Influence of whipping temperature on the whipping properties and rheological characteristics of whipped cream.

The effects of whipping temperature (5 to 15 degrees C) on the whipping (whipping time and overrun) and rheological properties of whipped cream were studied. Fat globule aggregation (aggregation ratio of fat globules and serum viscosity) and air bubble factors (overrun, diameter, and surface area) were measured to investigate the mechanism of whipping. Whipping time, overrun, and bubble diameters decreased with increasing temperature, with the exception of bubble size at 15 degrees C. The aggregation ratio of fat globules tended to increase with increasing temperature. Changes in hardness and bubble size during storage were relatively small at higher temperatures (12.5 and 15 degrees C). Changes in overrun during storage were relatively small in the middle temperature range (7.5 to 12.5 degrees C). From the results, the temperature range of 7.5 to 12.5 degrees C is recommended for making whipped creams with a good texture, and a specific temperature should be decided when taking into account the preferred overrun. The correlation between the whipped cream strain hardness and serum viscosity was high (R(2)=0.906) and persisted throughout the temperature range tested (5 to 15 degrees C). A similar result was obtained at a different whipping speed (140 rpm). The multiple regression analysis in the range of 5 to 12.5 degrees C indicated a high correlation (R(2)=0.946) in which a dependent variable was the storage modulus of whipped cream and independent variables were bubble surface area and serum viscosity. Therefore, fat aggregation and air bubble properties are important factors in the development of cream hardness. The results of this study suggest that whipping temperature influences fat globule aggregation and the properties of air bubbles in whipped cream, which alters its rheological properties.

7-Dehydrocholesterol-dependent proteolysis of HMG-CoA reductase suppresses sterol biosynthesis in a mouse model of Smith-Lemli-Opitz/RSH syndrome.

Smith-Lemli-Opitz/RSH syndrome (SLOS), a relatively common birth-defect mental-retardation syndrome, is caused by mutations in DHCR7, whose product catalyzes an obligate step in cholesterol biosynthesis, the conversion of 7-dehydrocholesterol to cholesterol. A null mutation in the murine Dhcr7 causes an identical biochemical defect to that seen in SLOS, including markedly reduced tissue cholesterol and total sterol levels, and 30- to 40-fold elevated concentrations of 7-dehydrocholesterol. Prenatal lethality was not noted, but newborn homozygotes breathed with difficulty, did not suckle, and died soon after birth with immature lungs, enlarged bladders, and, frequently, cleft palates. Despite reduced sterol concentrations in Dhcr7(-/-) mice, mRNA levels for 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate-controlling enzyme for sterol biosynthesis, the LDL receptor, and SREBP-2 appeared neither elevated nor repressed. In contrast to mRNA, protein levels and activities of HMG-CoA reductase were markedly reduced. Consistent with this finding, 7-dehydrocholesterol accelerates proteolysis of HMG-CoA reductase while sparing other key proteins. These results demonstrate that in mice without Dhcr7 activity, accumulated 7-dehydrocholesterol suppresses sterol biosynthesis posttranslationally. This effect might exacerbate abnormal development in SLOS by increasing the fetal cholesterol deficiency.

History effects and phase diagram near the lower critical point in YBa2Cu3O7 single crystals.

Using a sensitive torque magnetometer we have studied magnetization curves for untwinned overdoped YBa2Cu3O7 single crystals in fields of up to 28 T. We demonstrate the existence of history effects below the lower critical point and provide a full demarcation of the Bragg-glass phase. A pronounced symmetry is observed in the behavior of the phase lines, irreversible magnetization, and value of the magnetization jump near both critical points.

Novel elements located at -504 to -399 bp of the promoter region regulated the expression of the human macrophage scavenger receptor gene in murine macrophages.

The expressions of type I and type II macrophage scavenger receptors (MSRs) are highly specific in macrophages and related cell types. Although some reports have described the regulation of MSR gene expression and proposed some cis-elements related to cell-specific expression, the regulation of MSR remains largely unclear. This is due, in part, to an unacceptably low efficiency of transfection into monocyte/ macrophage cells. In the present study, we optimized the conditions of electroporation in murine macrophage (P388D1) cells. The efficiency of electroporation was increased 20-fold compared with previous methods. Using the optimized method, we focused on studying the regulation of the human MSR promoter in macrophages. We presently demonstrate that: a) the proximal -10 to +50 bp human MSR promoter region is necessary for the cell type-specific expression of human MSR; b) the 6.5 kbp upstream sequence suppresses the expression of human MSR; c) a promoter region extending from -504 to -399 bp produced the greatest increase in transcriptional activity; d) macrophage cell-specific transcription factors bind to the region as determined by electrophoretic mobility shift assay (EMSA) and a footprint assay; and e) mutations of the region reduced about 40-75% of the promoter activity in a transfecting assay. We concluded that novel elements located at the -504 to -399 bp region may play an important role in the regulation of the MSR gene expression in macrophages. We speculate that macrophage-specific factors binding to those elements may be responsible for the transcription regulation of the MSR gene in macrophages.

Direct detection of hepatitis B virus gene integrated in the Alexander cell using fluorescence in situ polymerase chain reaction.

Prolonged infection of hepatitis B virus (HBV) is reported to cause hepatocellular carcinoma (HCC) via liver cirrhosis. However, it is still unknown whether the HCC is induced by the HBV DNA integration or by inflammatory stimulation during the phase of liver cirrhosis. The aim of this study is to determine the intracellular or intranuclear distribution of HBV DNA with a highly sensitive assay. Here we directly detected the integration of HBV DNA by fluorescence in situ polymerase chain reaction (FISPCR). Since FISPCR products directly incorporate rhodamine-4-dUTP, the nucleus of Alexander cells integrated with HBV gene reacted with the HBV primers emits obvious fluorescence. The fluorescence values which were measured with an imaging analyzer show a significant difference between Alexander cells as compared to the controls. In conclusion, the target sequences of HBV were specifically amplified as fluorescent DNA after the present FISPCR procedure. This method could provide a novel and simple strategy for determining the quantitative role of viral DNA integration in oncogenesis.

HBV genome integration and genetic instability in HBsAg-negative and anti-HCV-positive hepatocellular carcinoma in Japan.

The aim of this study is to clarify the existence and the form of HCV RNA and HBV DNA genome integration and genetic instability in liver tissue with HBsAg-negative and anti-HCV-positive HCC. We investigated 16 Japanese patients with HBsAg-negative and anti-HCV-positive HCC. HBV genome integration into host cell genome by Southern hybridization and PCR was examined. Moreover, we analyzed loss of heterozygosity (LOH) and replication errors (RER) of chromosomes 2p, 3p and 17p using the PCR and an autosequencer to determine the three microsatellite regions D2S123, D3S1067, TP53. Eight (50.0%) of 16 were found to have integrated genome of HBV in tumor tissue (T) by PCR. In even the non-tumor regions (NT), seven patients (43.8%) were found to have HBV genome integration. The coincidence between T and NT was found in 4 (25%). Integration of HBV-X gene in T was revealed in three (18.7%), and HBV-integration was confirmed in all NT. No integration of the X gene alone was found in the liver tissue. Five (37.5%) of eight HBV DNA integrated cases simultaneously had HCV RNA minus strand. Concerning the genetic instability, RER were detected in two of 16 (12.5%). RER at 2p; D2S123 was observed in one of 16 (6.2%) and at 3p; D3S1067 was observed in one (6.2%). LOH at the D2S123 locus was observed in one of 12 tumors with heterozygosity (8.3%). There was no genetic instability (LOH or RER) of TP53 which was p53 locus on 17p in T. There was only one case of eight HBV DNA integrated cases (6.2%) with genetic instability of RER of 3p simultaneously in T. In conclusion, the majority of HBsAg-negative and anti-HCV-positive HCC liver tissue was found to have HCV-RNA and HBV DNA integration, and in some samples, HBV DNA integration and genetic instability were concurrently confirmed. It is speculated that multistep carcinogenesis may have been proposed for HCC oncogenetic progression.

Visceral leishmaniasis misdiagnosed as malignant lymphoma.

Visceral leishmaniasis is a chronic infectious disease caused by a protozoan parasite of the genus Leishmania, characterized by intermittent fever, monocytosis, hepatosplenomegaly and hypergammaglobulinemia. This morbid condition is rather difficult to diagnose correctly, especially at its early stage, because it is rarely encountered in Japan. Recently we treated a case of visceral leishmaniasis in which the patient was misdiagnosed as malignant lymphoma, and went through splenectomy and steroid administration, which made the diagnosis more difficult.

[Single and 4-week oral toxicity studies of prulifloxacin (NM441) in aged dogs].

Single-dose and repeated dose toxicity studies of prulifloxacin, a new antibacterial agent, were conducted in aged beagle dogs. I. A single-dose toxicity study Prulifloxacin was administered orally to aged female dogs at a single dose of 2500 and 5000 mg/kg. No death occurred in any group. Vomiting was observed in one of two animals at 2500 mg/kg and in both animals at 5000 mg/kg 3-4 hr after dosing. At 5000 mg/kg, vomiting was observed in both animals after feeding on the day after dosing. One animal also showed soft stool. Thereafter, no abnormalities were observed in any animal. No test article related changes were noted in food consumption, water consumption, body weight or pathological examination in any group. The results show that the lethal dose of prulifloxacin is judged to be greater than 5000 mg/kg in aged female dogs. II. A repeated dose toxicity study Aged male and female dogs were given the test article orally for 4 weeks at doses of 0 (control), 20, 100 and 500 mg/kg. No death occurred in any group. At 500 mg/kg, vomiting was observed every day or intermittently throughout the dosing period and salivation was observed almost every day from day 6 to the end of the dosing onward. Decreases or lack of food and water consumption, and decrease of body weight were noted at 500 mg/kg. At 100 mg/kg, slight decreases in food consumption and body weight were noted in the females. No abnormalities were noted in ophthalmoscopic or electrocardio-graphic examination. In urinalysis, decreases in Na+, K+ and Cl- concentrations and the total excretion amount were noted mostly at 500 mg/kg. A low specific gravity was noted in males at 500 mg/kg. In hematology and serum biochemistry, high GPT, BUN and creatinine, and decreases in WBC were noted in both sexes at 500 mg/kg. A high GOT was noted in males, and low Cl- in females at 500 mg/kg. At 100 mg/kg, a high GPT was noted. Rough surface in the kidney and chronic interstitial nephritis (basophilic change of tubule, atrophy of tubule, thickening of tubular basement membrane, interstitial mononuclear cell infiltration, interstitial focal fibrosis) were increased at 500 mg/kg. No toxicological findings were seen in the 20 mg/kg group. The results show that the NOAEL of prulifloxacin is 20 mg/kg for 4-week repeated dose toxicity in aged dogs.

[A photoallergenicity study of prulifloxacin (NM441) in guinea pigs].

Photoallergenicity of prulifloxacin, a new antibacterial agent, was examined using guinea pigs compared with those of the other quinolone antibacterial drugs, ofloxacin (OFLX), lomefloxacin (LFLX), ciprofloxacin (CPFX), enoxacin (ENX) and nalidixic acid (NA). Prulifloxacin and other drugs were orally administered at minimal phototoxic doses 1 hr before UVA (18 J/cm2) irradiation. This photosensitization procedure was daily repeated for 5 days. On 16 days after the final sensitization, the animals were challenged with UVA (18 J/cm2) after the administration of correspondent substances at maximal non-phototoxic doses. Photoallergic reactions were induced by OFLX (40 mg/kg), LFLX (3 mg/kg), CPFX (170 mg/kg) and ENX (80 mg/kg), but were not observed in prulifloxacin (170 mg/kg) and NA (30 mg/kg). These results show that photoallergenicity of prulifloxacin were less severe than those of the other quinolone antibacterial drugs under the conditions of this study.

[Diagnosis of hepatocellular carcinoma using chicken anti-monoclonal antibody--as tumor marker on the heterophilic hanganutziu-deicher antigen].

The Hanganutziu-Deicher (HD) antigen is a heterophilic antigen with N-glycolylneuraminic acid as the terminal carbohydrate, and has attracted much attention as one of tumor-associated antigens. This antigen is absent from normal tissues of human and chicken but expressed in human neoplasms. Extensive research on HD antigen has not be made yet to show the intimate correlation with human neoplasm, but it is attracting an attention as a diagnostic marker for the definition of cancer. We made two different chicken monoclonal antibodies against HD antigen as a pathological tool for hepatocellular carcinoma (HCC). The hybrid cell, which produced antibodies, were prepared by means of fusion technology with HD3 antigen-immunized chicken spleen cells and HAT-sensitive chicken B cell line termed R27H4. The two antibodies had a different characteristic, one recognized only glycolipid, and the other recognized glycoprotein as well as glycolipid. Glycolipid type HD antigen and glycoprotein type HD antigen were identified by using two chicken anti-HD monoclonal antibodies. Glycolipid type HD antigen was detected by flow cytometry in 4 out of 24 HCC samples (87.5%). In our study, increased serum levels of IgG type and/or IgM type HD antibodies were observed in 21 out of 24 patients with HCC (87.5%). The presence of these antibodies is attributable to the expression of the HD antigen in cells of HCC. Eleven out of 24 patients with HCC were negative for AFP and PIVKA-II, and 10 out of these 11 patients (90.9%) were positive for anti-HD antibodies. We consider that patients with HCC should be screened for HD antigen and antibody for an early diagnosis of hepatocellular carcinoma; the same as for AFP and PIVKA-II both of which are tumor-associated antigens that have been associated with for hepatocellular carcinoma.

[A study on nephrotoxicity of arbekacin and vancomycin in rats].

Nephrotoxicities of arbekacin (ABK) and/or vancomycin (VCM) were examined by administrating rats intravenously with single doses or 10 times repeated daily doses. ABK was found less toxic to kidney than VCM, and the toxicity was strengthened by combined treatment with VCM and ABK. Fosfomycin decreased the nephrotoxicity when added to the single or combined treatment with ABK and VCM.

Detection of N-glycolylneuraminic acid-containing glycoproteins from various animal erythrocytes by chicken monoclonal antibody against Hanganutziu-Deicher antigens.

Two chicken monoclonal antibodies (MAbs), HU/Ch2-7 and HU/Ch6-1, detecting Hanganutziu-Deicher (HD) antigens with N-glycolylneuraminic acid (NeuGc) at a terminal carbohydrate were reactive with bovine, sheep and horse erythrocytes examined by flowcytometry (FCM). The FCM profiles of the three animal erythrocytes treated with trypsin were different from those of non-treated cells and from each other depending on MAbs used. To identify the nature of antigenic molecules, recognized by HU/Ch2-7 and HU/Ch6-1 MAbs, solubilized erythrocytes from the above three animals were analyzed by a Western blotting method. The MAb HU/Ch2-7 identified HD antigen-specific glycoprotein in each of animal erythrocytes. These results indicate that the MAb HU/Ch2-7 is a valuable reagent for the detection of NeuGc-containing gangliosides and glycoproteins.

[Structural and function of the human macrophage scavenger receptor].

Macrophage scavenger receptors (MSR) mediate the binding, internalization and processing of the wide range of negatively charged macromolecules. Functional receptors are trimers of two C-terminally different subunit containing 6 functional domains; cytoplasmic, transmembrane, spacer, alpha-helical coiled-coil, collagen-like, type specific domain. The C-terminal region of the collagen-like domain is essential for the ligand recognition of MSR. Human MSR gene consists of 11 exons, and two types of mRNAs are generated by alternative splicing from exon 8 to either exon 9 (type II) or to exons 10 and 11 (type I). Exon 1 encodes the 5' untranslated resion followed by a 12 kb intron which separates the transcription initiation site and the translation initiation site. Exon 2 encodes a cytoplasmic domain; Exon 3, a transmembrane domain; Exons 4 and 5, an alpha-helical coiled-coil; and exon 6 to 8, a collagen-like domain. The MSR gene consists of a mosaic of exons which encode the functional domains. The arrangement of exons helped determine the fine structural characteristics of functional domains.

[Structure and function of the scavenger receptor].

The macrophage scavenger receptors are consisted of six domains: cytoplasmic, membrane-spanning, spacer, alpha-helical coiled-coil, collagen-like and a type-specific C-terminal. The collagen-like domain is revealed to have important role for ligand binding. The receptor gene is located on human chromosome 8. The human scavenger gene spans approximately 80 kb and is composed of 11 exons. Two types of scavenger receptor mRNA were shown to result from alternative splicing of exon 9 for type II or 10 and 11 for type I to the common exon 1-8. The scavenger receptor proteins were detected in macrophages of various organs and tissues such as Kupffer cells, alveolar macrophages, macrophages in the spleen and lymph nodes and perivascular macrophages in the brain. In the atheromatous plaques, scavenger receptors may participate progression of foam cells. Elimination and detoxication of endotoxin by macrophage scavenger receptor may suggest the defending function against a wide variety of pathogenic agents.

Structure, organization, and chromosomal mapping of the human macrophage scavenger receptor gene.

Macrophage scavenger receptors (MSR) mediate the binding, internalization, and processing of a wide range of negatively charged macromolecules. Functional MSR are trimers of two C-terminally different subunits that contain six functional domains. We have cloned an 80-kilobase human MSR gene and localized it to band p22 on chromosome 8 by fluorescent in situ hybridization and by genetic linkage using three common restriction fragment length polymorphisms. The human MSR gene consists of 11 exons, and two types of mRNAs are generated by alternative splicing from exon 8 to either exon 9 (type II) or to exons 10 and 11 (type I). The promoter has a 23-base pair inverted repeat with homology to the T cell element. Exon 1 encodes the 5'-untranslated region followed by a 12-kilobase intron which separates the transcription initiation and the translation initiation sites. Exon 2 encodes a cytoplasmic domain, exon 3, a transmembrane domain, exons 4 and 5, an alpha-helical coiled-coil, and exons 6-8, a collagen-like domain. The position of the gap in the coiled coil structure corresponds to the junction of exons 4 and 5. These results show that the human MSR gene consists of a mosaic of exons that encodes the functional domains. Furthermore, the specific arrangement of exons played a role in determining the structural characteristics of functional domains.

Two chicken monoclonal antibodies specific for heterophil Hanganutziu-Deicher antigens.

Two chicken monoclonal antibodies (MAbs), HU/Ch2-7 and HU/Ch6-1, against heterophil Hanganutziu-Deicher (HD) antigens with N-glycolylneuraminic acid (NeuGc) at a terminal carbohydrate were established by cell fusions using chicken B cell lines lacking thymidine kinase and spleen cells from chickens immunized with II3NeuGc alpha-LacCer (HD3). The reactivities of these MAbs against several gangliosides including NeuGc-containing glycosphingolipids were examined by a thin-layer chromatography/immunostaining method. MAb HU/Ch2-7 (IgG) reacted strongly with HD3 and IV3NeuGc alpha-nLc4Cer (HD5) and weakly with VI3NeuGc alpha-nLc6Cer (HD7) and 4-O-acetyl-HD3. HU/Ch6-1 (IgG) reacted with HD3 and HD5, but did not react with the other HD antigens. The reactivities of these MAbs against HD antigen were greatly reduced by pre-treatment of the antigen with neuraminidase. These MAbs did not react with N-acetylneuraminic acid-containing gangliosides (GM1 and GM3). These results indicate that these two chicken MAbs are directed toward the antigenic epitope containing the NeuGc.