Treatment failure in a patient infected with Listeria sepsis combined with latent meningitis: A case report

BACKGROUND

Listeria is a food-borne disease, which is rarely prevalent in the normal population; it mostly occurs in pregnant women, newborns, immunodeficiency patients, and the elderly. The main manifestations of this disease in patients include sepsis, meningitis, etc, and the mortality rate remains high, although the onset of meningitis is relatively insidious.

CASE SUMMARY

A 75-year-old man presented with a fever for 1 wk and was admitted to the hospital for diagnosis and management of a lung infection. His condition improved after receiving anti-infective treatment for 2 wk. However, soon after he was discharged from the hospital, he developed fever again, and gradually developed various neurological symptoms, impaired consciousness, and stiff neck. Thereafter, through the cerebrospinal fluid metagenomic testing and blood culture, the patient was diagnosed with Listeria monocytogenes meningitis and sepsis. The patient died after being given active treatment, which included penicillin application and invasive respiratory support.

CONCLUSION

This case highlights the ultimate importance of early identification and timely application of the various sensitive antibiotics, such as penicillin, vancomycin, meropenem, etc. Therefore, for high-risk populations with unknown causes of fever, multiple blood cultures, timely cerebrospinal fluid examination, and metagenomic detection technology can assist in confirming the diagnosis quickly, thereby guiding the proper application of antibiotics and improving the prognosis.

MMP-10 rs17435959 Polymorphism is Associated with the Formation and Stability of Carotid Atherosclerosis Plaque: A Case-Control Study

BACKGROUND

Matrix metalloproteinase 10 (MMP-10) has a close relationship with carotid atherosclerosis (CAS) and cerebral infarction. The MMP-10 rs17435959 polymorphism causes a leucine to valine transition at codon 4 in exon 1 of the MMP-10 gene and may have functional effects.

OBJECTIVES

To investigate the relationship between the MMP-10 rs17435959 polymorphism and the formation and stability of CAS plaques.

MATERIALS AND METHODS

The present case-control study contains 738 visitors who came to our health examination center for the first time. According to the carotid ultrasound examinations, visitors were classified into the vulnerable plaque group (41-86 years old, 141 male, 105 female), the stable plaque group (41-86 years old, 141 male, 105 female) and the no plaque group (41-85 years old, 141 male, 105 female). All visitors in the three groups were sex- and- age-matched, and cardiovascular and cerebrovascular diseases were absent. The polymorphism was genotyped by real-time polymerase chain reaction- restriction.

RESULTS

Compared to the GG genotype, the frequency of the CC and CG genotypes was significantly more common in the vulnerable plaque group than in the no plaque group (18.7% vs. 7.7%, unadjusted P = 0.002). Moreover, compared to the G allele, the frequency of the C allele was significantly more common in the vulnerable plaque group than in the no plaque group (10.4% vs. 3.9%, unadjusted P = 0.000) and in the vulnerable plaque group than in the stable plaque group (10.4% vs. 5.1%, unadjusted P = 0.008). Binary logistic regression showed that the CC and CG genotype was independent risk factor for the formation (P = 0.019, OR = 1.961, 95% CI [1.117, 3.444]) and vulnerability (P = 0.035, OR = 1.842, 95% CI [1.045, 3.247]) of CAS plaques. Moreover, individuals who have the C allele showed a higher level of fibrinogen, which was an independent risk factor for the formation of CAS plaques (P = 0.000, OR = 2.425, 95% CI [1.475, 3.985]).

CONCLUSIONS

The rs17435959 polymorphism was associated with the formation and vulnerability of CAS plaques. Individuals who had variant-type MMP-10 showed higher levels of fibrinogen, which promoted the formation of CAS plaques.

Association of Crohn's Disease with Aryl Hydrocarbon Receptor Gene Polymorphisms in Patients from Southeast China

Aims The aryl hydrocarbon receptor (AhR) plays a pivotal role in regulating the innate and the acquired immune systems. The present study aimed to investigate the association of Crohn's disease (CD) with AhR polymorphisms in a cohort of patients from Southeast China. Methods An improved multiple ligase detection reaction technique was applied to examine the polymorphisms of rs2158041, rs2066853, and rs10249788 in 310 patients with CD and 573 controls. Results Compared to the controls, the variant allele (T) and genotype (CT+TT) of rs2158041 were less frequent in patients with CD (both p < 0.05). Similar conclusions were drawn from patients with ileal CD and with stricture CD as compared to the controls (all p < 0.0083). However, no significant differences were observed in allele and genotype frequencies of rs2066853 and rs10249788 between patients with CD and the controls (all p > 0.05). Although rs2158041 and rs10249788 were in complete linkage disequilibrium with rs2066853, respectively, only the frequency of haplotype (TG) formed by rs2158041 and rs2066853 was significantly lower in patients with CD than that in the controls (p < 0.05). Conclusions AhR (rs2158041) might be a susceptible locus for CD, especially for the two subtypes: ileal CD and stricture CD.

A Case-Control Study on Association of Ulcerative Colitis with FCGR2A Gene Polymorphisms in Chinese Patients

BACKGROUND AND AIMS

The Fc gamma receptor IIa (FcγRIIa), encoded by FCGR2A gene, has been suggested to play a crucial role in immunity by linking immunoglobulin G antibody-mediated responses with cellular effector and regulatory functions. Polymorphisms in FCGR2A have been shown to affect FcγRIIa/antibody interactions and have been potentially implicated in several autoimmune and inflammatory conditions. This study was designed to analyze the association between ulcerative colitis (UC) and FCGR2A polymorphisms in the Chinese population.

MATERIALS AND METHODS

A total of 422 patients with UC and 710 unaffected controls were recruited. Five single nucleotide polymorphisms of FCGR2A (rs1801274, rs10800309, rs4657039, rs511278, and rs6696854) were genotyped by SNaPshot. Analyses for linkage disequilibrium (LD) and haplotype studies of FCGR2A were performed for all study subjects.

RESULTS

The frequency of the minor homozygote (CC) of the rs1801274 SNP of FCGR2A was shown to be significantly lower in patients with UC than in controls (7.1% vs. 12.1%, p = 0.008). Two haplotype blocks, formed by FCGR2A (rs4657039, rs6696854, and rs10800309) and FCGR2A (rs1801274 and rs511278), respectively, were observed in the subsequent LD analysis. The TC haplotype constructed by the major allele of FCGR2A (rs1801274 and rs511278) was more prevalent in UC patients compared with controls (65.2% vs. 60.2%, p = 0.017).

CONCLUSIONS

The minor homozygote (CC) of FCGR2A (rs1801274) may contribute to decrease the susceptibility to UC and the TC haplotype formed by FCGR2A (rs1801274 and rs511278) may increase the risk of UC in the Chinese population.

[Modification factors associated with maternally inherited non-syndromic hearing loss]

Mutations in the mitochondrial DNA have been certified to be one of the most important causes of maternally inherited sensorineural hearing loss. Among these, mitochondrial 12S rRNA1555A>G, 1494C>T and other mutations are associated with both nonsyndromic and drug induced hearing loss caused by aminoglycosides. Individuals carrying 1555A>G or 1494C>T mutation have a variety of clinical manifestations, which implies that the 1555A>G or 1494C>T mutation is a chief factor underlying the development of deafness but insufficient to produce the clinical phenotype. Therefore other modifier factors, such as aminoglycosides, mitochondrial haplotypes, secondary mutation or nuclear modifier genes, may play an important role in the phenotypic expression of the deafness-associated mitochondrial 12S rRNA1555A>G or 1494C>T mutation. In this review, the modifier factors for the phenotypic expression of deafness-associated mitochondrial 12S rRNA1555A>G or 1494C>T mutations were summarized and proposed the pathogenesis of maternally inherited deafness.

Phylogenetic relationships of chrysanthemums in Korea based on novel SSR markers

Chrysanthemums are well known for their esthetic and medicinal values. Characterization of chrysanthemums is vital for their conservation and management as well as for understanding their genetic relationships. We found 12 simple sequence repeat markers (SSRs) of 100 designed primers to be polymorphic. These novel SSR markers were used to evaluate 95 accessions of chrysanthemums (3 indigenous and 92 cultivated accessions). Two hundred alleles were identified, with an average of 16.7 alleles per locus. KNUCRY-77 gave the highest polymorphic information content value (0.879), while KNUCRY-10 gave the lowest (0.218). Similar patterns of grouping were observed with a distance-based dendrogram developed using PowerMarker and model-based clustering with Structure. Three clusters with some admixtures were identified by model-based clustering. These newly developed SSR markers will be useful for further studies of chrysanthemums, such as taxonomy and marker-assisted selection breeding.

Comparison between Transuncal Approach and Upper Vertebral Transcorporeal Approach for Unilateral Cervical Radiculopathy - A Preliminary Report

OBJECTIVE

The surgical treatments for unilateral cervical radiculopathy have been performed by either the anterior or posterior approach. The anterior approach has usually been used more than the posterior approach. The authors compared the results of newly advanced upper vertebral transcorporeal (UVTC) approach with those of the original transuncal (TU) approach in the anterior approach.

METHODS

The anterior cervical microforaminotomy was performed for 60 patients (male:female=40:20) from June, 2000 to October, 2003. 40 patients were treated by the TU approach while 20 patients were operated on by the new UVTC approach. The authors analyzed postoperative changes of disc height, the spinal instability, the average length of hospital stay, the degree of patients' satisfaction and complications from each approach. The mean follow-up period was 9.5 months.

RESULTS

In the TU approach, postoperative intervertebral disc height was decreased from 7.1+/-0.65 mm to 6.2+/-0.61 mm. In the UVTC approach, postoperative intervertebral disc height was decreased from 6.6+/-0.43 mm to 6.3+/-0.41 mm. The average length of hospital stay was 5.2 days for the TU approach and 3.4 days for the UVTC approach. In the TU approach, 28 patients experienced excellent results, 11 patients experienced good results, one patient who experienced a fair result was operated by anterior cervical fusion because of a recurrent herniated disc. In the UVTC approach, 16 patients had excellent results and four patients experienced good results.

CONCLUSIONS

This comparative study demonstrates that the UVTC approach is a better surgical technique than the TU approach considering the preservation of disc height, spinal stability, length of hospital stay, degree of satisfaction and complications.

Identification and molecular characterisation of the complete genome of a Singapore isolate of hepatitis C virus: sequence comparison with other strains and phylogenetic analysis

The complete genomic sequence of a Singapore isolate of the hepatitis C virus (HCV) was obtained from serum of an individual chronically infected with HCV. Nine overlapping cDNA clones covering the entire viral genome was amplified by reverse-transcription-polymerase chain reaction (RT-PCR), This isolate (HCV-S1) comprised 9,609 nucleotides (nt), including 341 nt of the complete 5' untranslated region (5' UTR), a single open reading frame of 3,011 amino acids (aa) and 235 nt of the complete 3' UTR. Its genotype was identified as type lb from analyses of its sequences in the 5' UTR, NS3 and NS5B regions. When compared against nine reported HCV isolates, the overall aa homology of HCV-SI was closest with an Australian strain, HCV-A (94%) and a Japanese strain, HCV-JT (93.9%). Phylogenetic analysis revealed that it was most closely related to the Taiwan strain, HCV-TW and another Japanese strain, HCV-K1-R1.

The hepatitis C virus core protein interacts with NS5A and activates its caspase-mediated proteolytic cleavage

Viral proteins interact with one another during viral replication, assembly, and maturation. Systematic interaction assays of the hepatitis C virus (HCV) proteins using the yeast two-hybrid method have uncovered a novel interaction between core and NS5A. This interaction was confirmed by in vitro binding assays, and coimmunoprecipitation in mammalian cells. Core and NS5A are also colocalized in COS-7 cells. Interestingly, NS5A is cleaved to give specific-size fragments, when core is coexpressed in mammalian cells. Overexpression of core produced many dying and rounded cells and effects such as DNA laddering and the truncation of poly(ADP-ribose) polymerase 1 (PARP1), both indicators of apoptosis. These observations led us to investigate the link between the induction of apoptosis by core and the cleavage of NS5A. The proteolysis of NS5A and these apoptotic events can be inhibited by caspase inhibitor, Z-VAD, indicating that core induces apoptosis and the cleavage of NS5A by caspases. In cells infected by the HCV, core may provide the intrinsic apoptotic signal, which produces truncated forms of NS5A. The biological function of core-NS5A interaction and the downstream effect of NS5A cleavage are discussed.

Mutations that affect dimer formation and helicase activity of the hepatitis C virus helicase

Interaction between viral proteins is necessary for viral replication and viral particle assembly. We used the yeast two-hybrid assay to identify interactions among all the mature proteins of the hepatitis C virus. The interaction between NS3 and NS3 was one of the strongest viral protein-protein interactions detected. The minimal region required for this interaction was mapped to a specific subdomain of 174 amino acids in the N terminus of the helicase region. Random mutations in the minimal region were generated by PCR, and mutants that failed to interact with a wild-type minimal fragment were isolated using the yeast two-hybrid assay as a screen. Three of these mutations resulted in a reduction or a loss of interaction between helicases. Analytical gel filtration showed that in the presence of an oligonucleotide, wild-type helicases form dimers whereas the mutants remain mostly monomeric. All three mutants were partially or almost inactive when assayed for helicase activity in vitro. Mixing a mutant helicase (Y267S) with wild-type helicase did not dramatically affect helicase activity. These data indicate that dimerization of the helicase is important for helicase activity. The mutations that reduce self-association of the helicase may define the key residues involved in NS3-NS3 dimerization.

Involvement of both vectorial and transcytotic pathways in the preferential apical cell surface localization of rat dipeptidyl peptidase IV in transfected LLC-PK1 cells

Dipeptidyl peptidase IV (DPPIV) is a membrane glycoprotein with type II orientation. It is predominantly localized to the apical surface in epithelial cells. Previous studies (Bantles, J. P., Feracci, H. M., Shinger, B., and Hubbard, A. L. (1987) J. Cell Biol. 105, 1241-1251) using cellular fractionation and immunoprecipitation in rat liver suggest that DPPIV is targeted to the apical surface by an indirect pathway through transient appearance in the basolateral surface followed by specific transcytosis to the apical domain. In transfected Madin-Darby canine kidney (MDCK) cells using domain-selective biotinylation and streptavidin absorption, it was, however, shown that DPPIV is directly sorted to the apical surface (Low, S. H., Wong, S. H., Tang, B. L. Subramaniam, V. N., and Hong, W. (1991) J. Biol. Chem, 266, 13391-13396). These studies suggest that the sorting pathway for DPPIV may be cell type-specific, but it cannot be ruled out that the observed difference in the DPPIV sorting pathway may be due to different methods employed for dissecting the sorting pathway. In this study, we have expressed rat DPPIV, using an expression system driven by the Rous sarcoma virus enhancer and the SV40 early promoter region, in another epithelial cell line, LLC-PK1. As in MDCK cells, DPPIV is preferentially (about 90%) localized to the apical surface. Employing identical methods used previously in MDCK cells, it was found that both direct and transcytotic pathways are involved in the apical surface localization of DPPIV in this epithelial cell type. These observations clearly illustrate that the sorting pathway of rat DPPIV is cell type-specific.

Apical cell surface expression of rat dipeptidyl peptidase IV in transfected Madin-Darby canine kidney cells

Dipeptidyl peptidase IV (DPPIV) is a type II membrane glycoprotein that is predominantly localized to the apical plasma membrane in various epithelial cells. In order to understand in more detail the biogenesis and sorting of DPPIV, the cDNA for rat DPPIV was inserted into a mammalian plasmid expression vector so that DPPIV expression was driven by a control region composed of the SV40 early promoter region fused to the enhancer of the Rous sarcoma virus. Madin-Darby canine kidney cells transfected with this construct were found to express the DPPIV protein. In these transfected cells, the majority of DPPIV was present on the apial cell surface. This observation suggests that the information for apical surface localization is inherent in the DPPIV molecule itself and that this sorting information is decipherable in the epithelial cells of a different species. DPPIV is transported efficiently from the endoplasmic reticulum to the Golgi apparatus as assessed by pulse-chase experiments. Furthermore, evidence is presented which suggests that the majority of DPPIV is sorted intracellularly to the apical cell surface. The same protein has, however, been reported to be sorted by an indirect pathway through transcytosis from the basolateral to the apical cell surface in hepatocytes (Bartles, J.R., Feracci, H., M., Stinger, B., and Hubbard, A.L. (1987) J. Cell Biol. 105, 1241-1251). This study suggests that the same protein can take two different pathways in different cell types for its correct apical cell surface localization.

A Fischer rat substrain deficient in dipeptidyl peptidase IV activity makes normal steady-state RNA levels and an altered protein. Use as a liver-cell transplantation model

Dipeptidyl peptidase IV (DPPIV) is a serine exoproteinase expressed at high levels in epithelial cells of kidney, liver and small intestine. Recently Watanabe, Kohima & Fujimoto [(1987) Experientia 43, 400-401] and Gossrau et al. [(1990) Histochem. J. 22, 172-173] reported that Fischer 344 rats are deficient in this enzyme. We have examined DPPIV expression in Fischer 344 rats available from U.S. and German suppliers and find that livers of the U.S. Fischer rats, in contrast with their German counterparts, express active DPPIV (D+). Northern analysis of liver RNA showed comparable levels of 3.4 kb and 5.6 kb DPPIV transcripts in both D+ rats from the U.S. and German (D-) rats. Monoclonal antibody (MAb) 236.3 to DPPIV immunoprecipitated at 150 kDa enzymically active (105 kDa, denatured) protein from surface-labelled D+ hepatocytes and reacted with canalicular and sinusoidal membranes (as shown by immunofluorescence microscopy). MAb 236.3 failed to immunoprecipitate a labelled peptide from D- cell extract or to stain D- liver sections. Polyclonal antibody (PAb) specific for DPPIV immunoprecipitated an enzymically active peptide from D+ hepatocyte extracts and a smaller, inactive peptide from D- hepatocyte extracts. Peptide maps of DPPIV immunoprecipitated from D+ extracts with MAb 236.3 and PAb were identical, but differed from that of the D- hepatocyte component recognized by PAb. The molecular basis of the DPPIV deficiency in the D- rats thus appears to be the translation of an enzymically inactive protein missing the epitope recognized by MAb 236.3. We have exploited these D- rats as hosts for syngeneic transplantation of liver cells from D+ Fischer rats. DPPIV expression is stable in the transplanted cells and allows them to be readily distinguished from the surrounding D- tissue.

Molecular dissection of the NH2-terminal signal/anchor sequence of rat dipeptidyl peptidase IV

Dipeptidyl peptidase IV (DPPIV) is a membrane glycoprotein with a type II orientation in the plasma membrane. As shown in a cell-free translation system, the amino-terminal 34 amino acids of rat DPPIV are involved in translocating nascent polypeptide across the membrane of microsomes and in anchoring the translocated polypeptide in the microsomal membrane. The amino-terminal sequence performing this dual function is composed of: a central hydrophobic core of 22 amino acid residues; 6 amino-terminal residues preceding the hydrophobic core (MKTPWK); and 6 residues following the hydrophobic core. The six residues preceding the hydrophobic core are exposed on the outside (cytoplasmic side) of the microsomal membrane. Site-directed mutagenesis studies show that deletion of this cytoplasmic domain, excluding the amino-terminal initiating methionine, does not affect translocation of nascent DPPIV polypeptide, but does affect significantly anchoring of the translocated polypeptide in the microsomal membrane. In contrast, changing the two cytoplasmic Lys to Glu residues or shortening of the hydrophobic core from 22 to 15 residues or converting the last 11e of the shortened hydrophobic core into Ala affects neither translocation across nor anchoring of the DPPIV polypeptide in the microsomal membrane. These and other structural features of the DPPIV amino-terminal signal-anchor sequences are discussed along with other types of sequences for their role in targeting nascent polypeptides to the RER.

Alteration in the regulation of plasma membrane glycoproteins of the hepatocyte during ontogeny

The expression of four integral membrane glycoproteins was examined in detail utilizing monospecific antibodies during liver development. These included asialoglycoprotein receptor, a hepatocyte glycoprotein residing in the sinusoidal domain, and three bile canalicular glycoproteins, leucine aminopeptidase, dipeptidyl peptidase IV, and a Mr 110,000 glycoprotein denoted GP 110. It was observed that asialoglycoprotein receptor, GP 110, and dipeptidyl peptidase IV were present in low amounts in fetal liver and reached adult levels between 1 to 3 weeks. In contrast, leucine aminopeptidase was present in nearly adult amounts in 18-day-old fetal livers. These observations were qualitatively confirmed by indirect immunofluorescent staining of frozen thin liver sections obtained from fetal and adult rats. Further, in fetal livers it was found that leucine aminopeptidase was not localized to typical bile canalicular areas. Immunoprecipitation studies performed in the presence of proteolytic inhibitors using detergent-solubilized extracts of metabolically labeled liver minces revealed that GP 110 was present in low amounts as Mr 110,000 and Mr 105,000 polypeptides in 17-day fetal livers but by 21 days of gestation the larger polypeptide was the major synthesis product. Conversely, the apparent molecular weights of leucine aminopeptidase and dipeptidyl peptidase IV were not altered during development. Experiments determining relative rates of synthesis using excess amounts of antibodies showed that the concentrations of the three bile canalicular glycoproteins in liver during ontogeny reflect their rates of synthesis. These results underscore that plasma membrane constituents of the hepatocyte undergo dramatic changes in expression and localization as the liver changes its physiological role at birth.

Expression of enzymatically active rat dipeptidyl peptidase IV in Chinese hamster ovary cells after transfection

Dipeptidyl peptidase IV (DPPIV) is a cell surface membrane glycoprotein expressed in many tissues. We have subcloned the coding region of a full-length cDNA for DPPIV into the inducible eukaryotic expression vector pMSG. The resulting construct was used to transfect Chinese hamster ovary (CHO) cells. Stable transformants were found to express DPPIV, and the expression is enhanced by dexamethasone. Metabolic labeling of the transfected cells with [35S]Met followed by immunoprecipitation revealed the presence of two specific products of apparent Mr 100,000 (100-kDa form) and 110,000 (110-kDa form), respectively. Pulse-chase experiments demonstrated that the 100-kDa form can be chased into the 110-kDa form, suggesting the 100-kDa form is the precursor of the 110-kDa form. Further studies with endo H treatment demonstrated that the carbohydrate structures are of the high-mannose type, and of the complex type for the 100- and 110-kDa forms, respectively. The 110-kDa form is present at the cell surface as shown by its accessibility to cell surface iodination. The DPPIV expressed on the cell surface is resistant to digestion by relatively high concentrations of trypsin. Studies also demonstrated that the surface DPPIV is fairly stable with a half-life for turnover of about 40 h. Furthermore, the DPPIV produced in the transfected cells displays specific dipeptidyl peptidase activity. The stably transfected cells that express enzymatically active DPPIV in an inducible manner will provide an excellent system for further biochemical, functional, and cell biological characterizations of DPPIV.

Cloning and analysis of cDNA clones for rat kidney alpha-spectrin

We have isolated a 3922-base pair (bp) cDNA clone for rat nonerythroid alpha-spectrin from a rat kidney lambda gt11 cDNA library. Sequence analysis revealed that this cDNA contains an open reading frame of 3090 bp encoding for the C-terminal 1030 amino acid sequence of rat kidney alpha-spectrin. The 3'-untranslated region (including a 38-bp poly(A+) tail) contains an 832-bp sequence. A single mRNA of about 8 kilobase pairs was detected in rat liver, kidney, brain, heart, intestine, lung, testis, stomach, spleen, and muscle with varying abundances, which is consistent with and further confirms the presence of spectrins in nonerythroid tissues as demonstrated previously by immunoblot analysis. Southern blot analysis suggested that there is a single gene for nonerythroid alpha-spectrin. The derived amino acid sequence contains sequence from the spectrin 106-residue internal repeat 12 to the C terminus of rat kidney alpha-spectrin. Sequence comparison with human and chicken nonerythroid alpha-spectrin showed that nonerythroid alpha-spectrin is well conserved during evolution. The rat kidney alpha-spectrin sequence, when compared to rat brain alpha-spectrin, contains an extra 76-amino-acid sequence at the C terminus. Sequence comparison of all the internal repeats available revealed that the internal repeat 3, 4, 5, 6, 7, and 8 has highest sequence similarity with internal repeat 12, 13, 14, 15, 16, and 17, respectively. Therefore, internal repeats 3-8 and 12-17 are most likely derived from an ancestral gene through gene duplication, suggesting that the spectrin gene is derived from a half-spectrin gene by gene duplication and divergence during evolution.

Expression of dipeptidyl peptidase IV in rat tissues is mainly regulated at the mRNA levels

Dipeptidyl peptidase IV (DPPIV) is a serine peptidase that cleaves N-terminal dipeptides from polypeptides when the second residue is a proline or an alanine. We have recently cloned cDNAs for rat gp110, a membrane glycoprotein with Mr of 110,000 isolated initially from rat liver. Studies reported here establish that the gp110 for which we have cloned cDNAs is DPPIV. Using the antibodies against and cDNA for DPPIV, we have assessed the tissue distribution of DPPIV by molecular approaches. Immunoblot analysis demonstrated that DPPIV is present in the kidney, lung, and small intestine at high levels, in the liver and spleen at moderate levels, and in the heart at low levels. The highest levels of mRNA for DPPIV were detected in the kidney and small intestine as compared to moderate levels found in the lung, liver, and spleen. The lowest levels of DPPIV mRNA were found in the stomach, testis, and heart. No detectable DPPIV protein and mRNA were found in brain or muscle. LDPPIV protein and mRNA are present at much lower levels in fetal livers as compared to the adult liver. Indirect immunofluorescence microscopy demonstrated that DPPIV is localized in the bile canaliculus of hematocytes and in the apical membrane domains of kidney tubule and small intestine. Further studies by Southern blot analysis indicate that DPPIV is encoded by a single gene.

Membrane orientation of rat gp110 as studied by in vitro translation

We have recently isolated a full-length cDNA clone for a membrane glycoprotein with apparent Mr of 110,000, denoted gp110, that is expressed in rat liver, kidney, small intestine, and lung. Analysis of the amino acid sequence derived from cDNA sequencing demonstrated that there is a highly hydrophobic domain at the amino terminus (amino acid residues 1-29) that looks like the amino-terminal signal sequence. Using in vitro transcription and translation systems, we have expressed the full-length gp110 cDNA transcript, as well as transcripts derived from truncated gp110 cDNA that terminate translation at different sites. As expected, the amino-terminal signal sequence can promote the translocation across microsomal membranes of the downstream sequence. Like most translocations, the cotranslational translocation of the downstream sequence initiated by the gp110 amino-terminal signal sequence is mediated by signal recognition particle and docking protein. Unlike most amino-terminal signal sequences of lysosomal, secretory, and membrane proteins, the amino-terminal signal sequence of gp110 is not cleaved and may be involved in anchoring the polypeptide to the membrane. We, therefore, predict that the membrane orientation of gp110 is of type II with an extremely small amino-terminal cytoplasmic domain (6 residues).

Differential phosphorylation of murine class I major histocompatibility antigens

Recent studies have shown that the H-2K and H-2D transplantation antigens are expressed differentially in different tissues of mouse. Our previous investigations also established that in thioglycolate-stimulated peritoneal macrophages the H-2Dk antigen exists in distinct cell surface and intracellular forms. These two forms are glycosylated differently. In this report, we have found that (1) H-2Dk antigen is phosphorylated whereas H-2Kk antigen is not, and (2) only the cell surface form of H-2Dk antigen is phosphorylated in thioglycolate-stimulated macrophages derived from C3H/Heha mice. This differential phosphorylation of H-2 antigens will provide a model system for further studies on the molecular mechanism and function of phosphorylation of H-2 antigens.

Isolation and characterization of a Mr = 110,000 glycoprotein localized to the hepatocyte bile canaliculus

A Mr = 110,000 glycoprotein, GP 110, was partially purified using wheat germ agglutinin-Sepharose affinity chromatography from a bile canalicular-enriched membrane fraction denoted N2u of rat liver. This fraction was subjected to preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the Mr = 110,000 polypeptide was excised and used as an immunogen in rabbits. The antisera were found to specifically recognize a Mr = 110,000 polypeptide, named GP 110, in the N2u membrane fraction. In isolated hepatocytes, GP 110 was readily accessible to cell surface iodination catalyzed by lactoperoxidase at 4 degrees C and was judged by immunoprecipitation studies to contain about 2% of total radioactivity incorporated into externally oriented proteins of the cell. Immunoprecipitated GP 110 was shown by two-dimensional polyacrylamide gel electrophoresis to migrate with an approximate pI of 4.9. Indirect immunofluorescence on frozen liver sections demonstrated that GP 110 was primarily localized in the bile canaliculus. In corroborative studies employing subcellular fractionation, it was found that GP 110 was enriched nearly 19-fold in P2, a plasma membrane fraction primarily derived from the sinusoidal domain, and 44-fold in N2u. In contrast, only low levels of GP 110 were present in endoplasmic reticulum, mitochondrial, cytosolic, and nuclear-enriched fractions of liver. The physiological function of GP 110 is as yet unknown; antisera to it did not immunoprecipitate other known bile canalicular proteins of similar molecular weights. GP 110 was found to be extensively glycosylated relative to other known membrane proteins; approximately 33% of the apparent molecular weight appear to be carbohydrate. In agreement, limited removal of N-linked carbohydrate chains indicated that there are approximately eight chains/GP 110 polypeptide. Neuraminidase treatment of GP 110 resulted in a desialylated Mr = 85,000 polypeptide suggesting that the majority of carbohydrate chains on GP 110 are of the complex type.

[Treatment of 63 advanced ovarian carcinomas]

62 patients with advanced epithelial ovarian adenocarcinoma (37 stage III, 4 stage IV and 22 recurrent lesions) were treated in our hospital from 1977 to 1981, 38 patients underwent surgery. 25 with inoperable tumor initially received preoperative chemotherapy (VCF protocol: vincristine + cyclophosphamide + fluorouracil chiefly) followed by surgery. The response rate of chemotherapy was 48%. Apart from 1 progressive tumor during chemotherapy, 24/25 were explored. There were 10/24 with residual tumor less than 2 cm in diameter, giving a resection rate of 41.7% as compared with the resection rate of 42.1% (16/38) in the operation group. It is shown that the preoperative chemotherapy improves the resection rate. 44 patients received postoperative chemotherapy and 12, radiotherapy combined with chemotherapy or radiotherapy only. The overall 2.3 and 5 year survival rates of these 63 patients were 39.7%, 31.7% and 23.8%. The 2 and 3 year survivals were 41.9% and 32.3% in 31 patients with postoperative chemotherapy using VCF protocol. The results indicate that VCF protocol is effective for advanced epithelial ovarian cancer, especially patients with residual tumor less than 2 cm in size. Chemotherapy with more than 3 courses has better effect.