Expression cloning of a protective Leishmania antigen

Parasite-specific CD4+ T cells have been shown to transfer protection against Leishmania major in susceptible BALB/c mice. An epitope-tagged expression library was used to identify the antigen recognized by a protective CD4+ T cell clone. The expression library allowed recombinant proteins made in bacteria to be captured by macrophages for presentation to T cells restricted to major histocompatibility complex class II. A conserved 36-kilodalton member of the tryptophan-aspartic acid repeat family of proteins was identified that was expressed in both stages of the parasite life cycle. A 24-kilodalton portion of this antigen protected susceptible mice when administered as a vaccine with interleukin-12 before infection.

Analysis of Pichinde arenavirus transcription and replication in human THP-1 monocytic cells

Human promonocytic THP-1 cells were previously shown to be nonpermissive for Pichinde virus (PV) replication unless the cells were induced to differentiate to macrophages by stimulation with phorbol ester (PMA) (J. Virol. 65, 3575, 1991). The restriction did not involve receptor modulation, virus binding, nor internalization of virus but a requirement for a host cell function in PV replication was observed in that the phorbol ester effect required protein kinase C activation and was inhibited by actinomycin D. In this report we demonstrate that PV S RNA genomes, antigenomes, GPC mRNA and NP mRNA are expressed at high levels in PMA treated THP-1 cells but at significantly lower levels or not at all in untreated cells. We have also determined that degradation of input viral S RNA does not account for decreased PV RNA synthesis in the undifferentiated cells. This suggests that the restriction of PV replication in THP-1 cells is a post-penetration event which precedes transcription of viral mRNAs and replication of viral genomes and supports a role for differentiation-specific host cell factors early in PV replication.

[Reduced intracellular drug accumulation related to overexpression of P-glycoprotein cannot explain the complete drug resistance in MDR cell variant K562/Dox]

The purpose of this study was to determine what proportion of drug resistance of MDR cell variant K562/Dox was attributed to the reduced steady state intracellular drug accumulation related to overexpression of P-glycoprotein. K562/Dox was derived from repeated exposure of human erythroleukaemic cell line K562 cell to doxorubicin. As assessed with MTT assay, the resistance of K562/Dox to 7 cytotoxic drugs increased variably in the range between 1200 and 11 folds. K562/Dox cells were positively stained with anti-human p-glycoprotein monoclonal antibody JSB-1, indicating overexpression of P-gp. Intracellular drug accumulation in K562/Dox, though significantly reduced as compared with that in K562 cells, was maximally restored by concurrent exposure of cells to 6 mumol/L verapamil and 1.72 mumol/L either of the doxorubicin, epirubicin or daunorubicin. Similar results were obtained by exposure of cells to 12 mumol/L verapamil and 8.62 mumol/L drug, indicating that restoration of intracellular drug accumulation in MDR cells was dependent on the relative concentrations of verapamil to drug. However, the resistances of K562/Dox cells to epirubicin and daunorubicin still remained for about 5.6 and > 6.6 folds, respectively, even at verapamil concentration of 6 mumol/L, suggesting at least a relatively big fraction of drug resistance was not directly related to the altered cellular pharmacokinetics associated with overexpression of P-glycoprotein.

Influence of steric stabilization of liposome-encapsulated hemoglobin on Listeria monocytogenes host defense

Liposome-encapsulated hemoglobin (LEH) products are being investigated as potential blood substitutes. To determine if changes in LEH composition can modify the immune response, red blood cell substitutes based on conventional lipids containing phosphatidylinositol (LEH1) and sterically stabilized lipid vesicles containing polyethylene glycol phosphatidylethanolamine (LEH2) were tested for effects on host resistance. On Day 0, groups of 18 to 20 female CD-1 mice were given an intravenous (i.v.) infectious challenge with a 20% lethal dose of Listeria monocytogenes. Mice received a single i.v. dose of LEH1, LEH2, or albumin vehicle on Day +1 or Day -3 relative to infectious challenge. Mice dosed with LEH1 and LEH2 on Day +1 died rapidly from Listeria infection; but mice dosed with LEH2 lived significantly longer than did mice receiving LEH1. By contrast, when administered on Day -3, LEH1 had no significant effect on host immunity, while LEH2 increased susceptibility to Listeria infection. In addition, LEH1 and LEH2 both caused significant reduction of phagocytic activity as measured by rat alveolar macrophage (AM) ingestion of latex microspheres. AM incubated 4 hr with either LEH1 or LEH2 prior to addition of microspheres ingested fewer beads in a dose-dependent manner. No difference in in vitro phagocytic activity was observed between LEH1 or LEH2. The inability to differentiate LEH formulations based on in vitro phagocytic activity suggests that the in vivo Listeria infection model may be more relevant in discerning the immunotoxicity of the LEH formulations tested.

Mutational analysis of patients with X-linked adrenoleukodystrophy

Adrenoleukodystrophy (ALD) is an X-linked neurodegenerative disorder characterized by elevated very long chain fatty acid (VLCFA) levels, reduced activity of peroxisomal VLCFA-CoA ligase, and variable phenotypic expression. A putative gene for ALD was recently identified and surprisingly encodes a protein (ALDP) that belongs to a family of transmembrane transporters regulated or activated by ATP (the ABC proteins). We have examined genomic DNA from ALD probands for mutations in the putative ALD gene. We detected large deletions of the carboxyl-terminal portion of the gene in 4 of 112 probands. Twenty-five of the ALD probands whose ALD genes appeared normal by Southern blot analysis were surveyed for mutations by Single Strand Conformation Polymorphism (SSCP) procedures and DNA sequence analysis. SSCP variants were detected in 22 probands and none in 60 X-chromosomes from normal individuals. Mutations were detected in all of the ALD probands. The mutations were distributed throughout the gene and did not correlate with phenotype. Approximately half were non-recurrent missense mutations of which 64% occurred in CpG dinucleotides. There was a cluster of frameshift mutations in a small region of exon 5, including an identical AG deletion in 7 unrelated probands. These data strongly support the supposition that mutations in the putative ALD gene result in ALD.

[Clinical significance of urodynamic study in benign prostatic hyperplasia]

Urodynamic study, including UFR, cystometry, UPP, and EMG was carried out in 74 patients with benign prostatic hyperplasia (BPH) during the past 5 years. The correlations of prostate volume (57.3 +/- 6.3 ml), prostate length (4.94 +/- 1.23 cm) and detrusor pressure (6.54 +/- 4.73 kPa) were analysed. The results showed that urodynamic study plays an important role in indicating the time and method of operative treatment and predicting the prognosis of BPH operation. The fistularization of the bladder should be performed on the patients with the bladder disfunction. The measurement of the urethral resistance is of value in the diagnosis of posterior urethra obstruction than that of UFR.

Microencapsulation of hemoglobin in liposomes using a double emulsion, film dehydration/rehydration approach

A double emulsion, film dehydration/rehydration approach was developed for encapsulation of hemoglobin (Hb) at high concentration in liposomes. The liposome-encapsulated Hb (LEH) membrane was formulated to contain either phosphatidylinositol (PI) or polyethyleneglycol phosphatidylethanolamine (PEG-PE) along with partially hydrogenated egg-PC, cholesterol, and alpha-tocopherol in a molar ratio of 0.1:1:1:0.02, respectively. The methods introduced in this study followed a multi-step procedure. First, a primary emulsion of Hb in organic solvent containing dissolved lipids was formed. Next, the emulsion was dispersed into an aqueous continuous phase to form a water-in-oil-in-water type double emulsion. Other than the lipids noted above, no surfactants were used in this system. The double emulsion was then converted to LEH by the following steps: evaporating the organic solvent; dehydrating the water to form a dry, thin Hb-lipid film; rehydrating the film in Hb solution to form the LEH; reducing the size of the LEH using 'microfluidization' i.e., high pressure/hydrodynamic shear; and lastly washing the down-sized LEH in buffer. Physico-chemical properties of the model LEH were measured, including oxygen content, encapsulated Hb concentration, oxygen affinity and cooperativity, vesicular size distribution, viscosity, and stability. The suitability of LEH prepared in this manner as a red blood cell substitute was shown using continuous isovolemic exchange transfusion techniques in a small animal model: clearance, efficacy and acute toxicity were evaluated.

Interferon gamma-independent effects of interleukin 12 administered during acute or established infection due to Leishmania major

Interleukin 12 (IL-12) is a powerful stimulus for the growth of activated T and natural killer cells, their generation of interferon gamma (IFN-gamma), and the differentiation of T helper type 1 (Th1) effector cells from naive precursors in vitro. These activities are consistent with the capacity of exogenous IL-12 to heal otherwise susceptible BALB/c mice infected with the intramacrophage parasite Leishmania major. Using this characterized model of CD4 cell subset differentiation, we examined the immunologic effects of IL-12 administered either at the time of infection, when naive T cells are primed, or after 14 days of infection, by which time CD4+ subset differentiation has occurred. Given with the inoculation of parasites, IL-12 induced IFN-gamma and IL-10 and markedly suppressed IL-4. Effects on IL-10 and IL-4 were comparable in mice with homozygous disruption of the IFN-gamma gene (IFN-gamma 0/0), and suppression of IL-4 was unchanged by administration of neutralizing anti-IL-10 antibody. Induction of IFN-gamma and IL-10 mRNA by IL-12 also occurred in infected SCID mice. Given after day 14 of infection, however, IL-12 not only induced IFN-gamma and IL-10 but also induced IL-4 in normal and IFN-gamma 0/0 mice. These data demonstrate direct effects of IL-12 independent of IFN-gamma, IL-10, and IL-4 and demonstrate that the ineffectiveness of IL-12 administered following infection with L. major correlates with resistance of differentiated Th2 cells to the IL-4-suppressing activity of IL-12.

[A study of occupational asthma and specific IgE in sericulture workers]

Clinical investigation revealed that 75.6% (68/90) of sericulture workers examined had allergic respiratory symptoms. Of the 90 workers, 14 (15.6%) suffered from occupational asthma. Work-related allergens including silkworm cocoon (SC), silkworm urine (SU), moth excrete (ME) and moth scales (MS) were collected and prepared. Serum specific IgE levels were detected by ELISA. The results showed that the level of sIgE in asthmatic workers was significantly higher than that in the "common symptom" group, asymptomatic group and control group. No significant difference in total IgE was found between the workers and controls. The anti-SU-sIgE positive rate was significantly higher than those of sIgE to the other three allergens. These results indicate that the high levels of sIgE are responsible for occupational asthma in sericulture workers and that SU is an important allergen in these patients.

Cyclosporine and the reversibility of chronic vascular rejection

A model of chronic vascular rejection of cardiac allografts has been developed in inbred rats using the WF.1L/Gut congenic strain as donor into LEW recipients. The hearts beat for more than 200 days without the need for exogenous immunosuppression. The histopathology is characterized by cellular rejection, vasculitis, and myointimal arterial wall thickening, and by day 60 posttransplant, there are widespread occlusive vascular changes similar to those seen in human cardiac allografts. CsA, at a dose of 15 mg/kg/d, is effective in preventing as well as reversing the vasculopathy. These data (1) confirm other studies of ours on the reliability of the experimental model using this strain combination, (2) establish the time window of days 40 to 60 whereby mechanisms of lesion regression can be studied, (3) prove the MHC class I and class II antigen incompatibility are not a necessary condition for the generation of the vascular lesions, (4) show that CsA is a useful probe for study of the vasculopathy, and (5) suggest that the model is a useful probe of the mechanism of action of CsA.

Comparison of dietary habits, physical activity and body size among Chinese in North America and China

BACKGROUND

Chinese in North America have higher rates of many chronic diseases than do Chinese in Asia. However, there is a lack of data among comparisons of the environmental and lifestyle factors for Chinese in China and Chinese residing in North America.

METHODS

We examined self-reported dietary nutrient intakes, physical activity patterns and body mass index of 2488 healthy Chinese men and women residing in North America (US and Canada) and in the People's Republic of China.

RESULTS

On average, Chinese in China consumed more calories (males 2904 kcal in China, versus 2201 kcal in North America; females 2317 Kcal in China, versus 1795 Kcal in North America and more carbohydrate, but less fat (males 72.2 g in China versus 84.5 g in North America, females 56.6 g in China versus 70.8 g in North America), protein, vitamin A, beta-carotene and vitamin C than did Chinese in North America. Per cent calories from fat was 35% for Chinese in North America and 22% for Chinese in China. In contrast, the per cent of calories from carbohydrates was 62-68% in China and 48% in North America. Chinese in China reported spending more time in vigorous activity, sleeping and walking but less hours in sitting than Chinese in North America. Chinese in China weighted less and were leaner than North American Chinese.

CONCLUSIONS

These differences in nutrient intakes, physical activity and body size of Chinese living on two different continents suggest possible explanations for observed differences in chronic disease rates in the two populations.

[Detection of a gene mutation in familial adenomatous polyposis families by PCR-RFLP method]

A simple and rapid PCR-RFLP method was used to detect a mutation hotspot of adenomatous polyposis coli (APC) gene. Among seven familial adenomatous polyposis (FAP) families, we found individuals in family FD carrying a mutated APC gene or a mutated APC allele with AAAGA deletion in codon 1,309 region. Two young affected persons in twenties were detected by screening the family FD kindred with this PCR-RFLP method. The results are in good accordance with those of colonoscopic examination. The PCR-RFLP method we established proves to be a reliable and simple technique for early detection of some FAP patients. The results indicated the existence of same kind of APC gene mutations in Chinese FAP families as those in western countries.

CD4+ effector cells default to the Th2 pathway in interferon gamma-deficient mice infected with Leishmania major

Mice with homologous disruption of the interferon gamma (IFN-gamma) gene on the C57BL/6 background were infected with Leishmania major and the immune response assessed. In contrast to wild-type or heterozygous knockout mice, deficient animals were unable to restrict growth of the parasite and suffered lethal infection over 6-8 wk. Although wild-type and heterozygous littermates developed CD4+ cells that contained transcripts for IFN-gamma and lymphotoxin, typical of T helper type 1 (Th1) cells, the knockout mice developed CD4+ cells that contained transcripts for interleukin 4 (IL-4), IL-5, and IL-13, typical of Th2 cells. ELISPOT assays confirmed the reciprocal patterns of IFN-gamma or IL-4 production by T cells in similar frequencies in the respective groups of mice, and antibody analysis confirmed the presence of Th2-mediated isotype switching in the knockout mice. These data suggest that CD4+ T cells that normally respond to antigens by differentiation to Th1 cells default to the Th2 pathway in the absence of endogenous IFN-gamma.

[Photodynamic effect of chlorophyll derivative (CPD4) with pulsed copper-vapor laser on mouse transplanted tumor]

An experimental study on photodynamic effect of newly developed photosensitizer CPD4 with pulsed copper-vapor laser and pumped dye laser to mouse transplanted tumor (CT26) was carried out. The results showed that: (1) Ten days after treatment by CPD4 with 630nm laser, the mean tumor volume of control group (n = 9) was 1.0 +/- 0.68cm3, while that of treatment group (n = 18) was 0.45 +/- 0.5cm3 (P < 0.01), with an inhibitory rate of 55%. In the treatment group, 8 mice that were treated with a dose > or = 50mg/kg(iv) of CPD4, 280mW/cm2 of laser power density and 10 minutes of irradiation, were all cured with survival time over 6 months, while that of mice in the control group was 28.2 days (2) Under certain condition (light energy 120 J/cm2), with CPD4 as a sensitizer, the mean depths of tumor necrosis were 4.9 +/- 1.0mm (n = 5), 2.8 +/- 1.1mm(n = 11), 1.8 +/- 0.5mm(n = 9) for wavelength of 670nm, 630nm and 510nm, respectively (P < 0.01). When a conventional photosensitizer hematoporphyrin derivative was used, the depths of tumor necrosis were 0 (n = 6) 2.3 +/- 0.3 (n = 5) and 2.8 +/- 1.2 (n = 5)mm for 670, 630 and 510nm, respectively. Based on the above mentioned results, a rational treatment condition in clinical application of CPD4 with copper-vapor laser and pumped dye laser was suggested.

Characterization of anti-canine cytokine monoclonal antibodies specific for IFN-gamma: effect of anti-IFN-gamma on renal transplant rejection

Two murine monoclonal antibodies specific for IFN-gamma, ADI-1, and ADI-23 (both IgG1 kappa), were generated in BALB/c mice. The ADI-1 exhibited a higher avidity for canine rIFN-gamma than for nIFN-gamma and human rIFN-gamma. In contrast, the ADI-23 showed equal avidity for the three IFN-gamma preparations. The anti-canine IFN-gamma mAb did not bind to mouse and rat rIFN-gamma. The ADI-1, and ADI-23 mAb were also tested for binding to human rTFN-alpha and, contrary to our expectations, it was found that ADI-23 showed significant binding to human rTFN-alpha and rIFN-gamma, in contrast to ADI-1. Both anti-canine IFN-gamma mAb stained 48-h PHA-induced dog lymphoblasts. A two-site mAb ELISA was developed, which was linear in the range of 7-500 ng of canine rIFN-gamma, which indicated that the two mAb detected non-overlapping epitopes on the canine rIFN-gamma molecule. We studied the effect of ADI-1 on the prolongation of canine renal allografts. Recipients of kidney allografts, that were treated with ADI-1 by continuous arterial infusion, were prolonged to 22 and 25 days, compared to 9 and 13 days for animals given the IgG1 isotype control.

Leishmania promastigotes evade interleukin 12 (IL-12) induction by macrophages and stimulate a broad range of cytokines from CD4+ T cells during initiation of infection

Leishmania major are intramacrophage parasites whose eradication requires the induction of T helper 1 (Th1) effector cells capable of activating macrophages to a microbicidal state. Interleukin 12 (IL-12) has been recently identified as a macrophage-derived cytokine capable of mediating Th1 effector cell development, and of markedly enhancing interferon gamma (IFN-gamma) production by T cells and natural killer cells. Infection of macrophages in vitro by promastigotes of L. major caused no induction of IL-12 p40 transcripts, whereas stimulation using heat-killed Listeria or bacterial lipopolysaccharide induced readily detectable IL-12 mRNA. Using a competitor construct to quantitate a number of transcripts, a kinetic analysis of cytokine induction during the first few days of infection by L. major was performed. All strains of mice examined, including susceptible BALB/c and resistant C57BL/6, B10.D2, and C3H/HeN, had the appearance of a CD4+ population in the draining lymph nodes that contained transcripts for IL-2, IL-4, and IFN-gamma (and in some cases, IL-10) that peaked 4 d after infection. In resistant mice, the transcripts for IL-2, IL-4, and IL-10 were subsequently downregulated, whereas in susceptible BALB/c mice, these transcripts were only slightly decreased, and IL-4 continued to be reexpressed at high levels. IL-12 transcripts were first detected in vivo by 7 d after infection, consistent with induction by intracellular amastigotes. Challenge of macrophages in vitro confirmed that amastigotes, in contrast to promastigotes, induced IL-12 p40 mRNA. Reexamination of the cytokine mRNA at 4 d revealed expression of IL-13 in all strains analyzed, suggesting that IL-2 and IL-13 may mediate the IL-12-independent production of IFN-gamma during the first days after infection. Leishmania have evolved to avoid inducing IL-12 from host macrophages during transmission from the insect vector, and cause a striking induction of mRNAs for IL-2, IL-4, IL-10, and IL-13 in CD4+ T cells. Each of these activities may favor survival of the organism.

Efficacy, physical properties and pharmacokinetics of sterically-stabilized liposome-encapsulated hemoglobin

We recently reported that hemoglobin (Hb) encapsulated in liposomes (LEH) containing phosphatidyl-inositol (PI) was efficacious in rats. However, liposomes containing PI may temporarily compromise mononuclear phagocytic system (MPS) function. The objective of this study was then to determine whether a polyethylene oxide derivative of phosphatidyl ethanolamine (PEG-PE) would serve as an acceptable substitute for PI in our LEH formulation. In this study we compare the physical properties, pharmacokinetics and efficacy in life support obtained for Hb encapsulated with either PI or PEG-PE phospholipids. Both liposome compositions contained the same matrix lipids, egg derived phosphatidyl choline (PC) and cholesterol, were of similar size and contained the same amount of encapsulated Hb. The liposomes differed only in their phospholipid component, one containing 5 mol% PI and the other an equal amount of the sterically-stabilizing lipid PEG-PE. The physical characteristics of the PI and PEG-PE compositions were remarkably similar: only small amounts of Met-Hb were generated during processing and following 1 month frozen storage, oxygen affinity and cooperativity and steady shear viscosity values for 30% by volume suspensions (in isotonic/isooncotic saline containing albumin) were near the normal values expected for whole blood, incubation in plasma at 37 degrees C resulted in only small amounts of Hb release and shear had very little impact on Hb leakage. Circulation half-lives following 50% isovolemic exchange-transfusion in rats were also similar, about 15-20 hours for either formation. Animals survived following 97% isovolemic exchange-transfusion of both compositions, confirming the efficacy of each.

Differential effects of IFN-gamma on kidney cell expression of MHC class II molecules, kidney cell associated molecules and their stimulatory capacity in mixed lymphocyte kidney cell culture

Mixed cell co-cultures of lymphocytes responding to kidney cells (MLKC), islets of Langerhans (MLIC) and mixed lymphocyte culture (MLC), were used to clarify mechanisms in allogeneic and autoimmune (tissue-associated) antigen presentation. Fresh kidney cortical tubular cells (KC), Madin-Darby canine kidney (MDCK), and dog kidney (6247) (DK) cell lines were used in MLKC reactions, and islets of Langerhans were used in the MLIC as putative antigen presenting cells (APC). The stimulating cells were treated with purified or recombinant dog interferon-gamma (IFN-gamma), and the detection of class II MHC molecule expression was assessed by a moneclonal antibody (mAb) (B1F6). Transcription of MHC class II mRNA and IFN-gamma mRNA was measured by semiquantitative polymerase chain reaction, and detection of a kidney cell (tissue-associated) antigen molecule was assessed by the mAb I1F6 that recognizes 72 and 150 kDa tubular cell protein(s) (KT1). The MDCK cell line constitutively expressed low levels of MHC class II molecules and KT1. The steady-state level of the MHC class II mRNA transcription was virtually unaltered by treatment with IFN-gamma (400 units) for 48 hours; however, the MHC cell surface protein expression was enhanced. The KC and DK cell lines constitutively expressed KT1, but not MHC class II molecules; these cells required a minimum of 4000 units, and a 62-hour incubation with IFN-gamma was needed to upregulate both surface MHC class II molecules and the transcription of corresponding specific mRNA. In the MLKC reaction both the MDCK and DK cell lines, as well as fresh KC cells, could serve as lymphocyte activators. This could be amplified by exogenous IFN-gamma. The removal of APC from the responding T cell population did not reduce the IFN-gamma effect. This indicates that IFN-gamma treatment allows for the expression of all of the co-stimulating factors and/or adhesion molecules necessary for these cells to serve as (surrogate) APC (direct as opposed to indirect antigen presentation). The requirements for purified IFN-gamma to increase this amplification was greater in the MLKC reactions with kidney cells than in the MLC reactions. The mAbs anti-IFN-gamma and I1F6 differed in their ability to inhibit lymphocyte proliferation depending on the different cell types involved. The I1F6 inhibited the MDCK and DK cell-driven MLKC (in the absence of exogenous IFN-gamma).(ABSTRACT TRUNCATED AT 400 WORDS)

Constructing polycompetitor cDNAs for quantitative PCR

Analysis of mRNA levels using reverse transcription coupled with the polymerase chain reaction provides a powerful tool for studying cytokine regulation in cellular immunology. We report a novel method for cloning competitor cDNAs that is rapid, efficient and inexpensive. By linking multiple competitor cDNAs in tandem, polycompetitor constructs can be created that allow the use of a single reagent for individual PCR assays. Assays can be performed on minute samples of cell culture or tissue and can be reliably quantitated after routine gel electrophoresis without the use of densitometry or labeled nucleotides. The utility of this technique lies in the ability to produce a relatively inexpensive customized reagent that is simple to use and that allows for sensitive determinations of gene expression in a rapid and convenient manner. This method should allow investigators in many areas of biology to easily quantitate a broad range of important regulatory molecules.

Hemoglobin multiple emulsion as an oxygen delivery system

Multiple emulsion technology provides a mechanism for the encapsulation and in vivo delivery of drugs, proteins, and other materials which would otherwise be degraded, cleared rapidly, or toxic to the host. These feasibility studies were performed to evaluate a prototype Hb multiple emulsion as a stable oxygen delivery system. A concentrated solution of hemoglobin (Hb) was encapsulated in the form of a Hb-in-oil-in-water (Hb/O/W) multiple emulsion. Studies using mineral oil demonstrated that Hb multiple emulsions have several important characteristics that are compatible with utility as a blood substitute. These include: satisfactory rheological properties and good hydrodynamic stability compared to whole blood, high encapsulation concentration of Hb and high encapsulation efficiency with little met-hemoglobin generation, and satisfactory oxygen affinity and cooperativity compared to whole blood. Isovolemic exchange transfusions of Hb/O/W multiple emulsion can support life in rats whose hematocrit has been reduced to levels (5% or lower) that are incompatible with survival, and induces no acute toxicity. These results are consistent with the utility of Hb/O/W as an oxygen-carrying red blood cell substitute or organ perfusion media.

Lipopolysaccharide stimulates both nuclear localization of the nuclear factor kappa B 50-kDa subunit and loss of the 105-kDa precursor in RAW264 macrophage-like cells

Nuclear factor kappa B (NF-kappa B) is an important regulator of gene expression in cells of the immune system. One such gene, tumor necrosis factor, is induced by bacterial lipopolysaccharide (LPS) in macrophages, and this induction has been shown to be mediated in part by NF-kappa B activation in murine macrophages. In this study, immunochemical analysis was used to follow LPS activation of the NF-kappa B 50-kDa subunit in the RAW264 macrophage-like cell line. The recombinant NF-kappa B 50-kDa subunit was used as an immunogen to produce a rabbit antiserum, which was then affinity-purified using a portion of the NF-kappa B 50-kDa subunit that does not have homology to other members of the c-rel gene family. Untreated macrophages had little NF-kappa B in the nucleus as detected by Western immunoblotting. The protein was predominantly localized in the cytoplasmic fraction. Interestingly, NF-kappa B was found as the 50-kDa mature protein and 105-kDa precursor. After LPS treatment, there was a rapid nuclear translocation of NF-kappa B as detected by immunoblot analysis. There was also a rapid decrease in the amount of the cytoplasmic 105-kDa protein. This may indicate that the 105-kDa protein is a reservoir for the 50-kDa protein and that one of the actions of LPS is to increase the rate of 105-kDa precursor processing.

Transfected Leishmania expressing biologically active IFN-gamma

Infection of susceptible BALB/c mice with Leishmania major leads to progressive infection with the failure to expand and activate Th1 CD4+ T cells that elaborate IFN-gamma, a critically implicated cytokine for control of disease. We used the recently described capacity to express foreign genes in trypanosomatids to introduce into Leishmania the murine IFN-gamma gene on a drug-selectable plasmid under the constitutive control of intergenic tubulin sequences. Several clones of L. major were established and demonstrated to contain IFN-gamma DNA and IFN-gamma RNA that was appropriately trans-spliced with the Leishmania-specific leader sequence, and to secrete IFN-gamma into the media. The secreted IFN-gamma was biologically active as assessed by up-regulation of class II MHC Ag and induction of macrophage nitric oxide synthase activity in a macrophage cell line. Infection of nude mice with IFN-gamma-containing organisms resulted in significantly slower progression of disease as compared to infection with organisms containing the empty plasmid, suggesting that biologically important activation of infected macrophages might be occurring in vivo. Infection of genetically susceptible BALB/c mice, however, did not impede the expansion of Th2 cells and the inexorable progression of disease. Despite the demonstration of increased levels of IFN-gamma transcription in vivo, induction of nitric oxide synthase in macrophages and expression of Ly-6, and IFN-gamma-inducible Ag, on CD4+ lymphocytes could not be shown. In all cases, organisms recovered from tissue amastigotes contained the IFN-gamma plasmid and secreted active IFN-gamma. The data confirm earlier studies that IFN-gamma alone is not sufficient to impede activation and maturation of Th2 cells in susceptible mice, even when targeted directly to the infected cell.

Transfected Leishmania expressing biologically active IFN-gamma

Infection of susceptible BALB/c mice with Leishmania major leads to progressive infection with the failure to expand and activate Th1 CD4+ T cells that elaborate IFN-gamma, a critically implicated cytokine for control of disease. We used the recently described capacity to express foreign genes in trypanosomatids to introduce into Leishmania the murine IFN-gamma gene on a drug-selectable plasmid under the constitutive control of intergenic tubulin sequences. Several clones of L. major were established and demonstrated to contain IFN-gamma DNA and IFN-gamma RNA that was appropriately trans-spliced with the Leishmania-specific leader sequence, and to secrete IFN-gamma into the media. The secreted IFN-gamma was biologically active as assessed by up-regulation of class II MHC Ag and induction of macrophage nitric oxide synthase activity in a macrophage cell line. Infection of nude mice with IFN-gamma-containing organisms resulted in significantly slower progression of disease as compared to infection with organisms containing the empty plasmid, suggesting that biologically important activation of infected macrophages might be occurring in vivo. Infection of genetically susceptible BALB/c mice, however, did not impede the expansion of Th2 cells and the inexorable progression of disease. Despite the demonstration of increased levels of IFN-gamma transcription in vivo, induction of nitric oxide synthase in macrophages and expression of Ly-6, and IFN-gamma-inducible Ag, on CD4+ lymphocytes could not be shown. In all cases, organisms recovered from tissue amastigotes contained the IFN-gamma plasmid and secreted active IFN-gamma. The data confirm earlier studies that IFN-gamma alone is not sufficient to impede activation and maturation of Th2 cells in susceptible mice, even when targeted directly to the infected cell.

Two-way cross-neutralization mediated by a shared P (VP4) serotype between bovine rotavirus strains with distinct G (VP7) serotypes

Among bovine rotavirus strains, there are three G serotypes (G6, G8, and G10) and three P (VP4) serotypes (PB1, PB2, and PB3, which are defined on the basis of strains NCDV, UK, and B223, respectively). Plaque reduction neutralization assays with hyperimmune antisera disclosed two-way antigenic relationships of strain KN-4 with strain KK-3 (G10, PB3) as well as with strains NCDV (G6, PB1) and 0510 (G6, PB2). Neutralization assays with monoclonal antibodies specific for G6, G10, and PB3 revealed that KK-3 and KN-4 had the same P serotype (PB3) but that neither G6- nor G10-specific monoclonal antibody neutralized KN-4. Comparison of the VP7 gene sequence of KN-4 with those of other bovine rotavirus strains indicated that KN-4 was more similar to G6 bovine strains than to KK-3 and other G10 strains, suggesting that the G serotype of KN-4 was G6. From these results, we concluded that the two-way cross-neutralization between KN-4 and NCDV or 0510 was mediated by shared G6 serotype specificity, whereas the two-way cross-neutralization between KN-4 and KK-3 was mediated by shared P serotype specificity (PB3). Thus, KN-4 and KK-3 represent the first reported example of a two-way antigenic relationship mediated only by the P serotype. This article emphasizes the need for adopting a binary serotyping system and development of reagents which will enable classification of rotaviruses based on their G and P serotype specificities.

Clinical trial on termination of early pregnancy with RU486 in combination with prostaglandin

Termination of early pregnancy was performed in 1572 healthy women with RU486 (mifepristone, 600mg orally once), followed 36-60 hours later by administration of methyl ester of dl-15-methyl-PGF2 alpha (PG05, 1mg vaginal suppository). Complete abortion was accomplished in 91.2% (1433/1571), incomplete abortion in 4.8% (76/1571), and continued pregnancy in 3.9% (62/1571). The time elapsed between RU486 intake and complete expulsion was 2.4 +/- 1.3 days. Expulsion took place on the third day in 935 women (72%), and on the 4th day in 273 women (21.0%). Uterine bleeding occurred on the second or third day after RU486 intake in 1256 women (88.8%), and lasted 11.7 +/- 6.4 (SD) days, range 2-55 days. One subject had blood transfusion due to excessive bleeding. The main side effects were nausea/vomiting (22.3%), abdominal pain (10.2%), headache/dizziness (4.1%) and diarrhea (2.8%). Fatal side effects have not been reported in this study. About 73% of subjects with complete abortion assessed the treatment as good to excellent. Even in the failed cases, 25-42% of subjects considered the treatment as good. Further studies are needed to determine the optimal dose of the RU486 regimen. It should be emphasized that the treatment must be used under close medical supervision in order to monitor the uterine bleeding.

Physical map of the genome of Rhodobacter capsulatus SB 1003

A map of the chromosome of Rhodobacter capsulatus was constructed by overlapping the large restriction fragments generated by endonucleases AseI and XbaI. The analyses were done by hybridization of single fragments with the restriction fragments blotted from pulsed-field gels and by grouping cosmids of a genomic library of R. capsulatus into contigs, corresponding to the restriction fragments, and further overlapping of the contigs. A technical difficulty due to a repeated sequence made it necessary to use hybridization with cloned genes and prior knowledge of the genetic map in order to close the physical circle in a unique way. In all, 41 restriction sites were mapped on the 3.6-Mb circular genome and 22 genes were positioned at 26 loci of the map. Cosmid clones were grouped in about 80 subcontigs, forming two groups, one corresponding to the chromosome of R. capsulatus and the other corresponding to a 134-kb plasmid. cos site end labeling and partial digestion of cosmids were used to construct a high-resolution EcoRV map of the 134-kb plasmid. The same method can be extended to the entire chromosome. The cosmid clones derived in this work can be used as a hybridization panel for the physical mapping of new genes as soon as they are cloned.

Immunolocalization and expression of functional and nonfunctional cell-to-cell channels from wild-type and mutant rat heart connexin43 cDNA

The carboxyl terminal cytoplasmic domain of distinct gap junction proteins may play an important role in assembly of functional channels as well as differential responsiveness to pH, voltage, and intracellular second messengers. Oligonucleotide-directed site-specific mutagenesis in a paired Xenopus laevis oocyte expression system was used to examine the expression of mRNAs encoding wild-type and carboxyl terminal mutant connexin43 (Cx43) proteins. Oocytes were stripped, injected with mRNA or distilled water (dH2O), preincubated for 16-20 hours, and then paired for 5-10 hours; this process was followed by electrophysiological recording using the dual voltage-clamp technique. Initial experiments compared the relative junctional conductances (Gjs) in oocyte pairs expressing Cx43 (382 amino acid residues) and two truncated mutants lacking most or a portion of the cytoplasmic carboxyl terminal. The shortest mutant (M241) contained 240 amino acid residues and was devoid of all phosphorylatable serine residues in the cytoplasmic tail; its length approximated the length of liver connexin26. The longest mutant (M257) tested contained 256 amino acid residues, including two serine residues. Oocyte pairs expressing M241 yielded a Gj similar to that of oocytes injected with dH2O, whereas M257 yielded a Gj similar to that of oocytes injected with Cx43. Immunoprecipitation studies showed that Cx43, M257, and M241 proteins were readily detectable in oocytes injected with their respective mRNAs, indicating that the lack of Gj observed with the M241 mRNA was not due to reduced translation. Immunocytochemical studies revealed that wild-type and both truncated mutants were localized to the area of cell-to-cell contact between the paired oocytes, indicating that protein targeting to the membrane was not inhibited in oocytes injected with M241 mRNA. Oocyte pairs expressing mutants in which serine residues were replaced with nonphosphorylatable amino acids (serine codon No. 255 AGC was converted to GCC, alanine, designated as M255S----A, and serine codon No. 244 AGC was converted to GGC, glycine, designated as M244S----G) showed Gjs similar to M257, indicating that these serine residues and, by inference, their phosphorylation state are not critical for expression of functional channels. The importance of the length of the carboxyl terminus was assessed by comparing the Gjs in a series of mutants that were intermediate in length between M257 and M241. Gradual shortening of the carboxyl terminus produced a gradual reduction of Gj relative to M257. However, simple deletion of amino acid residues 241-257 from the wild-type Cx43 did not affect Gj relative to M257.(ABSTRACT TRUNCATED AT 400 WORDS)

Aerobic radioprotection of pBR322 by thiols: effect of thiol net charge upon scavenging of hydroxyl radicals and repair of DNA radicals

The extent of conversion of supercoiled pBR322 plasmid DNA to the open circular and linear forms can be measured by HPLC on a Waters Gen Pak FAX column following in vitro gamma irradiation of the DNA. This radiation effect has proven to be useful for the study of the radioprotection of DNA by thiols and other drugs. This system was used with gamma irradiation in air at pH 7.0 and physiological ionic strength to compare radioprotection by a series of thiols, disulfides, and thioethers, all having approximately 10(8) s-1 effective hydroxyl radical scavenging rate (10 mm dm-3 drug) and having net charge (Z) ranging from -2 to +3. All sulfur compounds exhibited substantial protection due to scavenging of hydroxyl radicals in bulk solution but thiols exhibited a 24-fold variation in relative ability to protect the plasmid DNA from strand breaks, as assessed from the dose-response curves: mercaptosuccinate (Z = -2), 0.53; GSH (Z = -1), 0.67; 3-mercaptopropionate (Z = -1) 0.80; mercaptoethanol (Z = 0), 1.00; dithiothreitol (Z = 0), 1.5; cysteamine (Z = +1), 3.7; N-(2-mercaptoethyl)-1,3-diaminopropane (WR-1065, Z = +2), 6.7; N1-(2-mercaptoethyl)spermidine (WR-35980, Z = +3), 12. Comparison of these results with those obtained using disulfide and thioether radioprotectors indicated that local scavenging of hydroxyl radicals near DNA increases slightly with Z, apparently as a result of variations in thiol concentration near DNA, but this accounts for only a small fraction of the change with Z found for cationic thiols. The marked increase in protection found for cationic thiols was attributed to chemical repair of DNA radicals and was in accord with predictions based upon recently measured rates for chemical repair of DNA radicals and was in accord with predictions based upon recently measured rates for chemical repair of pBR322 radicals. It is concluded that chemical repair of DNA radicals by anionic thiols does not compete with the oxygen fixation reaction in air and that protection by these thiols occurs primarily via the scavenging of hydroxyl radicals. However, chemical repair of DNA radicals is significantly enhanced by counterion condensation for cationic thiols and becomes a significant factor in their ability to protect DNA against radiation damage under aerobic conditions.

[Thin layer chromatographic studies on radix Ginseng, fructus Schisandrae and radix Salviae miltiorrhizae in yixinfumai granules]

The main constituents of Radix Ginseng, Fructus Schisandrae and Radix Salviae Miltiorrhizae in Yixinfumai Granules were studied by TLC. It was found that ginsenoside got hydrolyzed while the drugs were being boiled together. The main constituents of Fructus Schisandrae were schizandrol A and B; and those of Radix Salviae Miltiorrhizae were tanshinone and protocatechuic aldehyde.

[Effects of four adrenergic drugs on electroacupuncture analgesia]

The role of central nor-epinephrine (NE) in electroacupuncture (EA) analgesia is a controversial question., it is probably due to the complication of adrenergic receptors. The present results show: (1) Clonidine 30 micrograms/2ml/kg ip had no significant effect on the pain threshold, but decreased the analgesic effect of EA. Clonidine 1.5 and 3 micrograms were injected into the lateral cerebral ventricles. After 45 minutes, the analgesic effect of EA was lowered as compared with the saline controls respectively. (2) Yohimbine had no significant effect on the basal pain threshold, but (icv Yoh 50 micrograms) elevated the analgesic effect of EA. (3) 2-adrenoceptor agonist methoxamine decreased the analgesic effect of EA. (4) Another 2-adrenoceptor antagonist prazosin (icv 16 micrograms) enhanced the analgesic effect of EA. These results suggest that an activation of alpha 1- or alpha 2-adrenoceptors would decrease the analgesic effect of EA.

Immunochemical and biochemical characterization of purified canine interferon-gamma. Production of a monoclonal antibody, affinity purification, and its effect on mixed lymphocyte culture and mixed lymphocyte kidney culture reactions

We have advanced the hypothesis that the primary autolymphoproliferative response of dog T cells in mixed lymphocyte kidney cultures (MLKC) results from their recognition of tissue-specific (kidney-associated) antigen(s) presented in conjunction with class II MHC antigens. Lymphocyte culture-derived supernatants had been found previously to upregulate class II antigen expression on kidney cells and enhance T cell activation. In the present study we have isolated and characterized dog IFN-gamma, a class II-inducing substance that is secreted in the culture supernatant of activated T lymphocytes. Dog IFN-gamma was induced with A-23187 and PMA and purified stepwise using controlled-pore glass, Mono Q anion exchange chromatography, and Superose 6-gel filtration on FPLC. The purification resulted in two molecules of 42 Kd and 31 Kd molecular weights. An IgG1 monoclonal antibody was engendered to these molecules. With this mAb reagent, in immunochemical experiments, we have developed a sensitive ELISA and a method for purifying dog IFN-gamma by affinity chromatography. Species specificity studies indicated that purified dog IFN-gamma reacted with a polyclonal rabbit antihuman IFN-gamma, but not with a mAb to human IFN-gamma. However, the antidog IFN-gamma mAb that was generated also reacted with recombinant human IFN-gamma. In in vitro biological studies, the purified IFN-gamma (two mol. wt. species) upregulated the expression of canine class II MHC molecules on dog tubular epithelial cells and the dog kidney epithelial cell line (MDCK). The antidog IFN-gamma mAb blocked T cell proliferative response to kidney cell and, by inference, the interaction between endogenously released IFN-gamma in vitro with its cell surface receptor, thus inhibiting the induced upregulation of class II. Interestingly, although antidog IFN-gamma markedly blocked the MLKC (10 micrograms mAb/well), there was no effect on the allogeneic MLC. This observation indicates that the cytokine IFN-gamma may be a uniquely key substance amplifying the immune response of T cells to tissue-associated antigens on surrogate antigen-presenting cells that require induced upregulation of class II MHC antigen expression (MLKC), in contrast to reactions in which these antigens are already constitutively expressed on the antigen-presenting cells (mixed lymphocyte culture).

Liposome-encapsulated hemoglobin processing methods

An effective and safe red blood cell substitute is being developed based on double emulsion/evaporation techniques followed by high pressure homogenization to form liposome-encapsulated hemoglobin (LEH). Formulations are made up of hydrogenated phosphatidylcholine (PC, soy or egg), cholesterol, phosphatidylinositol (PI), and alpha-tocopherol in a molar ratio of 1:1:0.2:0.02, respectively. Resulting LEH-encapsulated hemoglobin (Hb) concentrations are greater than 80% of precursor Hb solutions. Met-Hb generation accompanying LEH processing appears to be small with only a 3% increase for encapsulated over precursor. These results correspond to an oxygen content for an LEH suspension sample (50% by volume LEH) of 15 volume% oxygen. Oxygen affinity and cooperativity values for LEH suspensions appear to be near the normal values expected for whole blood. The viscosity of LEH suspension samples (50% by volume LEH in phosphate-buffered saline containing 7.5 wt% albumin) were slightly higher than that of whole blood. The effect of shear rate on leakage of encapsulated Hb from LEH was small, i.e. 0.5% or less. Nearly total isovolemic exchange transfusion using a cannulated rat model demonstrates efficacy of LEH suspension samples. There appears to be no difference in rat internal organ weights between rats exchanged with control compared to rats exchanged with LEH. Circulation half-life following 50% isovolemic exchange-transfusion is about 15 to 18 hours.

Synthesis and Characterization of a Series of Liquid Crystal Monomers Containing a Novel Spacer Group Based on Vinylacetic Acid

A series of liquid crystal monomers with side chains involving a vinylacetic acid unit have been prepared, and their thermal and optical properties compared with those of related compounds containing the same mesogenic unit but a conventional polymethylene spacer group based on a terminal alkene.

[The screening model for early diagnosis of colorectal cancer in general population]

In this study, 75,813 asymptomatic individuals above 30 in Jiashan County of Zhejiang Province were recruited in the screening program. Based on results of risk assessment using a mathematical model (expressed as AD value) and Reverse Passive Hemagglutination Fecal Occult Blood test (RPHA FOB). 62,667 subjects (82.7%) who completed two procedures were divided into 4 groups: 1) AD greater than or equal to 0.3 FOB (+) accounts for 1.2% of total; 2) AD less than 0.3 FOB (+) 3.0%; 3) AD greater than or equal to 0.3 FOB (-) 26.8%; 4) AD less than 0.3 FOB (-) 68.9%. Individuals in groups 1 and 2 were subjected to 60 cm fiberoptic colonoscopic examination; and those of group 3 with AD greater than or equal to 0.5 or with AD less than 0.5 but a positive repeated FOB test was also eligible for 60 cm colonoscopy. Out of 4,299 eligible subjects 3,162 were examined with 60 cm sigmoidoscopy (73.6%). 21 cases of colorectal cancer and 331 cases of polyps (including 75 adenomas) were detected. Among 21 cancers known of Dukes' stages 10 were at early stages (10 Dukes' A and 5 Dukes' B) accounting for 71.5%. According to the screening protocol individuals with negative 60 cm colonoscopic findings and consistently positive FOB results indicate that the lesion may be located above the spleen flexure and require a full fiberoptic colonoscopic examination (150 cm) and/or x-ray air-barium enema.

[Steroidal constituents from Saussurea gossypiphora D. Don]

Four steroids were isolated from the Saussurea gossypiphora for the fist time. They were determined as 3-stigmastanol, beta-sitosterol, stigmast-7-en-3-ol and ergostan-3,24-diol by spectral and chemical methods.

Reproductive factors and colorectal cancer risk among Chinese females

We report results from a population-based case-control study of colorectal cancer among Chinese women in western North America (NA) and the People's Republic of China (China). A common protocol was used to assess reproductive characteristics and hormone use of 395 Chinese women (189 from NA and 206 from China) with cancer of the colon or rectum and of 1112 age-matched Chinese controls (494 from NA and 618 from China). In NA, risks for cancers of both the colon and rectum were lower among parous compared to nulliparous women (odds ratio for colorectal cancer, 0.6, P = 0.08), but the trend in risk was not smooth with increasing number of livebirths. This association with parity was absent for both cancer sites in China. There were no consistent patterns in the relationships between other reproductive factors (including age at menarche, age at first livebirth, menopausal status) and risk of colon and rectal cancer on either continent.

[Dynamic observation on the incidence and mortality rates of the nasopharyngeal carcinoma (NPC) in Zhongshan City 1970-1984]

The standardized incidence rate of NPC was 14.44/10(5) (male 20.31/10(5), female 8.95/10(5] and the standardized mortality rate was 10.91/10(5) (male 16.00/10(5), female 6.14/10(5] in Zhongshan city during 1970-1984. The fluctuation of incidence and mortality rates were 13.66-18.07/10(5) and 9.02-13.95/10(5) respectively. It was worthy to be mentioned that both the incidence and mortality rate of NPC were relatively stable in 1970-1984.

[Estrogen receptor content in human embryo]

Estrogen receptor (ER) content was measured in 27 human embryos, aged 3 to 7 months, with 17-fluoreceinated estrone (17-FE). ER was demonstrated in a uneven distribution pattern in most human embryonic organs. Most embryonic uteri and livers and a few lungs, stomachs and spleens were ER positive. The ER gradually increased with embryonic development in target organs such as the uterus, ovary and testes, as well as in some non-target areas such as mouth and upper digestive system. The ER decreased with embryonic development in the lower digestive system and were maintained at a low level in the lung, heart, brain and lymphoid organs. In the early embryo (3 to 4 months) the ER positive cells (A, B and C type) accounted for a greater proportion of embryonic cells than they did in the late embryonic period (5 to 7 months). The A and B type cell counts fell to the lowest point in the fifth month and increased again in the sixth month. The C and D type cells reached the lowest point in the fourth month in non-target organs but the D type cells then dramatically increased in the uterus, testes and liver. It was suggested that ER play an important role in human embryonic development and differentiation. The ER may influence proliferative ability of early embryonic organs and the late hormone-specific organ growth.

Diet, physical activity, and colorectal cancer among Chinese in North America and China

In a population-based case-control study of colorectal cancer among Chinese men and women in western North America and the People's Republic of China, a common protocol was used to assess past life-style characteristics of 905 cases diagnosed during 1981-1986 and 2,488 controls. Risks for cancers of both the colon and rectum increased with increased food energy from fat, protein, carbohydrate, and all energy sources combined, for both sexes and on both continents. Yet, in multivariate analysis, colorectal cancer risk was significantly associated only with saturated fat; no relationships were seen with other dietary sources of energy. Colon cancer risk was elevated among men employed in sedentary occupations. On both continents and in both sexes, risks for cancers of both the colon and rectum increased with increasing time spent sitting. Further, the association between colorectal cancer risk and saturated fat was stronger among the sedentary than among the active. Risk among sedentary Chinese Americans of either sex increased more than fourfold from the lowest to the highest category of saturated fat intake. Among migrants to North America, risk increased with increasing years lived in North America. These observations suggest (a) that colorectal cancer risk increases with duration of exposure to a sedentary life-style and a diet rich in saturated fat; (b) that higher incidence among Chinese-American men relative to women is due to longer duration of these habits among men, who have lived longer in North America; and (c) that higher risk among Chinese Americans of both sexes relative to risk among the general population in China is due to differences in such habits. Attributable risk calculations suggest that, if these associations are causal, saturated fat intakes exceeding 10 g/day, particularly in combination with physical inactivity, could account for 60% of colorectal cancer incidence among Chinese-American men and 40% among Chinese-American women.

Secondary structure of pig skin proteodermatan sulfate: a perspective from Raman spectroscopic studies in aqueous solution

Raman spectroscopic studies of pig skin proteodermatan sulfate in H2O are indicative of a well defined secondary structure consisting of alpha-helical, beta-turn, and possibly "random" structures. The above conclusion is surprisingly close to the secondary structure of the "core" protein of pig skin proteodermatan sulfate proposed in the previous paper (V. Renugopalakrishnan et al., Biopolymers 28, 1923-1933, 1989) from FT-IR and CD spectroscopic studies in aqueous solution.