polymers thus synthesized are characterized by 1H-NMR, water sorption and intrinsic viscosity. For the purpose of applicability, we have synthesized the polymers with different properties in reference to the molar ratios of propyl amine to 3-amino-hydroxypropyl in polymer synthesis.

A mutant cell line resistant to Vibrio parahaemolyticus thermostable direct hemolysin (TDH): its potential in identification of putative receptor for TDH

Thermostable direct hemolysin (TDH), a pore-forming toxin produced by Vibrio parahaemolyticus, is cytotoxic to Rat-1, a fibroblast cell line derived from rat embryo. Through mutagenesis of Rat-1 with nitrosoguanidine, we established a mutant cell line, MR-T1. MR-T1 was over 200 times more resistant to the cytotoxic activity of TDH than Rat-1. TDH increased membrane permeability of Rat-1 but not of MR-T1. Binding analysis showed that, while being able to bind to Rat-1. TDH failed to bind to MR-T1, indicating that MR-T1 is deficient in the putative receptor for TDH. Somatic hybrid cells between Rat-1 and MR-T1 were similarly sensitive to TDH as Rat-1. Moreover, TDH could bind to the hybrid cells as well as to Rat-1 cells. These results indicate that MR-T1 is promising for complementation cloning of a gene related to the putative receptor for TDH.

Analysis of functional domains of Vibrio parahaemolyticus thermostable direct hemolysin using monoclonal antibodies

Neutralizing monoclonal antibodies (mAbs) against Vibrio parahaemolyticus thermostable direct hemolysin (TDH) were used in probing the functional domains of this toxin. While pre-incubation of TDH with mAb 2A-13C inhibited further binding of TDH to erythrocytes, pre-incubation with another mAb 1-24 did not, indicating that mAb 1-24 epitope resides in a domain which is not involved in binding of TDH to erythrocytes. On the other hand after binding to erythrocytes, TDH could react with mAb 1-24 but poorly with mAb 2A-13C, indicating that the mAb 2A-13C epitope is masked, possibly by erythrocyte surface. As both antibodies are TDH-specific and do not react with TRH (TDH-related hemolysin), we used TDH/ TRH chimeric proteins to identify location of the epitopes for mAbs by inhibition ELISA as well as Western blotting. The results showed that the mAb 1-24 epitope resides on a region near the C-terminal of TDH (residues 99-139), while the mAb 2A-13C epitope resides on the N-terminal (residues 1-31). All these results suggested that, in TDH, the N-terminal region may be involved in binding process while the region near C-terminal may be involved in postbinding process.

Cloning and expression of an Arabidopsis thaliana cDNA encoding a monofunctional aspartate kinase homologous to the lysine-sensitive enzyme of Escherichia coli

As in many bacterial species, the first enzymatic reaction of the aspartate-family pathway in plants is mediated by several isozymes of aspartate kinase (AK) that are subject to feedback inhibition by the end-product amino acids lysine or threonine. So far, only cDNAs and genes encoding threonine-sensitive AKs have been cloned from plants. These were all shown to encode polypeptides containing two linked activities, namely AK and homoserine dehydrogenase (HSD), similar to the Escherichia coli thrA gene encoding a threonine-sensitive bifunctional AK/HSD isozyme. In the present report, we describe the cloning of a new Arabidopsis thaliana cDNA that is relatively highly homologous to the E. coli lysC gene encoding the lysine-sensitive AK isozyme. Moreover, similar to the bacterial lysine-sensitive AK, the polypeptide encoded by the present cDNA is monofunctional and does not contain and HSD domain. These observations imply that our cloned cDNA encodes a lysine-sensitive AK. Southern blot hybridization detected a single gene highly homologous to the present cDNA, plus an additional much less homologous gene. This was confirmed by the independent cloning of an additional Arabidopsis cDNA encoding a lysine-sensitive AK (see accompanying paper). Northern blot analysis suggested that the gene encoding this monofunctional AK cDNA is abundantly expressed in most if not all tissues of Arabidopsis.

[Isolation and determination of the seeds of Pachyrrhizus errosus protein by high performance gel filtration chromatography (GFC)]

From the seeds of Pachyrrhizus errosus, three protein constituents, namel PE1, PE2 and PE3, have been isolated and purified by extraction with 5mmol/L phosphate saline (0.9% NaCl) buffer (PB) at pH 7.2, and S-Sepharose Fast Flow Column (2.6cm x 15cm) chromatography which eluted with 5mmol/L phosphate buffer (pH 7.0) containing 1mmol/L NaCl. Three proteins were burther separated on two connected Protein-Pak 60+Protein-Pak 125 [7.5mm x 39cm, 10microm] columns with mobile phase of 0.2mol/L phosphate buffer (pH 6.5). The flow rate was kept constant at 0.8mL/min by YSB-2 type high press pump. The effluent was monitored at a wavelength of 280nm on photodiode array detector. These three proteins are proved to be homogeneous by SDS-PAGE, IEF and HPGFC experiments, and all present the typical absorption spectra in ultraviolet region. The moleculer weights of the three proteins are approxiamtely 33000D, 14500D and 14000D respectively by SDS-PAGE. But as using HPGFC analysis, the MW value of PE2 is 28000D. This indicates PE2 may be composed of two chains joined by disulfide bond, which is further proved from the latter amino acid composition analysis. The isoelectric points of three proteins are 4.5, 6.5 and 7.5 respectively by using IEF. The amion acids compositions of the three proteins were determined with OPA post-column derivatization/fluorescence detection.

In vivo and in vitro evidence for an anti-Rho activity induced by the phage P4 polarity suppressor protein Psu

The polarity suppression (Psu) protein of bacteriophage P4 causes suppression of transcriptional polarity in Escherichia coli by overcoming Rho termination factor activity. Two new psu mutants defective in polarity suppression are described. The psu5 mutation deletes codons 95-98 from about the middle of the gene, and the mutant protein is inactive. The psu6 mutation changes Phe169 to Val and encodes a temperature-sensitive protein. Constitutive overexpression of psu+ from a plasmid prevents colony formation, but overexpression of mutant genes (psu5, psu6) does not, suggesting that Psu disturbs essential host function(s). Rho protein synthesis is enhanced several-fold in cells containing wild-type Psu, due to readthrough at the rho attenuator, while the physical stability of Rho is maintained. As a consequence, Psu-producing cells accumulate significantly more Rho than normal cells, reminiscent of termination-defective rho mutants. The polarity suppression activity induced by Psu is demonstrated in vitro by the efficient readthrough of Rho-dependent terminators lambda tR1 and TIS2 during coupled transcription-translation. Purified Rho protein restores termination at TIS2 when added to Psu-containing reactions but NusG does not. The data support the hypothesis that Psu has or elicits an anti-Rho function.

Spontaneous growth in Chinese patients with Turner's syndrome and influence of karyotype

The pretreatment mixed cross-sectional and longitudinal height measurements of 203 patients with Turner's syndrome (TS) were analysed. Only one observation was included per year per child and a total of 858 observations formed the basis of the growth study. The mean and SD values were fitted separately by a second-degree polynomial function, giving smoothed growth curves. The spontaneous growth pattern of Chinese girls with TS runs parallel to published Caucasian TS growth curves. The mean final height of Chinese patients with TS was 142 cm compared to 147 cm and 139 cm observed in Northern European and Japanese patients, respectively. Patients with the 46, X, i(Xq) karyotype were found to be significantly shorter, whereas children with the 45, X/46, XY and 46, X, del(Xq) karyotypes were significantly taller among this group of patients. Patients with TS who were disomic for Xp are significantly taller than patients who were monosomic for Xp. Our results suggest that karyotype can have a significant effect on the growth of children with TS.

Gastric acidity influences the blood response to a beta-carotene dose in humans

The effect of gastric acidity on the blood response to a single dose of 120 mg beta-carotene in humans was investigated in 12 normal subjects (5 women, 7 men) aged 23-68 y. Omeprazole was used for 7 d to obliterate gastric acid secretion and to raise gastric pH to > 4.5. In a crossover design, six subjects were randomly assigned to take beta-carotene with omeprazole either at the beginning (day 9) or at the end (day 26) of the study. The beta-carotene response in blood was not altered by the experimental order. Results from the high-gastric-pH phase (ie, with omeprazole) were analyzed together and compared with the results from the low-gastric-pH phase (ie, without omeprazole). The increases of serum concentrations of both trans beta-carotene and cis beta-carotene 6 and 24 h after the beta-carotene dose were significantly greater at a low gastric pH (pH = 1.3 +/- 0.1, ie, without omeprazole) than those at a high gastric pH (pH = 6.4 +/- 0.3, ie, with omeprazole), P < 0.02. Similarly, 24 h after beta-carotene administration, the area under the blood beta-carotene response curve (trans plus cis beta-carotene) was significantly greater at a low gastric pH (6825 +/- 760 nmol.h/L) than at a high gastric pH (3390 +/- 550 nmol.h/L), P < 0.002. In investigations of bacterial overgrowth, gelatin capsule disintegration and isomeric profiles associated with high and low pH, we could not identify factors to explain the differences observed in the blood response curves between low-gastric-pH and high-gastric-pH conditions. A suppressed blood response of beta-carotene at a high intraluminal pH may have been due to the slower movement of negatively charged micelles through the unstirred water layer and cell membrane.

Human plasma carotenoid response to the ingestion of controlled diets high in fruits and vegetables

Plasma carotenoid responses were determined in 36 healthy men and women before and after being fed controlled diets with a moderate amount of fat (26% of total energy) and a high carotenoid content (approximately 16 mg/d) for two 15-d periods. In addition, broccoli (205 g/d) was provided either during the first or the second 15-d residency period in a crossover design. Plasma was digested with lipase and cholesterol esterase, and carotenoids were extracted and measured by using HPLC. Three oxygenated carotenoids (lutein, zeaxanthin, and cryptoxanthin), three hydro-carbon carotenoids (alpha-carotene, all-trans-beta-carotene, and 13-cis-beta-carotene), and four geometric isomers of lycopene (15-cis-, 13-cis-, 9-cis-, and all-trans-lycopene) were separated by using a C30 carotenoid column. A small unidentified peak coeluted with standard 9-cis-beta-carotene and was identified as zeta-carotene (lambda(max) = 400 nm). The concentrations of plasma lutein, cryptoxanthin, alpha-carotene, 13-cis-beta-carotene, all-trans-beta-carotene, and cis- and trans-lycopenes were all significantly increased (P < 0.05) on days 6-16 by the high-fruit and -vegetable diets. The provision of additional broccoli for 5 d to the basic high-carotenoid diet resulted in a further significant increase in the serum concentration of lutein compared with the feeding of the basic high-carotenoid diet alone. Most of the measurable carotenoids of human plasma can be increased by moderate alterations in diet within a short time, although the magnitude of the plasma response may be related to the baseline carotenoid concentrations.

[On the conservation and regeneration of Taxus resources]

In recent years, the taxol isolated from the stem bark of some plants of Taxus has been widely as an antitumor agent. But the development of taxol is limited by the scarcity of wild Taxus resources. This paper seeks to discuss the ways to conserve and promote the regeneration of these resources.

[Study on the death of Escherichia coli induced by hydrostatic pressures]

The effect of hydrostatic pressure on the death of E. coli was studied in this paper. The results indicated that E. coli could be killed by hydrostatic pressure above 800 bar. At 2300 bar E. coli was totally killed in 30 minutes. The time course of E. coli death induced by pressure indicated that the most E. coli was killed in the first 10 minutes after the pressure was applied. It was also found that the lower temperature favored killing E. coli under pressure.

Red-band holographic storage in azo dye sensitized by noncoherent light

Biphoton holographic storage recorded with 633-nm He-Ne beams has been investigated in Methyl Yellowdoped polystyrene film sensitized by weak noncoherent light from a low-pressure Hg lamp. It is demonstrated that the holography in the sample is erasable without fading. The dynamic behavior of the hologram is dependent on the cis-trans isomerization by noncoherent light and 633-nm beams and photoinduced heat.

In vivo biosynthesis of retinoic acid from beta-carotene involves and excentric cleavage pathway in ferret intestine

This study was done to determine whether retinoic acid can be produced by excentric cleavage of beta-carotene in vivo. By using an inhibitor of retinaldehyde oxidation, citral, either retinaldehyde or beta-carotene was incorporated in a micellar solution and perfused through the upper portion of small intestine of ferrets. After 2 h perfusion of 1 microM retinaldehyde, retinoic acid rose in portal blood (+3.5 +/- 1.3 nmol/L) and was detected in the intestinal mucosa (30 +/- 2 pmol/g). When citral was added at 2 mM along with retinaldehyde, retinoic acid decreased in the portal blood and retinoic acid was not detected in the intestinal mucosa. With or without the presence of citral (2 mM), the perfusion of beta-carotene (10 microM) during 2 h caused a significant rise of retinoic acid in portal blood (+2.6 +/- 0.6 nmol/L and + 4.1 +/- 0.6 nmol/L, respectively) and in liver; moreover, significant amounts of retinoic acid were detected in the intestinal mucosa (19 +/- 3 pmol/g and 36 +/- pmol/g, respectively. This study demonstrates that after intestinal perfusion of beta-carotene in the ferret in vivo, a substantial amount of retinoic acid is formed via an excentric cleavage pathway.

Construction of a brewing yeast having glucoamylase activity and its fermentation characteristics

The brewing yeast having glucoamylase activity was constructed by integrating glucoamylase cDNA from Asapergillus niger into the genome of brewing yeast B48. The integration was achieved by cotransformation of YEP type plasmid pKG1 carrying glucoamylase expression-secretion element and was verified by Southern blot analysis. The engineered yeast was stable, and the fermentation test demonstrated that the lower residual dextrin level was obtained compared with control strain B48. Thus the fermentation rate was raised to 80.5%. No alteration of growth and brewing properties was observed. Beer quality was judged to be good.

Measurement of carotenoids, retinoids, and tocopherols in human lenses

PURPOSE

To determine the levels of carotenoids, retinoids, and tocopherols in normal and cataractous human lenses.

METHODS

Concentrations of carotenoids, retinoids, and tocopherols were measured by high-performance liquid chromatography (HPLC) in 12 American normal lenses, 9 American cataractous lenses, and 10 Indian cataractous lenses.

RESULTS

On a per gram wet weight of tissue basis, human lenses contained 11 to 25 ng xanthophylls (lutein and zeaxanthin), 31 to 50 ng retinol, 21 to 25 ng retinyl palmitate, 1573 to 2550 ng alpha-tocopherol, and 257 to 501 ng gamma-tocopherol. Concentrations of lutein, zeaxanthin, and retinol were significantly higher in Indian cataractous lenses than in American normal or cataractous lenses. There were no differences in the lutein-zeaxanthin, retinoid, or alpha-tocopherol contents between American normal lenses and American cataractous lenses. The range of ratios of lutein to zeaxanthin in human lenses was 1.6 to 2.2. The mean age of the Indian lens donors was 20 years younger than the American lens donors. Comparisons using contralateral lenses indicated that there was significant interindividual variance in human lens concentrations of xanthophylls, retinoids, and tocopherols. beta-carotene and lycopene, major carotenoids in human serum and other tissues, were not detected in human lenses.

CONCLUSIONS

Xanthophylls (lutein and zeaxanthin) are the only carotenoids detected in human lens. Retinol, retinyl palmitate, and alpha- and gamma-tocopherols also are present in human lens. Determinants of lens concentration of nutrients are not defined, but dietary factors are likely to be important.

Investigation on breastfeeding and lactational amenorrhoeic women in mountainous areas of Pengxian County, Southwest China

OBJECTIVE

To determine the distributions of the duration of postpartum breastfeeding, amenorrhoea, and contraceptive use, a community-based epidemiological investigation was carried out in Pengxian County, Southwest China in March 1992.

METHODS

1,040 women who had given live births during the reference period were interviewed. A current-status life table analysis was used.

RESULTS

At 1 month postpartum, 100% infants were breastfed, at 6 months 95%, and at 12 months 82%. The level of amenorrhoea at 1 month postpartum was 90%, at 3 months 74%, at 6 months 62%, and at 12 months 36%. Contraceptive use was initiated at the second month postpartum with 19% of users, at 6 months 48%, and at 12 months 91%.

CONCLUSION

The results indicate that at population level advising women to begin using contraceptives in 3 months postpartum is fairly reasonable, and the non-medicated IUD is recommended to be the first choice for the lactating women.

Similar metabolites formed from beta-carotene by human gastric mucosal homogenates, lipoxygenase, or linoleic acid hydroperoxide

To determine the basis for the formation of excentric cleavage products of beta-carotene (beta-C) after incubation with human gastric mucosal homogenates, we have studied the effect of lipoxygenase in beta-C metabolism. beta-C was incubated with human gastric mucosal homogenates, soybean lipoxygenase with linoleic acid, or the lipoxygenase primary product, 13(S)-hydroperoxycis,trans-9,11-octadecadienoic acid (13-LOOH). The beta-C metabolites, beta-apo-14', -12', -10', and -8'-carotenals, beta-apo-13-carotenone, retinoic acid, and retinal were detected and quantified by HPLC after a 30-min incubation with 1.8 microM beta-C. The products from the lipoxygenase plus linoleic acid incubation and from the lipoxygenase primary product, 13-LOOH, with beta-C were exactly the same as the products from a human gastric mucosal homogenate incubation. Significantly larger amounts of the same beta-C metabolites were formed when beta-C was incubated with gastric mucosal homogenates and lipoxygenase together. Furthermore, nordihydroguaiaretic acid (NDGA), a specific lipoxygenase inhibitor, was found to significantly inhibit the formation of beta-apo-carotenoids and retinoids produced by gastric mucosal homogenates incubated with beta-C. The similarity of the beta-C metabolites when beta-C was incubated with human gastric mucosal homogenate, lipoxygenase plus linoleic acid, or 13-LOOH and the inhibition of beta-C metabolite production by NDGA in gastric tissue incubation with beta-C suggest that lipoxygenase is involved in beta-C metabolism in gastric mucosa. The activity of 13-LOOH in our hands would indicate that an enzyme-linked process is occurring in gastric tissue producing fatty acid hydroperoxides, and that the hydroperoxide, or a radical species derived from it, is able to carry out the oxidation of beta-C independently of the enzyme.

Supplementing ferrets with canthaxanthin affects the tissue distributions of canthaxanthin, other carotenoids, vitamin A and vitamin E

To study the effects of canthaxanthin supplementation on the tissue distribution of canthaxanthin, other carotenoids, vitamin A and vitamin E, 26 spayed female ferrets (2 mo of age) were used. Ferrets were assigned to receive a commercial ferret diet and a gavage of canthaxanthin [50 mg/(kg body wt.d)] or a gavage of placebo beadlets (0 mg canthaxanthin) 5 d/wk. Serum canthaxanthin concentrations in the canthaxanthin-fed group increased from 0 at baseline to 37.76 +/- 5.34 nmol/L trans and 77.10 +/- 12.60 nmol/L cis canthaxanthin at 12 mo. Further accumulation of canthaxanthin did not occur with continuous dosing. After 2 y of receiving canthaxanthin beadlets by gavage, the ferrets did not show a detectable concentration of canthaxanthin in the eyes, nor did they have clinical signs of toxicity. Canthaxanthin concentrations were highest in liver, with high concentrations also seen in fat, lung and small intestine. The sum of alpha and beta-carotene concentrations detected in livers was significantly higher in the canthaxanthin-fed group than in the placebo-fed group, but not significantly higher when individual carotenes were compared. However, alpha-tocopherol concentrations in the livers and lungs and lutein/zeaxanthin in the fats of the ferrets fed canthaxanthin were significantly lower than in those fed the placebo. Retinoid concentrations in tissues of the ferrets fed canthaxanthin were not different from those of the placebo-fed group. The effects of canthaxanthin supplementation on other antioxidants and vitamin A nutrients demonstrate either a synergistic or antagonistic relationship, depending on the specific tissue assayed.

Children's development effecting blood oxygen desaturation following apnea

One hundred and fifty-six children aged from 4 months to 12 years undergoing elective plastic surgery were included in this study. All children were ASA physical status I, under normal development, ranging from 64 to 140 cm in body height and from 6.0 to 41.0 kg in body weight. Following 2-minute preoxygenation, the time when SpO2 dropped to 95% and 90% in apneic period had a close correlation with age, weight and height of children by means of linear and non-linear regression analysis. The smaller the children's weight, the higher the incidence of severe arterial desaturation after reinstitution of manual ventilation with 100% oxygen at SpO2 of 90%. It is suggested that younger children are more susceptible to hypoxemia than older ones during apnea and provided no problem existing other than oxygen delivery, an SpO2 of 95% might be the safe limitation of apnea in pediatric anesthesia induction.

Timing of laparoscopic surgery in gallstone pancreatitis

OBJECTIVE

To study the effect of the timing of laparoscopic cholecystectomy following acute gallstone pancreatitis.

SETTING

University-based county teaching hospital.

DESIGN

Retrospective case series.

PATIENTS

One hundred forty-two patients with gallstone pancreatitis treated by laparoscopic cholecystectomy between April 1991 and September 1993. There were 16 men and 126 women, with a mean age of 39.5 years. The mean serum amylase level at admission was 1616 U/L. All patients were operated on more than 48 hours after admission, after clinical and biochemical resolution of pancreatitis. Preoperative endoscopic retrograde cholangiopancreatography was performed in 25 patients (more than 48 hours after admission), with common bile duct stones being identified and removed in 10.

RESULTS

Twenty patients had three or more Ranson's criteria. Of these, nine had laparoscopic cholecystectomy attempted within the first week of admission. Six (67%) of these patients required conversion to open procedures (two for common bile duct exploration, one for repair of a common hepatic duct injury, and three for anatomic distortion due to inflammation). The mean postoperative stay of the nine patients was 5.4 days. The other 11 patients with three or more Ranson's criteria were operated on after 1 week, and only two required conversion to open cholecystectomy (18%). The mean postoperative stay in these 11 patients was 2.3 days. The difference in conversion rate approached but did not reach statistical significance (P = .08). The postoperative stay, however, was significantly shorter in the group of patients who underwent late operations (P = .03). There were 122 patients with fewer than three Ranson's criteria. In this group, there was no difference in length of postoperative stay between patients operated on earlier and those operated on later (2.4 vs 3.9 days; P = .49; n = 74 and n = 48, respectively). Of these 122 procedures, eight were converted to open procedures (6.6%). There was no significant difference in conversion rates in these patients regardless of whether they were operated on earlier or later.

CONCLUSIONS

Based on these data, we believe, first, that laparoscopic cholecystectomy is safe in patients recovering from gallstone pancreatitis (mortality rate, 0%; bile duct injury, 0.7%). Furthermore, early operation can safely be recommended in patients with mild pancreatitis. However, in patients with three or more Ranson's criteria, operation during the first week following admission is associated with an increase in operative complications, an increased rate of conversion, and longer postoperative stays.

Role of endogenous cytokines in endotoxin- and interleukin-1-induced pulmonary inflammatory response and oxygen tolerance

Endotoxin lipopolysaccharide and the cytokines, tumor necrosis factor (TNF) and interleukin-1 (IL-1), are known to protect adult rats against O2 toxicity. However, whether the effect of endotoxin is mediated by these cytokines is not clear. We have previously demonstrated that depletion of 84% rat alveolar macrophages (AM), which reduced lipopolysaccharide (LPS)-induced release of TNF by 86%, had no effect on LPS-induced O2 tolerance. In this study, we demonstrated that coinsufflation of LPS with anti-TNF antibody and IL-1 receptor antagonist (IL-1ra), which completely inhibited LPS-induced TNF and IL-1 activities, had no effect on LPS-induced alveolar inflammatory response and O2 tolerance. Likewise, coinsufflation of IL-1 and anti-TNF antibody, which completely neutralized IL-1-induced TNF activity, had no effect on IL-1-induced alveolar inflammatory response and O2 tolerance. In contrast, IL-1ra completely abolished IL-1-induced inflammatory response and markedly inhibited IL-1-induced O2 tolerance. These results suggest that LPS-induced alveolar inflammatory response and O2 tolerance are not mediated by endogenous TNF and IL-1. Similarly, endogenous TNF does not mediate IL-1-induced alveolar inflammatory response and O2 tolerance.

Serum retinoic acid levels in patients with resected benign and malignant colonic neoplasias on beta-carotene supplementation

To determine whether patients with colon cancer metabolize beta-carotene differently from benign colon polyp patients, a normal control group (n = 13) and groups of resected colon polyp patients (n = 29) or resected colon cancer patients (Dukes A and B1, n = 21) were supplemented with placebo or beta-carotene (30 mg/day) taken with their morning meals for three months. Serum samples at zero and three months of the study were analyzed blindly for retinoic acid and beta-carotene. The results showed that beta-carotene levels in the serum of colon polyp and colon cancer groups were 8- to 12-fold higher than in the untreated control or the placebo-treated groups. The benign polyp subjects (n = 17) receiving beta-carotene showed a significant rise in serum trans-retinoic acid at three months compared with Time 0. The trans-retinoic acid values from the colon cancer group receiving beta-carotene (n = 11) or placebo (n = 10) were significantly lower than the values from the beta-carotene-supplemented colon polyp group. It appears that trans-retinoic acid levels in response to beta-carotene supplementation are different between treated cancer and benign patients because of different body demands for retinoic acid.

Cellular distribution of pulmonary Mn and CuZn superoxide dismutase: effect of hyperoxia and interleukin-1

Pulmonary superoxide dismutase (SOD) plays an important role in the lung defense against O2 toxicity. We have previously demonstrated that tracheal insufflation of interleukin-1 alpha (IL-1) selectively enhances pulmonary MnSOD and protects rats against O2 toxicity. However, little is known about the cellular distribution of pulmonary MnSOD- and CuZnSOD-specific proteins. We performed immunohistochemistry in plastic sections (2 microns thick) to determine the effects of hyperoxia and IL-1 on the cellular distribution of pulmonary MnSOD and CuZnSOD in rats. MnSOD and CuZnSOD were present in all lung cells. Smooth muscle and endothelial cells appeared to contain higher immunoreactive MnSOD and CuZnSOD proteins than other lung cell types. Exposure of rats to 100% O2 for 24 hr had no effect on the cellular distribution and intensity of pulmonary MnSOD. However, at 50 hr after O2 exposure the intensity of pulmonary MnSOD was reduced. In contrast, tracheal insufflation of IL-1 markedly enhanced the intensity of pulmonary MnSOD in rats exposed to O2 for 50 hr. Neither O2 exposure nor IL-1 insufflation had any apparent effect on the distribution and intensity of pulmonary CuZnSOD. We conclude that IL-1 selectively enhances pulmonary MnSOD and that this effect is manifested in most lung cells, particularly smooth muscle and endothelial cells.

[Isolation and sequencing of glucoamylase gene from a glucoamylase over producing strain]

Chromosomal DNA was isolated from the mycelia of Aspergillus niger T21, a strain producing glucoamylase at a high level. Southern blot analysis indicated that the glucoamylase gene is situated on a 2.5kb EcoR I -EcoR V fragment. Chromosomal DNA was digested completely with EcoR I, EcoR V. The fragments in the range of 2.0-3.0kb were isolated through electrophoresis in agarose gel. The pooled fragments were ligated onto pBR322 vector prior to transformation into E. coli DH5. Four glucoamylase-specific recombinants were screened by in situ hybridization from the transformants. Restriction mapping and sequencing for one of the four were performed. Data show that the glucoamylase gene from A. niger T21 is a 2.3kb fragment containing four intervening sequences in the coding region.

The use of lobectomy in the management of severe closed-head trauma

A retrospective review is presented of 20 patients with traumatic brain injury who were treated during the course of their illness by lobectomies either after a herniation or other significant deterioration or to reduce elevated intracranial pressure. All the patients suffered from blunt head trauma. Patient ages ranged from 19 to 59 years (average, 34 yr). The initial Glasgow Coma Scale score ranged from 3 to 15 (average, 8.2). There were 14 frontal lobectomies, 2 temporal, 3 frontal and temporal, and 1 occipital. Surgery was performed between 0 and 8 days after injury (average, 2.8). Outcome was favorable (good or moderately disabled) in 11 patients and unfavorable (severely disabled, persistently vegetative, or dead) in 9. No patients survived in a persistently vegetative state. A higher initial Glasgow Coma Scale score was positively correlated with a more favorable outcome (P < 0.03). Younger patients also showed a significant positive relationship to outcome (P < 0.0005). Better pupillary reactivity showed a significant trend toward a more favorable outcome (P < 0.04). The type of lesions identified on computed tomographic scans had no association with outcome. A lobectomy can be a useful adjuvant in the management of severe brain injury, especially in younger patients with relatively higher initial Glasgow Coma Scale scores who subsequently deteriorate or develop elevated intracranial pressure.

A statistical analysis of factors related to symptomatic cerebral vasospasm

A retrospective review of patients presenting to our institution with aneurysmal subarachnoid hemorrhage between 1980-1990 was accomplished. Eleven variables were examined as to their relationship to clinical vasospasm: age, sex, clinical grade, amount of subarachnoid blood on CT, aneurysm location, incidence of vasospasm, incidence of complications, use of calcium channel blockers, time to surgery, length of stay, and outcome. Data were analyzed with univariate and multivariate logistical regression methodology. By univariate analysis, age under 20, amount of subarachnoid hemorrhage, and clinical grade were associated with a higher risk of vasospasm. Using multivariate logistic regression, these factors, along with age under 35, were correlated as being predictive of clinical vasospasm. When all patients are grouped into either good or bad outcome, and a similar analysis is performed, only in the poor outcome group is the amount of subarachnoid hemorrhage and clinical grade correlated with vasospasm. This suggests that there is a group of patients with a predisposition to vasospasm that is independent of subarachnoid hemorrhage and clinical grade, and that these patients may have a more favorable outcome.

Epidermis and serum protect retinol but not retinyl esters from sunlight-induced photodegradation

Sunlight-induced photodegradation of retinyl esters and retinol in human skin, blood and cultured keratinocytes was investigated. Using high-performance liquid chromatography with an extraction method that avoided saponification, the analysis of human foreskin (Caucasian) showed that levels of retinyl esters and retinol were approximately 3.5 and 5.0 times higher, respectively, in the epidermis than in the dermis. Upon irradiation by sunlight, a significant reduction in epidermal retinyl esters was observed in both summer and winter. However, epidermal retinol, dermal retinol and dermal retinyl esters did not show statistically significant reductions. When serum from volunteers who had taken a large dose of retinyl palmitate to elevate serum retinyl esters was exposed to sunlight, the retinyl esters in the serum rapidly disappeared after 10 min of exposure--similar to the photodegradation seen for retinyl palmitate in an organic solvent. While retinol in an organic solvent rapidly photodegraded similar to serum retinyl palmitate, serum retinol slowly declined upon sunlight irradiation. When cultured keratinocytes that took-up 3H-retinol and thereafter contained 3H-retinyl esters and 3H-retinol were exposed to sunlight, 80% of the 3H-retinyl esters disappeared upon sunlight irradiation whereas only about 20% of the 3H-retinol did so. These results suggest that the epidermis, serum and keratinocytes selectively protect retinol from sunlight-induced photodegradation. It is most likely that serum retinol-binding protein and cellular retinol-binding protein protect retinol, a vital epithelial growth factor, from photodegradation.

Protection against oxygen toxicity by tracheal insufflation of endotoxin: role of Mn SOD and alveolar macrophages

Endotoxin and the cytokines, tumor necrosis factor and interleukin-1, are known to protect adult rats against O2 toxicity. However, whether the effect of endotoxin is mediated through its direct effect on lung cells or through cytokines is not clear. In this study, we demonstrated that endotoxin at a dosage of 5 micrograms/rat (14-20 micrograms/kg) attenuated O2-induced pulmonary injury and markedly prolonged the survival of rats exposed to 100% O2. Endotoxin was more protective when given by intratracheal insufflation or intravenous injection than by intraperitoneal injection. The endotoxin-induced O2 tolerance was associated with a selective enhancement of pulmonary manganese superoxide dismutase, but not Cu,Zn SOD, mRNA. In addition, depletion of 84% rat alveolar macrophages by liposome-encapsulated dichloromethylene diphosphonate, resulted in a marked reduction (86%) of endotoxin-induced release of tumor necrosis factor into the alveolar space. However, endotoxin was still protective in these alveolar macrophage-depleted animals.

Pathologists' participation in postmortem examinations for patients with dementia

Pathologists (n = 571) in Michigan were surveyed to examine the problem of limited access to autopsy experienced by families of patients with dementia and to assist with the implementation of the Michigan Dementia Program. The survey determined the extent to which pathologists performed autopsies for patients with dementia and/or were willing to do so as part of a statewide Postmortem Examination Program. Responses from 394 pathologists (69%) indicated that 49% were willing to perform brain removal and 44% were interested in learning more about the statewide program. The survey results were used to recruit pathologists, to identify potential problems, and to provide baseline data against which to measure the effects of a fully implemented program.

Prognostic indicators in fungemia of the surgical patient

OBJECTIVE

The objective of this study is to identify prognostic factors affecting mortality in surgical patients with culture-proved fungemia and to examine how amphotericin B affects mortality after controlling for these factors.

DESIGN

The study is based on a retrospective logistic regression analysis of general surgical patients with blood cultures positive for fungi. We analyzed the patients' ages; whether they received triple antibiotics, had diabetes, had malignant neoplasia, received steroids, had concomitant bacteremia, or took antibiotics for greater than 7 days; and total dose of amphotericin B.

SETTING

The study was carried out at a university-based county hospital.

PATIENTS

Analysis of microbiology records for blood cultures that were positive for fungi from November 1987 to January 1992 revealed 63 general surgical patients. Patients with burns and those undergoing organ transplantation were excluded. Forty charts were complete and available for review.

MAIN OUTCOME

Death was the outcome variable studied.

RESULTS

Stepwise logistic regression analysis of death revealed age to be a risk factor for mortality. Treatment with at least 210 mg of amphotericin B was associated with relative risk of death of 0.055.

CONCLUSION

Amphotericin B is effective even at low doses at decreasing the mortality in surgical patients with fungemia. On the other hand, increasing age is associated with an increased risk of mortality. Found not to be associated were concomitant bacteremia, concurrent triple antibiotic therapy, malignant neoplasia, and steroid use.

Intestinal perfusion of beta-carotene in the ferret raises retinoic acid level in portal blood

To determine whether beta-carotene (beta-C) can serve as a source of intestinally-derived retinoic acid (RA), either 15,15'-[14C]beta-C or unlabeled beta-C was perfused through 30 cm jejunal segments of ferrets in vivo. Portal vein blood was sampled periodically via an indwelling catheter. RA was identified in portal blood by comparing retention times in HPLC, by UV absorption, and by derivatization (methylation) and subsequent GC-MS analysis. The RA concentration in the portal blood increased 3-fold with perfusion of beta-C (P < 0.05), and remained at 18 nmol/L during the perfusion of beta-C. The single peak of RA in HPLC was shown to consist of four separate peaks by GC-MS, which may be cis-trans isomers of RA. The concentration of RA in portal blood returned to the initial level (5 nmol/L) after a 2 h period of intestinal perfusion with 5% dextrose. Retinyl ester concentration in portal blood did not change before or after the perfusion, whereas retinol decreased significantly during the perfusion of beta-C. This study clearly indicates that a considerable quantity and number of polar metabolites, including RA, are formed from beta-C in the ferret intestine which are transported via the portal vein to the liver.

Polyethylene glycol-conjugated superoxide dismutase protects rats against oxygen toxicity

Superoxide dismutase (SOD) has an important role in the protection against O2 toxicity. Conjugation of Cu,Zn-SOD to polyethylene glycol (PEG-SOD) prolongs its plasma half-life and facilitates its cellular uptake. However, prior studies have shown that intravenous injection of PEG-SOD does not protect animals against O2 toxicity. In this study, we demonstrated that tracheal insufflation of PEG-SOD resulted in a dose-dependent protection against O2 toxicity. Nine of 15 rats (60%) insufflated with 25,000 U PEG-SOD survived continuous 100% O2 exposure for more than 7 days compared with control rats (n = 45), all of which died within 3 days of O2 exposure (P < 0.025). In contrast, insufflation of 25,000 U SOD, 9.7 mg methoxy-PEG (equivalent to the amount of methoxy-PEG present in 25,000 U PEG-SOD), or a combination of SOD and methoxy-PEG had no protective effect. Furthermore, intravenous or intraperitoneal injection of PEG-SOD did not afford significant protection. Protection against O2 toxicity by PEG-SOD insufflation was associated with attenuated O2-induced pulmonary injury as evidenced by a reduced volume of pleural effusion. Insufflation of PEG-SOD markedly increased pulmonary SOD activity (to 300 and 370% of controls at 24 and 50 h, respectively) without affecting pulmonary catalase activity. We conclude that insufflation of PEG-SOD protects rats against O2 toxicity, possibly by enhancing pulmonary SOD activity.

Application of photodynamic therapy to the treatment of atherosclerotic plaques

Photodynamic therapy is a therapeutic modality long studies for its application to the treatment of malignant neoplasms. Recently, studies have suggested its potential use in the treatment of atherosclerosis. In this study, two atherosclerotic plaques were induced in the abdominal aortas of 35 rabbits. The animals then received Photofrin II (Quadralogic Technologies Inc., Pearl River, NY), a photosensitizer, at doses of 5 mg/kg and 2.5 mg/kg. After 48 hours, the plaques were irradiated by a fiberoptic connected to an argon ion laser. Fluency rates from 32 mW to 256 mW and energy doses from 1.6 to 60 joules were applied. Only one of the paired plaques was irradiated, the other remaining as a control. Four weeks after treatment, the vessels were assessed. Of 26 plaques treated with photodynamic therapy, 22 were no longer grossly visible, while the nine animals that received light irradiation but no Photofrin II all had visible plaque (P < 0.001). Studies of the vessel sections confirmed a reduction in intimal thickness from 0.74 +/- 0.15 mm in matched controls as compared with 0.51 +/- 0.13 mm in animals with treated plaques. There was a concomitant enlargement of the luminal diameter from 1.13 +/- 0.51 to 1.41 +/- 0.72. On the microscopic level, plaque reduction was most complete in the groups treated with 40 and 60 joules. Different fluency rates and drug dosages did not lead to differing outcomes. Our findings indicate that photodynamic therapy with dihematoporphyrin ether met our goal of reducing plaque size and may represent a means of treating atherosclerotic plaques.

Magnetic resonance imaging and pathological correlates of meningiomas

We examined the relationships between specific magnetic resonance imaging features and certain gross and microscopic characteristics of meningiomas, including vascularity, gross texture (consistency), and venous sinus involvement. Magnetic resonance imaging scans, surgery reports, and the histopathological findings of tumors were examined retrospectively in 54 patients. Sinus involvement was accurately predicted on T1-weighted images in 9 of 10 cases (P = 0.001) and tumors with cystic changes in 3 of 3 cases. T1-weighted images were not useful for predicting vascularity unless actual flow voids could be visualized (five of six cases). There was no correlation between T1 signal intensity, tumor consistency, or histological findings. In tumors without detectable vascularity on T1-weighted images, hyperintensity relative to gray matter on T2-weighted images was correlated with increased vascularity (P = 0.004). Tumors with soft consistency (P = 0.007), cellular atypia, invasion, angioblastic, or melanocytic components were also hyperintense, compared with gray matter on T2-weighted images (P = 0.0266). Aggressive meningiomas were found to be more vascular (P = 0.045). No correlation was found between the degree of surrounding edema or contrast enhancement with histopathological findings, vascularity, or consistency.

Fibrinogen degradation product fragment D induces endothelial cell detachment by activation of cell-mediated fibrinolysis

We studied the effects of fibrinogen degradation product (FDP) fragment D on endothelial monolayer integrity and the mechanisms of fragment D-induced endothelial cell detachment from the substratum. Incubation of bovine pulmonary artery endothelial cells (BPAEC) with fragment D caused concentration- and time-dependent cell detachment from the substratum. The optimal response occurred at fragment D concentrations of 2 microM and required an incubation time of 24 h. BPAEC challenged with fragment D increased the concentration and activity of urokinase-type plasminogen activator (uPA) in the conditioned medium within 2 to 4 h of incubation. Fragment D also induced the release of tissue-type plasminogen activator, but to a lesser extent than uPA. Fragment D concurrently increased plasminogen activator (PA) activity in a concentration-dependent manner. Increased PA activity was followed by augmentation of cell-associated plasmin activity and subsequent increase in the degradation of 125I-fibrinogen and 125I-vitronectin precoated in the subendothelial matrix. Pretreatment of BPAEC with anti-uPA antibody, and inhibitors of uPA (dansyl-GGACK) and plasmin (aprotinin) prevented approximately 60% of the fragment D-induced endothelial cell detachment. We conclude that FDP fragment D increases secretion of endothelial PAs and enhances the generation of plasmin, thereby contributing to proteolysis of extracellular matrix and endothelial cell detachment. Fragment D may be a critical mediator linking activation of fibrinolysis to vascular endothelial injury in inflammatory disorders.

Intestinal uptake and lymphatic absorption of beta-carotene in ferrets: a model for human beta-carotene metabolism

To determine the appropriateness of the ferret as a model for human beta-carotene (beta-C) metabolism, we have perfused both 15,15'-beta-[14C]C and unlabeled beta-C through the upper 30-cm portion of the small intestine of ferrets in vivo. The effluents of a mesenteric lymph duct cannulation and a common bile duct cannulation, as well as portal vein blood periodically sampled via an indwelling catheter, were collected. Ten percent (9.5 +/- 0.06%) of the total administered beta-C was taken up by the intestine after a 4-h perfusion. Of the radioactivity taken up, 68.6 +/- 6.5% remained in the intestinal mucosa, 3.2 +/- 0.2% was recovered in the lymph, and 28.2 +/- 6.5% (calculated) was absorbed via the portal system. The total uptake/absorption of beta-C was 12.9 +/- 6.8 nmol.h-1.30 cm intestine-1. Large amounts of unchanged beta-C and relatively small amounts of both beta-apo-12'-carotenal and beta-apo-10'-carotenal were isolated in the intestinal mucosa after a 4-h perfusion with beta-C. Considerable amounts of metabolites more polar than retinol were formed and comprised 35% of the total radioactivity recovered in the intestinal mucosa. Polar metabolites were absorbed mostly into the portal venous system, whereas retinol and retinyl esters were absorbed mainly into the mesenteric lymph. Of the total absorbed radioactivity in lymph, 10 +/- 1.0% appeared as unchanged beta-C, with peak absorption occurring at 3 h after beginning the perfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

[Regulation of purine biosynthesis. I. Isolation of add:: MudJ (lacZ, Kanr) insertions and genetic mapping]

Report here is the isolation of adenosine deaminase deficient mutants and genetic mapping. Engineering transposon MudJ (lacZ, Kanr) was used for mutagenesis and six add:: MudJ were obtained among 20,000 Kanr transductants. Adenosine deaminase activity of these mutants were assayed and all are negative. Cotransduction analysis of add::MudJ indicated that add is 70% linked to pmi(31') and 37% linked to zxx1900::Tn10d-tet insertion which is 10% linked to purR(30'). Three points cross showed that add is located between pmi and Tn10d-tet insertion. Therefore the gene order is purR-zxx1900::Tn10d-tet-add-pmi.

[Clinical studies of the treatment of hypertensive cerebral hemorrhage by simple serotaxic exsuction]

51 cases of hypertensive cerebral hemorrhage (Group A) treated with exsuction on the basis of the medical conservative therapy are reported. And meanwhile a control group of 51 cases (Group B) is treated only with conservative therapy. Comparison of the result of these two groups shows that complete absorption of hematoma in Group A appears 2 weeks earlier than that of group B; both the mortality rate and the disability rate are significantly lower in the former. Follow-up study shows that most cases of group A enjoy their lives very well. Indication of exsuction, operation maneuvers, operation methods and the correlation between the volume and site of hematoma and curative effect are discussed.