Parallel synthesis and screening of a solid phase carbohydrate library

A solid phase carbohydrate library was synthesized and screened against Bauhinia purpurea lectin. The library, which contains approximately 1300 di- and trisaccharides, was synthesized with chemical encoding on TentaGel resin so that each bead contained a single carbohydrate. Two ligands that bind more tightly to the lectin than Gal-beta-1,3-GalNAc (the known ligand) have been identified. The strategy outlined can be used to identify carbohydrate-based ligands for any receptor; however, because the derivatized beads mimic the polyvalent presentation of cell surface carbohydrates, the screen may prove especially valuable for discovering new compounds that bind to proteins participating in cell adhesion.

Synthetic peptides derived from the sequence of human C-reactive protein inhibit the enzymatic activities of human leukocyte elastase and human leukocyte cathepsin G

Peptides derived from the primary sequence of the acute phase reactant C-reactive protein (CRP) are shown to inhibit in vitro the enzymatic activities of human leukocyte elastase (hLE) and human leukocyte cathepsin G (hCG), which are associated with tissue damage occurring in the course of several chronic inflammatory conditions. CRP-derived peptides were synthesized based on their sequence similarity to domains within the natural inhibitors of hLE and hCG. The octapeptide Val89-Thr-Val-Ala-Pro-Val-His-Ile96 (CRP 89-96) is shown to inhibit hLE and hCG to a larger extent than peptides of similar chain lengths corresponding to the active sites of their natural inhibitors, alpha 1-protease inhibitor and alpha-antichymotrypsin, respectively. Several additional peptides containing this core sequence were synthesized and shown to be inhibitors, in contrast to peptides derived from other regions of CRP as well as the intact protein, which are totally inactive. The inhibitory capability of CRP-derived peptides, which may be generated in vivo by neutrophil-mediated proteolysis as part of a complex regulatory homeostatic mechanism, may now be used as a basis for the design of novel therapeutic substances. The present finding may shed some light on the enigmatic physiological functions of CRP.

Helicobacter canis isolated from a dog liver with multifocal necrotizing hepatitis

On the basis of biochemical, phenotypic, and 16S rRNA analysis, a novel gram-negative bacterium, isolated from normal and diarrheic dogs as well as humans with gastroenteritis, has been recently named Helicobacter canis. A 2-month-old female crossbred puppy was submitted to necropsy with a history of weakness and vomiting for several hours prior to death. The liver had multiple and slightly irregular yellowish foci up to 1.5 cm in diameter. Histologically, the liver parenchyma contained randomly distributed, occasionally coalescing hepatocellular necrosis, often accompanied by large numbers of mononuclear cells and neutrophils. Sections of liver stained by the Warthin-Starry silver impregnation technique revealed spiral- to curve-shaped bacteria predominantly located in bile canaliculi and occasionally in bile ducts. Aerobic culture of liver was negative, whereas small colonies were noted on Campylobacter selective media after 5 days of microaerobic incubation. The bacteria were gram negative and oxidase positive but catalase, urease, and indoxyl acetate negative; nitrate was not reduced to nitrite, and the organism did not hydrolyze hippurate. The bacteria were also resistant to 1.5% bile. Electron microscopy revealed spiral-shaped bacteria with bipolar sheathed flagella. By 16S rRNA analysis, the organism was determined to be H. canis. This is the first observation of H. canis in active hepatitis in a dog and correlates with recent findings of Helicobacter hepaticus- and Helicobacter bilis-related hepatic disease in mice. Further studies are clearly warranted to ascertain whether H. canis-associated hepatitis is more widespread in canines as well as a cause of previously classified idiopathic liver disease in humans.

Clonality assays and megakaryocyte culture techniques in essential thrombocythemia

The development of techniques permitting in vitro growth of human megakaryocytes progenitors and more recently identification of the proto oncogene c-mpl (Mpl-R) and its ligand (Mpl-L) have created new opportunities for studying pathophysiology of E.T. Plasma or serum of E.T. patients was unable to overestimulate MK colony formation by normal bone marrow cells. Significant increases in circulating CFU MK in E.T. patients have been repeatedly observed while in E.T. marrow, due to inappropriate sampling, colony number was not significantly different from normal. Spontaneous colony formation is observed in approximately 100% bone marrow and 85% blood from E.T. patients. Spontaneous colony formation persisted in plasma clot assay without added plasma or serum and in serum free agar cultures but only at a slightly lower rate than in plasma clot. Spontaneous colony formation in culture condition without plasma and serum were never observed with normal bone marrow and blood. Spontaneous MK growth was observed in a higher proportion of E.T. patients than erythroid colony formation but both phenomenon can occur in about 50% of the patients. CFU MK colony formation disappeared in serum free cultures using highly purified CD 34 cells. MK development is not completely independent of regular control. An hypersensitivity of E.T. MK progenitors to growth factors known to stimulate normal hematopoiesis (IL3.IL6, GM CSF, has been shown as well as a decreased sensitivity to negative regulators (TGF beta), has been suggested. The number of spontaneous MK colonies was not significantly decreased by added anti IL3, IL6 or anti GM CSF, antibodies in culture medium. Pre incubation of blood non adherent mononuclear cells of E.T. patients with antisense oligonucleotides to c-mpl significantly decreased the cloning efficiency of spontaneous megakaryocyte growth as compared to the introduction of scrambled oligomers. Finally m RNA expression of the Mpl-L (TPO) was not formed in MK spontaneously grown in serum free liquid cultures after 12 days. These results suggest that human c-mpl proto oncogene may be implicated in the pathway of spontaneous megakaryocytopoiesis in MPD but an absence of autocrine-stimulation by TPO of spontaneous growth in MPD. Analysis of peripheral blood cell clonality was performed in 55 E.T. patients using either the DNA methylation pattern of the androgen receptor (AR) gene or mRNA transcripts of G6PD or IDS genes. 51 out of 55 patients were informative. Non random X inactivation was found on unfractioned blood in 73% as compared with 23% in normal females (skewed Lyonisation). In 12 patients monoclonality of hematopoiesis was definitely confirmed by recording polyclonality of the mononuclear fraction or of T lymphocytes. In 4 patients monoclonal hematopoiesis was limited to platelets, 7 patients remained polyclonal in whole blood and all cellular fractions studied. MK colony formation (provided that the serum free agar culture system is clearly standardised) and clonality studies on whole blood or granulocyte, T lymphocyte and platelet fractions may be proposed as positive criteria for diagnosis of E.T.

[Radioembolization with 32P-labelled glass microspheres for advanced hepatocellular carcinoma]

We evaluated the efficacy and side effect of 32P-Labelled glass microspheres (32P-GMS) as a radioembolizer for patients with advanced hepatocellular carcinoma (HCC). 24 patients with unresectable HCC received internal radiation treatment of 32P-GMS. The tumor size varied from 3.6 to 18 cm. Hepatic arterial embolization was carried out through intraoperative or Seldinger's method. The mean absorbed radiation dose of the liver was 3250 rad (range from 1200 rad to 8000 rad). The radiation intensity within the tumor was 3.3 times stronger than in liver tissue. Not significant bone marrow renal toxicity was noted within 1 to 3 months. > 50% of tumor shrinkage was found in 17 cases, and < 50% of tumor reduction in 5 cases. The cumulative survival rate of 3, 6, 12, 18, 24 months was 92%, 75%, 54%, 33% and 29%. Hepatic arterial instillation of 32P-GMS appears to be safe and effective for unresectable HCC even with portal vein thrombosis.

Prevention of disability and rehabilitation--results from a collaborative project in China

Eight different geographical districts in China varying in urban and rural characteristics from 6 provinces and 2 municipalities were selected as pilot areas of the project. The interventions included early detection and treatment of neuritis, self-care training, adapted footwear, surgery, comprehensive treatment of complicated ulcers, and prostheses. Main changes in eye, hand and foot impairments between baseline assessment and assessment at 2 years have been presented in this paper.

Persistent hepatitis and enterocolitis in germfree mice infected with Helicobacter hepaticus

Helicobacter hepaticus has been associated with naturally occurring hepatitis in certain inbred strains of mice, and in A/JCr mice it has been linked to the development of hepatic adenomas and adenocarcinomas. H. hepaticus was orally inoculated into 30 axenic, outbred female mice, and the mice were studied longitudinally to fulfill Koch's postulates and to ascertain the pathogenic potential of the organism under defined germfree conditions. Ten cage contact mice were also housed in the same germfree isolator to study transmission patterns, and 10 germfree mice were maintained in separate isolators as controls. Mice serially euthanized from 3 weeks through 24 months postinoculation (p.i.) were surveyed by culture and PCR for H. hepaticus in liver and intestinal tissues. Tissues were analyzed for histopathological changes, and sera were assayed for the presence of immunoglobulin G antibody to H. hepaticus and changes in the liver enzyme alanine aminotransferase. Inoculated mice and cage contact mice were persistently infected with H. hepaticus as identified by culture and PCR, in both the intestine and, less frequently, the liver, for the duration of the 2-year study. Animals developed persistent chronic hepatitis, and in some animals enterocolitis was noted. Hepatocellular carcinoma was diagnosed in one H. hepaticus-infected mouse. The level of H. hepaticus serum antibody was highest in experimentally infected mice at 12 to 18 months p.i.; this corresponded in general to the time interval when the highest levels of alanine aminotransferase were recorded. Although cage contact mice became persistently infected with H. hepaticus, lesions were less severe and the levels of serological biomarkers utilized in the study were lower. The H. hepaticus-infected mouse will provide an ideal model to study putative bacterial virulence determinants and how they interact with the host to induce chronic inflammation and tumorigenesis.

Local immune response in Helicobacter pylori-infected cats and identification of H. pylori in saliva, gastric fluid and faeces

Helicobacter pylori-infected cats were screened by culture and polymerase chain reaction (PCR) for the presence of H. pylori in salivary secretions, gastric juice, gastric tissue and faeces. H. pylori was cultured from salivary secretions in six of 12 (50%) cats and from gastric fluid samples in 11 of 12 (91%) cats. A 298 base pair polymerase chain reactions (PCR) product specific for an H. pylori 26000 MW surface protein was amplified from dental plaque samples from five of 12 (42%) cats and from the faeces of four of five (80%) cats studied. Analyses of serum and mucosal secretions by enzyme-linked immunosorbent assay (ELISA) revealed an H. pylori-specific immunoglobulin G (IgG) response, and elevated IgA anti-H. pylori antibody levels in salivary and local gastric secretions. Immunohistochemical analyses of gastric tissue revealed the presence of IgM+ B cells assembled into multiple lymphoid follicles surrounded by clusters of CD4+ and CD8+ T cells. The lamina propria also contained single cells or aggregates of IgA+ and IgM+ B cells. These observations show that H. pylori can be identified in feline mucosal secretions, and that a localized IgA immune response develops in gastric tissue of H. pylori-infected cats. The findings suggest a zoonotic risk from exposure to personnel handling H. pylori-infected cats in vivaria.

[Experimental study on repair of mandibular defect by allogenic decalcified bone compounded with autogeneic bone marrow in rabbits]

Twenty adult rabbits were used in our experiment. The bone defects were made at the lower border of the bilateral mandible. A compound bone graft (allogenic decalcified bone with autogeneic bone marrow, ADB) was implanted in the right bone defect as the experimental group. The left mandible was taken as the control group and autogeneic cancellous bone was grafted. The process of new bone formation was evaluated by X-ray plain film, 99Tc-PYP Scintigraphy, histological, and histochemical, and transmmission electronic microscope examinations. The results demonstrated histogically that ADB induced new bone formation. The quantity of new bone produced by compound bone graft in the experimental group was much more than that in control group (P < 0.05). The compound bone graft can promote and accelerate bone defect healing.

Chronic proliferative hepatitis in A/JCr mice associated with persistent Helicobacter hepaticus infection: a model of helicobacter-induced carcinogenesis

Helicobacter hepaticus causes hepatitis in selected strains of mice and in A/JCr mice is linked to liver cancer. To analyze whether H. hepaticus persists in specified ecological niches, to determine whether biomarkers of infection exist, and to analyze the influence of H. hepaticus on hepatocyte proliferation, a longitudinal study of H. hepaticus-infected A/JCr mice was undertaken. A/JCr mice were serially euthanatized from 3 through 18 months and surveyed by enzyme-linked immunosorbent assay; bacterial culture of liver, colon, and cecum; histology; electron microscopy; hepatocyte proliferation indices determined by using 5-bromo-2'-deoxyuridine; and measurement of the liver enzyme alanine aminotransferase. In infected animals throughout the 18-month study, H. hepaticus was consistently isolated from the lower bowel but only sporadically from the liver. By electron microscopy, H. hepaticus was noted infrequently and only in bile canaliculi. Infected mice, particularly males, showed chronic inflammation; oval cell, Kupffer cell, and Ito cell hyperplasia; hepatocytomegaly; and bile duct proliferation. The inflammatory and necrotizing lesion was progressive and involved the hepatic parenchyma, portal triads, and intralobular venules. Hepatic adenomas were noted only in male mice, whereas 5-bromo-2'-deoxyuridine proliferation indices were markedly increased in both sexes, but especially in males, compared to control A/J mice. Infected mice also developed sustained anti-H. hepaticus serum immunoglobulin G antibody responses and elevated alanine aminotransferase levels. H. hepaticus, which persists in the lower bowels and livers of A/JCr mice, is associated with a chronic proliferative hepatitis, and hepatomas in selected male mice indicate that this novel bacterium may cause an increased risk of hepatic cancer induction in susceptible strains of mice. This murine model should prove useful in dissecting the molecular events operable in the development of neoplasms induced by bacteria belonging to this expanding genera of pathogenic Helicobacter species.

Aggregation of phospholipid vesicles induced by the ribosome inactivating protein saporin

Saporin-S6(SO-6) is a single chain ribosome inactivating protein, which can inhibit protein synthesis by inactivating eukaryotic ribosomes. The interaction of SO-6 with phospholipid model systems was described. SO-6 can specifically interact with negatively-charged phospholipid vesicles and it induces the aggregation of the lipid vesicles. The kinetics of the vesicle aggregation induced by SO-6 was studied. The saturating protein/lipid molar ratio was determined to be 1:100 based on titration experiments. The aggregation is dependent on the temperature in a range that was many times higher than the phase transition temperature of the phospholipid. The effect of pH on the aggregation of the vesicles can not be explained by simple deprotonation of side chain amino groups of the protein, and may be related to conformational changes of the protein. The maintenance of physiological ionic strength was required for the aggregation of SO-6 with vesicles. Finally, the interaction was prompted by Ca2+ ions, and was totally inhibited by EDTA, which suggests that SO-6 may interact with phospholipid vesicles in a Ca(2+)-dependent manner.

Evaluation of various oral antimicrobial formulations for eradication of Helicobacter hepaticus

Helicobacter hepaticus colonizes the cecum and colon of several strains of mice from a variety of commercial suppliers, persistently infects mice, causes chronic hepatitis, is linked to hepatic tumors in A/JCr mice, and has been associated with inflammatory bowel disease of athymic and scid mice. For this reason, eradication of the organism from infected mouse colonies is desirable. We recently reported that amoxicillin or tetracycline-based triple therapy (amoxicillin or tetracycline in combination with metronidazole and bismuth) given by oral gavage 3 times daily for 2 weeks eradicated H. hepaticus in 8- to 10-week-old A/JCr mice. To establish a more convenient therapy regimen for eradicating H. hepaticus, we evaluated water and dietary administration of various antibiotic combinations in A/JCr and DBA/2 mice naturally infected with H. hepaticus. The A/JCr male mice received amoxicillin-based triple therapy in drinking water or by oral gavage, or received tetracycline-based triple therapy in the drinking water. The DBA/2J female mice received amoxicillin-based triple therapy in a specially formulated dietary wafer or by oral gavage, or received enrofloxacin in drinking water. All treatments were given for a 2-week period. Control animals received no treatment. One month after treatment, H. hepaticus was recovered from the liver, cecum, or colon of A/JCr control mice and mice receiving amoxicillin- or tetracycline-based triple therapy in drinking water but not in mice receiving amoxicillin-based triple therapy by oral gavage. Helicobacter hepaticus was not recovered from DBA/2J mice receiving amoxicillin-based triple therapy in dietary wafer or by oral gavage but was recovered from control mice and 7 of 10 mice receiving enrofloxacin in drinking water. Results indicate that amoxicillin-based triple therapy administered in the diet or by oral gavage is effective in eradicating H. hepaticus. Antibiotics administered in the water, however, were not effective in eradicating the organism.

An apparent functional correlation between variations in amino acid residues in HLA-DR4.1 and 4.2 serological subtypes and oligonucleotide characterization

HLA-DR4 can be subdivided serologically into two specificities, DR4.1 and DR4.2, using well-defined monospecific alloantisera used in the 11th International Histocompatibility Workshop. In this study, a total of 1095 random DR4-positive individuals from several ethnic groups were tested first for serotype DR4.1/4.2 and then for DRB1*04 alleles using polymerase chain reaction (PCR) followed by sequence-specific oligonucleotide probe hybridization (SSOPH). An almost 100% correlation between samples testing positive for DR4.1 and the presence of alanine at position 74 was observed, while samples testing positive for DR4.2 correlated with the presence of glutamic acid at position 74. DRB1*04 alleles 0401, 0402, 0404, 0405, 0408, 0409 and 0410 are aligned in functional groups which coincide with the serological subtype of DR4.1. DRB1*04 alleles 0403, 0406, 0407 and 0411 coincide with subtype DR4.2. Amino acid substitutions at positions 57, 71 and 86 indicate other significant variations between alleles within the serological subgroup of DR4.1 and define five minor subgroups. The serologic and oligonucleotide allelic subgroups are in turn correlated with recognized cellular Dw antigens. While sequence data provide evidence of structural differences, data on cellular antigens support a functional association between these designated groups and their significance in transplantation and GVHD. Testing results are categorized by ethnic group in order to establish frequency data for donor selection criteria.

Natural and experimental Helicobacter mustelae reinfection following successful antimicrobial eradication in ferrets

BACKGROUND

Recrudescence or reinfection may occur after eradication of Helicobacter pylori in humans.

MATERIALS AND METHODS

We used the ferret Helicobacter mustelae model to investigate the effect of prior infection and eradication on reinfection by experimental and natural routes. Two groups of ferrets with naturally acquired H. mustelae infection were treated with an eradication protocol using amoxicillin, metronidazole, and bismuth subsalicylate. The ferrets were monitored for recrudescence by repeated cultures of endoscopic gastric mucosal biopsies. The ferrets were challenged at 17 months (group I) and 6 months (group II) after eradication with a strain of H. mustelae having a distinctive restriction endonuclease analysis pattern. The eradication protocol was repeated to eliminate the infection produced by experimental challenge. The ferrets were then cohoused intermittently with naturally infected ferrets.

RESULTS

The original H. mustelae infection was successfully eliminated by the eradication protocol. No recrudescence was observed in group I for 12 months nor for 3 months in group II after eradication. All ferrets became persistently reinfected with the challenge strain. The infection from the challenge strain was eradicated successfully. No ferrets in group I and all ferrets in group II became infected through cohousing.

CONCLUSIONS

These results suggest that though prior infection with H. mustelae may confer some protection against reinfection, such protection is not universal in all circumstances; that susceptibility to reinfection by contact with infected animals varies between individuals; and that age may be a factor in this individual variability. These results are applicable to studies of reinfection after eradication of H. pylori in humans.

Inflammatory large bowel disease in immunodeficient mice naturally infected with Helicobacter hepaticus

Large bowel disease detected clinically by rectal prolapse was studied in 64 immunodeficient mice (37 athymic NCr-nu/nu, 12 BALB/c AnNCr-nu/nu, 9 C57BL/6NCr-nu/nu, and 6 C.B17/Icr-scid/NCr) naturally infected with Helicobacter hepaticus. Rectal prolapse was found in approximately 5% of immunodeficient mice maintained in a research facility over a period of 3.5 years. All mice had various degrees of chronic proliferative typhlitis, colitis, and proctitis, usually without concomitant hepatitis. Some mice had severe proliferative proctitis with cystic hyperplasia. Histologic study of the large bowel of 48 athymic NCr-nu/nu mice without H. hepaticus infection and housed in another clean facility revealed only 12% of the mice with minimal-to-mild large bowel inflammation. Helicobacter hepaticus infection is associated with large bowel disease in immunodeficient mice but is not seen in H. hepaticus-infected immunocompetent mice. This new pathogenic bacterial infection should be considered as another potential cause or co-factor for rectal prolapse and large bowel disease in mice.

Experimental study on microthrombi and myocardial injuries

The experiment was conducted with SD male rats. After they had been each given an intravenous injection of high molecular weight dextran (0.8 ml/100 g body wt) once a day for 4 days, they were brought under the observation of ECG and mesentery microcirculation. Microthrombi were found in the venules and capillaries of each rat of the experimental group, while in the microcirculation of the control group rats, no microthrombi were found. No changes were found in the ECGs of the rats (n = 6) in the control group after the injections, while the rats in the subject group all suffered a rise in the S-T segment of ECG, an indication of myocardial injuries. The rise was significantly in positive correlation to the increase in microthrombi in number (r = 0.944, P < 0.01). The erythrocytes of the rats in the subject group clustered to become rouleau-like, and platelets aggregated by tens and hundreds to form microthrombi. Their blood also showed a significant decrease in number of platelets. The degree of platelet aggregation and the scores of the rise on ECG were significantly in positive correlation as shown by the results: y = 20 + 94x, r = 0.94, P < 0.01. The plasma TXB2 of the subject group increased obviously but the change of 6-K-PGF1 alpha in the blood was not significant. The content of plasma TXB2 and the scores that indicated the rise in the S-T segment of the ECG showed significantly a positive correlation by the analysis of linear regression equation: y = 109.997 +/- 116.25x, r = 0.889, P < 0.05. The activity of Na(+)-K(+)-ATPase on the myocardial cell membranes of the rats with microthrombi was significantly reduced as compared with that of the rats in the control group (P < 0.01). The activity of the Na(+)-K(+)-ATPase was significantly in negative correlation to the rise in the S-T segment of ECG (P < 0.05). This study demonstrates that the above changes are the causes of myocardial injuries in rats with circulatory thrombi.

Identification of widespread Helicobacter hepaticus infection in feces in commercial mouse colonies by culture and PCR assay

The identification of a new murine pathogen, Helicobacter hepaticus, and its association with chronic active hepatitis and liver tumors prompted an evaluation of the prevalence of H. hepaticus in commercially available mice. Of the 28 different strains or stocks, totaling 160 mice from four major commercial vendors, cultured for H. hepaticus, 100% of mice from two outbred strains from one vendor were infected with H. hepaticus, whereas 9 of 13 inbred mouse strains from another vendor were infected. This high prevalence of H. hepaticus established a need for a rapid and reproducible, noninvasive assay for the screening of colony-maintained mice being used for biomedical research. The culturing of fecal material by using 0.45-microns-pore- size filtration for H. hepaticus consistently yielded reproducible results but required extended periods of time. (1 to 3 weeks) to obtain a definitive answer. Although it is rapid, the use of a direct PCR-based detection assay with fecal specimens is restricted by inhibitory agents. to circumvent these inhibitory agents and to augment our H. hepaticus culture technique, we have developed a novel PCR system in which the bacteria are isolated from fecal material in the presence of polyvinylpyropyrollidone and lysed by treatment with Chelex 100. The PCR is performed with Tth polymerase supplemented with a polymerase enhancer. By this PCR method, 24 H. hepaticus culture-positive and 30 H. hepaticus culture-negative fecal samples were correctly identified. Moreover, two samples which were PCR positive and culture negative initially were positive by both methods upon retesting of fresh material. Southern blot hybridizations and sequencing of PCR products showed them to be H. hepaticus specific. A comparison of results obtained under identical conditions indicated a 100-fold increase in sensitivity with Tth polymerase over Taq polymerase. This PCR method can be used as a noninvasive means of rapidly screening large numbers of colony mice for H. hepaticus.

Long-term supplementation of canthaxanthin does not inhibit gastric epithelial cell proliferation in Helicobacter mustelae-infected ferrets

The effect of canthaxanthin (CX), a nonprovitamin A carotenoid, on gastric epithelial proliferation was studied in ferrets colonized with Helicobacter mustelae, which causes a chronic gastritis and an increased gastric epithelial cell proliferation. Seven spayed female ferrets were dosed by gavage with CX beadlets (50 mg/kg body wt, 5 d/wk) over 2 y, whereas seven control animals were given placebo beadlets. At the end of the 2-y-period, ferrets were killed, and gastric tissues were obtained from the antrum and body regions. A cell-proliferating biomarker, proliferating cell nuclear antigen (PCNA), was assayed by immunohistochemistry. The PCNA positivity was measured by a computer-based image analysis system. Serum concentrations of carotenoids, retinoids and tocopherols were analyzed by HPLC. Serum antioxidant status was measured by the oxygen radical absorbance capacity (ORAC) assay. The PCNA positivity in both antrum and body regions was not significantly different between CX-fed ferrets and controls. Serum CX concentrations were significantly higher in CX-fed ferrets vs. controls (P < 0.001), whereas levels of other carotenoids, retinoids and tocopherols were not significantly different. The ORAC values were not significant different between groups. This study does not suggest inhibitory effects of CX on gastric epithelial cell proliferation in H. mustelae infected ferrets.

Inability of an isogenic urease-negative mutant stain of Helicobacter mustelae to colonize the ferret stomach

Eight ferrets specific-pathogen-free for Helicobacter mustelae were given, per dose, approximately 3.0 x 10(7) CFU of either the wild-type parent strain of H. mustelae (NCTC 12032) (two ferrets) the isogenic urease-negative mutant strain of H. mustelae (10::Tn3Km) (four ferrets), or sterile culture broth (two ferrets). Infection status was monitored by endoscopic gastric biopsy for urease activity, histopathology, and culture and by serology at 3, 6, 10, and 21 weeks. All ferrets were necropsied at 25 weeks. Both negative control ferrets remained uninfected, both ferrets receiving the H. mustelae wild-type parent strain became infected after two doses of the organism, and all four ferrets given two doses of the isogenic urease-negative mutant strain of H. mustelae remained uninfected throughout the 6-month study. Histopathology correlated with infection status. H. mustelae-infected ferrets exhibited diffuse mononuclear inflammation in the subglandular region and the lamina propria of the gastric mucosa, while uninfected ferrets showed no or minimal inflammation. These results suggest that urease activity is essential for colonization of the ferret stomach by H. mustelae.

Assessing the level of student reflection from reflective journals

The concept of reflective learning has been widely adopted in many of the nursing curricula today. Reflective learning is of particular relevance to the education of professionals, as it encourages students to integrate theory with practice, appreciate the world on their own behalf, and turn every experience into a new potential learning experience. While nurse educators have widely accepted the educational benefits of reflection, research into reflective learning is hampered by the lack of reliable and widely accepted methods for assessing whether reflection takes place and the level of any reflection. This study attempted to develop and test coding systems for written reflective journals based on two well-known models of reflective thinking. The reflective journals submitted by the students were subjected to content analysis at two levels. The findings of this study suggest that student writing can be used as evidence for the presence or absence of reflective thinking. The process of allocating students to three categories of non-reflector, reflector and critical reflector was straightforward and reliable. Identifying textual elements within journals and allocating them to the finer levels of reflection within a more complex model of reflective thinking was, however, more problematic and considerably less reliable.

Helicobacter pylori-induced gastritis in the domestic cat

Helicobacter pylori has been cultured from the inflamed gastric mucosae of naturally infected cats; the lesions in H. pylori-infected cat stomachs mimic many of the features seen in H. pylori-infected human stomachs. To determine whether H. pylori-negative specific-pathogen-free cats with normal gastric mucosae were susceptible to colonization by this bacterium and whether gastritis developed after infections, four H. pylori-negative cats treated with cimetidine were orally dosed three times with 3 ml (1.5 x 10(8) CFU/ml) of H. pylori every 4 days. All four cats became persistently colonized as determined by gastric cultures and PCRs from serial gastric biopsy samples and necropsy samples at 7 months postinfection. H. pylori was not isolated from the two control cats, nor were their gastric tissues positive by PCR; one of the two cats had a few focal lymphocytic aggregates in the body submucosa, whereas the second cat had a normal gastric mucosa. All four H. pylori-infected cats had multifocal gastritis consisting of lymphoid aggregates plus multiple large lymphoid nodules, which were most noticeable in the antral mucosa. In addition, one H. pylori-infected cat had a moderate diffuse infiltration of polymorphonuclear leukocytes in the subglandular region of the antrum. H. pylori-like organisms were focally distributed in glandular crypts of the antrum. Two of the H. pylori-infected cats had significant (eightfold) increases over baseline in levels of immunoglobulin G H. pylori serum antibody. The H. pylori isolates from the four experimentally infected cats had restriction fragment length polymorphism patterns specific for the flaA gene that were identical to those of the inoculating strain. H. pylori readily colonizes the cat stomach and produces persistent gastritis.

Evaluation of antibiotic therapies for eradication of Helicobacter hepaticus

The newly recognized murine pathogen Helicobacter hepaticus is known to colonize the ceca and colons of several strains of mice from a variety of commercial suppliers. Additionally, the organism persistently infects mice, causes a chronic hepatitis, and is linked to hepatic tumors in the A/JCr inbred mouse strain. For this reason, eradication of the organism from infected mouse colonies is desirable. Treatment modalities for eradication of H. hepaticus from the gastrointestinal system consisted of oral administration of various antibiotic combinations previously evaluated for eradication of experimental H. felis gastric infection in mice. A/JCr mice (8 to 10 weeks old) naturally infected with H. hepaticus were divided into six treatment groups of 10 animals each. Animals received monotherapy of amoxicillin, metronidazole, or tetracycline or triple therapy of amoxicillin-metronidazole-bismuth (AMB) or tetracycline-metronidazole-bismuth (TMB). All medications were administered by oral gavage three times daily for 2 weeks. One month after the final treatment, mice were euthanatized and livers, ceca, and colons were cultured for H. hepaticus. All untreated control animals had H. hepaticus isolated from the cecum and/or colon. H. hepaticus was not recovered from the livers, ceca, or colons of the AMB or TMB treatment groups. All animals receiving the various antibiotic monotherapies had H. hepaticus isolated from the cecum and colon. We conclude that at the doses and the route evaluated, AMB and TMB triple therapies are effective for eradication of H. hepaticus in 8- to 10-week old A/JCr mice.

A 25.7 × 10(3) M(r) hydra metalloproteinase (HMP1), a member of the astacin family, localizes to the extracellular matrix of Hydra vulgaris in a head-specific manner and has a developmental function

Hydra extracellular matrix (ECM) is composed of a number of components seen in vertebrate ECM such as laminin, type IV collagen, fibronectin, and heparan sulfate proteoglycan. A number of functional studies have shown that hydra ECM plays an important role in pattern formation and morphogenesis of this simple metazoan. The present study was designed to identify matrix degrading proteinases in hydra and determine their potential function in hydra morphogenesis. Using SDS-PAGE gelatin-zymography, five gelatinolytic bands were identified with relative molecular masses of 67 × 10(3), 51–58 × 10(3) (a triplet) and 25–29 × 10(3), respectively. Inhibition studies indicated that all of these gelatinases were metalloproteinases. Gelatin-zymography indicated that there was a differential distribution of these gelatinases along the longitudinal axis of hydra, with the 67 × 10(3) M(r) gelatinase being concentrated in the body column, while the 51–58 × 10(3) M(r) gelatinase triplet and the 25–29 × 10(3) M(r) gelatinase concentrated in the head region. Purification procedures were successfully developed for the 25–29 × 10(3) M(r) metalloproteinase which has been termed hydra metalloproteinase 1 (HMP1) and which appeared as a single band with a SDS-PAGE mobility of 25.7 × 10(3) M(r). The N-terminal sequence of purified HMP1 indicated that it has structural homology with metalloproteinases that belong to the astacin family. Subsequent cloning and sequencing of cDNA clones confirmed the identification of HMP1 as an astacin-like metalloproteinase. Immunocytochemical studies with antibodies generated against the purified enzyme and to a synthetic peptide indicated that HMP1 was localized to the ECM of tentacles. Functional studies were performed in which purified HMP1, anti-HMP1 IgG, or suspected substrates of HMP1 (e.g. growth factors such as TGF-beta 1) were introduced into the interepithelial compartment of hydra using a ‘DMSO loading’ procedure. These studies indicated that HMP1 has a functional role during a number of developmental processes such as head regeneration and cell differentiation/transdifferentiation of tentacle battery cells.

Long-term colonization with single and multiple strains of Helicobacter pylori assessed by DNA fingerprinting

The gastric pathogen Helicobacter pylori establishes long-term chronic infections that can lead to gastritis, peptic ulcers, and cancer. The species is so diverse that distinctly different strains are generally recovered from each patient. To better understand the dynamics of long-term carriage, we characterized H. pylori isolates from initial and follow-up biopsy specimens from a patient population at high risk of H. pylori infection and gastric cancer. Eighty-five isolates were obtained from 23 patients and were analyzed by genomic restriction enzyme analysis, arbitrarily primed PCR fingerprinting, (random amplified polymorphic DNA analysis), and/or restriction of specific PCR-amplified genes (restriction fragment length polymorphism analysis). A single strain was found in sequential biopsy specimens from 12 of 15 patients (80%) receiving sucralfate. In the remaining three patients treated with sucralfate, two strains were identified in two patients and three strains were identified in the third patient. In contrast, a single strain was found in sequential biopsy specimens from only three of eight patients (37%) receiving bismuth, metronidazole, and nitrofurantoin. Two strains were identified in five other patients receiving bismuth-antibiotic (63%). Immunoglobulin G antibodies to H. pylori were present in the sera of all patients. Thus, H. pylori colonization can persist for long periods (up to at least 4 years), despite high titers of immunoglobulin G antibodies in serum. Resistance to metronidazole was noted in some strains before and/or after treatment, but all strains remained susceptible to amoxicillin, tetracycline, and nitrofurantoin. We conclude that H. pylori genotypes, as measured by several sensitive DNA fingerprinting methods, can remain stable for years in vivo, despite the acquisition or loss of drug resistance, circulating antibody, or exposure to antibiotics or sucralfate.

Tandem mass spectrometry analysis of synthetic opioid peptide analogs

Five synthetic opioid peptides that were designed to have specific opioid receptor-binding properties were studied by low energy collision-induced dissociation (CID) tandem mass spectrometry (MS/MS). The MS/MS data are required for the analysis of those peptides in ovine plasma in a study to determine the placental transfer of the peptide to the fetus. The synthetic enkephalin-related peptides were: Tyr-D-Arg-Phe-Lys-NH2, (DALDA), N,N-diallyl-Tyr-Aib-Aib-Phe-Leu-OH, (ICI 174,864), Tyr-D-Thr-Gly-Phe-Leu-Thr, (DTLET), Tyr-D-Pen-Gly-Phe-D-Pen-OH, (DPDPE), and D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2, (CTAP). Liquid secondary ion mass spectrometry (LSIMS) was used for sample desorption-ionization, and a hybrid (E1BE2qQ) tandem mass spectrometer was used to collect the product-ion spectra. A protonated molecule ion, [M + H]+, was observed for each peptide. Amino acid sequence-determining fragment ion were produced by CID and collected by MS/MS for the three linear peptides, and also for the two disulfide-bond-containing peptides in their unreduced and dithiothreitol (DTT)-reduced forms. The detection level for the [M + H]+ ion of DTLET was ca. 3 pmol; and the stabilities of the CTAP and ICI analogs in plasma were studied.

In-vitro hepatotoxic factor in Helicobacter hepaticus, H. pylori and other Helicobacter species

Several inbred strains of mice in closed breeding colonies were found to have spiral-shaped bacteria associated with active, chronic hepatitis. A new species of Helicobacter, H. hepaticus, was isolated from the infected livers of some strains of mice. Other strains of mice were colonised with H. hepaticus in the caecum and colon, but not the liver. Filtersterilised supernatant fluid from five strains of H. hepaticus was tested in a mouse liver cell line (ATCC no. CCL 9.1) for cytotoxic activity. All strains produced a toxic factor causing morphological changes in the cells at dilutions up to 1 in 1000. Toxicity was observed after exposure to the supernatant fluid for 48-72 h. Other Helicobacter spp. that also produced the cytopathic effect (CPE) in the liver cell line were H. felis, H. acinonyx, H. pylori and one strain of H. mustelae. "Helicobacter rappini" and H. muridarum did not cause CPE in the liver cells. The soluble factor was stable at 4 degrees C for up to 3 months. It was also stable at 56 degrees C for 30 min, but was inactivated by boiling for 15 min. It was inactivated by incubation with trypsin. A partially purified preparation of the cytotoxin had a mol. wt of c. 100,000 and did not have urease activity. The cytotoxin produced by H. hepaticus did not cause vacuole formation in HeLa cells.

Determination of GDP-Fuc:Gal beta 1-4GlcNAc-R (Fuc to GlcNAc) alpha 1,3 fucosyltransferase activity by a solid-phase method

We report the development of a solid-phase assay for the activity of the enzyme GDPFuc:Gal beta 1-4GlcNAc-R (Fuc to GlcNAc) alpha 1,3 fucosyltransferase (alpha 1,3FT). This enzyme generates the blood group antigen Lewis x (Lex)Gal beta 1-4(Fuc alpha 1-3)GlcNAc-R from the acceptor Gal beta 1-4GlcNAc-R. In our method, the tetrasaccharide Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc (lacto-N-neotetraose, LNnT) from human milk was chemically conjugated to bovine serum albumin (BSA) to generate LNnT-BSA. As a source of alpha 1,3FT to develop the assay, we used extracts of COS7 cells created to stably express the human FucTIII and FucTIV genes, both of which have alpha 1,3FT activity. LNnT-BSA was immobilized in microtiter wells and incubated with GDPFuc and cell extracts. The Lex antigen generated by alpha 1,3FT was detected with a monoclonal IgM antibody (anti-CD15). Binding of this IgM-type antibody to product was detected by one of two methods. Method 1 was based on the binding of alkaline phosphatase-conjugated goat anti-mouse IgM. Method 2 was based on the binding of a streptavidin conjugate of the recombinant bioluminescent protein aequorin to biotinylated goat anti-mouse IgM. The alpha 1,3FT assay was linear with respect to time (0-3 h), extract added (0-40 micrograms), and was dependent on GDPFuc (20 microM optimal) and LNnT-BSA. Both methods 1 and 2 allowed measurement of alpha 1,3FT in extracts of the human cell line HL-60.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of selenite on cell surface fibronectin receptor

Incubation of cells with selenite, under conditions in which there is no effect on cell viability, results in a decrease in the rate of their subsequent attachment to extracellular matrix proteins such as fibronectin (1). The attachment was inhibited by a pentapeptide containing the RGD sequence and by antibody against the cellular fibronectin receptor (alpha 5 beta 1 integrin), indicating that it is receptor-mediated. To investigate whether exposure to selenite has an effect on fibronectin receptors, we assayed for their presence on the cell surface by measuring the ability of cells to attach to a surface that had been coated with antibodies to the receptor. Brief exposure of cells to low concentrations of selenite resulted in a significant decrease in their ability to attach to monoclonal antibodies against the alpha 5 or beta 1 subunits of the fibronectin receptor, as well as to polyclonal antibodies against the complete receptor. This indicates that exposure to selenite results in a decrease in receptors that are present at the cell surface. Exposure of the cells to selenate, selenocystine or selenomethionine did not result in a significant decrease in cell surface receptors. Preincubation of the cells with selenite was required for the effect, indicating that selenite does not directly interfere with receptor structure or function.

Human polymorphonuclear leukocytes lack detectable nitric oxide synthase activity

Nitric oxide regulates polymorphonuclear leukocyte (PMN) function, but whether or not human PMNs express nitric oxide synthase (NOS) activity is controversial. We studied NOS activity in human PMNs by using human aortic endothelial cells (HAECs) for comparison. The conversion of L-arginine to L-citrulline, a relatively specific measure of NOS activity, was easily measured and inducible in fractionated HAECs, and &gt; 90% of all L-arginine conversion was blocked by the NOS inhibitor, N omega-amino-L-arginine (L-NAA). In fractionated PMNs, L-arginine conversion was low and was unaffected by L-NAA. In addition, NOS activity was not induced in PMNs by LPS, IL-1 beta, or IFN-gamma. In a whole-cell assay, total L-arginine conversion was much lower in human PMNs compared with HAECs (3.38 +/- 0.21 vs 157.5 +/- 10.28 pmol/h/10(6) cells, respectively; p &lt; 0.01). This conversion in whole PMNs was not increased in vitro by LPS, IFN-gamma, IL-1 beta, or TNF-alpha nor decreased by W13, a calmodulin inhibitor. Furthermore, PMNs isolated from four volunteers before and after challenge with i.v. LPS (4 ng/kg) showed no increase in L-arginine to L-citrulline conversion. Nitrite and nitrate release from human PMNs was 35-fold lower than for HAECs and was not inhibited by L-NAA. These data suggest that human PMNs do not express NOS activity.

Human polymorphonuclear leukocytes lack detectable nitric oxide synthase activity

Nitric oxide regulates polymorphonuclear leukocyte (PMN) function, but whether or not human PMNs express nitric oxide synthase (NOS) activity is controversial. We studied NOS activity in human PMNs by using human aortic endothelial cells (HAECs) for comparison. The conversion of L-arginine to L-citrulline, a relatively specific measure of NOS activity, was easily measured and inducible in fractionated HAECs, and > 90% of all L-arginine conversion was blocked by the NOS inhibitor, N omega-amino-L-arginine (L-NAA). In fractionated PMNs, L-arginine conversion was low and was unaffected by L-NAA. In addition, NOS activity was not induced in PMNs by LPS, IL-1 beta, or IFN-gamma. In a whole-cell assay, total L-arginine conversion was much lower in human PMNs compared with HAECs (3.38 +/- 0.21 vs 157.5 +/- 10.28 pmol/h/10(6) cells, respectively; p < 0.01). This conversion in whole PMNs was not increased in vitro by LPS, IFN-gamma, IL-1 beta, or TNF-alpha nor decreased by W13, a calmodulin inhibitor. Furthermore, PMNs isolated from four volunteers before and after challenge with i.v. LPS (4 ng/kg) showed no increase in L-arginine to L-citrulline conversion. Nitrite and nitrate release from human PMNs was 35-fold lower than for HAECs and was not inhibited by L-NAA. These data suggest that human PMNs do not express NOS activity.

Cloning and biological function of laminin in Hydra vulgaris

The Cnidarian, hydra, lends itself to studies related to the role of extracellular matrix (ECM) components in development because of its high regenerative capacity and its simple structure, which is organized as an epithelial bilayer with an intervening ECM termed the mesoglea. Previous immunocytochemical and biochemical studies have established that hydra mesoglea contains many of the major matrix components (e.g., fibronectin, laminin, type IV collagen, and heparan sulfate proteoglycan) associated with the ECM of vertebrate and more complex invertebrate species. Additional studies have also established that ECM components have a critical role in hydra development as monitored during head regeneration and morphogenesis of hydra cell aggregates. In the present study a monoclonal antibody (mAb52) raised to isolated hydra mesoglea was used as a probe in additional functional studies and to screen a cDNA expression library made from poly(A)+ RNA isolated from Hydra vulgaris. Immunofluorescent analysis indicated that mAb52 was localized along the entire longitudinal axis of adult polyps in what is termed the subepithelial zones of hydra mesoglea. Cytochemical studies found these subepithelial zones to be rich in anionic sites. Previous studies have shown that mAb52 blocks hydra cell aggregate development and experiments in the current study have shown that mAb52 also blocks in vivo interstitial cell (I-cell) migration in hydra grafts. Sequence analysis of cDNA clones isolated using mAb52 indicated that the protein encoded by these clones had structural homology with mammalian and Drosophila laminin B1 chain and hybridized to a single 6.75-kb band on Northern blots of total hydra RNA. One interesting difference in hydra laminin B1 was the presence of a FTGTQ amino acid sequence in place of the vertebrate YIGSR cell binding domain. Under nonreducing conditions, polyclonal antibodies against FTGTQ bound to the same > 200-kDa band on Western blots of mesoglea as mAb52 and also immunolocalized to the subepithelial zones. Under reducing conditions, anti-FTGTQ antibodies bound to a single band with a mass of approximately 200 kDa. In addition, FTGTQ peptide inhibited adhesion of dissociated hydra cells to mesoglea and anti-FTGTQ antibodies inhibited hydra cell binding to substrates coated with mesoglea or FTGTQ peptide. Anti-FTGTQ antibodies also inhibited in vivo I-cell migration in hydra grafts. Given the early divergence of Cnidarians during evolution, these studies indicate the highly conserved nature of laminin and provide additional information regarding the critical role of ECM components during hydra development.

Helicobacter hepaticus sp. nov., a microaerophilic bacterium isolated from livers and intestinal mucosal scrapings from mice

A bacterium with a spiral shape and bipolar, single, sheathed flagella was isolated from the livers of mice with active, chronic hepatitis. The bacteria also colonized the cecal and colonic mucosae of mice. The bacterium grew at 37 degrees C under microaerophilic and anaerobic conditions, rapidly hydrolyzed urea, was catalase and oxidase positive, reduced nitrate to nitrite, and was resistant to cephalothin metronidazole. On the basis of 16S rRNA gene sequence analysis, the organism was classified as a novel helicobacter, Helicobacter hepaticus. This new helicobacter, like two other murine Helicobacter species, H. muridarum and "H. rappini," is an efficient colonizer of the gastrointestinal tract, but in addition, it has the pathogenic potential to elicit persistent hepatitis in mice.

Characterization of an opioid peptide-containing protein and of bovine α-lactalbumin by electrospray ionization and liquid secondary ion mass spectrometry

Mass spectrometry methods have been used to characterize two proteins: an opioid peptide-containing protein extracted from bovine pituitary, and bovine α-lactalbumin (BAL). A protein that contains β-endorphin was found in bovine pituitary, and that protein was characterized with electrospray ionization mass spectrometry (ESIMS), gel permeation chromatography, reversed-phase high performance liquid chromatography (RP-HPLC), radioimmunoassay, trypsinolysis, and liquid secondary ion mass spectrometry (LSIMS).BAL is a protein that was used as a model to develop analytical methods to study opioid peptide-containing proteins. Commercial BAL was purified by RP-HPLC, and its molecular weight (M.W.) was determined by ESIMS. The shift in mass observed following dithiothreitol (DTT) reduction estimated the number of disulfide bonds.For all of the data obtained for BAL with or without RP-HPLC separation, ESIMS determined the M.W. of the peptides produced by trypsin treatment of BAL, and LSIMS selected a precursor ion, the protonated molecule ion [M + H](+), of a tryptic peptide, which was analyzed by tandem mass spectrometry. Following DTT reduction, ESIMS and LSIMS detected each peptide that contained disulfide bonds in that mixture of tryptic peptides.

Nitric oxide regulates endotoxin-induced TNF-alpha production by human neutrophils

We studied the effect of nitric oxide on LPS-induced TNF-alpha production by human neutrophils. Human neutrophils exposed to LPS and IFN-gamma did not show measurable increases in intracellular cyclic GMP (cGMP). However, cGMP increased upto 30-fold (p < 0.01) in neutrophils incubated with both sodium nitroprusside (SNP), an exogenous source of nitric oxide, and N-acetylcysteine (NAC), which increases the bioavailability of nitric oxide; this increase indicates that neutrophils contain a nitric oxide-sensitive guanylate cyclase. SNP, with or without NAC, did not increase TNF-alpha production in human neutrophils cultured in medium alone. However, LPS-dependent TNF-alpha production was increased by exposure to SNP (p < 0.05); this effect was further increased by the addition of NAC (p < 0.02). IFN-gamma greatly increased LPS-mediated TNF-alpha production by human neutrophils (p < 0.01), and SNP plus NAC was found to further augment this production (p < 0.01). The up-regulation of TNF-alpha production by nitric oxide was not associated with increased amounts of LPS-induced TNF-alpha mRNA, and was not reproduced by exposing neutrophils to cGMP analogues. These data suggest that nitric oxide released by endothelial and vascular smooth muscle cells may exert a paracrine effect on human neutrophils and augment the inflammatory response in sepsis by increasing the production of cytokines. Although the mechanism of this effect remains unknown, it does not seem to be dependent on cGMP or increased levels of TNF-alpha mRNA.

Nitric oxide regulates endotoxin-induced TNF-alpha production by human neutrophils

We studied the effect of nitric oxide on LPS-induced TNF-alpha production by human neutrophils. Human neutrophils exposed to LPS and IFN-gamma did not show measurable increases in intracellular cyclic GMP (cGMP). However, cGMP increased upto 30-fold (p &lt; 0.01) in neutrophils incubated with both sodium nitroprusside (SNP), an exogenous source of nitric oxide, and N-acetylcysteine (NAC), which increases the bioavailability of nitric oxide; this increase indicates that neutrophils contain a nitric oxide-sensitive guanylate cyclase. SNP, with or without NAC, did not increase TNF-alpha production in human neutrophils cultured in medium alone. However, LPS-dependent TNF-alpha production was increased by exposure to SNP (p &lt; 0.05); this effect was further increased by the addition of NAC (p &lt; 0.02). IFN-gamma greatly increased LPS-mediated TNF-alpha production by human neutrophils (p &lt; 0.01), and SNP plus NAC was found to further augment this production (p &lt; 0.01). The up-regulation of TNF-alpha production by nitric oxide was not associated with increased amounts of LPS-induced TNF-alpha mRNA, and was not reproduced by exposing neutrophils to cGMP analogues. These data suggest that nitric oxide released by endothelial and vascular smooth muscle cells may exert a paracrine effect on human neutrophils and augment the inflammatory response in sepsis by increasing the production of cytokines. Although the mechanism of this effect remains unknown, it does not seem to be dependent on cGMP or increased levels of TNF-alpha mRNA.

[Immunochemical identification of kinesin in Physarum polycephalum]

Physarum polycephalum, a low eukaryote ameba provides an attractive system for studying contractile proteins. In this work, we have identified a kinesin-like protein in the plasmodium of Physarum polycephalum by western blotting, using monoclonal antibody against kinesin (bovine brain). The molecular weight of the polypeptide which immunologically cross-reacts with kinesin from bovine brain is about 137kd. It suggests that the 137kd polypeptide is the heavy chain of the kinesin in Physarum polycephalum.

Localization of two gonadotropin receptors in the salmon gonad by in vitro ligand autoradiography

Receptors for two salmon gonadotropins, GTH I and GTH II, were localized by use of in vitro ligand autoradiography of coho salmon gonads at various stages of sexual maturation. The results in both sexes revealed the presence of two types of GTH receptors: type I (GTH-RI), which interacts with both GTHs, and type II (GTH-RII), which interacts specifically with GTH II. GTH-RI was found at all stages of spermatogenesis examined and was localized on cells that were most likely Sertoli cells; however, it could not be determined whether GTH-RI was also localized on Leydig cells. In contrast, GTH-RII was found only in Leydig cells in the testis from a spermiating fish. In the vitellogenic ovary, GTH-RI was localized in the thecal layer and intensely on granulosa cells; in the preovulatory follicle, in contrast, GTH-RI was found in the thecal layer and in interstitial connective tissue, but not in the granulosa layer. Among all the stages of oogenesis examined, only granulosa cells of the preovulatory follicle exhibited GTH-RII. The appearance of GTH-RII coincides well with the increase in plasma levels of GTH II that occurs during final oocyte maturation and spermiation in coho salmon. The nature, distribution, and timing of appearance of these two receptors can explain, at least in part, the results of previous studies on steroidogenic activities of the two GTHs. The present study also suggests the functional homology of salmon GTH I and GTH II to mammalian FSH and LH, respectively, during gonadal development.

Protein synthesis is not required for the inhibitory effect of selenite on cell colony formation and RNA synthesis

Selenite has been shown to undergo intracellular metabolism that results in its conversion to other low molecular weight Se-containing species and also to its incorporation into a selenocysteine residue in selenoprotein. In order to investigate whether the incorporation into protein is required for the cytotoxic effects of selenite, we have examined whether inhibition of protein synthesis prevents the inhibitory effect of selenite on the ability of cells to form colonies or to synthesize RNA. We have found that treatment of HeLa cells with cycloheximide inhibited protein synthesis by > 90% but had no effect on the inhibitory effect of selenite on cell colony formation or RNA synthesis. Since protein synthesis is not necessary for these cytotoxic effects of selenite they are unlikely to result from an increase in the synthesis of selenoproteins.

Mass spectrometric detection of preproenkephalin A-derived peptides in bovine pituitary

A new analytical system, including chromatography separation, enzyme digestion, radioimmunoassay detection, and mass spectrometry characterization, has been designed to detect native preproenkephalin A-derived peptides in the bovine pituitary. The direct evidence of these intact peptides was provided by the mass spectrometric detection of the (M+H)+ ions of ME-Lys at m/z 702 and of ME-Arg at m/z 730, following trypsin digestion and the detection of ME-like immunoreactivity in HPLC fractions.

Isomorphous binding of mercury-substituted thiosaccharides to pertussis toxin crystals yields crystallographic phases

An isomorphous derivative of pertussis toxin crystals was prepared using a 2-alpha-mercuric analog of N-acetyl neuraminic acid in a method analogous to the use of inhibitors labelled with heavy atoms to solve crystal structures of enzymes. This derivative exploits the specific binding between pertussis toxin and terminal sialic acid residues on receptor glycoproteins. Difference Patterson maps yielded heavy-atom sites which refined with good statistics, indicating that the protein probably does not undergo a conformational change on receptor binding. Mercuric analogs of other monosaccharides should be easily obtainable using the same synthetic strategy, suggesting a general method for derivatizing crystals of carbohydrate-binding proteins.

Epstein-Barr virus infection, salted fish and nasopharyngeal carcinoma. A case-control study in southern China

Two hundred and five histologically confirmed cases of nasopharyngeal carcinoma (NPC) in southern China, and an equal number of matched controls, were investigated for their dietary habits, occupational exposure, use of tobacco and alcohol, history of relatives with NPC, and IgA against Epstein-Barr virus (EBV) capsid antigen (IgA/VCA). Positive IgA/VCA and intake of salted fish were associated with a strong excess risk of NPC. The association persisted after adjustment for other factors. The combination of salted fish and EBV was strongly associated with NPC, and more so than EBV or salted fish per se. Multivariate analyses showed that IgA/VCA was the most important predictor of NPC, and salted fish the second most important. These results suggest that EBV has a strong effect on the development of NPC. The exclusion of EBV and genetic factors in earlier epidemiological studies may have resulted in an overestimation of salted fish as important etiological factor causing NPC.

Plasminogen-dependent activation of latent transforming growth factor beta (TGF beta) by growing cultures of osteoblast-like cells

Osteoblasts secrete transforming growth factor beta (TGF beta) as a biologically inert, latent complex that must be dissociated before the growth factor can exert its effects. We have examined the production and proteolytic activation of latent TGF beta (LTGF beta) by clonal UMR 106-01 rat osteosarcoma cells and neonatal mouse calvarial (MC) osteoblast-like cells in vitro. Synthetic bPTH-(1-34) increased the activity of tissue-type (tPA) and urokinase-type (uPA) plasminogen activators (PA) in cell lysates (CL) of UMR 106-01 cells. The concentration of active TGF beta in serum-free CM from cultures treated with bPTH-(1-34) and plasminogen was significantly greater than in CM from untreated controls and cultures treated with either bPTH-(1-34) or plasminogen alone. This effect occurred at concentrations of PTH-(1-34) that increased PA activity and was prevented by aprotinin, an inhibitor of plasmin activity. Treatment with bPTH-(1-34) had no effect on the concentration of TGF beta in acid-activated samples of CM. Functional consequences of proteolytically activated TGF beta was examined in primary cultures of neonatal MC osteoblast-like cells. Human platelet TGF beta 1 caused a dose-dependent increase in the migration of these cells in an in vitro wound healing assay. Cell migration was also stimulated in cultures treated with bPTH-(1-34) and plasminogen together. This effect was blocked by an anti-TGF beta 1 antibody. The results of these studies demonstrate that (1) LTGF beta secreted by osteoblasts in vitro is activated under conditions where the plasmin activity in the cultures is increased, and (2) the TGF beta generated by plasmin-mediated proteolysis is biologically active. We suggest that the local concentration of TGF beta in bone may be controlled by the osteoblast-associated plasminogen activator/plasmin system. Furthermore, since several calciotropic factors influence osteoblast PA activity, this system may have an important role in mediating their anabolic and/or catabolic effects.

Evidence of an intermediate-size beta-endorphin-containing precursor molecule in bovine pituitary by mass spectrometry

A new analytical system has been designed to characterize intermediate-sized precursor molecules from two different precursors-the preproenkephalin Abovine,1-263 precursor molecule, which produces methionine enkephalin and from the proopiomelanocortin, POMCbovine,1-265 precursor molecule, which produces beta-endorphin. A possible intermediate-sized precursor that leads to beta-endorphin was found in bovine pituitary by means of electrospray ionization mass spectrometry, in combination with gel permeation chromatography, reversed-phase high performance liquid chromatography, radioimmunoassay, trypsinolysis, and liquid secondary ion mass spectrometry.

Postpartum haemorrhoids--evaluation of a cooling device (Anurex) for relief of symptoms

Postpartum haemorrhoids are a common problem, for which the recently marketed cooling device, Anurex (Roussel Uclaf Australia, Pennant Hills, NSW), was evaluated in 129 women randomly allocated to treatment and control groups. There was no difference in the rate of resolution of pain between the groups. The test group estimated a greater duration of pain relief, but this was not statistically significant. Anal bleeding and itching were not significantly reduced in the test group. There was no difference between discomfort scores related to application of the device in the groups, but a significant number in the test group encountered difficulty in insertion of the device. It is concluded that the introduction of the Anurex device as a standard method of treatment of postpartum haemorrhoids is not justified.

Antigenic specificity and morphologic characteristics of Chlamydia trachomatis, strain SFPD, isolated from hamsters with proliferative ileitis

Profound diarrhea associated with proliferating intestinal cells containing intraepithelial campylobacter-like organisms (ICLO) occurs in a variety of mammalian hosts, particularly swine and hamsters. Recently, intracellular bacteria were isolated from proliferative intestinal tissue of hamsters and propagated in intestine cell line 407. Oral inoculation of hamsters with cell culture lysates containing these organisms reproduced the disease in susceptible hamsters. In the present study, an intracellular bacterium from the INT 407 cell line was shown by a variety of techniques to be a member of the genus Chlamydia and has been designated Chlamydia sp. strain SFPD. McCoy cells infected with Chlamydia sp. strain SFPD demonstrated bright fluorescent-stained intracytoplasmic inclusions when examined with fluorescein-labeled species-specific C. trachomatis monoclonal antibodies. The organism also reacted to fluorescein-labeled polyclonal but not monoclonal ICLO "omega" antisera. Ultrastructural examination of the Chlamydia sp. strain SFPD from McCoy cells revealed electrondense elementary bodies and a less electron-dense reticulate-like body that was circular; both features are consistent in morphology to developmental forms of Chlamydia and do not conform to ICLO morphology. Molecular studies, 16S ribosomal sequence analysis, and sequencing of the outer membrane protein confirmed that the isolate is a C. trachomatis closely related to the mouse pneumonitis strain of C. trachomatis.

[Analysis on postoperative prognosis in relation to blood ketone body ratios in surgical patients with liver disease]

Eighty-one patients with liver disease were studied for the postoperative changes in the arterial blood ketone body ratio (KBR) and routine liver function tests. The postoperative patients were classified into three groups-according to the postoperative changes in KBR. In the 54 patients of group A, KBR did not decrease to below 0.7, only 2 cases with complications (3.7%); in the 25 patients of group B, KBR decreased transiently to 0.4-0.7 and then increased to over 0.7, 9 cases with complications (36.0%), but they were ameliorated concomitantly with the restoration of KBR; in the 2 cases of group C, KBR decreased irreversibly to below 0.4, and a variety of complications occurred, so the patients finally died of multiple organ failure (MOF). It was found that routine liver function tests were less reliable direct indicators for the onset of postoperative hepatic insufficiency than KBR, which reflected the oxidoreduction state of liver mitochondria.

An epidemiological survey of deformities and disabilities among 14,257 cases of leprosy in 11 counties

This study was planned and conducted in Yang Zhou Prefecture, covering 11 counties that were formerly areas with a high prevalence of leprosy. Out of 14,257 leprosy patients, 8122 (56.97%) cases with deformities and disabilities were found. The disability rate is much higher in patients with MB leprosy (81.15%) than in PB leprosy (53.04%). The statistical data and the type of deformities and disabilities are presented. The influences of various host factors and disease factor which cause disability and deformity are discussed.