Apoprotein composition of very low density lipoproteins of human serum

Methods for quantitation of the major apoproteins of human serum very low density lipoprotein have been developed employing tetramethylurea, which delipidates the lipoprotein and selectively precipitates apolipoprotein B. Six soluble apoproteins are separated by electrophoresis in polyacrylamide gel. One of these is a previously unrecognized species of R-alanine (R4-alanine), more anionic than the R3-alanine polypeptide. Conditions of staining have been found which yield reproducibly linear chromogenic response with native lipoprotein and with each purified apoprotein. Recovery of protein in the seven species measured accounts for over 97% of the total in the very low density lipoprotein of normolipidemic individuals and in most samples from individuals with endogenous hyperlipemia. The mean content of apolipoprotein B in 43 samples from normolipidemic subjects was 36.9(+/-1.2 SEM)% of total protein, The distribution of the major soluble apoproteins as mean (+/-SEM) percentage of the soluble fraction was : R-serine, 5.3+/-o.5; arginine-rich, 20.6+/-1.0; R-glutamic, 10.6+/-0.4; R2-alanine, 28.3+/-0.7; R3-alanine, 26.9+/-0.5; and R4-alanine, 8.0+/-0.5. Distribution of the apoproteins was a function of particle diameter of very low density lipoprotein in fractions separated by gel permeation chromatography and by density gradient ultracentrifugation. In fractions below 700-800 A, apolipoprotein B comprised an increasing percentage of the total protein with decreasing particle diameter. Among the soluble proteins the percentage of the arginine-rich and R-serine polypeptides increased and that of the R-glutamic polypeptide declined progressively with decreasing particle size. Apoprotein distribution was similar in fractions of similar particle size from normolipidemic and hyperlipemic subjects with the exception that all fractions from the hyperlipemic subjects contained more R-serine and some, more arginine rich polypeptide. Even in the absence of chylomicrons, the distribution of soluble apoproteins in particles of diameters greater than 700-800 A was usually similar to that of the smallest particles. This suggests that the largest particles may include products of the partial catabolism of chylomicrons.

Expression and localization of human herpesvirus 8-encoded proteins in primary effusion lymphoma, Kaposi's sarcoma, and multicentric Castleman's disease

To investigate the expression of human herpesvirus 8 (HHV8)-encoded proteins in the cells of primary effusion lymphoma (PEL), Kaposi's sarcoma (KS) and multicentric Castleman's disease (MCD), nine rabbit polyclonal antibodies to K2, ORF26, K8, K8.1, K10, K11, ORF59, ORF65, and ORF73 were developed. Western blot analysis in PEL cell lines (TY-1 and BCBL-1) revealed that the expression of these proteins, except ORF73 (LANA), was induced by tetradecanoylphorbol acetate (TPA) treatment, indicating that these proteins are lytic proteins. Immunofluorescence assay in primary PEL cells derived from pericardial effusion and PEL cell lines with and without TPA treatment revealed that primary PEL cells exhibited the same expression pattern as noninduced PEL cell lines, and the treatment changed localization of K8, ORF59, and ORF65 proteins. Immunohistochemistry revealed that 90% of KS spindle cells expressed the ORF73 protein, whereas a small population of KS cells expressed K8, K10, K11, ORF59, and ORF65 proteins. In MCD, ORF73, ORF59, K8, K2, and K10 proteins were expressed in the cells at mantle zone of the follicle. These data indicate that KS and PEL cells expressed predominantly latent proteins, whereas MCD expressed both latent and lytic proteins, suggesting that HHV8 plays a different role in the pathogenesis of HHV8-associated diseases.

Cholestasis: lamellar structure of the abnormal human serum lipoprotein

An abnormal lipoprotein was visualized directly in serum by electron microscopy of preparations negatively stained with potassium phosphotungstate. It appears as a unique disk-shaped particle with major axis measuring 400 to 600 angstroms and minor axis measuring about 100 angstroms. Chemical analysis, viscosity measurements, and x-ray diffraction analysis of purified preparations indicate that the particle, consisting of a one-to-one molar mixture of cholesterol and choline phosphatides associated with a small amount of protein, is a flattened vesicle, the wall of which is a continuous lipid bilayer.

Metabolism of apoprotein B of plasma very low density lipoproteins in the rat

As an extension of metabolic studies of the cholesteryl ester component of rat very low density lipoproteins, we have studied the metabolism of the B apoprotein component labeled by intravenous injection of [3H]lysine. The B apoprotein separated from other apoproteins by delipidation and selective precipitation with tetramethylurea could not be distinguished from B apoprotein prepared by the conventional gel filtration technique. After injection of [3H]lysine, specific activity of B apoprotein was maximal in very low density and low density lipoproteins 1 and 11/2-h later, respectively, in a manner consistent with a precursor-product relationship. When protein-labeled very low density lipoproteins were injected into rats, the relationships of specific activity again indicated that B apoprotein of very low density lipoproteins may be the sole precursor of that of low density lipoproteins. However, less than 10% of the B apoprotein that disappeared from very low density lipoproteins appeared in density lipoproteins. To evaluate the sites of removal of B aproprotein of very low density lipoproteins from plasma, protein-labeled very low density lipoproteins were incubated with unlabeled high density lipoproteins to reduce radioactivity in non-B apoproteins selectively by molecular exchange. Most of the B apoprotein was rapidly removed by the liver. The extensive hepatic uptake of both the cholesteryl ester and B apoprotein components of rat very low density lipoproteins may explain the characteristically low concentrations of plasma low density lipoproteins in the rat.

Isolation of Borna disease virus from human brain tissue

Serological and molecular epidemiological studies indicate that Borna disease virus (BDV) can infect humans and is possibly associated with certain neuropsychiatric disorders. We examined brain tissue collected at autopsy from four schizophrenic patients and two healthy controls for the presence of BDV markers in 12 different brain regions. BDV RNA and antigen was detected in four brain regions of a BDV-seropositive schizophrenic patient (P2) with a very recent (2 years) onset of disease. BDV markers exhibited a regionally localized distribution. BDV RNA was found in newborn Mongolian gerbils intracranially inoculated with homogenates from BDV-positive brain regions of P2. Human oligodendroglia (OL) cells inoculated with brain homogenates from BDV-positive gerbils allowed propagation and isolation of BDVHuP2br, a human brain-derived BDV. Virus isolation was also possible by transfection of Vero cells with ribonucleoprotein complexes prepared from BDV-positive human and gerbil brain tissues. BDVHuP2br was genetically closely related to but distinct from previously reported human- and animal-derived BDV sequences.

The effects of tramadol and its metabolite on glycine, gamma-aminobutyric acidA, and N-methyl-D-aspartate receptors expressed in Xenopus oocytes

We assessed the effects of tramadol, a centrally acting analgesic, and its major metabolite, on neurotransmitter-gated ion channels. Tramadol binds to mu-opioid receptors with low affinity and inhibits reuptake of monoamines in the central nervous system. These actions are believed to primarily contribute to its antinociceptive effects. However, little is known about other sites of tramadol's action. We tested the effects of tramadol and its M1 metabolite (0.1-100 microM) on human recombinant neurotransmitter-gated ion channels, including glycine, gamma-aminobutyric acid(A) (GABA(A)), and N-methyl-D-aspartate (NMDA) receptors, expressed in Xenopus oocytes. Tramadol and M1 metabolite did not have any effects on glycine receptors. GABA(A) receptors were significantly inhibited only at large concentrations (100 microM). NMDA receptors were inhibited in a concentration-dependent manner. Tramadol and M1 metabolite inhibited the glutamate-concentration response curve without changing the half-maximal effective concentration or the Hill coefficient, indicating a noncompetitive inhibition. This study suggests that glycine receptors do not provide the antinociceptive effect of tramadol and that the inhibition of GABA(A) receptors at large concentration might correlate with convulsions. The inhibitory effect on NMDA receptors may contribute to the antinociceptive effect of tramadol at relatively large concentrations.

HHV-8 infection status of AIDS-unrelated and AIDS-associated multicentric Castleman's disease

Multicentric Castleman's disease (MCD) is a clinicopathologically defined entity characterized by systemic lymphadenopathy with unique pathomorphology such as angiosclerosis, blood vessel proliferation in and around follicles, and plasmacytosis. While its pathogenesis has remained unclarified for many years, identification of the human herpesvirus 8 (HHV-8) in at least some MCD cases has opened new perspectives in this field. Because previous reports have described many inconsistencies regarding HHV-8 positivity in MCD, we intended to clarify this issue by the introduction of more convincing methodologies. For this investigation, we introduced two antibodies produced in our laboratories that recognize a latent gene product ORF73 and a lytic gene product ORF59, together with two well-recognized methods, in situ hybridization for the detection of lytic phase transcript T1.1/nut-1, and genomic polymerase chain reaction (PCR). Eighty-two cases of MCD were collected from Japan (n = 75) and France (n = 7). In three cases, the patients were suffering from acquired immunodeficiency syndrome (AIDS). Immunohistochemistry and in situ hybridization showed identical results: only three out of 82 cases were positively stained, and all the positive cases were found to be the patients with AIDS. Genomic PCR was done in 43 cases, and only one case produced positive results: the only AIDS case among the 43 cases studied by genomic PCR. Histopathologically, the HHV-8-positive cases showed the highest intensity of angiosclerosis and germinal center / perifollicular vascular proliferation, while plasmacytosis was not severe in the HHV-8-positive cases. Some of the HHV-8-negative MCD cases displayed similar histopathology, but at a far less intense level, except for the plasmacytosis. These results suggest that: (i) all three of the HHV-8-positive MCD patients in the present group are the patients with AIDS; and (ii) HHV-8-positive MCD patients develop typical but marked angiosclerosis and vascular proliferation that might be differentiated from HHV-8-negative MCD patients, who showed far less intense changes.

High expression of HHV-8-encoded ORF73 protein in spindle-shaped cells of Kaposi's sarcoma

Human herpesvirus 8 (HHV-8) has been demonstrated previously in Kaposi's sarcoma (KS) tissues by immunohistochemistry, in situ polymerase chain reaction, and in situ hybridization. The HHV-8-encoded protein ORF73 is a 222- or 234-kd protein named latent nuclear antigen (LNA) or latency-associated nuclear antigen (LANA) that is identified in HHV-8-infected cell lines by immunofluorescence assay. In the present study, a rabbit antibody against a recombinant ORF73 protein was developed. Immunofluorescent staining of a HHV-8-infected cell line, TY-1, showed that the staining pattern of the anti-ORF73 antibody overlapped completely the LANA staining pattern obtained using KS patients' sera. Immunoblotting analysis showed that the anti-ORF73 antibody reacted specifically with 222- and 234-kd proteins that were present in TY-1 and BCBL-1 cell lysates. Immunohistochemistry using a catalyzed signal amplification system demonstrated that the anti-ORF73 antibody reacted exclusively with the majority of KS spindle-shaped cells, showing a nuclear dot-like staining pattern. Some of the ORF73 protein-positive cells also expressed CD34 and vimentin but not CD68 or factor-VIII-related antigen. These data indicate that the anti-ORF73 antibody recognizes LANA and that most KS cells are infected with HHV-8 in the latent phase. Our findings also suggest that ORF73 protein plays an important role in the pathogenesis of KS.

Microtubule network facilitates nuclear targeting of human cytomegalovirus capsid

We assessed the requirement of the host cytoskeleton for the intracytosolic transport of incoming human cytomegalovirus (HCMV) capsids. Treatments with microtubule (MT)-depolymerizing drugs nocodazole and colchicine led to a drastic decrease in levels of IE1 antigen, whereas cytochalasin B had no effect on the level of IE1 as determined by Western blot analyses. Sequential treatment including nocodazole washout and removal of cell surface virion revealed that HCMV entry into the cells occurred normally in the absence of the MT network. This finding was also supported by data obtained by monitoring pUL83 signals with an immunofluorescent assay (IFA). Furthermore, we demonstrated a close association of incoming HCMV capsids with MTs by IFA and ultrastructural analyses. In the absence of the MT network, the capsids which had entered the cytoplasm did not move to close proximity of the nucleus. These data suggest that HCMV capsids associate with the MT network to facilitate their own movement to the nucleus before the onset of immediate-early (IE) gene expression and that this association is required to start efficient IE gene expression.

Mechanism of NKT cell activation by intranasal coadministration of alpha-galactosylceramide, which can induce cross-protection against influenza viruses

In a nasal vaccine against influenza, the activation of natural killer T (NKT) cells by intranasal coadministration of alpha-galactosylceramide (alpha-GalCer) can potently enhance protective immune responses. The results of this study show that the NKT cell-activated nasal vaccine can induce an effective cross-protection against different strains of influenza virus, including H5 type. To analyze the mechanism of NKT cell activation by this nasal vaccine, we prepared fluorescence-labeled alpha-GalCer by which we detect a direct interaction between NKT cells and alpha-GalCer-stored dendritic cells in nasal mucosa-associated tissues. Accordingly, although very few NKT cells exist at mucosa, the nasal vaccination induced a localized increase in NKT cell population, which is partly dependent on CXCL16/CXCR6. Furthermore, we found that NKT cell activation stimulates mucosal IgA production by a mechanism that is dependent on interleukin (IL)-4 production. These results strengthen the basis of nasal vaccination via NKT cell activation, which can induce immune cross-protection.

Induction of protective immunity in animals vaccinated with recombinant vaccinia viruses that express PreM and E glycoproteins of Japanese encephalitis virus

A cDNA clone representing the genome of structural proteins of Japanese encephalitis virus (JEV) was inserted into the thymidine kinase gene of vaccinia virus strains LC16mO and WR under the control of a strong early-late promoter for the vaccinia virus 7.5-kilodalton polypeptide. Indirect immunofluorescence and fluorescence-activated flow cytometric analysis revealed that the recombinant vaccinia viruses expressed JEV E protein on the membrane surface, as well as in the cytoplasm, of recombinant-infected cells. In addition, the E protein expressed from the JEV recombinants reacted to nine different characteristic monoclonal antibodies, some of which have hemagglutination-inhibiting and JEV-neutralizing activities. Radioimmunoprecipitation analysis demonstrated that two major proteins expressed in recombinant-infected cells were processed and glycosylated as the authentic PreM and E glycoproteins of JEV. Inoculation of rabbits with the infectious recombinant vaccinia virus resulted in rapid production of antiserum specific for the PreM and E glycoproteins of JEV. This antiserum had both hemagglutination-inhibiting and virus-neutralizing activities against JEV. Furthermore, mice vaccinated with the recombinant also produced JEV-neutralizing antibodies and were resistant to challenge with JEV.

Human herpesvirus 8-associated solid lymphomas that occur in AIDS patients take anaplastic large cell morphology

Human herpesvirus type 8 (HHV-8; Kaposi's sarcoma-associated herpesvirus) is a recently isolated human herpesvirus frequently identified in Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman's disease. Here we report three cases of HHV-8-bearing solid lymphomas that occurred in AIDS patients (Cases 1-3). All three patients were homosexual men presenting extranodal masses in the lungs (Case 1) or skin (Cases 2 and 3), together with the presence of Kaposi's sarcoma (Case 1), primary effusion lymphoma (Case 2), or multicentric Castleman's disease (Case 3). These solid lymphomas exhibited anaplastic large cell morphology and expressed CD30, corresponding to the recent diagnostic criteria of anaplastic large cell lymphoma (ALCL). The chromosomal translocation t(2;5)-associated chimeric protein p80NPM/ALK was not observed in any of these cases. HHV-8 was detected in all of these cases by polymerase chain reaction, immunohistochemistry of HHV-8-encoded ORF73 protein, and in situ hybridization of T1.1. Epstein-Barr virus was detected only in Cases 2 and 3 by in situ hybridization. It is interesting that inoculation of a cell line obtained from a primary effusion lymphoma cell in Case 2 to severe combined immunodeficiency mice produced HHV-8-positive and Epstein-Barr virus-negative tumors in inoculated sites. These tumor cells exhibited phenotypes of ALCL that were identical to the subcutaneous tumor cells of this particular patient. These findings clearly show that HHV-8 can associate with solid lymphomas and that it can take anaplastic large cell morphology. Those lymphomas should be distinguished from the classical ALCL as were defined by the revised European-American classification of lymphoid neoplasms even though morphology and a part of immunophenotype mimic that of classical ALCL.

High prevalence of human papillomaviruses in the normal oral cavity of adults

Human papillomavirus (HPV) infection in the normal oral cavity was studied by the sensitive polymerase chain reaction (PCR) using primers for the L1 region of human papillomavirus DNA and high fidelity amplification system. Cells were scraped from the oral mucosae of 7 (mean age; 42 years) and 30 (mean age; 32 years) volunteers with and without skin warts, respectively. Human papillomavirus DNA was detected in 30/37 (81.1%) specimens and their copy numbers per cell were 10(-1) to 10(-4) (mean, 10(-3)). The human papillomavirus types determined by PCR-based sequencing analysis were HPV-18 (26/30; 86.7%), -61 (18/30; 60%), -59 (7/30; 23.3%), -16 (2/30; 6.7%), -6 (1/30; 3.3%) and an unknown type (HPV-X71) (1/30; 3.3%). Multiple human papillomavirus types were present in 17/30 (56.7%) specimens. HPV-6 was detected in 2 of 7 skin warts and differed from the human papillomavirus types of the corresponding oral specimens. These data suggest that human papillomavirus infection in the oral mucosa occurs much more frequently than previously considered.

Identification of antigenic proteins encoded by human herpesvirus 8 and seroprevalence in the general population and among patients with and without Kaposi's sarcoma

To establish a sensitive and specific antibody assay, potent antigenic proteins encoded by human herpesvirus 8 (HHV8) were studied. Fifteen recombinant HHV8-encoded proteins were produced as glutathione S-transferase fusion proteins. The sera from AIDS-associated Kaposi's sarcoma (KS) patients reacted with four proteins encoded by open reading frames (ORFs) K8.1, 59, 65, and 73 in a Western blot assay. An enzyme-linked immunosorbent assay (ELISA) using these four proteins as antigens (mixed-antigen ELISA) revealed that all 26 sera derived from KS patients (24 with and 2 without human immunodeficiency virus infection) became positive for anti-HHV8 antibodies. The presence of HHV8 was demonstrated in 14 (1. 4%) of 1,004 sera from the Japanese general population and 10 (1.9%) of 527 sera from patients without HHV8-associated diseases. The presence of immunoglobulin G (IgG) and IgM antibodies against HHV8 examined further by the mixed-antigen ELISA and Western blotting revealed IgG antibody in all ELISA-positive sera, while IgM antibody against ORF K8.1 was absent. These data suggest that the ORF 73 and 65 proteins are potent antigens for a sensitive serological assay.

Oncolytic viral therapy using a spontaneously generated herpes simplex virus type 1 variant for disseminated peritoneal tumor in immunocompetent mice

The present study demonstrates that a clonal derivative (HF10) of HSV-1 strain HF effectively treated disseminated peritoneal neoplasm in an immunocompetent animal model and that all of survived mice acquired resistance to rechallenge with tumor cells. The survival time of mice treated with HF10 was longer than that of mice treated with hrR3, indicating that the oncolytic effect of HF10 was more potent than that of hrR3 in this animal model. HF10 induces syncytia formation in vitro, whereas hrR3 forms rounded CPE. The sequential administration of HF10 gave a long term survival of more than 90 days after tumor injection, with no signs of disease, in 8 of the 9 treated mice. The results suggest that treatment of disseminated peritoneal tumor with HF10 induces a specific antitumor immune response. Genomic structure determination showed that HF10 has a deletion of 3.9-kilobase pair (kbp) in the right end of UL and UL/IRL junction, resulting in the loss of UL 56 expression. A 2.3 kbp deletion and extensive rearrangement were also observed in the left end of the genome.

Expression of p53 and human herpesvirus-8 (HHV-8)-encoded latency-associated nuclear antigen with inhibition of apoptosis in HHV-8-associated malignancies

BACKGROUND

Kaposi sarcoma (KS) and primary effusion lymphoma (PEL) cells express human herpesvirus-8 (HHV-8)-encoded latency-associated nuclear antigen (LANA) (open reading frame [ORF] 73 protein), suggesting that LANA plays an important role in the pathogenesis of HHV-8-associated malignancies. Recently, the binding of LANA to p53 was demonstrated in vitro. In the current study, the authors investigated the association between p53 and LANA expression with apoptosis in HHV-8-associated malignancies in vivo.

METHODS

Twenty-six cases of KS, 1 case of HHV-8-associated solid lymphoma, 2 PEL cell lines, and an HHV-8-associated lymphoma engrafted in severe combined immunodeficiency (SCID) mice were examined. Immunohistochemistry using the catalyzed signal amplification system was employed to detect LANA and p53 on paraffin embedded tissues and the immunofluorescence technique was used on cell lines. To detect apoptosis, the TdT-mediated dUTP nick end labeling (TUNEL) method was used. For mutation analysis of p53, exons 5-9 of the p53 gene were amplified by polymerase chain reaction and examined by direct sequencing.

RESULTS

Immunohistochemistry revealed that LANA and p53 were expressed in the tumor cells of all these specimens, and apoptotic cells were rarely detected in them using the TUNEL method. Immunofluorescence assay revealed that LANA colocalized with p53 in the nuclei of PEL cells. Sequencing analysis indicated that there was no mutation in the deduced amino acid sequences of p53 in KS tissues.

CONCLUSIONS

These data suggest colocalization of p53 and LANA and the inhibition of apoptosis in HHV-8-associated malignancies in vivo, supporting the results found in vitro that p53 inhibition by LANA suppresses cell death, as reported previously. These results also suggest that the p53 pathway is crucial in the pathogenesis of HHV-8-associated malignancies.

Role of the gag and pol genes of human immunodeficiency virus in the morphogenesis and maturation of retrovirus-like particles expressed by recombinant vaccinia virus: an ultrastructural study

An ultrastructural study was performed on rabbit epithelial RK-13 cells and CD4+ human T lymphocyte lines infected with various recombinant vaccinia viruses (RVVs) expressing genes of human immunodeficiency virus (HIV): the mature p17 or p24 gag domain alone, the entire or truncated gag gene, the reverse transcriptase domain, or the gag-pol genes with a frameshift mutation. Cells infected with RVVs that produced the gag polyprotein with a predicted Mr of more than 48K showed budding and release of HIV-like particles into the extracellular space. These particles were not observed in cells expressing a truncated gag gene (p17 and p24 regions). Mature HIV-like particles were observed extracellularly when the entire gag gene and the protease region of the pol gene were expressed. In contrast, in cells infected with RVVs that contained the gag-pol gene with a frameshift mutation, neither recognizable budding structures nor extracellular HIV-like particles could be detected. These results suggest that the gag gene, particularly its 3' terminus, is necessary for the assembly of HIV particles. In addition, the protease region of the pol gene seems to be required for morphological maturation of HIV particles, but complete proteolytic cleavage of the gag protein may prevent bud formation.

The presence of mucosal human papillomavirus in Bowen's disease of the hands

BACKGROUND

Bowen's disease (BD) of the genital skin region is generally associated with human papillomavirus (HPV) infection. Various molecular analyses have identified mainly HPV-16 in the lesions. However, the HPV genotypes associated with BD of the hands have not yet been characterized.

METHODS

The skin specimens of 12 patients with BD of the hands were investigated clinicopathologically and immunohistochemically, and the total DNAs extracted from the skin were analyzed for the presence of HPV DNA using Southern blot hybridization and polymerase chain reaction (PCR) in combination with restriction fragment length polymorphisms (RFLP) and direct sequencing analysis of the amplified products. In addition, the histologic localization of HPV DNA was examined by in situ hybridization in paraffin embedded sections of HPV positive patients.

RESULTS

In 8 of 12 BD lesions (66.7%), HPV types (HPV-16, -31, -54, -58, -61, -62, and -73) were detected by Southern blot hybridization and/or PCR with RFLP and direct sequencing analysis. In 6 of 7 HPV positive lesions examined (85.7%), the viral genomes were identified by in situ hybridization in the nuclei of keratinocytes in the upper stratum malpighii and/or stratum corneum.

CONCLUSIONS

These results demonstrate that BD of the hands is frequently associated with HPV infection. The seven HPV genotypes are known as mucosal (genital) HPVs and to the authors' knowledge, this is the first time HPV-31, -54, -58, -61, -62, and -73 have been identified in BD lesions. These findings strongly suggest that HPVs related to mucosal lesions play an important role in the development of BD of the hands.

Classic type of Kaposi's sarcoma and human herpesvirus 8 infection in Xinjiang, China

We report 17 cases of the classic type of Kaposi's sarcoma in Xinjiang, which is located in the north-western area of China surrounded by Mongolia in the east, Russia in the north and Kazakhstan in the west. Fifteen of the patients were of the Uygur people. All patients were male and did not have acquired immunodeficiency syndrome. Most of the lesions were found in the lower and/or upper extremities, with 16 patients showing multiple lesions. Immunohistochemical examination of the lesions revealed that human herpesvirus 8 (HHV-8)-encoded latency-associated nuclear antigen was expressed in the nuclei of spindle-shaped tumor cells. HHV-8 DNA was detected by polymerase chain reaction in all seven cases examined. Phylogenetic tree analysis revealed that DNA sequences of the HHV-8-encoded K1 gene in the seven Kaposi's sarcoma cases were classified as subtype C that was common in the Mediterranean, the Middle East and East Asian countries. In addition, using immunofluorescence we investigated the seroprevalence of HHV-8 in 73 Uygur patients with diseases other than Kaposi's sarcoma. Surprisingly, the serological study revealed that 34 of the patients (46.6%) were positive for antibodies against HHV-8, suggesting that HHV-8 infection is widespread in Xinjiang area. The occurrence of the classic type of Kaposi's sarcoma with a high seropositivity rate implies that Xinjiang is the most endemic area for HHV-8 infection in the world known to date. Considering that Xinjiang is located at the middle point of the Silk Road that used to extend from Rome to China, these data imply that the virus may have been in circulation in this area due to the migration of the people via the Silk Road.

Lectin--digoxigenin conjugates: a new hapten system for glycoconjugate cytochemistry

We report the use of a novel hapten system for lectin cytochemistry. Various lectins conjugated to the steroid hapten digoxigenin (DIG) and monospecific anti-digoxigenin antibodies were applied for the light and electron microscopic detection of glycoconjugates in tissue sections. Both IgG and Fab' anti-DIG antibodies were complexed to particles of colloidal gold and compared to commercially available alkaline phosphatase and horseradish peroxidase conjugated Fab' as general second step reagents. The three different markers performed equally well on paraffin sections whereas the gold-labeled antibodies were superior reagents for semithin and ultrathin sections of Lowicryl K4M embedded tissues. In conjunction with the latter marker, no pretreatment to abolish endogenous enzyme activity was necessary. At the light microscope level, gold signal amplification by the photochemical silver reaction was required. DIG, in contrast to biotin, does not occur in animal tissues thus eliminating the need for blocking reactions prior to lectin incubation. Compared to affinity techniques using glycoprotein-gold complexes as second step reagent the DIG hapten system required smaller amounts of lectins. The staining patterns were indistinguishable from those obtained in other lectin-gold techniques and the specificity of the labeling could be demonstrated in sugar inhibition tests.

Cricoid pressure impedes positioning and ventilation through the laryngeal mask airway

PURPOSE

To assess the effect of cricoid pressure on the positioning of and ventilation through the laryngeal mask airway (LMA).

METHODS

In a double-blind, randomized design, the LMA was inserted with (CP[+] group, n = 20) or without double-handed cricoid pressure (CP[-] group, n = 20). Ventilation through the LMA was assessed by measuring expiratory tidal volume and judged as adequate when a mean expiratory tidal volume of > or = 10 ml.kg-1 could be obtained. The LMA position was examined by fibreoscopy. The position of the mask relative to the cricoid cartilage and the cervical spine was radiologically examined (n = 10 in each group).

RESULTS

Ventilation was adequate in all patients in the CP[-] group but in only five patients (25%) of the CP[+] group (P < 0.001). The glottis was visible fibreoptically below the mask aperture in all patients in the CP[-] group, but in only three patients in the CP[+] group (P < 0.001). Fibreoscopy showed that the mask was not inserted far enough in the remaining 17 patients of the CP[+] group. The reason for unsuccessful ventilation in the CP[+] group was excessive gas leakage (n = 2) and/or partial or complete airway obstruction (n = 13), which was noted fibreoptically. The radiographs showed that the tip of the mask in the CP[-] group was located below the level of the cricoid cartilage (C6 or C7 vertebra). The mask tip in the CP[+] group was above this level (C4 or C5 vertebra) (P < 0.01).

CONCLUSION

Cricoid pressure impedes positioning of and ventilation through the LMA.

Detection of the Neu5 Ac (alpha 2,3) Gal (beta 1,4) GlcNAc sequence with the leukoagglutinin from Maackia amurensis: light and electron microscopic demonstration of differential tissue expression of terminal sialic acid in alpha 2,3- and alpha 2,6-linkage

The Maackia amurensis leukoagglutinin has been shown to react specifically with the Neu5Ac (alpha 2,3) Gal sequence of asparagine-linked complex type oligosaccharides. We report here the preparation of Maackia amurensis lectin-gold complexes and their application for light and electron microscopic detection of the Neu5 Ac (alpha 2,3) Gal sequence in various tissues. The use of the lectin directly gold labeled was superior to a two-step cytochemical affinity technique using a fetuin-gold complex. The Maackia amurensis lectin-gold staining was inhibited by pre-incubation of the lectin-gold complexes with 50 mM alpha 2,3 sialyllactose, whereas alpha 2,6 sialyllactose up to concentrations of 1 M had no effect, thus demonstrating the high specificity of the histochemical staining. In addition to N-glycanase-sensitive asparagine-linked oligosaccharides, beta-elimination-sensitive serine/threonine-linked oligosaccharides could be detected. Data are presented which show that cellular staining patterns obtained with Maackia amurensis lectin-gold complexes may differ from those with elderberry bark lectin-gold, which detects the Neu5 Ac (alpha 2,6) Gal/GalN Ac sequence. Electron microscopic double labeling for direct study of the differential distribution of the Neu5 Ac (alpha 2,3) Gal and Neu5 Ac (alpha 2,6) Gal sequences is reported. Therefore, the availability of two sialic acid binding lectins with different linkage specificity for histochemistry provides the first opportunity to study tissue and cell type expression of these terminal sequences of glycoproteins.

Effects of epidural anaesthesia on surgical stress-induced immunosuppression during upper abdominal surgery

BACKGROUND

Previously, we have demonstrated that surgical stress rapidly induced transient hyporesponsiveness of blood cells to endotoxin and that monocyte mCD14 and HLA-DR expression decreased soon after the start of surgery under general anaesthesia. This study was designed to investigate the effects of epidural anaesthesia on surgical stress-induced immunosuppression in patients undergoing upper abdominal surgery.

METHODS

After having obtained informed consent, patients were randomly allocated to receive general anaesthesia (Group G) or general anaesthesia with epidural anaesthesia (Group E). Perioperative changes in neutrophil phagocytic activity, neutrophil respiratory burst activity, monocyte mCD14 and HLA-DR expression, plasma IL-10 concentration, and the LPS-induced TNF-alpha production in whole blood were measured.

RESULTS

Surgical stress rapidly depressed neutrophil phagocytic activity, monocyte mCD14 and HLA-DR expression, and LPS-induced TNF-alpha production ex vivo (P < 0.05 vs preoperation) in both Group G and Group E. In contrast, the plasma IL-10 concentration increased significantly 2 h after the start of surgery (P < 0.05) in both groups. There were no significant differences between the two groups. The neutrophil respiratory burst activity did not change during the operation in either group.

CONCLUSION

This study showed that the innate immune system is suppressed from the early period of upper abdominal surgery. Subgroup analysis suggested that epidural anaesthesia to T4 dermatome as well as general anaesthesia may not protect patients from this immunosuppression. These results in part explain the impairment of host-defense mechanisms seen in the perioperative period.