[Cleft palate repair with a combined method of mucosal flap pushback of the hard palate]

From January of 1992, we applied a combined method to repair cleft palate in 20 patients and received satisfactory results. The method is characterized by pushing back the mucosal flap of the hard palate, a Z-plasty on the nasal mucosa, repositioning the levator muscle to lengthen the palate, circumferential pharyng oplasty using denervated extensor hallucis brevis muscle, without making relaxing incisions and elevating the mucoperiosteal flap, avoiding interference to the greater and lesser palatine vessels and nerves, without relaxing palatal aponeurosis. The advantages of this method are preserving the normal anatomy and function of the palate and nasopharyngeal cavity, improving the function of velopharyngeal closure and minimizing secondary deformities.

[Establishment of an effective way for separating and culturing tumor infiltrating lymphocytes]

The key to preparing TILs for clinical application is to enhance its capacity of proliferation and cytotoxicity. For this purpose we have made a study of methodology and established an effective way consisting of 3 processes to separate and culture TILs. It included: (1) mechanical splitting; (2) digesting with 0.05% collagenase I and 0.003% DNAase I mixture in room temperature for 6 hrs and 18hrs in cool, and (3) centrifuging with 75% and 100% Ficoll non-continuous grade density. The separated TILs were suspended in conditional culture medium for proliferation. Most of them reached the amount of 10(9) at the end of culture, which was essential for clinical therapy. Their NK and LAK activities were 56.3 +/- 11.7% and 48.6% +/- 10.6% respectively, in which the CD6+ T cells played an important role. The results suggest this a perfect way for separating and culturing TILs.

Effects of benzodiazepines on potassium-induced increase in free cytosolic calcium concentration in astrocytes: interactions with nifedipine and the peripheral-type benzodiazepine antagonist PK 11195

The benzodiazepines diazepam and midazolam at submicromolar concentrations potentiated the increase in free cytosolic calcium concentration in astrocytes in primary cultures evoked by an elevation of the extracellular potassium concentration ([K+]0), but they had little stimulatory effect at normal [K+]0 and none at maximally elevated [K+]0. Nifedipine, an inhibitor of the L-channel, counteracted both the effect of the elevated [K+]0 as such and the benzodiazepine modulation. PK 11195, an antagonist of the peripheral-type benzodiazepine receptor, counteracted the effect of the benzodiazepines, but had no effect on the increase in free cytosolic calcium evoked by the elevated [K+]0.

Identification and characterization of radiation damaged products of monophosphate nucleosides by on-line capillary isotachophoresis-electrospray ionization mass spectrometry

Analysis of trace levels of DNA damage as a biomarker of human exposure to radiation levels represents a significant challenge. Capillary isotachophoresis (CITP) is well suited for this application due to its high separation efficiency, large sample loading capacity, and relative ease of interfacing with highly specific and sensitive mass spectrometric detectors. This study describes the use of reversed anionic CITP coupled on-line with electrospray ionization-mass spectrometry (ESI-MS) for the identification and characterization of small quantities of radiation induced damage to deoxynucleotide monophosphates. CITP with ESI-tandem MS also provides structural information on the nature of the damage in addition to the molecular weight. This approach has the attraction of allowing the direct on-line determination of damaged nucleotides, as well as the free bases and nucleosides, and avoids the need for sample hydrolysis and/or derivatization.

Reaction of ferrate (VI)/ferrate (V) with hydrogen peroxide and superoxide anion--a stopped-flow and premix pulse radiolysis study

The reduction of ferrate(VI) to ferrate(V) by superoxide ions was studied over the pH range 2.6-13.0 using the premix pulse radiolysis technique. The pH dependence indicates that only the unstable protonated forms of ferrate, H2FeO4 (pKa3.5) and HFeO4- (pKa7.3) are reactive, k(HFeO4(-) + O2) = (1.7 +/- 0.2) x 10(7) M-1 s-1. The stable ferrate ion, FeO4(2-), showed no significant reactivity towards either hydrogen peroxide or superoxide anion. The rate constants for the spontaneous dimerization and decomposition of the protonated ferrates, e.g. k(HFeO4(-) + HFe04) approximately 250 M-1s-1, are orders of magnitude slower than their corresponding reduction reduction by superoxide indicating an outer-sphere mode of electron transfer for the latter process. In contrast the ferrate(VI) species H3FeO4+ (pKa = 1.6 +/- 0.2), H2FeO4, and HFeO4- oxidize hydrogen peroxide, e.g. k(HFeO4(-) + H2O2) = 170 M-1 s-1), at rates which correspond closely to their dimerization rates suggesting an inner-sphere controlled mechanism.

Gangliosides of migrating and nonmigrating corneal epithelium in organ and cell culture

PURPOSE

To identify major gangliosides - the sialated glycolipids - of corneal epithelium; to determine which specific gangliosides, if any, are synthesized in a higher amount or are downregulated during corneal epithelial cell migration; and to determine what role, if any, they play in the modulation of corneal epithelial cell proliferation.

METHODS

[3H]-galactose-labeled and unlabeled glycolipids of migrating and nonmigrating rabbit corneal epithelium in cell and/or in organ culture were chromatographed on DEAE Sephadex to isolate gangliosides. The gangliosides eluted from the ion-exchange column were further characterized by thin-layer chromatography (TLC), glycosidase digestions, and TLC-immunostain analysis. A [3H]-thymidine incorporation assay was used to determine the effect of exogenous gangliosides on corneal epithelium cell proliferation.

RESULTS

Upon TLC of the acidic fraction eluted from the DEAE column, only two radiolabeled glycolipids (GL1 and GL2), migrating as a doublet, were detected. Regardless of whether the epithelia were prepared by cell culture or organ culture, both GL1 and GL2 were present in a significantly higher amount in migrating compared to nonmigrating epithelia. Further characterization of GL1 and GL2 identified them as gangliosides known as GM3. TLC-immunostain analysis, as well as orcinol staining of thin-layer chromatograms of gangliosides of unlabeled cells, revealed that GM3 also accumulates in a higher amount in migrating compared to nonmigrating epithelial cell cultures. Exogenous addition of GM3, but not various other gangliosides, inhibited corneal epithelial cell proliferation in a dose-dependent manner.

CONCLUSIONS

GM3 is the major ganglioside present in corneal epithelium, and its levels are elevated during corneal epithelial cell migration. It is suggested that the ganglioside plays a role in events that modulate corneal epithelial cell proliferation.

In vitro and in vivo biotransformation of 6,7-dimethyl-2,4-di-1-pyrrolidinyl-7H-pyrrolo[2,3-D]pyrimidine (U-89843) in the rat

The biotransformation of 6,7-dimethyl-2,4-di-1-pyrrolidinyl-7H-pyrrolo[2,3-d]pyrimidine (U-89843) has been studied in rat both in vitro and in vivo. Major metabolites observed by HPLC analysis of rat plasma, liver cytosol, and microsomal incubations were characterized by UV, LC/MS, and comparison with synthetic standards. The structures of the metabolites were shown to be the C-6 hydroxymethyl (U-97924), C-6 formyl (U-97865), and C-6 carboxyl analogs of U-89843. In the male rat, formation of U-97924 is mediated by cytochrome P4502C11. Kinetic analysis of U-97924 formation indicated that it was a high-affinity/high-capacity process (KM = 4.2 +/- 0.5 microM; Vmax = 21.2 +/- 0.8 nmol/mg/min). Formation of U-97865 via enzymatic oxidation from the primary metabolite U-97924 was catalyzed by both the microsomal subcellular fraction in a NADPH-dependent process (presumably via cytochrome P450) and in cytosol by NAD(+)-dependent alcohol dehydrogenase. Upon incubation with cytosolic fractions, U-97865 was found to undergo NAD(+)-dependent oxidation, mediated by aldehyde dehydrogenase, to the corresponding carboxylic acid. Although significant levels of U-89843, U-97924, and U-97865 were observed in vivo in rat plasma, only a minor amount of the carboxylic acid together with larger amounts of unidentified polar metabolites were excreted in urine and feces.

CD22 associates with protein tyrosine phosphatase 1C, Syk, and phospholipase C-gamma(1) upon B cell activation

Cross-linking B cell antigen receptor (BCR) elicits early signal transduction events, including activation of protein tyrosine kinases, phosphorylation of receptor components, activation of phospholipase C-gamma (PLC-gamma), and increases in intracellular free Ca2+. In this article, we report that cross-linking the BCR led to a rapid translocation of cytosolic protein tyrosine phosphatase (PTP) 1C to the particulate fraction, where it became associated with a 140-150-kD tyrosyl-phosphorylated protein. Western blotting analysis identified this 140-150-kD protein to be CD22. The association of PTP-1C with CD22 was mediated by the NH2-terminal Src homology 2 (SH2) domain of PTP-1C. Complexes of either CD22/PTP-1C/Syk/PLC-gamma(1) could be isolated from B cells stimulated by BCR engagement or a mixture of hydrogen peroxidase and sodium orthovanadate, respectively. The binding of PLC-gamma(1) and Syk to tyrosyl-phosphorylated CD22 was mediated by the NH2-terminal SH2 domain of PLC-gamma(1) and the COOH-terminal SH2 domain of Syk, respectively. These observations suggest that tyrosyl-phosphorylated CD22 may downmodulate the activity of this complex by dephosphorylation of CD22, Syk, and/or PLC-gamma(1). Transient expression of CD22 and a null mutant of PTP-1C (PTP-1CM) in COS cells resulted in an increase in tyrosyl phosphorylation of CD22 and its interaction with PTP-1CM. By contrast, CD22 was not tyrosyl phosphorylated or associated with PTP-1CM in the presence of wild-type PTP-1C. These results suggest that tyrosyl-phosphorylated CD22 may be a substrate for PTP-1C regulates tyrosyl phosphorylation of CD22.

Thiophosphate derivatives as inhibitors of tyrosine phosphatases

Thiophosphorylated proteins or peptides are poor substrates of protein phosphatases. As a competitive inhibitor of a protein tyrosine phosphatase, a tyrosine-thiophosphorylated nonapeptide ENDYINASL displays a KI value of 0.25 microM, in comparison with the Km value of 3.1 microM exerted by the enzyme toward the phosphorylated form of the peptide. Furthermore, adenosine 5'-O-3-thiotriphosphate is also an effective competitive inhibitor of the enzyme with a KI value of 1.4 microM. In contrast, ATP and 5'-adenylimidodiphosphate are much less effective, indicating that the thiophosphate group plays a major role in the inhibition process. Further supporting this is the fact that sodium thiophosphate is a more effective inhibitor than inorganic phosphate (IC50 = 0.47 mM versus 15 mM). The inhibition by thiophosphate compounds is specific for PTPs. The data suggest the application of thiophosphate derivatives as specific inhibitors of PTPs.

Inhibitors of cholesterol biosynthesis increase hepatic low-density lipoprotein receptor protein degradation

Inhibitors of cholesterol biosynthesis are believed to lower serum cholesterol levels by enhancing the removal of serum low-density lipoprotein (LDL) by increasing hepatic LDL receptor function. Thus, the effects of several different inhibitors of cholesterol biosynthesis were examined for their effects on the expression of the hepatic LDL receptor in rats. We found that administration of inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase such as lovastatin, pravastatin, fluvastatin, and rivastatin resulted in increased hepatic LDL receptor mRNA levels. Surprisingly, these agents failed to increase levels of immunoreactive LDL receptor protein in rat liver even when the dose and length of treatment were increased. Treatment of rats with zaragozic acid A, an inhibitor of squalene synthase, caused even greater increases in hepatic LDL receptor mRNA levels, but did not increase levels of immunoreactive protein. Further investigation revealed that the rate of degradation of the hepatic LDL receptor was increased in rats given inhibitors of cholesterol biosynthesis. The greatest increase in the rate of degradation was seen in animals treated with zaragozic acid A which caused the largest increase in hepatic LDL receptor mRNA levels. In contrast, hepatic LDL receptor protein was stabilized in cholesterol-fed rats. It appears that increased potential for LDL receptor protein synthesis, reflected in increased mRNA levels, is offset by a corresponding increase in the rate of receptor protein degradation resulting in constant steady-state levels of hepatic LDL receptor protein. These findings are suggestive of increased cycling of the hepatic LDL receptor. This postulated mechanism can provide for enhanced hepatic uptake of lipoproteins without increasing steady-state levels of LDL receptor protein.

Pharmacokinetics and antitumor effects of mitoxantrone after intratumoral or intraarterial hepatic administration in rabbits

The intratumoral (i.t.) delivery of anticancer drugs aims at controlling tumor growth and thereby provides palliative treatment for liver neoplasms. Mitoxantrone is a good candidate for local or regional administration because (1) its metabolism is mainly hepatic, (2) it has a steep dose-response curve for multiple solid tumors, and (3) its fixation in tissues is sustained without vesicant effects after extravasation. We compared the tolerance, pharmacokinetics, and antitumor effects of mitoxantrone on hepatic VX2 tumors in rabbits treated with i.t. intraarterial hepatic (i.a.h.) or i.v. mitoxantrone, i.t. ethanol; or i.t. 0.9% NaCl and in control animals. Tumor growth rates (TGRs) were evaluated at 9 days after treatment. Myelosuppression was the limiting toxicity of i.v. mitoxantrone at 1.5 mg/kg (maximal tolerated dose, MTD), but neither i.t. nor i.a.h. administration led to hematologic toxicity at the same dose. The mitoxantrone retained in tumors after i.t. administration was seen as blue-stained areas of complete necrosis according to histologic analysis. Pharmacokinetic parameters showed a significantly decreased systemic exposure to the drug after both regional treatments, although the i.a.h. route appeared to have an edge over the i.t. route. TGRs were significantly reduced after i.t. mitoxantrone (81 +/- 62%), i.a.h. mitoxantrone (337 +/- 110%), and i.t. ethanol treatments (287 +/- 117%) as compared with control values (886 +/- 223%; p < 0.01). Treatment with i.v. mitoxantrone (816 +/- 132%) had no antitumor effect, nor did NaCl injections (868 +/- 116%). Mitoxantrone given i.t. induced the highest antitumor effects, resulting in a 3.5-fold reduction in TGRs as compared with i.a.h. mitoxantrone and i.t. ethanol treatments (p < 0.02). Treatment with i.t. mitoxantrone provided efficient antitumor therapy without producing major side effects. This method should be considered as palliative treatment for nonresectable liver tumors and other localized malignancies.

Experimental study on the early efficacy of excimer laser with adjunctive balloon angioplasty in dog's femoral artery

The effect of domestically-manufactured excimer laser with adjunctive balloon angioplasty in achieving revascularization and reduction of residual stenosis was assessed. 20 femoral arteries with thrombosis and occlusion from 12 dogs were subject to angiography. At first excimer laser angioplasty was done followed by balloon angioplasty. The diameter and residual stenosis of revascularized vessel were measured. The result showed that 17 out of 20 vessels (85%) were revascularized. The diameter of revascularized vessel by excimer laser were 1.22 +/- 0.14 mm, while residual stenoses were 54% +/- 5%. After adjunctive balloon angioplasty the diameter and residual stenoses were 2.04 +/- 0.16 mm and 20% +/- 7% respectively (P < 0.05 and P < 0.01). Complication in form of vasoperforation occurred in 3/20 vessels (15%). It is concluded that China- manufactured excimer laser angioplasty is effective when used for revascularization. While the reduction of narrowing and residual stenoses was enhanced after adjunction of balloon angioplasty. This method can be employed in treating peripheral occlusive disease effectively and safely.

Dose-response effects of dietary fiber on NMU-induced mammary tumorigenesis, estrogen levels and estrogen excretion in female rats

The dose-related effects of the fiber-rich isolate, soft white wheat bran (SWWB), and the pure fiber, cellulose, on N-nitrosomethylurea (NMU)-induced mammary tumorigenesis was assessed in F344 female rats. SWWB (45% total dietary fiber, TDF) was added to the AIN-76A high-fat diet at 9, 12, 15 and 18%; cellulose (98% TDF) was added to the same diet at 4.5, 6, 7.5 and 9%, to give equivalent amounts of TDF. The experimental diets were fed 3 days post-NMU and continued for a period of 25 weeks, at which time the experiment was terminated and tumors enumerated. It was found that significant inhibition of mammary carcinoma occurred only at 9% SWWB, non-significant inhibition occurred at 12% SWWB, and no inhibition was seen at higher doses. Cellulose-fed animals exhibited consistently higher tumor yields regardless of dose. The difference in tumor yields between the 9% SWWB group and the remaining seven groups was attributable to an increased incidence in tumors characterized histologically as intraductal proliferation and ductal carcinoma in situ in the latter. Analysis of blood, urine and fecal estrogens was conducted to test whether dietary fiber exerted its tumor-inhibiting effect by altering the enterohepatic recycling of estrogens. Although SWWB, in general, lowered urinary estrogen excretion, increased fecal estrogen excretion and lowered blood estrogens, there was no consistent correlation between the amount of SWWB consumed, estrogen status and tumor yields. These results suggest that (i) wheat bran fiber at 9%, or minor constituents associated with it, contain anti-promoting properties that cellulose lacks; (ii) SWWB appears to exert its effects by suppressing the clonal expansion phase of mammary carcinogenesis; (iii) there is an upper limit (12-15% w/w) to the protective effects of SWWB; and (iv) the effects of SWWB on mammary tumorigenesis may not be attributed to alterations in the enterohepatic recycling of estrogens.

Iron(II) oxidation by H chain ferritin: evidence from site-directed mutagenesis that a transient blue species is formed at the dinuclear iron center

The iron storage molecule, ferritin, consists of an iron core surrounded by a shell of 24 protein subunits, which, in mammals, are of two types, H and L. Prior to storage of iron as a hydrous ferric oxide within the protein shell, Fe(II) is catalytically oxidized at dinuclear centers within H chains. When 48 Fe(II) atoms/molecule were added to 1 microM recombinant human H chain apoferritin (apo-HuHF), in 0.1 M Mes (pH 6.5), oxidation was 80% complete within about 0.2 s while 99% of the Fe(II) was oxidized within 10 s. A broad visible absorption band (400-800 nm, with a maximum at 650 nm) appeared during the fast phase of Fe(II) oxidation. It reached a plateau at 0.2-0.3 s and then declined while Fe(II) oxidation proceeded to completion and absorbance in the near-UV (300-400 nm) increased. The transient visible species was not observed when Tyr-34 was replaced by phenylalanine or when other conserved amino acids at the ferroxidase centers were substituted by residues which are unable to bind iron or which alter the charge balance. When a second increment of 48 iron atoms was added, 10 min after the first, the visible absorbance was absent and the rate of oxidation slower. Restoration of full oxidative activity took over 24 h. The data indicate that the fast oxidation of Fe(II) by apo-HuHF and the transient visible absorbance associated with it are due to Fe(II) oxidation at the ferroxidase centers.

[Serologic screening on nasopharyngeal cancer in 338,868 persons in 21 cities and counties of Guangxi Region, China]

Serological screening on nasopharyngeal cancer in 338,868 persons living in 21 cities and counties of Guangxi Zhuang Autonomous Region was carried out from January 1991 to September 1993. Results showed 9367 persons were positive for IgA antibodies to Epstein-Barr virus (EBV) capsid antigen, and 306 of them positive for IgA to EBV early antigen. One hundred and thirteen cases of nasopharyngeal cancer were detected in the former with 100 cases (88.5%) in the early stage, and 63 cases in the latter with 58 (92.1%) cases in the early stage. It suggested certain relationship existed between EBV and nasopharyngeal cancer, and serologic screening could be beneficial for secondary prevention of it.

Chromosomal mapping of the mouse A3 adenosine receptor gene, Adora3

A3 adenosine receptor is a member of Gi protein-coupled receptors that mediate inhibition of adenylate cyclase activity upon binding to the ligand. We determined the chromosome localization of the mouse A3 gene for future genetic studies, utilizing an interspecific backcross panel formed from the cross (C57BL/6J x Mus spretus) F1 x M. spretus. Genomic DNAs from 94 individuals in the backcross were analyzed by Southern hybridization with murine A3 receptor cDNA probe. Unique map positions were determined by haplotype analysis with 1388 previously mapped loci in the mouse backcross. The mouse A3 receptor gene (Adora3) mapped to chromosome 3, in tight linkage with DNA marker D3Bir15.

Phospholipid binding and lecithin-cholesterol acyltransferase activation properties of apolipoprotein A-I mutants

Recombinant human apolipoprotein A-I (apo A-I) and three deletion mutants: apo A-I(delta Leu44-Leu126), apo A-I(delta Glu139-Leu170), and apo A-I(delta Ala190-Gln243), purified from the periplasmic space of Escherichia coli, were studied. The rate of turbidity decrease following mixing of apo A-I(delta Ala190-Gln243) with dimyristoylphosphatidylcholine (DMPC) vesicles at 23 degrees C was 10-fold lower than that of the other apo A-I proteins, confirming that the carboxy-terminal region of apo A-I plays a role in rapid lipid binding. The Stokes radii of reconstituted high-density lipoproteins (rHDL), containing dipalmitoylphosphatidylcholine and cholesterol, were larger for the three apo A-I mutants [6.3 nm for apo A-I(delta Leu44-Leu126), 6.1 nm for apo A-I(delta Glu139-Leu170), and 6.5 nm for apo A-I(delta Ala190-Gln243)] than for intact apo A-I (5.0 nm). The mutant rHDL all contained 4 apo A-I molecules per particle as compared to 2 for intact apo A-I. Circular dichroism measurements revealed 8 alpha-helices per apo A-I molecule, 5 per apo A-I(delta Leu44-Leu126), 6 per apo A-I(delta Glu139-Leu170), and 4 per apo A-I(delta Ala190-Gln243) molecule as compared to predicted values of 8, 5, 6, and 6 alpha-helices, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduced hepatic LDL-receptor, 3-hydroxy-3-methylglutaryl coenzyme A reductase and sterol carrier protein-2 expression is associated with pregnancy loss in the diabetic rat

Hepatic low density lipoprotein receptor (LDLR), 3-hydroxy-3-methylglutaryl coenyzme A reductase (HMGR), cholesterol 7α-hydroxylase, and sterol carrier protein-2 are important proteins associated with the uptake, synthesis, degradation and transport of cellular cholesterol. Since cholesterol is critically important for steroid hormone synthesis and is an essential component in membrane biosynthesis, this study investigated whether these proteins are altered in the normal pregnant and streptozotocin (STZ)-induced diabetic pregnant rat. The goal of these experiments was to determine whether diabetic reproductive dysfunction is associated with a significant change in maternal cholesterol homeostasis. Diabetic animals were grouped based on their ability or inability to maintain pregnancy up to day 15 post-conception. LDLR and HMGR mRNA levels were significantly reduced in animals which did not maintain pregnancy whereas diabetic animals with fetuses had normal LDLR and HMGR mRNA levels. Hepatic LDLR, HMGR, and SCP2 protein levels were examined in normal pregnant and diabetic pregnant animals by Western blot analysis. SCP2 levels were reduced in all diabetic animals, particularly in the diabetic animals which lost their fetuses. The decline in SCP2 was associated with an increase in sterol carrier protein-X (SCPx), a protein related to SCP2. SCPx has been shown to have thiolytic activity and is thought to have a role in β-oxidation of fatty acids. HMGR was also significantly reduced in diabetic animals which lost their fetuses. Cholesterol 7α-hydroxylase mRNA was slightly, but not significantly, reduced in all diabetic animals. Serum very low density lipoprotein (VLDL) +LDL cholesterol increased significantly in the STZ-treated diabetic rats while the HDL cholesterol levels declined in these animals. Reduced hepatic LDLR and HMGR mRNA levels were consistently associated with reduced serum progesterone and an inability to maintain pregnancy. The results of this study suggest that the maintenance of maternal cholesterol metabolism is a critical factor directly associated with successful pregnancy outcome in the diabetic rat.

Treatment of the cholesterol biosynthetic defect in Smith-Lemli-Opitz syndrome reproduced in rats by BM 15.766

BACKGROUND & AIMS

The Smith-Lemli-Opitz syndrome is a recessive inherited disorder characterized by neurological developmental defects and dysmorphic features with a defect in cholesterol synthesis at the conversion of 7-dehydrocholesterol to cholesterol. BM 15.766 inhibits 7-dehydrocholesterol-delta 7-reductase and reproduces the biochemical defect. The aim of this study was to investigate the effects of cholesterol, cholic acid, and lovastatin feeding on rats fed BM 15.766.

METHODS

Plasma cholesterol and 7-dehydrocholesterol concentrations were related to the hepatic 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase.

RESULTS

With the inhibitor treatment, plasma cholesterol concentrations decreased 67%; 7-dehydrocholesterol concentrations increased from trace to 17 mg/dL; and hepatic HMG-CoA reductase activity and messenger RNA levels were stimulated 74% and two times, respectively. In inhibitor-treated rats, feeding cholesterol increased plasma cholesterol concentrations 3.7 times, decreased 7-dehydrocholesterol concentrations 88%, and reduced elevated HMG-CoA reductase activity and messenger RNA levels 74% and 49%. Feeding cholic acid increased plasma cholesterol without reducing 7-dehydrocholesterol concentrations. The combination of cholic acid and cholesterol enhanced plasma cholesterol 9.5 times without decreasing 7-dehydrocholesterol levels. Feeding lovastatin depressed plasma cholesterol further without reducing 7-dehydrocholesterol levels.

CONCLUSIONS

Cholesterol is essential to correct abnormal cholesterol synthesis induced by BM 15.766 in rats by expanding the pool and inhibiting HMG-CoA reductase. Neither cholic acid nor lovastatin are effective separately, but cholic acid plus cholesterol may offer some additional benefit.

Plasma membrane sialoglycoproteins of human corneal epithelium in culture

A number of studies, using either rat or rabbit models, have focused on delineating the role of cell surface glycoconjugates in corneal epithelial cell migration and wound healing. We have recently identified the cell surface sialoglycoproteins of rabbit corneal epithelium and have shown that the levels of at least three membrane glycoproteins are markedly altered during cell migration. Because species-related differences may be present, it is important to select an appropriate animal model for studies designed to contribute to the understanding of the mechanism of human corneal wound healing. The purpose of this study was to identify the cell surface sialoglycoproteins of human corneal epithelium. Plasma membrane sialoglycoproteins of primary cultures of human corneal epithelium were labeled with NaB3H4 after oxidation by mild NaIO4 treatment. The labeled glycoproteins were analyzed by SDS-polyacrylamide gel electrophoresis and fluorography. Four different preparations of human corneal epithelial cell cultures were analyzed, and results were compared with those of rabbit corneal epithelium. Of the 11 radiolabeled sialoglycoproteins we identified recently in rabbit corneal epithelium, eight were also present in human corneal epithelium. These similarities in the electrophoretic patterns of the plasma membrane glycoproteins of the two species suggest that rabbit is most likely an appropriate animal model for studies designed to contribute to the understanding of the structure and function of cell surface glycoproteins of human corneal epithelium.

[Research on the different blood types umbilical cord blood hematopoietic progenitors mixed culture in vitro]

Using single layer agar culture method, we make a study on culture of human hematopoietic progenitor cell from umbilical cord blood. The result showed the mean value of the granulocyte macrophage progenitor cells (CFU-GM) from twenty neonates cord blood was 95.6 +/- 36.5/10(6) MNC. We compared the mixed culture of two different blood types neonates cord blood hematopoietic progenitors with single sample and found little difference between them in number and growth characteristics. This may provide a theoretical basis for clinical transplantation of mixed human cord progenitor cells.