Selenium deficiency: report of a case

We report an 18-month-old Japanese boy with selenium deficiency. He had dry skin with irregularly shaped, erythematous changes on the cheeks, groin, hip, and extremities, erosions on the external urethral and anal orifices, and sparse, short, thin, light-coloured hair. He had received parenteral nutrition for 5 months because of juvenile polyposis. At presentation, his serum selenium level was less than 2.0 microg/dL (normal range, 10.6-17.4 microg/dL). His skin lesions responded well to supplementary treatment with sodium selenite. His skin symptoms were similar to those attributable to a deficiency of zinc which, like selenium, is an essential trace element. According to the literature, selenium deficiency is responsible for cardiomyopathy, which was diagnosed in our patient. The clinical similarity to zinc deficiency and the literature yielded important clues for a diagnosis of selenium deficiency in this patient.

Morphological and biochemical studies of human beta-mannosidosis: identification of a novel beta-mannosidase gene mutation

BACKGROUND

There are seven well-known lysosomal storage diseases that produce angiokeratoma corporis diffusum clinically. beta-Mannosidosis (MANB1; OMIM248510), first reported in humans in 1986, is a rare hereditary lysosomal storage disease caused by a deficiency of the enzyme beta-mannosidase. Since then, 13 cases of beta-mannosidase deficiency in ten families have been described. A human beta-mannosidase mutation has been reported only by Alkhayat et al. in 1998.

OBJECTIVES

To clarify its pathogenesis we did electron microscopic, biochemical and molecular biological investigations of a Japanese patient with beta-mannosidosis.

METHODS

Ultrastructural analyses, enzyme assays, cell culture and mRNA and genomic DNA were sequenced to find mutations in the beta-mannosidase gene.

RESULTS

Electron microscopy of skin biopsy specimens from the patient showed cytoplasmic vacuolation of lysosomes in blood and lymph vessels, endothelial cells, fibroblasts, secretory portions of eccrine sweat glands, neural cells and basal keratinocytes in the epidermis. This vacuolation was also observed in cultured keratinocytes and fibroblasts. Assays of seven enzyme activities in plasma and cultured skin fibroblasts showed a marked decrease of beta-mannosidase activity. Sequencing the beta-mannosidase cDNA revealed a four-base (ATAA) insertion between exons 7 and 8, resulting in a frameshift at codon 321 and termination at codon 325. Analysis of the patient's genomic DNA revealed a novel homozygous A(+1)-->G splice site mutation in intron 7.

CONCLUSIONS

To our knowledge, this is the first case of beta-mannosidosis reported in Japan and the second report in which a gene mutation is identified. The biological importance of beta-mannose moieties in glycoproteins in basal keratinocytes is suggested.

Novel mutations in GJB2 encoding connexin-26 in Japanese patients with keratitis-ichthyosis-deafness syndrome

BACKGROUND

Germline missense mutations in the GJB2 gene that encodes connexin-26 (Cx26) have recently been found to be the cause of the keratitis-ichthyosis-deafness (KID) syndrome.

OBJECTIVES

To define the GJB2 mutations in three Japanese patients with KID syndrome.

METHODS

Genomic DNA was extracted from peripheral blood and used to amplify the GJB2 gene. Direct sequencing and endonuclease digestion were used for mutation analysis and DNA-based diagnosis.

RESULTS

We identified two heterozygous mis-sense mutations (D50Y, D50N) in the GJB2 gene in three Japanese patients with KID syndrome. All mutations were located on the first extracellular domain of Cx26.

CONCLUSIONS

These data expand the GJB2 mutation database and show that a dominant mutation of Cx26 can cause KID syndrome in Japanese patients.

A new case of alpha-N-acetylgalactosaminidase deficiency with angiokeratoma corporis diffusum, with Ménière's syndrome and without mental retardation

alpha-N-acetylgalactosaminidase (alpha-NAGA) deficiency is a rare hereditary lysosomal storage disease, and only three alpha-NAGA-deficient patients with angiokeratoma corporis diffusum (Kanzaki) have been described. We report a further case in a 47-year-old Japanese woman, the product of a consanguineous marriage. The remarkable findings in this patient were her normal intelligence, Ménière's syndrome, disturbance of peripheral sensory nerves, hearing loss and cardiac hypertrophy. alpha-NAGA enzyme activity in her plasma was 0.77% of the normal value. Other enzyme activities, such as alpha-galactosidase, beta-galactosidase, alpha-L-fucosidase, beta-mannosidase and aspartylglucosaminidase, were within normal limits. A large quantity of amino acid O-glycans was detected in her urine. Gene analysis revealed a novel point mutation (G-->A transition) at nucleotide 11018 (986 in the cDNA) resulting in an Arg-329-Gln substitution. Kanzaki disease has the same enzyme defect as Schindler disease, but the manifestations are quite different.

Early onset sarcoidosis masquerading as juvenile rheumatoid arthritis

Symptoms of early onset sarcoidosis characterized by skin eruptions, arthritis, and uveitis mimic those of systemic type juvenile rheumatoid arthritis (JRA). We report 2 Japanese patients with early onset sarcoidosis, both of whom were initially diagnosed and treated as having JRA. Intermittent fever and synovial swelling may mask sarcoidosis in children less than 4 years old.

Analyses of the transglutaminase 1 gene mutation and ultrastructural characteristics in a Japanese patient with lamellar ichthyosis

We described a Japanese female with lamellar ichthyosis whose transglutaminase 1 gene (TGM1 gene) was mutated. DNA sequence analysis revealed that the patient had a homozygous mutation, i.e. a point mutation from G to A at nucleotide 1494 resulting in the substitution of glycine for arginine at codon 143. Her mother was heterozygous for this mutation. In situ transglutaminase assay in the patient's skin showed loss of enzyme activity. Ultrastructural examination revealed incomplete formation of cornified cell envelopes and electron-dense materials adjacent to plasma membranes. These results suggest that defective transglutaminase activity caused by homozygous TGM1 gene mutation (G143R) results in disruption of cornified envelope assembly and the clinical phenotype of lamellar ichthyosis.

[Autopsy case of adenoid cystic carcinoma of the trachea: endobronchial treatment improves quality of life]

A 67-year-old man presented with dyspnea on exertion. Bronchoscopic examination revealed a tumor arising from the middle portion of the trachea and extending to the right main bronchus. The pathological diagnosis was adenoid cystic carcinoma. Radiotherapy and subsequent endobronchial electrocautery were performed, and elicited a partial response. In the clinical course. Dumon and Ultraflex stents were placed in the trachea asynchronically. Brachytherapy and esophageal stent placement were also performed for tumor control in the trachea and esophagus. Autopsy revealed that the tumor had invaded the trachea and esophagus, and bacterial mediastinitis was also demonstrated. Because the tumor was successfully controlled during the following 4 years and 9 months, we concluded that endobronchial therapy such as stent placement or electrocautery is useful for maintaining good quality of life.

A case of symptomatic heterozygous female Fabry's disease without detectable mutation in the alpha-galactosidase gene

We report a case of symptomatic heterozygous female Fabry's disease with low alpha-galactosidase blood activity. We could not find any mutations in the coding regions of either the signal peptide or the enzyme subunit in our case.

A novel point mutation affecting the tyrosine kinase domain of the TRKA gene in a family with congenital insensitivity to pain with anhidrosis

A nerve growth factor receptor encoded by the TRKA gene plays an important part in the formation of autonomic neurons and small sensory neurons in dorsal root ganglia and in signal transduction through its intracytoplasmic tyrosine kinase domain. Recently, three mutations in the tyrosine kinase domain of TRKA have been reported in patients with congenital insensitivity to pain with anhidrosis, which is an autosomal recessive disorder characterized by recurrent fever due to absence of sweating, no reaction to noxious stimuli, self-mutilating behavior, and mental retardation. We examined the TRKA gene in five generations of a large Japanese family with many consanguineous marriages who live in a small remote island of the southern part of Japan. We found a novel point mutation at nucleotide 1825 (A-->G transition) resulting in Met-581-Val in the tyrosine kinase domain. Two of the three affected patients were homozygous for this mutation; however, the third affected patient was heterozygous. Further analysis revealed that the third patient was a compound heterozygote with the Met-581-Val mutation in one allele and with a single base C deletion mutation at nucleotide 1726 in exon 14 in the other allele, resulting in a frameshift and premature termination codon.

Expression of adrenomedullin, a hypotensive peptide, in the trophoblast giant cells at the embryo implantation site in mouse

Adrenomedullin (AM) is a newly discovered hypotensive peptide which is believed to play an important role for blood pressure control in the adult. Although it has been well established that a major production site of AM is vascular endothelial cells, we now show that AM is most highly expressed in trophoblast giant cells, which are derived from the conceptus and are directly in contact with maternal tissues at the implantation site. Northern blot and in situ hybridization analyses show that the AM mRNA begins to be detected just after implantation and its level peaks at 9.5 days postconception (d.p.c.) in those cells. Expression then falls dramatically after 10.5 d.p.c., coincident with the completion of the mature chorioallantoic placenta. Immunohistochemical analyses show that the AM peptide is secreted from the trophoblast giant cells into the surrounding tissues, i.e., embryo, decidua, and maternal circulation. In contrast, the expression of an AM receptor was not detected by Northern blot analyses in either embryo or trophoblast giant cells at 7 d.p.c., when the AM gene is most highly expressed in the trophoblast giant cells. This suggests that the AM produced and secreted from the embryo's trophoblast giant cells acts on the maternal tissues rather than on the embryonic tissues. Based on these results, we propose that the high production of AM may be the mechanism by which the embryos survive at the early postimplantation period by pooling maternal blood in the implantation site in order to secure nutrition and oxygen before the establishment of efficient embryo-maternal circulation through the mature placenta.

Genome-wide mapping of unselected transcripts from extraembryonic tissue of 7.5-day mouse embryos reveals enrichment in the t-complex and under-representation on the X chromosome

Mammalian embryos can only survive if they attach to the uterus (implantation) and establish proper maternal-fetal interactions. To understand this complex implantation pathway, we have initiated genomic analysis with a systematic study of the cohort of genes expressed in extraembryonic cells that are derived from the conceptus and play a major role in this process. A total of 2103 cDNAs from the extraembryonic portion of 7.5-day post-conception mouse embryos yielded 3186 expressed sequence tags, approximately 40% of which were novel to the sequence databases. Furthermore, when 155 of the cDNA clones with no homology to previously detected genes were genetically mapped, apparent clustering of these expressed genes was detected in subregions of chromosomes 2, 7, 9 and 17, with 6.5% of the observed genes localized in the t-complex region of chromosome 17, which represents only approximately 1.5% of the mouse genome. In contrast, X-linked genes were under-represented. Semi-quantitative RT-PCR analyses of the mapped genes demonstrated that one third of the genes were expressed solely in extraembryonic tissue and an additional one third of the genes were expressed predominantly in the extraembryonic tissues. The over-representation of extraembryonic-expressed genes in dosage-sensitive autosomal imprinted regions and under-representation on the dosage-compensated X chromosome may reflect a need for tight quantitative control of expression during development.

Staining of eccrine and apocrine neoplasms and metastatic adenocarcinoma with IKH-4, a monoclonal antibody specific for the eccrine gland

The histogenesis of apocrine and eccrine neoplasms has always interested dermatopathologists. In addition, the histologic differential diagnosis of eccrine carcinoma from metastatic adenocarcinoma is of practical importance. We describe a novel monoclonal antibody IKH-4 which stains the eccrine secretory coil, but not the apocrine secretory segment. Positive staining was observed in eccrine hidradenoma, eccrine poroma, eccrine spiradenoma, papillary eccrine adenoma, eccrine hidrocystoma, syringoma, eccrine carcinoma, and in 1 case of syringocystadenoma papilliferum. Negative staining was observed in apocrine adenocarcinoma, hidradenoma papilliferum, erosive adenomatosis of the nipple, and primary and metastatic adenocarcinomas. IKH-4 antibody was useful in differentiating eccrine from apocrine neoplasms and in differentiating eccrine carcinoma from metastatic adenocarcinomas.

A case of chromomycosis with tumor-like growth

A 66-year-old woman who lived on Tokunoshima Island, a small and remote southern island of the Japanese archipelago, had suffered from chromomycosis for more than 30 years and presented with a tumor-like growth on the posterior crural region of his right leg. Fonsecaea pedrosoi was identified as the pathogen from its growth pattern and micromorphological characteristics. The patient was successfully treated with 5-fluorocytosine, itoraconazole, and topical thermotherapy.

Cloning and expression analyses of mouse dystroglycan gene: specific expression in maternal decidua at the peri-implantation stage

While constructing a catalog of mouse cDNAs which are expressed in the maternal-fetal interface during the peri-implantation period, we encountered a 1.6 kb cDNA clone showing a strong sequence similarity to the 3' untranslated region of the human dystroglycan gene. We cloned an additional 1.7 kb cDNA by reverse transcriptase-PCR (RT-PCR) and confirmed that this is a true mouse homolog of human dystroglycan cDNA by sequence analyses, Southern blotting, and genetic mapping of this gene on the distal region of mouse chromosome 9. Although it is well established that dystroglycan, a transmembrane protein, plays an important role in muscle tissues by bridging intracellular dystrophin to the laminin in the extracellular matrix, its role in non-muscle tissues remains elusive. To further investigate the role of the dystroglycan gene at the peri-implantation stage, we analyzed the expression patterns of this gene by in situ hybridization, which revealed that this gene is specifically expressed in decidual cells, especially in the cells surrounding the implantation site at 6.5, 7.5, and 8.5 day post conception (p.c.) stages, but not expressed in non-pregnant endometrial cells of uterus nor in the decidua at 12.5 day p.c. Further analyses by RT-PCR confirmed that the amount of dystroglycan mRNA in 8.5 day p.c. decidua was indeed 100-fold higher than that of non-pregnant uterus and 12.5 day p.c. mature placenta. These results suggest that dystroglycan may work as a mediator for adhesion between decidual cells themselves or between decidual cells and trophoblast cells, and provide a structural and functional support for maintaining pregnancy at its early stage.

Chronic lupoid leishmaniasis. Evaluation by polymerase chain reaction

BACKGROUND

The cutaneous lesions in chronic lupoid leishmaniasis resemble those of lupus vulgaris, both clinically and histologically. The differential diagnosis is difficult and may depend on the detection of a few Leishmania amastigotes in the histologic sections, the growth of the promastigotes in cultures, or the identification of amastigotes by other techniques. Polymerase chain reaction was used to detect Leishmania amastigote DNA in tissue samples obtained from 65 patients with chronic lupoid leismaniasis, and the results were confirmed by Southern blot analysis.

OBSERVATIONS

The histologic findings of a predominantly epithelioid cell granuloma surrounded by lymphocytic infiltrate in chronic lupoid leishmaniasis are very similar to those observed in lupus vulgaris. Extensive histologic examination of the sections in this series revealed occasional macrophages containing a few amastigotes in only 12 cases. Cultures in NNN medium yielded Leishmania promastigotes in 20 cases. Polymerase chain reaction studies using a Leishmania-specific primer identified Leishmania DNA in 30 of 63 cases, and those using a Mycobacterium tuberculosis primer were found to be negative for mycobacteria in 47 cases tested, including 11 cases with a positive tuberculin skin reaction.

CONCLUSIONS

The histologic findings in chronic lupoid leishmaniasis resemble those of lupus vulgaris. Polymerase chain reaction studies were useful in identifying amastigotes in 30 (47.6%) of 63 cases. This study confirms the presence of DNA molecules of Leishmania amastigotes in samples of formalin-fixed, paraffin-embedded granulomatous tissue obtained from patients with chronic lupoid leishmaniasis.

Failure to detect paramyxovirus RNA in the skin of connective tissue disease

Etiology of connective tissue disease is unknown. The association of infectious agents has been suspected serologically, ultrastructurally and recently by means of molecular biological techniques. We extracted RNA from lesions of 25 discoid lupus erythematosus, 9 systemic LE, and 3 systemic sclerosis biopsies, and reverse transcription-polymerase chain reaction was performed for all paramyxoviruses known to infect human beings. None of the samples yielded positive signal for any of the viruses. The existence of paramyxovirus in the skin of connective tissue disease is very unlikely.

[Epidemiological study for comparative biological profiles on MRSA strains isolated in 1992 vs. 1993]

The trend of epidemiological study against MRSA strains which were isolated in 1992 and in 1993 was investigated. Number of stains tested yearly consisted of 30 isolates that were considered to play pathogenic roles for inpatients in clinical departments at our institute. In comparing with biological studies on MRSA strains and the epidemiological surveillance of the background of the isolation, the data summarizes as followings; 1) No. of MRSA strains which were producible for TSST increased from 24/30, 80% up to 30/30, 100%. 2) No. of enterotoxin type harbouring biotype of B/C increased 0/30, 0% up to 12/30, 40%. 3) No. of type of plasmid DNA profile increased in varying from 3 types (A, B, C) to 8 types (A-H). 4) The in vitro activity of antimicrobials, as such MINO, GM, IPM, CMZ was less potent than that of the prior year, and even for VCM, ABK, the activity proved less potent in 1-2 tubes in MIC90. 5) No. significant hospital acquired infection was detected between the inpatients, with MRSA infection and isolates from plasmid DNA profiles. 6) Since the ratio of the coincidence of plasmid DNA profiles of MRSA was only in 4 patients out of 27, 14.9 &, nosocomial infections with MRSA brought to patients have not only been considered by medical, paramedical staff, but that the infection may be caused by broad contamination at the institute.

Histopathologic and ultrastructural studies of angiokeratoma corporis diffusum in Kanzaki disease

A novel metabolic disease, angiokeratoma corporis diffusum (Kanzaki), was the subject of an extensive histopathologic and ultrastructural study. Findings included dilated lymph and blood vessels in the upper dermis with an orthokeratortic, thickened, horny layer in well developed angiokeratoma. In the early papules, a few sporadic dyskeratotic keratinocytes were present in the epidermis with or without a thickened horny layer. Vesicular clear vacuolation was clearly observed in the cytoplasm of the secretory portion of the eccrine sweat glands, but none was observed in the vascular endothelial cells with hematoxylin-eosin staining. Using electron microscopy, lysosomal vacuolation was observed in many cell types, including eccrine sweat gland cells, vascular endothelial cells, dermal fibroblasts, dermal neural cells, lymphocytes of peripheral blood in the skin, and glomerular endothelial cells, but none was noted in the epithelial cells of the kidney. Widely dilated vacuoles were found to contain only a small amount of fuzzy filamentous material in the vascular endothelial cells, filamentous or electron-dense granular substances in fibroblasts, and electron-dense, lamellated or homogeneous structures in eccrine sweat gland cells and in neural cells. Ultracytochemical examination revealed glycoconjugates in dilated lysosomes. Characteristics of Kanzaki Disease were shown to differ from those of Fabry disease or any other lysosomal storage disease.

Naturally occurring escape mutants of hepatitis B virus with various mutations in the S gene in carriers seropositive for antibody to hepatitis B surface antigen

Hepatitis B virus (HBV) DNA was extracted from sera of six carriers with hepatitis B e antigen as well as antibody to hepatitis B surface antigen and sequenced within the pre-S regions and the S gene. HBV DNA clones from five of these carriers had point mutations in the S gene, resulting in conversion from Ile-126 or Thr-126 of the wild-type virus to Ser-126 or Asn-126 in three carriers and conversion from Gly-145 to Arg-145 in three of them; clones with Asn-126 or Arg-145 were found in one carrier. All 12 clones from the other carrier had an insertion of 24 bp encoding an additional eight amino acids between Thr-123 and Cys-124. In addition, all or at least some of the HBV DNA clones from these carriers had in-phase deletions in the 5' terminus of the pre-S2 region. These results indicate that HBV escape mutants with mutations in the S gene affecting the expression of group-specific determinants would survive in some carriers after they seroconvert to antibody against surface antigen. Carriers with HBV escape mutants may transmit HBV either by donation of blood units without detectable surface antigen or through community-acquired infection, which would hardly be prevented by current hepatitis B immuneglobulin or vaccines.

A case of epidermolysis bullosa hereditaria--dominant dystrophic type of Cockayne and Touraine

We report a patient with the Cockayne and Touraine type epidermolysis bullosa dystrophica domains. A 6-year-old Japanese female developed blisters and erosions on the extremities 3 months after birth. Immunohistology showed a linear binding pattern of the monoclonal antibody against type VII collagen (LH:2) on the epidermal basement membrane. By means of electron microscopy and morphometric analysis, it became apparent that the anchoring fibrils were rudimentary in structure and reduced in number.

Reactivation of precore mutant hepatitis B virus leading to fulminant hepatic failure following cytotoxic treatment

Three hepatitis B virus carriers who were HB(e)Ag negative and having normal liver function developed fulminant hepatitis with evidence of HBV replication following intensive chemotherapy for non-Hodgkin's lymphoma. Each was continuously negative for HB(e)Ag. Analysis of the precore region of HBV isolated from each demonstrated that the HBV of each had a point mutation in the precore region that inhibited the synthesis and the release of hepatitis B(e) antigen. This observation suggests that all HB carriers receiving either immunosuppressive or cytotoxic therapy should be monitored closely even if standard assays suggest that viral replication is not present. Sudden enhanced replication of a HBV mutant as a result of such therapy can be a cause of either very severe hepatitis or occasionally fulminant hepatitis.

Fulminant hepatitis related to transmission of hepatitis B variants with precore mutations between spouses

A precore defective variant of hepatitis B virus has been indicated to cause fulminant hepatitis in various instances such as intrahospital outbreaks or mother-to-child transmission of hepatitis B virus. To learn whether similar variants are involved in interspouse transmission, we analyzed three cases of fulminant hepatitis B that developed in formerly healthy subjects whose only exposure to hepatitis B virus was contact with their longtime spouses, who were carriers of HBV and positive for antibody to HBe. The DNA clones for precore and S genes were propagated from patients and spouses and sequenced. Because of the conservation of S-gene sequences and the identity of subtypes between patient and spouse, it was suggested that patients were infected with hepatitis B virus from their spouses, not from other sources. A TGG-to-TAG mutation at the 28th codon of the precore gene of hepatitis B virus was commonly observed in all DNA clones from patients with fulminant hepatitis and from their spouses. A 29th-codon GGC-to-GAC mutation was additionally evident in DNAs from one patient-and-spouse couple. A significant rise in the circulating hepatitis B virus concentration was transiently observed in the index spouse of this case just before development of fulminant hepatitis in her husband. The increase in circulating HBV DNA was associated with a rise in abundancy of variants with mutations at both the 28th and 29th codons, compared with variants with only a 28th-codon mutation. The double mutation in hepatitis B virus DNA may either help the virus escape immune surveillance or replicate at a higher rate than before.

Anaplastic large cell lymphoma, so-called Ki-1 lymphoma: a report of a case of long course

A 55-year-old female with a complaint of tumors on the right lower extremity was reported. The condition was diagnosed as anaplastic large cell lymphoma, so-called Ki-1 lymphoma, by its histological and immunohistochemical features. The clonal proliferation of the infiltrating cells of the skin lesions was confirmed by the analysis of T cell receptor gene rearrangement. The lesions have repeatedly occurred on the right lower extremity for more than ten years. In this report, we also discuss the prognosis of anaplastic large cell lymphoma with or without skin lesions.

Hepatitis B virus mutants with precore-region defects in two babies with fulminant hepatitis and their mothers positive for antibody to hepatitis B e antigen

Clones of hepatitis B virus (HBV) DNA were propagated from sera of two babies who developed neonatal fulminant hepatitis B, as well as from sera of their mothers who carried HBV with antibody to hepatitis B e antigen, and the precore-region sequences were determined. A point mutation from guanine to adenine, converting codon 28 for tryptophan (TGG) to a stop codon (TAG), was detected in 18 of 20 HBV DNA clones from mother and all 31 clones from baby in one family, and invariably in 55 clones from mother and three clones from baby in the other family. These results indicate that HBV mutants defective in the precore region in some carrier mothers with antibody to hepatitis B e antigen may transmit fulminant hepatitis B to their babies.

Ultrastructural immunocytochemical studies of blood group substances in human eccrine glands

We investigated the ultrastructure of blood group antigens A, B, and H in human eccrine glands by means of the immunogold labeling technique. Blood group antigens A, B, and H were found in the Golgi apparatus, secretory granules, and over the apical and basolateral cell membranes of dark cells of eccrine glands depending on the blood group phenotype of the donors. Both A and B antigens were found in the dark cells of AB donors. The labeling pattern of the Golgi stacks seemed to have a polarity whereby the anti-blood group A antibody labeled all the stacks, whereas anti-blood groups B and H bound to the trans side of the Golgi complex. These observations suggest that the blood group substances are secreted into the lumen after being processed through the Golgi apparatus and the immature and mature granules in the dark cells of human eccrine glands.

Enzyme-linked immunosorbent assay for antibodies against the capsid protein of hepatitis C virus with a synthetic oligopeptide

An enzyme-linked immunosorbent assay was developed for the determination of antibodies against the putative capsid protein of hepatitis C virus (HCV). A 36-mer oligopeptide with a sequence of RRGPRLGVRATRKTSERSQPRGRRQPIPKVRRPEGR (CP9) was synthesized; it was selected on the translation product of the presumptive HCV core gene, because of a high local hydrophilicity and excellent conservation by different HCV strains. The synthetic peptide was immobilized on a solid-support to capture antibodies directed to CP9 (anti-CP9) in test sera, which were detected by Fab' fragments of monoclonal anti-human IgG/gamma labeled with horseradish peroxidase. The specificity of anti-CP9 was confirmed by absorption tests. Anti-CP9 was detected in 13 (68%) of 19 patients with sporadic acute non-A, non-B (NANB) hepatitis and in 15 (83%) of 18 patients with post-transfusion acute NANB hepatitis. In 7 cases of acute NANB hepatitis who were followed, anti-CP9 developed earlier than antibodies against HCV (anti-HCV) detectable by a commercial assay kit. Among patients with chronic NANB liver diseases, anti-CP9 was detected in 103 (77%) of 133 with chronic hepatitis, 70 (62%) of 113 with liver cirrhosis and 31 (76%) of 41 with hepatocellular carcinoma. Anti-CP9 and anti-HCV overlapped in 175 (54%) among 324 cases of acute or chronic NANB liver diseases; 58 (18%) were positive only for anti-CP9 while 49 (15%) were positive only for anti-HCV. HCV RNA was detected, by amplifying HCV cDNA with polymerase chain reaction, in 10 of 11 sera positive only for anti-CP9. Among sera from 606 blood donors, 21 were positive only for anti-CP9. HCV RNA was detected in 5 (24%) of them, all of which had A492 values greater than 0.600 in ELISA for anti-CP9. Based on these results, anti-CP9 would complement anti-HCV for the diagnosis of HCV infection and contribute toward further decreasing posttransfusion NANB hepatitis.

The 5'-terminal sequence of the hepatitis C virus genome

The 5'-terminal sequence of the genome of hepatitis C virus (HCV) was determined for two distinct HCV strains in human and chimpanzee carriers. It had a 5'-noncoding region of at least 324 nucleotides, well preserved by the two strains with a high homology (99.1%), followed by 1348 nucleotides that continued to the documented sequence of prototype HCV spanning 7310 nucleotides (European Patent Application #88310922.5). Based on these results, HCV is considered to possess an uninterrupted open reading frame encoding at least 2886 amino acid residues. Two structural genes were postulated on the 5'-terminal sequence of the HCV genome. One gene in the upstream region, highly conserved by the two strains at the amino acid level and rich in basic amino acids such as arginine, appeared to encode the viral capsid protein. The other gene in the downstream region was divergent between the two strains at both nucleotide and amino acid levels. It coded for nine potential N-glycosylation sites, and was considered to encode the viral envelope protein. Disclosure of the 5'-terminal sequence of the HCV genome would facilitate its taxonomic classification, and contribute toward immunological diagnosis of infection and development of vaccines.

Subtyping hepatitis B virus DNA in free or integrated forms by amplification of the S-gene sequences by the polymerase chain reaction and single-track sequencing for adenine

The S-gene fragments of hepatitis B virus (HBV) DNA in serum, or integrated in chromosomes of human hepatoma cells (PLC/PRF/5), were amplified by the polymerase chain reaction, cloned into an M13 phage vector, and then sequenced only for adenine. The subtype determinant d or y was established by the presence or absence of adenine as nucleotide 365, and w or r by that of nucleotide 479 in the S gene. The results were identical with those obtained by enzyme immunoassay with monoclonal antibodies. A high sensitivity for the detection of HBV DNA, amplified by the polymerase chain reaction, allowed subtyping of HBV in sera containing HBsAg in concentrations too low to be subtyped by immunological methods. Furthermore, subtyping at the nucleotide level can be applied to tissues containing HBV DNA sequences in integrated forms, such as hepatocellular carcinomas, stored frozen or in formalin.

Hepatitis B viruses with precore region defects prevail in persistently infected hosts along with seroconversion to the antibody against e antigen

The C gene of hepatitis B virus (HBV) codes for a nucleocapsid protein made of 183 amino acid residues and is preceded in phase by the precore (pre-C) region, encoding 29 residues. The pre-C-region product is required for the synthesis and secretion of hepatitis B e antigen (HBeAg), which is made of the C-terminal 10 amino acid residues of the pre-C-region product and the N-terminal 149 residues of the C-gene product. HBV mutants with pre-C-region defects prevailed in the circulation of three asymptomatic carriers as they seroconverted from HBeAg to the corresponding antibody (anti-HBe), and these mutants finally replaced nondefective HBV. HBV DNA clones were propagated from sera of an additional 15 carriers with anti-HBe and sequenced for the pre-C region. Essentially all HBV DNA clones (56 of 57 [98%]) revealed mutations that prohibited the translation of a functional pre-C-region product. A point mutation from G to A at nucleotide 83, converting Trp-28 (TGG) to a stop codon (TAG), was by far the commonest and was observed in HBV DNA clones from 16 (89%) of 18 carriers seropositive for anti-HBe. In addition, there were point mutations involving ATG codon to abort the translation initiation of the pre-C region, as well as deletion and insertion to induce frameshifts. Such mutations leading to pre-C-region defects were rarely observed in persistently infected individuals positive for HBeAg or in patients with type B acute hepatitis after they had seroconverted to anti-HBe. These results would indicate a selection of pre-C-defective mutants in persistently infected hosts, along with seroconversion to anti-HBe, by immune elimination of hepatocytes harboring nondefective HBV with the expression of HBeAg.

The distribution of concanavalin A- and cationized ferritin-binding sites on plasma membrane of human platelet and the changes of these sites in cells responding to adenosine diphosphate

Investigations were carried out to study the distribution of the concanavalin A- and cationized ferritin-binding sites on the plasma membrane of human platelets and to ascertain the changes of these sites in cells stimulated with adenosine diphosphate (ADP) with time as well. The concanavalin A-binding sites of the unwashed fixed platelets were sparsely distributed on the plasma membrane at a distance of up to 80 nm from the outer leaflet of the plasma membrane. The washed unfixed platelets, however, showed a dense distribution within a range of 70 nm from the outer leaflet of the plasma membrane. Changes in the distribution of concanavalin A-binding sites on the plasma membrane of platelets stimulated with ADP were characterized by a marked increase in the number of binding sites and by protrusion up to a distance of 150 nm from the outer leaflet of the plasma membrane 1 minute after the reaction had occurred. The concanavalin-A binding sites may be semicryptic in view of the fact that they were exposed by washing or protruded as a result of the stimulation with ADP. The cationized ferritin binding sites were uniformly distributed with high density on the plasma membrane of the unwashed fixed platelets. In washed unfixed platelets, however, they were sparsely distributed with cluster formation. It is suggested that the glutaraldehyde fixation itself has an effect on the binding of the cationized ferritin particles on the plasma membrane of platelets. The various changes in the concanavalin A-binding sites appearing 1 minute after the reaction with ADP may represent morphological evidence indicating that the platelets have acquired adhesiveness.

Type III glycogenosis with deposition of urate and amyloid

A case of a 44-year-old man with hepatic form of glycogenosis was presented. The patient had abdominal distension and muscular weakness. The glucose tolerance test showed a diabetic pattern, though he had hypoglycemia in fasting state. The fructose tolerance test showed an ability of conversion from fructose to glucose. The double glucagon test showed no rise of blood glucose in fasting state but a rise 2 hours after meal. These symptoms and laboratory data supported the clinical diagnosis of type III glycogenosis. At autopsy, glycogen was markedly deposited in the liver, and slightly in the kidneys and heart. The glycogen pooled in the hepatic cells histochemically showed a normal reaction to several glycogen stainings. Electron microscopy by using Thiéry's method revealed that the pooled glycogen particles were clearly arranged as rosettes measuring 1,000A in largest diameter composed of clustered monoparticulates. There were marked hyalinization of the islets of Langerhans containing amyloid. As to its pathogenesis, this change can be interpreted as a morphological expression of the hypofunction of beta-cells ascribed to long-standing hypoglycemia.

Virilizing adrenal adenoma stimulated by dexamethasone in a middle-aged woman

In a middle-aged woman with virilizing adenoma, 2 mg dexamethasone increased urinary excretion of 17-ketosteroids (17-KS) and 17-hydroxycorticosteroids, whereas 8 mg dexamethasone increased urinary excretion only of 17-KS. With discontinuation of dexamethasone, 17-KS excretion returned to the predexamethasone level. Dexamethasone depressed the basal level of cAMP synthesis and basal testosterone production by the normal adrenal tissue in vitro. Dexamethasone also depressed the increase of cAMP produced by ACTH in the normal tissue. In contrast, dexamethasone increased basal cAMP synthesis and stimulated testosterone secretion in the tumor tissue. ACTH and dexamethasone were additive in their effects on cAMP and testosterone in the tumor tissue. It is suggested that dexamethasone acted directly on the adrenal tumor to stimulate steroid secretion in this patients.