Nationwide survey shows that methicillin-resistant Staphylococcus aureus strains heterogeneously and intermediately resistant to vancomycin are not disseminated throughout Japanese hospitals

A total of 6,625 methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates obtained from 278 hospitals throughout Japan were obtained between November and December 1997 and were examined for their sensitivities to vancomycin using Mueller Hinton (MH), brain heart infusion (BHI), agar plates, or the broth microdilution method. A concentrated inoculum of an MRSA strain or the use of highly enriched medium, such as BHI medium, allows an individual cell to grow on agar plates containing a vancomycin concentration greater than the MIC for the parent strain. However, cells of the colonies which grew on BHI agar plates containing the higher vancomycin concentrations did not acquire a level of vancomycin resistance greater than that of the parent strain and were not subpopulations of heterogeneously vancomycin-resistant MRSA. There was no significance in the fact that these colonies grew on the higher concentration of vancomycin: none showed stable resistance to vancomycin at a concentration above the MIC for the parent strain, and no cell from these colonies showed a relationship between the MIC and the ability of these colonies to grow on higher concentrations of vancomycin. The vancomycin MIC was not above 2 microg/ml for any of the cells originating from these colonies. No Mu3-type heterogeneously resistant MRSA strains, which constitutively produce subpopulations from MRSA clinical isolates with intermediate vancomycin resistance at a high frequency, were detected. There was a unipolar distribution of the MICs ranging from 0.25 to 2 microg of vancomycin/ml among the 6,625 MRSA clinical isolates, indicating that there was no Mu50-type intermediately vancomycin-resistant MRSA (MIC, 8 microg/ml by National Committee for Clinical Laboratory Standards criteria) among the clinical isolates, and there was no evidence of dissemination of Mu3-type MRSA heteroresistant to vancomycin.

Fulminant myocarditis in polymyositis

Cardiac involvement in patients with polymyositis is usually asymptomatic and associated with a mild clinical course. A female patient with muscle weakness and cardiogenic shock, who was diagnosed with polymyositis and fulminant myocarditis, is described. A large amount of methylprednisolone, in addition to intra-aortic balloon pumping and percutaneous cardiopulmonary support, led to the recovery of her cardiac function. However, a massive cerebral embolism occurred and she died. Postmortem histopathological examination showed necroses of muscles and diffuse invasion of mononuclear cells in both the myocardium and the biceps muscle of her arm. Although the mechanism of cardiac dysfunction is not clear, immunosuppressive therapy was effective for fulminant myocarditis in the present case.

Unique action determinants of double acting topoisomerase inhibitor, TAS-103

O6-methylguanine-DNA methyltransferase (MGMT), gamma-glutamylcysteine synthetase (gamma-GCS), and glutathione (GSH) are found to participate in resistance to TAS-103, a topoisomerase I/II inhibitor. In 13 human cancer cell lines, MGMT expression correlated with IC50 for TAS-103, whereas gamma-GCS expression inversely correlated with the IC50 value, suggesting MGMT may work to decrease TAS-103 activity but gamma-GCS may increase it. A reduced gamma-GCS and GSH, and an increased MGMT were associated with the development of resistance in A549 and DLD cells, and gamma-GCS inhibition by buthionine sulphoximine increased the TAS-103 resistance, whereas MGMT inhibition by both O6-benzyl-guanine and MGMT-antisense transfection sensitized cells to TAS-103.

Macrophage migration inhibitory factor in hepatocellular carcinoma and liver cirrhosis; relevance to pathogenesis

The levels of macrophage migration inhibitory factor (MIF), a proinflammatory and carcinogenic cytokine, were significantly higher in the sera from patients with hepatocellular carcinoma (HCC; 25.6+/-15.3 ng/ml, n=55) and liver cirrhosis (LC; 18.9+/-10.7 ng/ml, n=26) compared with sera from patients with gastrointestinal cancer (6.8+/-7.5 ng/ml, n=29) and normal controls (5.6+/-1.2 ng/ml, n=45; P<0.01). Hepatocytes from patients with LC and HCC, but not from chronic hepatitis, expressed very high levels of MIF. A possible association between overexpression of MIF and hepatocarcinogenesis is suggested.

[Mitral valve stenosis due to primary cardiac granulocytic sarcoma relapsing 8 years after complete remission: a case report]

A 28-year-old man was admitted because of dyspnea on effort. His tricuspid valve had been affected by granulocytic sarcoma and manifested tricuspid valve stenosis 8 years previously. After chemotherapy and radiation therapy, the tumor had disappeared and the tricuspid valve stenosis was relieved. Echocardiography showed that the posterior leaflet of the mitral valve was affected by the tumor, and Doppler ultrasonography revealed mild mitral valve stenosis. Biopsy of the anterior chest wall detected granulocytic sarcoma. Chemotherapy was started. The tumor size was reduced and the mitral valve stenosis became slight. Primary cardiac granulocytic sarcoma is very rare and stenosis of the atrioventricular valve by relapse of this tumor after complete remission is extremely unusual.

Antigen-presenting cells at the liver tissue in patients with chronic viral liver diseases: CD83-positive mature dendritic cells at the vicinity of focal and confluent necrosis

Although defective functions of peripheral blood or splenic antigen-presenting cells (APCs) are implicated in the pathogenesis of persistent infection in murine and human hepatitis B virus (HBV) and hepatitis C virus (HCV)-carriers, little is known regarding liver-infiltrating APCs in patients with chronic liver diseases. Using immunohistochemical methodology and antigen retrieval technique, we have detected APCs such as HLA DR-positive cells, interdigitating cells (IDCs) and CD83-positive mature and activated dendritic cells (DCs) at the liver specimens from 39 patients with chronic hepatitis (CH) and 10 patients with liver cirrhosis (LC). All 3 types of APCs were detected at the portal areas in both CH and LC, the most abundant being the HLA DR-positive APCs. CD83-positive, mature and activated DCs were detected in patients with CH around the areas of focal and confluent necrosis at the liver parenchyma in close association with T cells. The localization of CD83-positive mature and activated DCs at the liver tissues from patients with CH warrants further study about the role of these DCs in the induction of hepatocellular damage. This may also help to design DC-based therapy for patients with chronic liver diseases.

Regulation of hyaluronan synthase gene expression in human periodontal ligament cells by tumour necrosis factor-alpha, interleukin-1beta and interferon-gamma

Accumulation and fragmentation of hyaluronic (HA) accompanies the inflammatory changes in the periodontium and gingival crevicular fluid are involved in periodontitis, but the mechanism for this is unknown. Recently, three human hyaluronan-synthase (HAS1, 2, and 3) genes have been cloned and characterised as synthesising hyaluronans of different molecular weights. Both HAS1 and HAS2 synthesise high molecular-weight HA, whereas HAS3 produces lower molecular weight HA. In the present study the regulation of HAS genes by cytokines in cultured human periodontal ligament (PDL) cells was investigated using a novel real-time fluorescence polymerase chain reaction detection system. Human PDL cells derived from premolars were cultured with or without tumour necrosing factor (TNF)-alpha (1-100 ng/ml), interleukin (IL)-1beta (0.1-10 ng/ml) and interferon (IFN)-gamma (1-100 ng/ml). Expression of HAS mRNA was assessed in cultured cells treated with these cytokines for 0-24 h. The expression of HAS2 mRNA was enhanced about 4.5- and 2.2-fold at maximum after 3-h stimulation with 10 ng/ml TNF-alpha and 1 ng/ml IL-1beta, respectively, whereas IFN-gamma exerted little effect on HAS2 or HAS3 mRNA expression during the experiment. Expression of HAS3 mRNA was increased by about 14- and 10-fold after 3-h stimulation with 10 ng/ml TNF-alpha and 1 ng/ml IL-1beta, respectively. These results suggest that TNF-alpha and IL-1beta regulate HAS expression, and consequently may result in an accumulation of HA and an increase in HA of a lower molecular-weight.

Recurrence of idiopathic thromboembolism during anticoagulant therapy

Patients with acute pulmonary embolism and venous thromboembolism are usually treated with anticoagulant therapy for at least 3 months as the optimum duration. A patient with recurrent idiopathic venous thromboembolism at the eighth month during anticoagulation (warfarin to target international normalized ratio of 2.0-3.0) is described. The case suggests that patients with idiopathic venous thromboembolism have a high risk of recurrence, even if a strict anticoagulant regimen is followed.

Molecular cloning of rabbit hyaluronic acid synthases and their expression patterns in synovial membrane and articular cartilage

cDNAs for hyaluronic acid synthases (HAS2 and HAS3) were cloned from a cDNA library of cultured rabbit synovial membrane cells. The cDNA encoding the open reading frame of rabbit HAS2 and HAS3 was 1659 nucleotides in length with a predicted molecular mass of about 63 kDa. The amino acid sequence showed that the rabbit HAS2 was 98.7 and 98.4%, and HAS3 was 98.2 and 97.5% identical with human and mouse forms of the proteins, respectively. The predicted sequences for hyaluronic acid (HA) binding motifs and the catalytic domains related to beta 1-4 and beta 1-3 linkages, essential for HA synthesis, were almost conserved in both rabbit HAS2 and HAS3, similarly to human and mouse HASs. RT-PCR analysis and in situ hybridization revealed that the mRNA of HAS2 was highly expressed in the synovial membrane and articular cartilage, whereas the expression of HAS3 mRNA was slightest in these tissues. Thus, it is demonstrated that rabbit HASs are highly conserved in sequence content as compared to the human and mouse homologues described previously, and that HAS2 is predominantly expressed in the synovial membrane and articular cartilage, but HAS3 is not.

Deglutitive movement of the tongue under local anesthesia

The purpose of the present study was to investigate whether or not sensory input from the tongue affects deglutitive tongue movement. Subjects were seven healthy volunteers with anesthetic applied to the surface of the tongue (surface group) and seven healthy volunteers with the lingual nerve blocked by anesthetic (blocked group). We established six stages in deglutition and analyzed deglutitive tongue movement and the time between the respective stages by cineradiography before and after anesthesia. After anesthesia in both surface and blocked groups, deglutitive tongue movement slowed and bolus movement was delayed. The deglutitive tongue tip retreated in the blocked group. These results suggest that delay of tongue movement by anesthesia causes weak bolus propulsion and that deglutitive tongue tip position is affected by sensory deprivation of the tongue or the region innervated by the inferior alveolar nerve.

Lessons from an international survey of paper cases of 10 real patients from an early arthritis clinic. CRI (Club Rhumatismes et Inflammation) Group

OBJECTIVE

To determine how experts would classify 10 early-arthritis cases (7 atypical) and to study discrepancies in diagnoses relative to ACR criteria for rheumatoid arthritis (RA) or ESSG criteria for spondyloarthropathy (SpA).

METHODS

Ten real cases (5 met ACR criteria for RA, 6 ESSG criteria for SpA, 3 both and 2 neither) followed for 28.5 +/- 4.8 months were sent as paper cases to 20 international and 12 French experts. Each expert selected a diagnosis among 8 possible choices and rated it on a 0-10 confidence scale. For each case, 3 analog scales (0-100 mm) were used to indicate the probability of RA, SpA or undifferentiated arthritis (UA).

RESULTS

Experts often disagreed about diagnoses (up to 5 different diagnoses for a given case, with a mean of 3.9 per case). Similarly, expert opinions on probabilities for RA and SpA differed widely, with great overlap between confidence for RA, SpA and UA. Fulfilment of ACR or ESSG criteria was poorly related to the experts' diagnosis and evaluation of probabilities for RA and SpA. However, UA was a relatively infrequent choice (19%).

CONCLUSIONS

There was no general consensus about the nosology of early RA and SpA. Classification of atypical early arthritis was not resolved by currently available criteria for RA and SpA. This may have implications for therapy in early disease.

Distinct mechanisms of loss of estrogen receptor alpha gene expression in human breast cancer: methylation of the gene and alteration of trans-acting factors

We have previously shown that the distal promoter (promoter B) of the estrogen receptor alpha (ER alpha) gene is responsible for the enhanced expression of the ER alpha gene seen in human breast cancer and that a novel trans-acting factor, estrogen receptor promoter B associated factor 1 (ERBF-1), is required for transcription from promoter B in breast cancer cells. In development of breast cancer, loss of ER alpha gene expression is one of the most important steps in acquiring hormone resistance, though the mechanisms are poorly understood. Recent studies have reported that methylation of the ER alpha gene promoter A and exon 1 was inversely associated with ER alpha gene expression in human breast cancer and cell lines. The methylation status of the promoter B region, which is responsible for overexpression of ER alpha protein in cancer tissue, has not been investigated. In this report, we found that the methylation status of promoter B, as well as that of promoter A, was inversely associated with ER alpha gene expression in human breast cancer and cell lines. Specific methylation of ER alpha gene promoters in vitro directly decreased transcription of the ER alpha gene in a reporter assay. Demethylating treatment induced transcription of ER alpha mRNA from promoter B in ZR-75-1 cells, which showed no transcription from promoter B, despite weak ERBF-1 expression, but not in ER alpha-negative MDA-MB-231 and BT-20 cells, which lack ERBF-1. ZR-75-1 cells showed promoter activity equal to that of MCF-7 cells in a reporter assay. Our results indicate that methylation of promoter B of the ER alpha gene is important for loss of ER alpha gene expression in human breast cancer, and methylation of the promoters can directly modulate ER alpha gene expression. However, loss of critical transcriptional factors such as ERBF-1 may also be involved in some ER alpha-negative cases.

[A case of fixed drug eruption due to ephedrine hydrochloride]

We report the case of a 29-year old female who developed a fixed drug eruption due to ephedrine hydrochloride administered intravenously during the cesarean section. On the day of the operation a palm-sized dark brown macula with half egg-sized erosion appeared on her right lower thigh. We diagnosed her disease as fixed drug eruption and examined the causative agent among all the 14 drugs used from admission to the appearance of fixed drug eruption. Each of systemic challenge, patch test on the lesion, intradermal and subcutaneous injection on the lesion with ephedrine hydrochloride showed positive reaction. As far as we have been able to search, our case is the first one of fixed drug eruption due to ephedrine hydrochloride.

Context-dependent EKLF responsiveness defines the developmental specificity of the human epsilon-globin gene in erythroid cells of YAC transgenic mice

We explored the mechanism of definitive-stage epsilon-globin transcriptional inactivity within a human beta-globin YAC expressed in transgenic mice. We focused on the globin CAC and CAAT promoter motifs, as previous laboratory and clinical studies indicated a pivotal role for these elements in globin gene activation. A high-affinity CAC-binding site for the erythroid krüppel-like factor (EKLF) was placed in the epsilon-globin promoter at a position corresponding to that in the adult beta-globin promoter, thereby simultaneously ablating a direct repeat (DR) element. This mutation led to EKLF-independent epsilon-globin transcription during definitive erythropoiesis. A second 4-bp substitution in the epsilon-globin CAAT sequence, which simultaneously disrupts a second DR element, further enhanced ectopic definitive erythroid activation of epsilon-globin transcription, which surprisingly became EKLF dependent. We finally examined factors in nuclear extracts prepared from embryonic or adult erythroid cells that bound these elements in vitro, and we identified a novel DR-binding protein (DRED) whose properties are consistent with those expected for a definitive-stage epsilon-globin repressor. We conclude that the suppression of epsilon-globin transcription during definitive erythropoiesis is mediated by the binding of a repressor that prevents EKLF from activating the epsilon-globin gene.

The effects of high magnitude cyclic tensile load on cartilage matrix metabolism in cultured chondrocytes

Excessive mechanical load is thought to be responsible for the onset of osteoarthrosis (OA), but the mechanisms of cartilage destruction caused by mechanical loads remain unknown. In this study we applied a high magnitude cyclic tensile load to cultured chondrocytes using a Flexercell strain unit, which produces a change in cell morphology from a polygonal to spindle-like shape, and examined the protein level of cartilage matrixes and the gene expression of matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs) and proinflammatory cytokines such as IL-1beta and TNF-alpha. Toluidine blue staining, type II collagen immunostaining, and an assay of the incorporation of [35S]sulfate into proteoglycans revealed a decrease in the level of cartilage-specific matrixes in chondrocyte cultures subjected to high magnitude cyclic tensile load. PCR-Southern blot analysis showed that the high magnitude cyclic tensile load increased the mRNA level of MMP-1, MMP-3, MMP-9, IL-1beta, TNF-alpha and TIMP-1 in the cultured chondrocytes, while the mRNA level of MMP-2 and TIMP-2 was unchanged. Moreover, the induction of MMP-1, MMP-3 and MMP-9 mRNA expression was observed in the presence of cycloheximide, an inhibitor of protein synthesis. These findings suggest that excessive mechanical load directly changes the metabolism of cartilage by reducing the matrix components and causing a quantitative imbalance between MMPs and TIMPs.

Mechanism of regulation of the hypoxia-inducible factor-1 alpha by the von Hippel-Lindau tumor suppressor protein

In normoxic cells the hypoxia-inducible factor-1 alpha (HIF-1 alpha) is rapidly degraded by the ubiquitin-proteasome pathway, and activation of HIF-1 alpha to a functional form requires protein stabilization. Here we show that the product of the von Hippel-Lindau (VHL) tumor suppressor gene mediated ubiquitylation and proteasomal degradation of HIF-1 alpha under normoxic conditions via interaction with the core of the oxygen-dependent degradation domain of HIF-1 alpha. The region of VHL mediating interaction with HIF-1 alpha overlapped with a putative macromolecular binding site observed within the crystal structure of VHL. This motif of VHL also represents a mutational hotspot in tumors, and one of these mutations impaired interaction with HIF-1 alpha and subsequent degradation. Interestingly, the VHL binding site within HIF-1 alpha overlapped with one of the minimal transactivation domains. Protection of HIF-1 alpha against degradation by VHL was a multistep mechanism, including hypoxia-induced nuclear translocation of HIF-1 alpha and an intranuclear hypoxia-dependent signal. VHL was not released from HIF-1 alpha during this process. Finally, stabilization of HIF-1 alpha protein levels per se did not totally bypass the need of the hypoxic signal for generating the transactivation response.

A noninvasive method of measuring wave intensity, a new hemodynamic index: application to the carotid artery in patients with mitral regurgitation before and after surgery

Wave intensity (WI) is a new hemodynamic index, which is defined as (dP/dt)(dU/dt) at any site of the circulation, where dP/dt and dU/dt are the time derivatives of blood pressure and velocity, respectively. Arterial WI in normal subjects has two positive sharp peaks. The first peak occurs during early systole when a forward-traveling compression wave is generated by the left ventricle. The magnitude of this peak increases markedly with an increase in cardiac contractility. The second peak, which occurs towards the end of systole, is caused by generation of a forward-traveling expansion wave by the ability of the left ventricle to actively stop aortic blood flow. The interval between the R wave of the ECG and the first peak of WI (R-1st peak interval) and the interval between the first and second peaks (1st-2nd interval) are approximately equal to the preejection period and left ventricular ejection time, respectively. Using a combined Doppler and echo-tracking system, we obtained carotid arterial WI noninvasively. We examined the characteristics of WI in 11 patients with mitral regurgitation (MR) before and after surgery, and 24 normal volunteers. In the MR group before surgery, the second peak was decreased and the (1st-2nd interval)/(R-R interval) ratio was reduced, compared with the normal group (140 +/- 130 vs 750 +/- 290mmHg m/s3. P < 0.0083; 20.7% +/- 3.4% vs 26.7% +/- 2.8%, P < 0.083). There were no significant differences in the first peak between the normal group and the MR group before and after surgery. The second peak in the MR group was increased significantly (P < 0.016 vs before surgery) to 1,150 +/- 830mmHg m/s3 in the early period after surgery (stage I), and to 1,090 +/- 580mmHgm/s3 in the late period after surgery (stage II). These values did not differ significantly from that of the normal group. At stage I, the (R-1st peak interval)/ (R-R interval) ratio was increased from 13.4% +/- 2.7% to 20.6% +/- 5.6% (P < 0.016 vs before surgery). At stage II, this ratio decreased to 16.2% +/- 2.8% (P < 0.016 vs stage I). but was still significantly higher than that before surgery. The (1st-2nd interval)/(R-R interval) ratio increased significantly after surgery (P < 0.016 vs before surgery) to values (27.0% +/- 4.5% at stage I and 28.9% +/- 2.6% at stage II) which did not differ significantly from that of the normal group. The recovery of the second peak after surgery suggests that the left ventricle had recovered the ability to actively stop aortic blood flow. Wave intensity is useful for analyzing changes in the working condition of the heart.

A cineradiographic study of deglutitive tongue movement and nasopharyngeal closure in patients with anterior open bite

The purpose of this study was to investigate the movement of the tip and the dorsal surface of the tongue during deglutition in patients with anterior open bite using cineradiography. The subjects were 10 female patients with anterior open bites and 10 female controls with normal overbites. By cineradiography we established 7 stages of tongue movement and bolus position during deglutition and analyzed the tongue position, tongue movement and the time. The tongue-tip position was more protrusive during deglutition in anterior open bite than in the controls. After the head of the bolus arrived at the opening of the esophagus, the rear part of the dorsal surface of the tongue demonstrated slower movement in patients with anterior open bite than in controls. The nasopharynx closed earlier in patients with anterior open bite than in controls. It is suggested that anterior open bite patients had compensatory coordination of tongue movement, soft palate movement and pharyngeal constrictor muscle activity during deglutition.

Degos' disease with constrictive pericarditis: a case report

A 47-year-old man with Degos' disease was examined by echocardiography, which showed hypokinesis of the apical left ventricular wall with pericardial effusion. To evaluate the myocardial perfusion and coronary flow reserve, 201Tl scintigraphy and intracoronary Doppler flowmetry were performed. The coronary flow reserve was not decreased nor was there angiographical coronary stenosis, although a pressure study revealed constrictive dysfunction of both ventricles. The constrictive pericarditis might have been induced by pericardial vasculitis, thereby causing the left ventricular wall motion abnormality.

Amino acid substitutions in the VanS sensor of the VanA-type vancomycin-resistant Enterococcus strains result in high-level vancomycin resistance and low-level teicoplanin resistance

The vancomycin-resistant enterococci GV1, GV2 and GV3, which were isolated from droppings from broiler farms in Japan have been characterized as VanA-type VRE, which express high-level vancomycin resistance (256 or 512 microg ml(-1), MIC) and low-level teicoplanin resistance (1 or 2 microg ml(-1), MIC). The vancomycin resistances were encoded on plasmids. The vancomycin resistance conjugative plasmid pMG2 was isolated from the GV2 strain. The VanA determinant of pMG2 showed the same genetic organization as that of the VanA genes encoded on the representative transposon Tn1546, which comprises vanRSHAXYZ. The nucleotide sequences of all the genes, except the gene related to the vanS gene on Tn1546, were completely identical to the genes encoded on Tn1546. Three amino acid substitutions in the N-terminal region of the deduced VanS were detected in the nucleotide sequence of vanS encoded on pMG2. There were also three amino acid substitutions in the vanS gene of the GV1 and GV3 strains in the same positions as in the vanS gene of pMG2. Vancomycin induced the increased teicoplanin resistance in these strains.

Beta-globin YAC transgenes exhibit uniform expression levels but position effect variegation in mice

Expression of a construct integrated at different genomic locations often varies because of position effects that have been subcategorized as stable (decreased level of expression) and variegating (decreased proportion of expressing cells). It is well established that locus control regions (LCRs) generally overcome position effects in transgenes. However, whether stable and variegated position effects are equally overcome by an intact LCR has not been determined. We report that single-copy yeast artificial chromosome transgenes containing an unmodified human beta -globin locus were not subject to detectable stable position effects but did undergo mild to severe variegating position effects at three of the four non-centromeric integration sites tested. We also find that, at a given integration site, the distance and the orientation of the LCR relative to the regulated gene contributes to the likelihood of variegating position effects, and can affect the magnitude of its transcriptional enhancement. DNase I hypersensitive site (HSS) formation varies with the proportion of expressing cells, not the level of gene expression, suggesting that silencing of the transgene is associated with a lack of HSS formation in the LCR region. We conclude that transcriptional enhancement and variegating position effects are caused by fundamentally different but inter-dependent mechanisms.