Structure and functional analysis of the multistress response gene DDR2 from Saccharomyces cerevisiae

The DDR2 gene is a multistress response gene in Saccharomyces cerevisiae that is transcriptionally activated by more than thirteen xenobiotic agents and environmental or physiological stresses. The DDR2 gene encodes a small hydrophobic 61 amino acid polypeptide located on chromosome XV adjacent to the SPE2 locus. Disruption alleles of the DDR2 gene have been constructed and these ddr2 delta mutants show no defect in heat shock recovery or thermotolerance and appear normal for DNA damage sensitivity and mutagenesis.

Hepatic Fas antigen expression before and after interferon therapy in patients with chronic hepatitis C

To assess the relationship between hepatitis C virus infection and Fas antigen expression on hepatocytes, we examined changes in hepatic Fas antigen expression in the presence or absence of active hepatitis C virus infection. Twenty patients with chronic hepatitis C infection were treated with interferon and underwent pre- and posttreatment liver biopsies. Patients were classified according to the absence (group A; n = 9) or the presence (group B; n = 11) of hepatitis C virus RNA (HCV-RNA) in the liver after interferon therapy. An immunohistochemical assay showed Fas antigen staining in hepatocytes membranes and cytoplasm with expression concentrated mainly in periportal areas. The percentage of Fas-positive cells in the liver before treatment was not different between group A (39.5+/-19.1%) and group B (32.5+/-15.6%). Hepatic Fas expression was reduced significantly after treatment (24.3+/-10.6%) compared with the pretreatment values in group A (p < 0.05) but not in group B (25.9+/-16.9%). There was no significant difference between the two groups in the degree of histologic improvement. These results suggest that hepatic Fas expression is associated with persistent infection of hepatitis C virus.

[Two cases of relapse or refractory germ cell tumor who had been treated with combination chemotherapy of cisplatin and carboplatin]

We tried a combination chemotherapy with cisplatin (CDDP) and carboplatin (CBDCA) (CDDP/CBDCA regimen) as salvage therapy for 2 cases with recurrent or refractory Germ Cell Tumor (GCT). Case 1 was a 29-year-old man with 2nd relapsed embryonal carcinoma and seminoma originating from testis. Case 2 was a 23-year-old man with primary refractory embryonal carcinoma and yolk sac tumor originating from mediastinum. CDDP and CBDCA were administered at the dose of 120 mg/m2 and 350 mg/m2 on day 1, and vinblastin was administered at the dose of 10 mg/body on day 2. In one of two cases, a complete response was obtained. Non-hematologic toxicity of CDDP/CBDCA regimen was tolerable. It is suggested that this combination chemotherapy is useful for GCT recurrence.

Th0-like CD4+ T cells protect mice with murine retrovirus-induced immunodeficiency syndrome (MAIDS) against co-infection with Listeria monocytogenes

We examined the host defence mechanism against infection with Listeria monocytogenes, a facultative intracellular bacterium, in mice with murine acquired immunodeficiency syndrome (MAIDS) caused by LP-BM5 murine leukaemia virus (MuLv) infection. Although LP-BM5 MuLV infection in C57BL/6 mice leads to a stage of immunodeficiency characterized by severe compromise of cell-mediated immunity, the mice with established MAIDS infected with LP-BM5 8 weeks previously, showed resistance to an intraperitoneal infection with Listeria monocytogenes. These MAIDS mice also showed resistance to a lethal dose of secondary listerial challenge, while the delayed-type hypersensitivity response to heat-killed Listeria (HKL.) was severely impaired in MAIDS mice. The resistance of MAIDS mice to listerial infection was mediated by CD4+ alpha beta T cells but neither by gamma delta T cells nor natural killer (NK) cells. Interferon-gamma (IFN-gamma) and interleukin-10 (IL-10) were produced by CD4+ T cells from Listeria-infected MAIDS mice in response to the in vitro stimulation with HKL, whereas IFN-gamma but not IL-10 were produced by those from Listeria-infected control mice. These results suggest that T-helper 0 (Th0)-like immune responses of CD4+ T cells occur and participate in host defence mechanisms against listerial infection in MAIDS mice.

[Repeated pneumonia in the middle lobe caused by congenital bronchoesophageal fistula]

A 52-year-old woman was admitted to our hospital because of repeated episodes of pneumonia in the middle lobe. She had also experienced coughing during meals. The history and chest CT findings suggested the presence of a bronchoesophageal fistula. An upper GI series revealed a fistula between an esophageal diverticulum and the superior segment bronchus of the right lower lobe. Fiberoptic bronchoscopy done immediately after the upper GI series revealed barium sulfate leaking from the superior segment bronchus of the right lower lobe into the middle lobe bronchus. These findings indicated that the repeated pneumonia in the middle lobe was caused by a congenital bronchoesophageal fistula. Examination of the resected fistula showed that it was a Braimbridge type I bronchoesophageal fistula. Although of at least 49 cases of congenital bronchoesophageal fistulas with esophageal diverticula have been reported in the Japanese medical literature, we know of no previous case in which such a fistula was associated with middle-lobe pneumonia.

Apoptosis by CD95 (Fas)-dependent and -independent mechanisms in Peyer's patch lymphocytes in murine retrovirus-induced immunodeficiency syndrome

CD95 (Fas)/CD95 ligand (CD95 L)-mediated apoptosis is thought to be involved in the delayed progression of murine AIDS (MAIDS) induced by LP-BM5 murine leukemia virus (MuLV). We show evidence of apoptosis in lymphocytes of Peyer's patches (PP) at the early stage of MAIDS. Both T and B cells in PP expressed CD95 at the early stage of MAIDS and decreased in number thereafter. The decrease in T cells was not evident in CD95-mutated lpr mice with MAIDS, suggesting that CD95/CD95 L interaction is involved in the apoptosis of T cells in PP during the course of MAIDS. On the other hand, the number of B cells was also decreased in PP of lpr mice with MAIDS. The proliferative ability of B cells in PP of MAIDS mice in response to immunoglobulin M cross-linking or lipopolysaccharide was severely impaired, while the B cells normally proliferated in response to anti-CD40 monoclonal antibody. These findings imply that aberrantly activated B cells in PP undergo apoptosis independently of the CD95/CD95 L system during the course of infection with MAIDS virus.

Identification of TRAF6, a novel tumor necrosis factor receptor-associated factor protein that mediates signaling from an amino-terminal domain of the CD40 cytoplasmic region

CD40 signalings play crucial roles in B-cell function. To identify molecules which transduce CD40 signalings, we have utilized the yeast two-hybrid system to clone cDNAs encoding proteins that bind the cytoplasmic tail of CD40. A cDNA encoding a putative signal transducer, designated TRAF6, has been molecularly cloned. TRAF6 has a tumor necrosis factor receptor (TNFR)-associated factor (TRAF) domain in its carboxyl terminus and has a RING finger domain, a cluster of zinc fingers and a coiled-coil domain, which are also present in other TRAF family proteins. TRAF6 does not associate with the cytoplasmic tails of TNFR2, CD30, lymphotoxin-beta receptor, and LMP1 of Epstein-Barr virus. Deletion analysis showed that residues 246-269 of CD40 which are required for its association with TRAF2, TRAF3, and TRAF5 are dispensable for its interaction with TRAF6, whereas residues 230-245 were required. Overexpression of TRAF6 activates transcription factor NFkappaB, and its TRAF-C domain suppresses NFkappaB activation triggered by CD40 lacking residues 246-277. These results suggest that TRAF6 could mediate the CD40 signal that is transduced by the amino-terminal domain (230-245) of the CD40 cytoplasmic region and appears to be independent of other known TRAF family proteins.

Bullous pemphigoid associated with internal malignancies: identification of 180-kDa antigen by western immunoblotting

We report three cases of bullous pemphigoid associated with internal malignancies. Two cases were associated with gastric cancer and one with rectal cancer. Immunoblot analysis, using epidermal extract of normal human skin, revealed that these patients' sera reacted only with bullous pemphigoid antigen with a molecular weight of 180 kDa (BP180). The relationship of BP180 to malignant tumours is discussed.

[Pharmacokinetic and clinical studies on azithromycin in children]

Azithromycin (AZM) is a new oral macrolide antibiotic drug. AZM either in 10% fine granules form or in 100 mg capsule form was studied for its pharmacokinetics and treatment efficacy in pediatric patients with various infections. 1. Pharmacokinetics. Plasma and urine samples were collected from four patients with pharyngitis and post-dosing drug levels were determined. The drug was given once daily at 10 mg/kg body weight for 3 days. The drug concentrations found in plasma at 96 hours after the first dosing (48 hours after the final dosing) lay in a range of 0.02 and 0.04 microgram/ml and in urine at 120 hours after the first dosing (72 hours after the final dosing) in a range between 3.2 and 7.7 micrograms/ml. AZM was found in two patients but no effect was observed on blood levels of theophylline determined between 48 and 96 hours after the first dosing in the treatment of underlying bronchial asthma. 2. Clinical study results. Clinical studies of AZM was carried out in 25 pediatric patients with bacterial infections that mainly affected the respiratory tract. The patients received either 10% fine granules at 10 or 20 mg/ kg body weight or 100 mg capsules at 10 mg/kg body weight once daily over 3 to 6 days. The drug was found markedly effective in six patients, moderately effective in thirteen patients, while the investigators could not assess the drug efficacy in six patients. Although no side effect was reported in the study, two patients experienced slight decrease in WBC.

[The usefulness of induced sputum in the diagnosis of pulmonary tuberculosis]

This study was designed to compare the results of culture for tubercle bacilli using induced sputum by an ultrasonic nebulizer and gastric aspirates from same patients who were suspected of having active tuberculosis with little or no sputum and had received no prior chemotherapy. 22 patients included in this series were either culture positive for tubercle bacilli or showed unequivocal radiographic improvement after three months of therapy with three anti-tuberculosis drugs. Induced sputum from 17 patients and gastric aspirates from seven patients were culture positive for M.tuberculosis. This difference is significant (p < 0.01). Paired induced sputum and gastric aspirates were both positive for tubercle bacilli in seven patients. The finding of acid-fast bacilli on microscopy or tubercle bacilli in culture in four of the seven patients were available much earlier with induced sputum than with gastric aspirates. Positive gastric aspirates and negative induced sputum for tubercle bacilli was not seen. These results suggest that induced sputum by an ultrasonic nebulizer is superior to gastric aspirates in terms of high sensitivity and early finding for tubercle bacilli and induced sputum and gastric aspirates do not supplement each other.

[Report of a case of intraosseous meningioma: a review of the literature and diagnostic value using MRI study]

A 40-year-old woman with intraosseous meningioma is reported. She was admitted because of a slowly growing, bony hard, fixed mass in the temporal area that was covered by the normal scalp. The neurological examination on admission was negative. Plain skull radiogram demonstrated an area of hyperostotic change in the temporal region. Bone-targeted CT demonstrated irregularity in the structure of the skull bone. Selective external carotid angiogram showed a homogeneous tumor stain in the region of the skull thickening. Macroscopically complete tumor resection (Simpson's grade 1) was carried out. Her postoperative course was uneventful. The skull tumor had the typical feature of meningotheliomatous meningioma. MRI showed a mass lesion of the temporal bone on T1- and T2-weighted images, and a well-enhanced mass lesion of the outer dura and outer table of the skull bone on Gd-DTPA enhanced T1 images. The findings of the preoperative MRI study using Gd-DTPA were identical with the tumor area on histological study. Therefore, MRI with Gd-DTPA enhancement was considered a useful diagnostic modality.

Extrathymic development of self-reactive gamma(delta) T cells in athymic BALB/c nu/nu mice

In the present report, we demonstrated that extrathymic gamma(delta) T cells proliferated in the mixed culture of lymph node cells of BALB/c nu/nu mice and irradiated syngeneic spleen cells (syngeneic MLR). Reverse transcription-polymerase chain reaction (RT-PCR) analyses revealed that V(delta)5 and V(delta)6 were dominantly expressed by the gamma(delta) T cells from the syngeneic MLR. Furthermore, the syngeneic MLR may expand V(delta)5+ T cells with BALB invariant delta (BID) sequence which is specifically detected in BALB background mice because V(delta)5 RT-PCR products from syngeneic MLR were digested with an AluI restriction enzyme which cut the D(delta)2-J(delta)1 junction of the BID sequence but not those of most non-BID V(delta)5 sequences. Interestingly, anti-mycobacterial and mammalian heat shock protein (Hsp) 60 mAb ML30 suppressed the generation of V(delta)5 with an AluI site in syngeneic MLR. These results suggest that extrathymically derived V(delta)5+ and V(delta)6+ gamma(delta) T cells recognize BALB/c self antigens and that the Hsp60 or an Hsp60-related molecule may be involved in the anti-self response of V(delta)5+ BID+ gamma(delta) T cells.

Re-evaluation of foot process effacement in acute puromycin aminonucleoside nephrosis

The sequence of morphological changes during foot process effacement in acute puromycin aminonucleoside (PAN) nephrosis was examined by means of NaOH maceration and freeze cracking for scanning electron microscopy (SEM). The micrographs of SEM and those of transmission electron microscopy (TEM) were quantitatively analyzed by computerized morphometry, and were correlated with renal function. On day 2 after PAN injection, the slit length was moderately decreased by both shortening and degradation of the foot processes. On day 4, membrane-bounded vesicles were scattered in the lamina rara externa. During foot process effacement, the basal surface of podocytes developed palm-like domains that represented the cytoplasmic areas between interdigitation. The decrease in the length of podocyte cell borders paralleled the decrease of 24-hour creatinine clearance. The development of the palm-like domains on the basal aspects of podocytes estimated by distance class analysis was closely correlated with the sudden onset of proteinuria. We conclude that foot process effacement in PAN nephrosis caused by the retraction and degradation of foot processes leads to the development of palm-like domains, which is correlated with podocyte detachment as well as massive proteinuria.

Apoptosis of crypt epithelial cells in ulcerative colitis

In the colon of ulcerative colitis (UC) patients, apoptotic bodies have been recognized in routine histopathological preparations. To investigate the extent of the apoptosis, colonic biopsies were examined from involved and uninvolved areas of untreated active UC and from normal areas in patients with colonic polyps, utilizing various markers of apoptosis. The markers included DNA breaks detected by TUNEL, Fas (CD95/APO-1) and Fas ligand (Fas-L) localized by immunohistochemistry, electron microscopic features of apoptosis, and laddering of extracted DNA. Apoptosis marker positive cells were found mainly on the luminal epithelium of the normal colon and were present in active UC in crypts of involved and uninvolved areas of the colon, in addition to the luminal epithelium. The DNA extracted from active UC colon electrophoresed as a ladder. These findings suggest that the loss of epithelial cells in active UC occurs mainly by apoptosis in crypts of involved and adjacent uninvolved areas and that the Fas/Fas-L interaction is a mediator of the apoptosis.

Genomic diversity of mec regulator genes in methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis

Low-affinity penicillin-binding protein PBP-2a encoded by mecA is closely related to methicillin resistance in staphylococci, and expression of PBP-2a is controlled by regulator elements encoded by mecR1 and mecI which are located adjacent to mecA on the chromosome. Deletion or mutation which occurred in mec regulator gene is considered to be associated with constitutive production of PBP-2a. The distribution of the mec regulator genes in 176 strains of Staphylococcus aureus and 33 strains of S. epidermidis isolated from a single hospital was studied by polymerase chain reaction amplification. Most clinical isolates of methicillin-resistant S. aureus (MRSA) (94.3%) and S. epidermidis (MRSE) (83.9%) possessed both mecI and mecR1 genes (type I), whereas no mec regulator genes were detected in mecA-negative isolates. In contrast, 7 MRSA and 5 MRSE isolates were found to have incomplete regulator genes, and they were classified into three groups; strains which lacked only mecI gene (type II), strains which lacked mecI and 3'-end of mecR1 gene (type III), and strains which lacked both regulator genes (type IV). Analysis of mecI gene from all the strains having mecI by restriction fragment length polymorphism after Mse I digestion indicated that three MRSA strains possessed one of the known point mutations identified previously. These findings indicated the predominance of a single type of MRSA possessing both mecI and mecR1 in the study period and also suggested a high genomic diversity in mec regulator region of staphylococci.

[Treatment of refractory hematologic malignancies by combination of cytarabine ocfosfate and etoposide]

We attempted a combination chemotherapy with cytarabine ocfosfate (SPAC) and etoposide for myelodysplastic syndrome (MDS), and acute non-lymphocytic leukemia developing after a prior history of MDS (MDS/ANLL). SPAC and etoposide were administered orally at the dose of 200 mg/day and 25 mg/day for 14 days, as standard regimen. Two cases complete remission (CR), 4 of partial remission (PR) were obtained among 9 patients. The plasma concentration of cytarabine (Ara-C) reached a plateau at around 4.5 ng/ml during the treatment period from the 7th to the 14th day, and it was detectable with a gradual decrease until the 28th day in spite of the last administration of SPAC on the 14th day. It is suggested that this combination chemotherapy is useful against MDS, MDS/ANLL and other resistant leukemia, especially in elderly patients who can not be treated by intensive combination chemotherapy.

[Outbreaks of pulmonary tuberculosis in a family and in a hospital. Analysis of restriction-fragment-length polymorphisms]

Restriction-fragment-length polymorphism, analysis was used to study two outbreaks of pulmonary tuberculosis, one in a family and one in a hospital. The DNA probe was derived from the insertion sequence IS 6110. Two groups of isolates were analyzed, both of which were suspected to be common sources of each infection. Both groups showed identical fingerprints within each group. These results suggest that analysis of restriction-fragment-length polymorphism is useful in epidemiological studies of pulmonary tuberculosis.