Bacterial components regulate the expression of Toll-like receptor 4 on human mast cells

Objectives and design: The aim of this study was to investigate whether the exposure of mast cells (MCs) to bacterial components affects the expression of Toll-like receptor (TLR) 4, and to elucidate the behavior of MCs during the early response to infection. Materials: Two human MC lines, HMC-1 and LAD2, were employed. Messenger RNA expression was observed by RT and real-time PCR. TLR4 expression was determined by Western blotting. TNF-α secretion was analyzed with ELISA. The degranulation ratio was measured with betahexosaminidase assay. Results: Although bacterial components increased TLR4 mRNA, only lipopolysaccharide (LPS) augmented the TLR4 protein expression. LAD2 pre-treated with LPS for 8 h resulted in 2-fold increased TNF-α secretion on LPS restimulation. Conclusion: These results suggest that the exposure of MCs to LPS may reinforce the innate immune system due to up-regulation of MC TLR4, followed by increased TNF-α release. Received 20 April 2006; returned for revision 14 July 2006; accepted by G. Wallace 11 August 2006     

Laboratory Surveillance for Prospective Plasmid-Mediated AmpC β-Lactamases in the Kinki Region of Japan

Extended-spectrum β-lactamases, plasmid-mediated AmpC β-lactamases (PABLs), and plasmid-mediated metallo-β-lactamases confer resistance to many β-lactams. In Japan, although several reports exist on the prevalence of extended-spectrum β-lactamases and metallo-β-lactamases, the prevalence and characteristics of PABLs remain unknown. To investigate the production of PABLs, a total of 22,869 strains of 4 enterobacterial species, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, and Proteus mirabilis, were collected during six 6-month periods from 17 clinical laboratories in the Kinki region of Japan. PABLs were detected in 29 (0.13%) of 22,869 isolates by the 3-dimensional test, PCR analysis, and DNA sequencing analysis. PABL-positive isolates were detected among isolates from 13 laboratories. Seventeen of 13,995 (0.12%) E. coli isolates, 8 of 5,970 (0.13%) K. pneumoniae isolates, 3 of 1,722 (0.17%) K. oxytoca isolates, and 1 of 1,182 (0.08%) P. mirabilis isolates were positive for PABLs. Of these 29 PABL-positive strains, 20 (69.0%), 6 (20.7%), 2 (6.9%), and 1 (3.4%) carried the genes for CMY-2, DHA-1, CMY-8, and MOX-1 PABLs, respectively. Pattern analysis of randomly amplified polymorphic DNA and pulsed-field gel electrophoretic analysis revealed that the prevalence of CMY-2-producing E. coli strains was not due to epidemic strains and that 3 DHA-1-producing K. pneumoniae strains were identical, suggesting their clonal relatedness. In conclusion, the DHA-1 PABLs were predominantly present in K. pneumoniae strains, but CMY-2 PABLs were predominantly present in E. coli strains. The present findings will provide significant information to assist in preventing the emergence and further spread of PABL-producing bacteria.β-Lactamase production is the most important factor for β-lactam resistance in Gram-negative rods (16). Plasmid-mediated β-lactamases, such as extended-spectrum β-lactamases (ESBLs), plasmid-mediated AmpC β-lactamases (PABLs), and plasmid-mediated metallo-β-lactamases (MBLs), hydrolyze broad-spectrum β-lactams. Detection of these plasmid-mediated β-lactamase-producing isolates is important for epidemiological studies and hospital infection control, because plasmid-mediated genes can spread to other organisms.The Study of Bacterial Resistance in the Kinki Region of Japan (SBRK) Antimicrobial Surveillance Program was established in 1997 to monitor the predominant pathogens and antimicrobial resistance patterns of nosocomial and community-acquired infections via a broad network of clinical laboratories differing in geographic location and size. Our previously reported survey data from the Kinki region of Japan revealed the prevalence of ESBLs and plasmid-mediated MBLs (21, 30); however, the epidemiology of PABLs remains unknown. For this reason, a laboratory-based surveillance study was conducted to determine the presence and prevalence of PABLs among members of the family Enterobacteriaceae.PABL CMY-1 was first found in a Klebsiella pneumoniae isolate in South Korea in 1989 (4, 5). Since then, additional organisms producing PABLs have been reported worldwide (25). PABLs are a heterogeneous group of enzymes that originated from the chromosomal genes of Enterobacter spp. (ACT-1/MIR-1 type), Citrobacter freundii (CMY/LAT type), Morganella morganii (DHA type), Hafnia alvei (ACC-1), and Aeromonas spp. (CMY/MOX type and FOX type). The most prevalent and most widely distributed PABLs are the CMY/LAT-type enzymes (25). In addition to these enzyme types, DHA-type enzymes have been identified in Taiwan (31) and China (15). In Korea (14, 26), DHA-, CMY/MOX-, and ACT-1/MIR-1-type enzymes have also been identified, while in the United States (1, 17), in addition to the types mentioned above, DHA-, ACT-1/MIR-1-, and FOX-type enzymes have been identified. To date, in Japan, MOX-1 (11), CMY-9 (9, 28), CMY-19 (28), CFE-1 (19), CMY-2 (18), and DHA-1 (18) have been found in clinical isolates. Muratani et al. (18) reported PABL producers among cephem-resistant K. pneumoniae isolates, but this report did not indicate the rate of occurrence of PABLs.For the present study, we collected 22,869 isolates from 17 clinical laboratories in the Kinki region of Japan, and we assessed the prevalence and types of PABL-positive bacteria.     

Blood vascular architecture of the palatine tonsil in the musk shrew (Suncus murinus): scanning electron microscopic study of corrosion casts

The musk shrew, Suncus murinus, is one of the primitive mammals and has a pair of palatine tonsils. In the present study, we investigated the blood microvascular architecture of the tonsil in this animal by scanning electron microscopy of corrosion casts. The paranodular arterioles entered the lymph nodule to form a coarse capillary plexus within the nodule. Some of the arterioles reached the dome region to give rise to a fine meshwork of dome subepithelial capillaries. This dome subepithelial capillary network did not show any hairpin or switch-back patterns, as seen in human and rabbit tonsils. Both of the nodular and dome capillaries were drained into the postcapillary venules in the periphery of the nodular or the paranodular region. On the surface of these cast venules, oval-shaped indentations were seen corresponding to the luminal surface of the high endothelial venules. These venules were collected into the large vein at the bottom of the tonsil. The blood vascular architecture of the musk shrew tonsil is basically the same as those of other mucosa-associated lymphoid tissues in mammals.     

Effects of recombinant leukocyte interferon on serum immunoglobulin concentrations and lymphocyte subpopulations in chronic hepatitis B

To investigate immune effects of interferon (IFN) therapy in hepatitis B e antigen (HBeAg)-positive chronic hepatitis B, serum immunoglobulin concentrations and peripheral lymphocyte subpopulations were sequentially studied before, during, and after therapy in nine patients who were treated with recombinant human -IFN in doses ranging from 3 to 10 million units per day for 28 days. Serum immunoglobulin A levels decreased significantly, from 414±23 mg/dl (mean ± SE) to 379±28 mg/dl (P<0.05), after the first week of therapy and to a bottom value of 323±20 mg/dl (P<0.001) at the fourth week. Immunoglobulin G levels decreased significantly, from 2603±175 to 2328±169 mg/dl (P<0.005), after the first week of therapy and to a bottom value of 2005±199 mg/dl (P<0.001) at the fourth week. Immunoglobulin M levels were also reduced significantly after 3 weeks of therapy (from 229±23 to 188±15 mg/dl;P<0.01). These reductions in immunoglobulins A, G, and M returned to pretreatment levels by 4 months after the end of the therapy. In lymphocyte subpopulations, significant depressions were found in CD3-, CD4-, CD8-, and B1-positive cells in peripheral blood after the first week of therapy (CD3, from 1700±114 to 1234±114/mm³,P<0.005; CD4, from 1036±88 to 780±64/mm³,P<0.005; CD8, from 620±57 to 426±60/mm³,P<0.05; and B1, from 519±84 to 276±48/mm³,P<0.01) followed during therapy, while Leul la-positive cells did not change significantly. During the 6-month follow-up period, three patients had a sustained clinical remission in which HBeAg disappeared from serum. Disappearance of HBeAg was unassociated with initial levels or percentage changes of serum immunoglobulins and peripheral lymphocytes expressing each of the test markers in these patients. These findings suggest that immune effects of IFN therapy are independent from its antiviral effects.     

Possible induction of [Met]enkephalin-Arg6-Gly7-Leu8 immunoreactivity in neurons of the rat superior colliculus following eye enucleation

The distribution of [Met]enkephalin-Arg6-Gly7-Leu8 (MEAGL)-immunoreactive (-IR) neurons and its modification after enucleation have been investigated in the rat superior colliculus. In normal rats and on the ipsilateral side of monocular-enucleated rats, small sized vertically elongated fusiform-shaped weakly immunostained neurons were dispersed throughout the sublamina of the stratum griseum superficiale (SGS). In bilaterally enucleated rats and on the contralateral side of monocular-enucleated rats, many small strongly immunoreactive MEAGL-containing neurons, projecting processes horizontally or obliquely toward the surface, appeared in the deepest part of the SGS and the superficial part of the stratum opticum (SO), in contrast to the disappearance of the fusiform-shaped weakly stained neurons in the SGS. MEAGL-IR fibers increased in density throughout the sublamina of the SGS, being densest in the deep SGS, accompanying their increase in the neighboring SO. Sporadically found MEAGL-IR neurons in the deep SO and the stratum griseum intermediale did not show the detectable change of immunoreactivity. These results indicate that enkephalin biosynthesis is undergone by different type of neurons in the normal and the ocular-derived superior colliculus, and suggest that some neurons in the adult superior colliculus have a potentiality to express the peptidergic phenotype.     

Expression of vimentin and epithelial membrane antigen in human malignant lymphomas

Immunoreactivity with monoclonal antibodies against the intermediate filament protein, vimentin, and epithelial membrane antigen (EMA) was examined in 330 cases of lymphoma (317 non-Hodgkin's and 13 Hodgkin's lymphomas), 12 reactive lymph nodes and mononuclear cells of the peripheral blood using either indirect immunoperoxidase staining or the avidin-biotin immunoperoxidase complex technique. The cell origin of each tumor was established using a panel of monoclonal antibodies against lymphocyte differentiation antigens. There were 41 T-cell, 247 B-cell and 29 undetermined lymphomas, and 13 cases of Hodgkin's disease in the series. Vimentin was expressed in 24 T-cell lymphomas (58.5%) and 60 B-cell lymphomas (24.2%). This difference in frequency was statistically significant. Vimentin expression in follicular lymphomas was less frequent than in diffuse B-cell lymphomas. In diffuse lymphomas, small and medium cell types were more reactive with anti-vimentin than large cell types. Reed-Sternberg cells (R-S cells) in Hodgkin's disease were positive for vimentin in 11 cases (84.6%). The frequency of EMA reactivity in lymphomas was low, particularly in T-cell lymphomas. No positive cases were found among follicular lymphomas. In diffuse non-Hodgkin's lymphomas, EMA was expressed only in mixed and large cell types, but never in smaller ones. In conclusion, monoclonal antibodies against vimentin and EMA appear to be of limited usefulness for the diagnosis of non-Hodgkin's lymphomas, but anti-vimentin antibody may be used as an adjunct to the diagnosis of R-S cells in Hodgkin's disease.     

Identification of intracerebral hemorrhage in the early-phase of MM1+2C-type sporadic Creutzfeldt–Jakob disease: A case report

We report a case of early-phase sporadic Creutzfeldt–Jakob disease (sCJD) complicated by intracerebral hemorrhage (ICH), classified as MM1 + 2C-type based on autopsy. A 61-year-old Japanese man presented to our hospital with speaking difficulties including repeated usage of the same words. He was hospitalized on the seventh day after symptom onset, and diffusion-weighted images on magnetic resonance imaging showed hyperintense regions in the frontal cortex and caudate nucleus. On the 11th day after symptom onset, head computed tomography revealed ICH in the right occipital and parietal lobes. Routine laboratory evaluations and angiography revealed no cause of ICH. Myoclonus of the extremities and drowsiness were observed on the 15th day after symptom onset. He reached the state of akinetic mutism approximately two months after symptom onset. The cerebrospinal fluid test revealed positive real-time quaking-induced conversion and 14-3-3 protein. Electroencephalography revealed periodic sharp wave complexes. A clinical diagnosis of probable Creutzfeldt–Jakob disease was made according to the diagnostic criteria. After a relapse of pneumonia, he passed away on the 103rd day after symptom onset. Postmortem examination revealed ICH in the right posterior cingulate gyrus. No pathological change that might have caused ICH was obtained. Although the effect of sCJD on the onset of ICH is undeniable, the cause of ICH was unknown. Prion protein immunohistochemistry revealed the following results: (1) weak synaptic-type deposits in the tissue rarefacted by ICH; (2) synaptic-type deposits in the cerebral cortex, which showed fine vacuoles; and (3) perivacuolar-type deposits in the inferior temporal gyrus and lingual gyrus, which showed frequent large confluent vacuoles. Although it could be considered MM1-type sCJD clinically, this case was neuropathologically diagnosed as having MM1 + 2C-type sCJD. It was shown that ICH may occur in early-phase sCJD. To improve sCJD prognosis, treatment of complications and careful follow up are important. Furthermore, pathological diagnosis is indispensable for sCJD type diagnosis.     

Report on the 89th Scientific Assembly and Annual Meeting of the Radiological Society of North America--analysis of radiation dose by a change of a scan parameter of multi-slice computed tomography by a film method

PURPOSE: It is for a purpose of this study to measure radiation dose by analyzing a dose profile of multi-slice computed tomography varying with helical pitch and a row slice thickness difference complicatedly. MATERIALS AND METHODS: We used multi-slice computed tomography, and helical pitch and row slice thickness change and scanned the helical scan. I used CTDI phantom of a diameter of 25 cm and I inserted roentgen diagnosis use film UR-2(new) which I put between my own phantom in center and 1 cm away from the outer surface and scanned it. And the provided level profile was converted into a dose profile with the dose-density curve which I made beforehand. I analyzed radiation dose than the dose profile. RESULT: In multi-slice computed tomography, radiation dose varied with assembly of row slice thickness and helical pitch. The change of a dose profile changed in a phantom surface part complicatedly. The maximum dose by the measurement of this time was 29 mGy in row slice thickness 0.5 mm, assembly of helical pitch 2.5. In addition, the minimum dose was 6.8 mGy in row slice thickness 3.0 mm, assembly of helical pitch 5.5. And, as for the difference of maximum dose in the same dose profile and the smallest dose, there were about 20 % in row slice thickness 1.0 mm, assembly of helical pitch 5.5. CONCLUSION: The dosimetry of multi-slice computed tomography by a film method enabled it to measure a change of a dose profile by a difference of a scan parameter by high interest solution ability. In addition, it is a method more superior in dosimetry of multi-slice computed tomography spreading through a Z-axis direction broadly than determination by computed tomography use ionization chamber dosimeter. Because radiation dose increases by a scan in thin row slice thickness and small helical pitch, care is necessary.