Optimal fluorescent-dye staining time for the real-time detection of microbes: a study of Saccharomyces cerevisiae

AIMS

To provide information on the time-dependent behaviour of microbe staining by fluorescent dyes in the order of seconds, which is important in terms of the recent rapid and online techniques for microbe measurements and/or environmental microbe analysis.

METHODS AND RESULTS

For combinations of yeast (Saccharomyces cerevisiae) and typical dyes, including DAPI (4',6-diamidino-2-phenylindole) and Auramine-O, a suspension of yeast cells in ultrapure water was injected into a dye solution in a micro cuvette placed inside a spectrofluorometer and the fluorescence intensity of the resulting solution was measured at 1 s intervals, starting immediately after the mixing and continued until the time for the maximum intensity using various concentrations of yeast and dyes. The relaxation time τ, which corresponds to ~63·2% of the maximum fluorescence intensity, was shown to decrease to below 1 s with increasing DAPI concentration, whereas it remained constant for 2-3 s with increasing Auramine-O concentration, for example at a yeast concentration of 100 µg ml^-1 .

CONCLUSIONS

For the conditions of yeast >10 µg ml^-1 , DAPI >1 µg ml^-1 and Auramine-O >0·1 µg ml^-1 , τ could be adjusted to below 5 s to achieve a rapid and stable staining.

SIGNIFICANCE AND IMPACT OF THE STUDY

Design and operating conditions for rapid and online measurements of microbes can be optimized.

Heat Dissipation through the Blood Contacting Surface of a Thermally Driven LVAS

A heat exchanger for a totally implantable heat driven LVAD is an essential element in overall system thermal management. The heat exchange is accomplished by supplying cooling water from a pusher-plate driven water pump to the engine and then to the heat exchanger on the pump housing. The temperature of the interface between the blood and pump surface is of critical importance for clinically acceptable operation of the system. Temperatures were measured by instrumenting a pump housing with thermocouples and an electric heater on a mock circulatory loop. Flows were varied from 1 to 8 l/min and heat input was 20 watts. At 1.0 l/min pump flow the maximum inner surface temperature rise is 4.5°C. In vitro tests were conducted to examine the effect of elevated temperature on platelete function. Both platelet aggregation and adhesion were reduced at elevated temperatures of 42 and 478C indicating a potential benefit of reduced thrombogenesis on the heated housing surface.

Maillard reaction, mitochondria and oxidative stress: potential role of antioxidants

Glycation and oxidative stress are two important processes known to play a key role in complications of many disease processes. Oxidative stress, either via increasing reactive oxygen species (ROS), or by depleting the antioxidants may modulate the genesis of early glycated proteins in vivo. Maillard Reactions, occur in vivo as well as in vitro and are associated with the chronic complications of diabetes, aging and age-related diseases. Hyperglycaemia causes the autoxidation of glucose, glycation of proteins, and the activation of polyol metabolism. These changes facilitate the generation of reactive oxygen species and decrease the activity of antioxidant enzymes such as Cu,Zn-superoxide dismutase, resulting in a remarkable increase of oxidative stress. A large body of evidence indicates that mitochondria alteration is involved and plays a central role in various oxidative stress-related diseases. The damaged mitochondria produce more ROS (increase oxidative stress) and less ATP (cellular energy) than normal mitochondria. As they are damaged, they cannot burn or use glucose or lipid and cannot provide cell with ATP. Further, glucose, amino acids and lipid will not be correctly used and will accumulate outside the mitochondria; they will undergo more glycation (as observed in diabetes, obesity, HIV infection and lipodystrophia). The objective of this paper is to discuss how to stop the vicious circle established between oxidative stress, Maillard Reaction and mitochondria. The potential application of some antioxidants to reduce glycation phenomenon and to increase the antioxidant defence system by targeting mitochondria will be discussed. Food and pharmaceutical companies share the same challenge, they must act now, urgently and energetically.

Scanning electron microscope imaging of bacteria based on DNA sequence

AIMS

To develop a scanning electron microscopic approach using in situ hybridization (SEM-ISH) for gaining both genetic and morphological information about target bacteria.

METHODS AND RESULTS

Target cells were hybridized with DNA-targeted polynucleotide probes, and a tyramide signal amplification system was used to increase the sensitivity. The protocol of SEM-ISH enabled to detect low copy number target DNA sequences in individual cells.

CONCLUSIONS

SEM-ISH allowed the in situ detection of bacteria carrying a specific gene.

SIGNIFICANCE AND IMPACT OF THE STUDY

Combining morphological study with SEM and ISH techniques appears to be a valuable tool to understand the spatial distribution of target cells in complex microbial communities on various materials.

Heat island mitigation using water retentive pavement sprinkled with reclaimed wastewater

In Japan, reclaimed wastewater has been recycled widely for non-potable urban applications and it is to be used for sprinkling roads to mitigate heat island in urban areas. To assess the heat island mitigation effects of the sprinkling reclaimed wastewater on water retentive pavement, we carried out a survey at Shiodome-District, Tokyo. The temperatures of air and roads, humidity, and WBGT (Wet-bulb globe temperature) were measured and heat flux was estimated to compare the condition of the areas with/without sprinkling. The following results were obtained. 1) Sprinkling reclaimed wastewater decreased the road surface temperature by 8 degrees during the daytime and by 3 degrees at night: temperatures equal to those on planting zones. Nevertheless sprinkling was done only in the daytime, the temperature decrease effect was not only obtained during the daytime: it continued through the night, due to the water retentive pavement. 2) Sprinkling reclaimed wastewater reduced the amount of sensible heat flux and increased that of latent heat flux. These results suggest that sprinkling reclaimed wastewater on water retentive pavement can effectively mitigate the heat island phenomenon.

Somatostatin inhibits the excitability of rat small-diameter trigeminal ganglion neurons that innervate nasal mucosa and project to the upper cervical dorsal horn via activation of somatostatin 2a receptor

This study investigated whether somatostatin (SST) modulates the excitability of nociceptive trigeminal ganglion (TRG) neurons that innervate the nasal mucosa and project to the upper cervical (C(1)) dorsal horn by using perforated-patch clamping, retrograde-labeling, and immunohistochemistry. Fluorogold (FG) retrograde labeling was used to identify the rat TRG neurons innervating the nasal mucosa, while microbeads (MB) were used to label neurons projected onto the superficial layer of the C(1) dorsal horn. FG-labeled small-diameter TRG neurons exhibited SST(2A) receptor immunoreactivity (19%) and half of these neurons were also labeled with MB. In whole-cell current-clamp mode, most (72%) of the dissociated FG-/MB-labeled TRG neurons were hyperpolarized by application of SST. The hyperpolarization was evoked by SST in a concentration-dependent manner (0.1-10 microM) and the responses were associated with a decrease in the cell input resistance. The minimum concentration to elicit a significant hyperpolarization was 1 microM. The repetitive firings during a depolarizing pulse were significantly reduced by SST (1 microM) application. The hyperpolarization and decreased firing evoked by SST were both blocked by the SST(2) receptor antagonist, CYN154806 (1 microM). Under voltage-clamp conditions, SST (1 microM) significantly increased the voltage-gated K(+) transient (I(A)) and sustained (I(K)) currents and these increases were abolished by coapplication of CYN154806 (1 microM). In the presence of both 4-aminopyridine (6 mM) and tetraethylammonium (10 mM), no significant changes in the membrane potential in response to SST application were found. These results suggest that modulation of trigeminal nociceptive transmission in the C(1) dorsal horn by activation of SST(2A) receptors occurs at the level of small-diameter TRG cell bodies and/or their afferent terminals, and that this may be related to regulation of protective upper-airway reflexes.

Normal esophageal mucosae adjacent to esophageal adenocarcinomas in both Japanese and U.S. patients have a field defect of methylation changes

4636

Background: Esophageal mucosae that reside next to gross cancer are often without histological premalignant changes. We hypothesized that DNA hypermethylation could be detected in “normal” tissues adjacent to esophageal adenocarcinomas (EAC). Methods: A cohort of patients from Japan (J, n=14) and the United States (US, n=41) with locally advanced EAC were evaluated for methylation status. Esophagectomy specimens provided a source of paired normal and tumor tissues. After DNA extraction, methylation specific PCR was used to evaluate the promoters of APC, p16 and MGMT in all samples. Methylation frequency was calculated for each patient and expressed as a percentage of total. Results: Age, gender, pathologic stage and epigenetic analyses of primary tumors were similar in each cohort. Methylation frequency of tumors was: APC (66% US; 70% J). p16 (39% US; 20% J). MGMT (63% US; 75% J). In adjacent histologically “normal” esophageal mucosae, the percentage of patients with methylation at 0, 1, 2 or 3 genes was 79%, 14%, 0%, 7% for the J group and 56%, 44%, 10% and 2% for the U.S. group. In both cohorts, the majority of the normal samples had no methylation changes. In over half of the total cohort, however, there was at least one gene in the adjacent histologically “normal” tissue positive for DNA hypermethylation. Very few samples in either group, however, had more than one gene methylated in histologically “normal” esophageal mucosae. In general, the same methylation pattern present in the “normal” tissue persisted in the primary malignancy. Conclusions: Histologically negative esophageal mucosae adjacent to cancer frequently show at least one hypermethylated gene in a multiple gene panel. These data suggest that for patients with EAC, regardless of nationality, there is a field defect of promoter hypermethylation changes in adjacent esophageal mucosae. These events reflect those of the primary malignancy, and are probably early and cumulative during carcinogenesis.

No significant financial relationships to disclose.

Unavoidable arterioplasty of the pulmonary main trunk for complete resection of mediastinal paraganglima--a case report

Anterior mediastinal paraganglioma is a rare neoplasm and its pathogenesis has not yet been fully understood. The treatment of choice is complete surgical resection, however, its hypervascular nature and proximity to the great vessels makes resection challenging. Operations for paraganglioma have been referred to as a surgical challenge. Moreover, definitive preoperative diagnoses of mediastinal paraganglioma are rarely made, which has made it difficult for thoracic surgeons to prepare for such a challenge preoperatively. We report a case of anterior mediastinal paraganglioma, which was resected successfully under cardiopulmonary bypass, followed by arterioplasty of the pulmonary main trunk.

Simple detection of small amounts of Pseudomonas cells in milk by using a microfluidic device

AIMS

Flow cytometry offers rapid and reliable analyses of bacteria in milk. However, a flow cytometer is relatively expensive and operation is rather complicated for an unskilled operator. We applied flow cytometry using a microfluidic device (on-chip flow cytometry) in detection of small amounts of milk-spoiling bacteria.

METHODS AND RESULTS

Pseudomonas cells in milk were in situ hybridized with Cy5-labelled probe specific for Pseudomonas spp. under optimized condition. Numbers of Pseudomonas cells in the stationary phase and in the starved state determined by on-chip flow cytometry were compared with those determined by conventional plate counting, and on-chip flow cytometry detected targeted cells in milk that were undetectable as colony forming units(CFU) on Standards Methods Agar.

CONCLUSIONS

The contamination in milk with fewer than 10 CFU ml(-1) of targeted cells in starved state was detectable with simple procedure (0.5 h milk-clearing, 1 h fixation, 2 h hybridization and 0.5 h on-chip flow cytometry following 12 h enrichment of cells).

SIGNIFICANCE AND IMPACT OF THE STUDY

On-chip flow cytometry following fluorescence in situ hybridization could be applicable to simple detection of milk-spoiling bacteria.

Activation of α2-adrenoreceptors suppresses the excitability of C1 spinal neurons having convergent inputs from tooth pulp and superior sagittal sinus in rats

The aim of the present study was to test the hypothesis that activation of alpha(2)-adrenoreceptors modulates the excitability of C1 neurons having convergent inputs from both the tooth pulp (TP) and the superior sagittal sinus (SSS), by using the microiontophoretic techniques of drug application and immunohistochemical approaches. Extracellular single-unit recordings were made from 38 C1 neurons responding to electrical stimulation of TP under pentobarbital-anesthetized rats. Seventy-one percent of C1 neurons (27/38) that responded to TP stimulation also responded to electrical stimulation of the SSS. In these neurons, L: -glutamate-evoked C1 neuronal discharge firings were increased in a dose-dependent manner. The mean glutamate-evoked firing rates were dose-dependently inhibited after microiontophoretic application of clonidine (alpha(2)-adrenoreceptor/imidazoline I(1) receptor agonist). The inhibition of glutamate-evoked C1 mean firings by clonidine was antagonized by the co-application of idazoxan (alpha(2)-adrenoreceptor/imidazoline I(2) receptor antagonist), yohimbine (alpha(2)-adrenoreceptor) but not the alpha(1)-adrenoreceptor antagonist, prazosin with affinity for alpha(2B)- and alpha(2C)-adrenoreceptors. The mean spontaneous discharge frequencies were significantly inhibited by the microiontophoretic application of clonidine and this inhibition was reversed by the co-application of idazoxan, yohimbine. Microiontophoresis of clonidine also resulted in a reduction of TP-/SSS-evoked activity and this effect was reversed by the co-application of yohimbine. Immunoreactivity for alpha(2A)-adrenoreceptor was found in the superficial layers of I-III in the C1 region. These results suggest that alpha(2)-adrenoreceptor agonist clonidine inhibits the excitability of C1 neurons having convergent inputs from TP and SSS afferents, and that the activation of alpha(2A)-adrenoreceptors onto C1 dorsal horn neurons may contribute as a useful therapeutic target for the alleviation of trigeminal referred pain associated with migraine and tooth pain.

Enhanced excitability of rat trigeminal root ganglion neurons via decrease in A-type potassium currents following temporomandibular joint inflammation

The aim of the present study was to investigate the effect of temporomandibular joint inflammation on the excitability of trigeminal root ganglion neurons innervating the temporomandibular joint using a perforated patch-clamp technique. Inflammation was induced by injection of complete Freund's adjuvant into the rat temporomandibular joint. The threshold for escape from mechanical stimulation in the temporomandibular joint-inflamed rats was significantly lower than that in control rats. Fluorogold labeling was used to identify the trigeminal root ganglion neurons innervating the site of inflammation. When voltage-clamp (V(h)=-60 mV) conditions were applied to these Fluorogold-labeled small diameter trigeminal root ganglion neurons (<30 mum), voltage-dependent transient K(+) current densities were significantly reduced in the inflamed rats compared with controls. In addition, the voltage-dependence of inactivation of the voltage-dependent transient K(+) current was negatively shifted in the labeled temporomandibular joint-inflamed trigeminal root ganglion neurons. Furthermore, temporomandibular joint inflammation significantly reduced the threshold current and significantly increased action potential firings evoked at two-fold threshold in the Fluorogold-labeled small trigeminal root ganglion neurons. Application of 4-aminopyridine (0.5mM) to control trigeminal root ganglion neurons mimicked the changes in the firing properties observed after complete Freund's adjuvant treatment. Together, these results suggest that temporomandibular joint inflammation increases the excitability of trigeminal root ganglion neurons innervating temporomandibular joint by suppressing voltage-dependent transient K(+) current via a leftward shift in the inactivation curve. These changes may contribute to trigeminal inflammatory allodynia in temporomandibular joint disorder.

Current bioremediation practice and perspective

The use of microbes to clean up polluted environments, bioremediation, is a rapidly changing and expanding area of environmental biotechnology. Although bioremediation is a promising approach to improve environmental conditions, our limited understanding of biological contribution to the effect of bioremediation and its impact on the ecosystem has been an obstacle to make the technology more reliable and safer. Providing fundamental data to resolve these issues, i.e., the behavior of the target bacteria directly related to the degradation of contaminants and the changes in microbial communities during bioremediation, has been a challenge for microbiologists since many environmental bacteria cannot yet be cultivated by conventional laboratory techniques. The application of culture-independent molecular biological techniques offers new opportunities to better understand the dynamics of microbial communities. Fluorescence in situ hybridization (FISH), in situ PCR, and quantitative PCR are expected to be powerful tools for bioremediation to detect and enumerate the target bacteria that are directly related to the degradation of contaminants. Nucleic acid based molecular techniques for fingerprinting the 16S ribosomal DNA (rDNA) of bacterial cells, i.e., denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP), enable us to monitor the changes in bacterial community in detail. Such advanced molecular microbiological techniques will provide new insights into bioremediation in terms of process optimization, validation, and the impact on the ecosystem, which are indispensable data to make the technology reliable and safe.

Multicolour digital image analysis system for identification of bacteria and concurrent assessment of their respiratory activity

AIMS

To develop a rapid and simple multicolour digital image analysis system for simultaneous identification of bacteria and assessment of their metabolic activity.

METHODS AND RESULTS

We developed an image analyser capable of distinguishing triple-stained bacterial cells. Bacteria were stained with a nucleic acid stain, a fluorescent antibody and a fluorescent metabolic indicator for enumeration, species identification and assessment of metabolic activity. This multicolour image analyser was used to simultaneously identify Escherichia coli O157:H7 in milk samples and assess their respiratory activity. The images of the triple-stained bacteria were captured using a combination of blue light and u.v. excitation and an epifluorescence microscope and were processed by our image analyser. We found a good correlation between the counts of actively respiring (r = 0.93) and total (r = 0.94) E. coli O157:H7 measured by digital image analysis and visual observation.

CONCLUSION

The multicolour digital image analysis system described here was able to quantify active pathogenic micro-organisms within 2 h.

SIGNIFICANCE AND IMPACT OF THE STUDY

This multicolour image analysis allows the rapid and simultaneous quantification of bacteria, identification of species and assessment of metabolic activity.

Role of capsaicin-sensitive primary afferent inputs from the masseter muscle in the C1 spinal neurons responding to tooth-pulp stimulation in rats

The aim of the present study was to demonstrate the convergence of inputs from masseter muscle (MM) and tooth pulp (TP) onto C1 spinal neurons and to determine whether the afferent fibers express the functional vanilloid receptor (VR1). Extracellular single-unit recordings were made from 61 C1 units responding to TP electrical stimulation with a constant temporal relationship to a digastric electromyogram signal in pentobarbital anesthetized rats. Eighty-four percent of C1 neurons responding to TP stimulation also responded to the ipsilateral MM stimulation. Of these neurons, 61% were considered to be afferent inputs from Adelta-fibers and the remaining units (39%) were C-fibers, based on calculation of the nerve conduction velocity. Intramuscular injection of capsaicin (0.05 and 0.1%) produced a reduction in a MM-induced C1 neuronal activity in a dose-dependent manner and this effect was antagonized by pretreatment with an antagonist of VR1, capsazepine. Some of these units were also excited by noxious heat stimulation (> 43 degrees C). The trigeminal root ganglion (TRG) neurons that innervated the MM were retrogradely labeled with Fluorogold (FG) and the small-diameter FG-labeled TRG neurons expressed the immunoreactivity for VR1. After intramuscular mustard oil injection (noxious chemical stimulation), the C1 neuronal activity induced by both touch and pinch stimuli was enhanced and their receptive field sizes were significantly expanded. These changes were reversed within 15-20 min. These results suggest that there may be the convergence of noxious afferents inputs from the MM and TP afferents on the same C1 neurons in rats, and that the afferent fibers expressing the functional VR1 may contribute to the hyperalgesia and/or referred pain associated with temporomandibular joint disorder.

High plasma concentrations of osteopontin in patients with interstitial pneumonia

Osteopontin (OPN) produced by alveolar macrophages functions as a fibrogenic cytokine in the development of bleomycin (BLM)-induced murine pulmonary fibrosis, and OPN mRNA is expressed on lung tissues from patients with idiopathic pulmonary fibrosis (IPF). The present study investigates plasma OPN levels in human interstitial pneumonia (IP) and their relationships with disease severity by analyzing the correlation between plasma OPN concentrations and pulmonary functions. The concentrations of OPN in plasma were measured in 17 patients with IP, in 9 with sarcoidosis and in 20 healthy controls using an antigen-capture enzyme-linked immunosorbent assay. The concentrations of OPN in plasma were significantly higher in IP patients than in those with sarcoidosis or in controls. Based on a Receiver Operating Characteristic curve analysis, cut-off points between 300 and 380 ng/ml discriminated between IP and control subjects with 100% sensitivity and 100% specificity. In such case, the sensitivity for sarcoidosis decreased (55.5-33.3%) in cut-offs with 100% specificity. Plasma OPN levels inversely and closely correlated with arterial oxygen tension (PaO2) in patients with IP. Immunohistochemically, OPN was localized predominantly in macrophages and airway epithelium. These findings suggest that plasma OPN levels were found to be associated with the presence of IP, and that OPN play an important role in the development of IP.

Rapid monitoring of microbial contamination on herbal medicines by fluorescent staining method

AIMS

To apply fluorescent staining method for fast assessment of microbial quality of herbal medicines.

METHODS AND RESULTS

The number of total bacteria and esterase-active bacteria on powdered traditional Chinese medicines were enumerated by fluorescent staining method using 6-carboxyfluorescein diacetate (6CFDA) and 4',6-diamidino-2-phenylindole (DAPI), and they were compared with colony-forming units (CFU). The CFU was approximately 10(3) per gram in ginseng radix, and no bacterial colonies were detected from others. However, the total bacterial number (TDC) was more than 10(7) per gram, and number of bacteria possessing esterase activity ranged from 1 to 3% of TDC.

CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY

Many bacteria in each Chinese medicine had enzyme activity and most of them could not be detected by conventional plate counting technique. Enumeration of bacterial cells on traditional Chinese medicines by fluorescent staining method requires less than 1 h. The double staining method with 6CFDA and DAPI could be applicable to rapid microbial monitoring of crude drugs.

Real-time PCR assays based on distinct genomic regions for cytomegalovirus reactivation following hematopoietic stem cell transplantation

Real-time PCR has many advantages compared with antigenemia and qualitative PCR assays for detecting cytomegalovirus (CMV) infection in patients following SCT. However, the procedure used in each report was not standardized. This study compares the CMV load detected by real-time PCR assays amplifying distinct genomic regions. Real-time PCR assays based on US17, UL65, immediate early protein (IE) and glycoprotein B(gB) were selected and comparisons were made between each genomic region, and with antigenemia and nested PCR (IE region) in 18 SCT patients. The CMV load detected by real-time PCR using all combinations of primers targeting distinct genomic regions and by antigenemia assays correlated well. However, US17 and UL65-PCR could detect CMV earlier than gB-PCR, antigenemia and nested PCR assays. In longitudinal analysis, gB-PCR demonstrated a trend for showing a lower viral load in some patients than US17-, UL65- and IE-PCR. Moreover, the results suggest that a cutoff level of 500 copies/ml might be used to decide when to initiate treatment. We propose that monitoring should be carried out using real-time PCR assays targeting the US17 region and that a CMV load of 500 copies/ml could be used as a cutoff value for initiating treatment in patients following SCT, receiving immunoglobulin prophylaxis.

Bacterial population dynamics and community structure in a pharmaceutical manufacturing water supply system determined by real-time PCR and PCR-denaturing gradient gel electrophoresis

AIMS

To control bacteria in the pharmaceutical water supply system.

METHODS AND RESULTS

Bacteria were enumerated by conventional culture method and fluorescent vital staining. Activated carbon treatment and storage in a tank provided favourable environments for bacterial growth. The bacterial population of the water in both the post-activated carbon treatment and the tank was analysed by denaturing gradient gel electrophoresis (DGGE) with PCR-amplified 16S rDNA fragments including V6, -7, and -8 regions. The bacterial community structure in activated carbon treated water was stable throughout the year. Several kinds of bacteria such as genus Aquaspirillum and Methylobacterium were found in the water after activated carbon treatment. The bacterial community structure was changed and other bacteria such as mycobacteria were detected after storage. Mycobacteria were quantified in water samples using real-time PCR targeting the 16S rDNA gene. Mycobacteria were also detected in tap water and their number was increased 10(3)-10(4)-fold higher after storage.

CONCLUSION

These data suggest the importance of culture-independent methods for quality control of water used in pharmaceutical manufacturing.

SIGNIFICANCE AND IMPACT OF THE STUDY

Critical steps and specified bacteria that should be controlled in the water supply system were recognized by culture-independent methods. These data will enable effective control of water used in the pharmaceutical industry.

Opioidergic modulation of excitability of rat trigeminal root ganglion neuron projections to the superficial layer of cervical dorsal horn

The aim of the present study was to investigate the effect of a micro-opioid receptor agonist DAMGO (Tyr-d-Ala-Gly-NMe-Phe-Gly-ol) on the excitability of trigeminal root ganglion (TRG) neurons, projecting onto the superficial layer of the cervical dorsal horn, by using the perforated-patch technique and to determine whether TRG neurons show the expression of mRNA or functional protein for micro-opioid receptors by using reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. TRG neurons projecting onto the superficial layer of the cervical dorsal horn were retrogradely labeled with Fluorogold (FG). The cell diameter of FG-labeled TRG neurons was small (<30 microm). Under voltage-clamp (V(h)=-60 mV), voltage-dependent K(+) currents were recorded in the TRG neurons and isolated by blocking Na(+) and Ca(2+) currents with appropriate ion replacement. Separation of the K(+) current components was achieved by the response to variation in the conditioning voltage. Two distinct K(+) current components, a transient (I(A)) and sustained (I(K)), were identified. DAMGO significantly increased I(A) by 57% (20 microM) and in a dose-dependent manner (1-50 microM). Similarly, I(K) was also enhanced by DAMGO administration (42%, 20 microM). The augmentation of both I(A) and I(K) was antagonized by a micro-opioid receptor antagonist, CTOP (d-Phe-Cys-Thr-d-Trp-Orn-Thr-Pen-Thr-NH(2)). Hyperpolarization of the membrane potential was elicited by DAMGO (20 microM) and the response was associated with a decrease in the input resistance. DAMGO induced hyperpolarization was blocked by CTOP. DAMGO-sensitive I(A) and I(K) currents were antagonized by K(+) channel blockers, 4-aminopyridine (4-AP) and tetraethylammonium (TEA). In the presence of both 4-AP and TEA, no significant changes in membrane potential induced by DAMGO application were observed. In the presence of BaCl(2), DAMGO evoked hyperpolarization with decreased resistance was observed. The firing rate of action potentials and the first spike duration induced by depolarizing step pulses were decreased in the presence of DAMGO. RT-PCR analysis demonstrated the expression of mRNA for micro-opioid receptors in the trigeminal ganglia. The micro-opioid receptor immunoreactivity was expressed in the small diameter FG-labeled TRG neurons. These results suggest that the activation of micro-opioid receptors inhibits the excitability of rat small diameter TRG neurons projecting on the superficial layer of the cervical dorsal horn and this inhibition is mediated by potentiation of voltage-dependent K(+) currents. We therefore concluded that modulation of nociceptive transmission in the trigeminal system, resulting in the functional activation of micro-opioid receptors, occurs at the level of small TRG cell bodies and/or their primary afferent terminals, which contribute to opioid analgesia in the trigeminal pain.

CTLA-4 blockade inhibits induction of Helicobacter pylori-associated gastritis in mice

The balance between Th1 and Th2 response determines the outcome of Helicobacter pylori infection. Interferon (IFN)-gamma plays an inductive role in gastric inflammation, whereas interleukin (IL)-4 counterbalances Th1 response and suppresses the development of gastritis. Th cell response is regulated by co-stimulatory factors. A co-stimulatory molecule, cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), plays an inhibitory role in IL-2-dependent cell growth and mediates an optimal inhibitory signal to Th1 and Th2 cells. We administered anti-CTLA-4 monoclonal antibody (MoAb), which blocks CTLA-4 signalling, to examine the relative role for this signalling during maturation of Th1 and Th2 cells in H. pylori infection in mice. Mice treated by anti-CTLA-4 MoAb within the first week of infection showed an inhibition of gastric inflammation, accompanied by an increasing ratio of H. pylori-specific IgG1/IgG2a in serum following infection. Furthermore, the treatment resulted in the higher ratio of IL-4/IFN-gamma by splenocytes in response to H. pylori antigen at 6 weeks after infection, compared with untreated mice. These results suggest that the predominance of Th2 response by CTLA-4 blockade leads to an inhibition of the development of gastric inflammation. CTLA-4 signalling could contribute to the regulation of Th subsets and the development of gastric inflammation in H. pylori infection.

Sequential analysis of testicular lesions and serum hormone levels in rats treated with a Psoralea corylifolia extract

In order to clarify pathogenetic targets for the testicular toxicity of a extract of Psoralea corylifolia (P. corylifolia), F344 rats were fed diet containing 3% P. corylifolia extract for up to 12 weeks and subjected to hormone assays and histopathological examination on the testis and epididymis at weeks 1, 2, 4, 8 and 12 (Exp 1). Similar analyses were performed on 1, 3, 7 and 14 days after a single gavage administration of the P. corylifolia extract at a dose of 10 g/kg b.w. (Exp 2). In Exp 1, increase in the numbers of degenerated and exfoliated germ cells and loss of elongated spermatids beyond steps 7 or 8 were initially observed in the seminiferous tubules at week 1, followed by more pronounced degeneration of germ cells with depletion of post-meiotic populations from week 2. The tubular degeneration was associated with Leydig cell atrophy and persistent reduction of serum testosterone and FSH levels throughout the treatment period and a slight reduction of serum LH in later stages. In Exp 2, reduction of serum testosterone and FSH levels preceded degeneration of germ cells in stage VII and VIII tubules at 3 and 7 days after the administration. The results suggest that rapid androgen deprivation reflecting direct interference with Leydig cell function and simultaneous disturbance of the pituitary-testicular axis play pivotal roles in P. corylifolia extract-induced germ cell injury in seminiferous tubules.

Clinical evaluation of combined endoscopic variceal ligation and sclerotherapy of gastric varices in liver cirrhosis

BACKGROUND AND STUDY AIMS

Endoscopic injection sclerotherapy (EIS) using cyanoacrylate and balloon-occluded retrograde transvenous obliteration (B-RTO) are the main procedures used to treat gastric varices. However, neither technique is free of problems. EIS for gastric varices may cause embolism in other organs; B-RTO requires a gastrorenal shunt and may aggravate esophageal varices. We have developed a combined form of endoscopic therapy involving band ligation and sclerotherapy which is an effective and safe procedure for treating gastric varices.

PATIENTS AND METHODS

Fifty-six patients with gastric varices and liver cirrhosis were treated at Almeida Memorial Hospital from June 1997 to May 2002 using the combined procedure. Each gastric varix was tightly ligated with O-rings, and 1 % polidocanol was injected into the submucosa around the ligated varix. If necessary, additional sclerotherapy was carried out after the initial treatment.

RESULTS

The rate of hemostasis for variceal bleeding was 100 %, and no critical complications were noted. Complete disappearance of the gastric varices was observed endoscopically in all cases. Computed tomography showed that collateral vessels outside the gastric wall were not occluded by the treatment. Endoscopic follow-up examinations were carried out, and gastric varices recurred in seven patients (12.5 %). Only two of the patients (3.6 %) had a small amount of oozing bleeding. Additional endoscopic variceal ligation (EVL) and/or EIS were performed in these seven cases, and none of the patients died as a result of a bleeding gastric varix.

CONCLUSIONS

The combined procedure was easily performed immediately after endoscopic examination, and required no special apparatus. It was found to be a safe and effective method of treating gastric varices.

Development of multicolour digital image analysis system to enumerate actively respiring bacteria in natural river water

AIMS

To develop a rapid and simple method for the assessment of metabolic activity of bacteria in natural environment.

METHODS AND RESULTS

A rapid and simple multicolour digital image analysis system for enumerating viable bacteria based on active fluorescent staining has been developed. This system can accurately differentiate actively respiring bacteria and non-respiring bacteria by distinctive colour information in the digital image captured by an epifluorescence microscope equipped with low magnification objective lens. An algorithm to distinguish bacteria from considerable detritus, which produced bright fluorescence in different colours, by colour segmentation has also been developed. This system was applied to river water samples, and the total and respiratory active bacterial counts by digital image analysis were highly related to those by epifluorescence microscopy (r2 = 0.96 and 0.93, respectively).

CONCLUSION

This system allowed the rapid and simple differentiation of bacteria from detritus and concurrent assessment of their metabolic activity, with results being available within 1 h.

SIGNIFICANCE AND IMPACT OF THE STUDY

The low magnification image analysis allows more rapid and simple quantification of bacteria and could considerably decrease image data amount and acquisition time. This system could be easily applied to the rapid analysis of microbes in various environments.

Efficacy of triple therapy comprising rabeprazole, amoxicillin and metronidazole for second-line Helicobacter pylori eradication in Japan, and the influence of metronidazole resistance

BACKGROUND

The widespread use of eradication therapy for Helicobacter pylori in Japan has led to an increase in antibiotic-resistant strains and the problem of re-treatment in cases of eradication failure.

AIM

To perform drug sensitivity testing for metronidazole in 92 H. pylori-positive patients who had failed eradication treatment with first-line triple therapy, consisting of a proton pump inhibitor, amoxicillin and clarithromycin, and were administered metronidazole-containing second-line therapy.

METHODS

Second-line eradication therapy, consisting of rabeprazole (20 mg b.d.), amoxicillin (750 mg b.d.) and metronidazole (250 mg b.d.), was administered for 1 week and the eradication rates and influence of metronidazole resistance were determined.

RESULTS

The eradication rates for rabeprazole-amoxicillin-metronidazole were 88% (81/92) using intention-to-treat analysis and 91% (81/89) using per protocol analysis. The eradication rates were 97% (61/63) for metronidazole-sensitive strains and 82% (18/22) for metronidazole-resistant strains.

CONCLUSIONS

As second-line H. pylori eradication treatment in Japan, rabeprazole-amoxicillin-metronidazole triple therapy is effective, even with metronidazole-resistant strains.

Successful bone marrow transplantation from an unrelated donor in a patient with adult T cell leukemia

We report a 51-year-old male with adult T cell leukemia (ATL) who received a BMT from an HLA-identical unrelated donor. The ATL proved refractory to chemotherapy, and he underwent BMT conditioned with CY/TBI. Complications of encephalitis of unknown origin were successfully treated with steroid therapy and the patient has been in CR for 16 months after BMT. Human T cell leukemia virus type 1 proviral DNA loads were reduced to undetectable levels in PBMC sampled 12 months after BMT. This encouraging result suggests that BMT from an unrelated donor should be considered for ATL even if the disease is refractory to chemotherapy.

Eradication rates of clarithromycin-resistant Helicobacter pylori using either rabeprazole or lansoprazole plus amoxicillin and clarithromycin

BACKGROUND

The resistance of Helicobacter pylori to clarithromycin has become one of the primary reasons for eradication failure.

AIM

To compare the eradication rates of triple therapy using amoxicillin (A), clarithromycin (C) and rabeprazole (R) or lansoprazole (L) against clarithromycin-sensitive and clarithromycin-resistant strains.

METHODS

Two hundred and ninety-five patients were randomly divided into four groups and treated for 1 week: 147 cases were treated with RAC, i.e. 49 cases with R20C400 (10 mg R + 750 mg A + 200 mg C, twice daily), 48 cases with R40C400 (20 mg R + 750 mg A + 200 mg C, twice daily) and 50 cases with R40C800 (20 mg R + 750 mg A + 400 mg C, twice daily); 148 cases with treated with LAC (30 mg L + 750 mg A + 200 mg C, twice daily).

RESULTS

According to intention-to-treat and per protocol analyses, the eradication rates were 88% and 91% with RAC and 78% and 81% with LAC; the eradication rates with R20C400, R40C400 and R40C800 were 94%, 81% and 86%, respectively, in the intention-to-treat analysis. In addition, the eradication rates for clarithromycin-sensitive strains with RAC and LAC were 98% and 89%, respectively, and for clarithromycin-resistant strains with RAC and LAC were 8.1% and 0%, respectively.

CONCLUSIONS

The eradication rate was significantly higher with RAC than LAC. The eradication rate for clarithromycin-resistant strains was low in both groups, and an improved eradication rate could not be achieved by changing the dose of clarithromycin or proton pump inhibitor.

Spontaneous normalization of negative T waves in infarct-related leads reflects improvement in left ventricular wall motion even in patients with persistent abnormal Q waves after anterior wall acute myocardial infarction

This study aimed to clarify whether spontaneous T-wave normalization (TWN) in infarct-related leads reflects improvement in left ventricular (LV) wall motion even in patients with persistent abnormal Q waves after acute myocardial infarction (AMI). Eighty-five patients were classified into the following 3 groups: patients with Q-wave regression (group A, n = 21), those with persistent abnormal Q waves and TWN (group B, n = 36), and those with persistent abnormal Q waves and absence of TWN (group C, n = 28). Groups A and B had greater improvement in LV ejection fraction and regional wall motion between 1 and 6 months after AMI than group C. In conclusion, spontaneous TWN in the healing stage of anterior AMI reflects functional recovery of viable myocardium in the infarct region even in patients with persistent abnormal Q waves.

Value of plasma B type natriuretic peptide measurement for heart disease screening in a Japanese population

BACKGROUND

Conflict exists regarding the usefulness of measuring plasma B type natriuretic peptide (BNP) concentrations for identifying impaired left ventricular (LV) systolic function during mass screening. Various cardiac abnormalities, regardless of degree of LV dysfunction, are prone to carry a high risk of cardiovascular events.

OBJECTIVE

To examine the validity of plasma BNP measurement for detection of various cardiac abnormalities in a population with a low prevalence of coronary heart disease and LV systolic dysfunction.

DESIGN AND SETTING

Participants in this cross sectional study attended a health screening programme in Iwate, northern Japan. Plasma BNP concentrations were determined in 1098 consecutive subjects (mean age 56 years) by direct radioimmunoassay. All subjects underwent multiphasic health checkups including physical examination, ECG, chest radiography, and transthoracic echocardiography.

RESULTS

Conventional diagnostic methods showed 39 subjects to have a wide range of cardiac abnormalities: lone atrial fibrillation or flutter in 11; previous myocardial infarction in seven; valvar heart disease in seven; hypertensive heart disease in six; cardiomyopathy in six; atrial septal defect in one; and cor pulmonale in one. No subjects had a low LV ejection fraction (< 40%). To assess the utility of plasma BNP measurement for identification of such patients, receiver operating characteristic analysis was performed. The optimal threshold for identification was a BNP concentration of 50 pg/ml with sensitivity of 89.7% and specificity of 95.7%. The area under the receiver operating characteristic curve was 0.970. The positive and negative predictive values at the cutoff level were 44.3% and 99.6%, respectively.

CONCLUSION

Measurement of plasma BNP concentration is a very efficient and cost effective mass screening technique for identifying patients with various cardiac abnormalities regardless of aetiology and degree of LV systolic dysfunction that can potentially develop into obvious heart failure and carry a high risk of a cardiovascular event.

Drug combinations with amoxycillin reduce selection of clarithromycin resistance during Helicobacter pylori eradication therapy

This study investigated the relationship between the drug combinations of the eradication regimens and the prevalence of acquired resistance to clarithromycin. Of 540 patients treated with anti-Helicobacter pylori regimens containing clarithromycin, 55 patients (31 males, mean age, 45.6 years) with failed eradication of H. pylori that was susceptible to clarithromycin before treatment were included. The E test was used to test for susceptibility to clarithromycin (minimum inhibitory concentration (MIC) <1 mg/l). Of the 55 patients, 33 (60.0%) developed clarithromycin resistance after failed eradication. Of the dual therapies, the combination of a proton pump inhibitor (PPI) and clarithromycin resulted in 88.9% (8/9) of the patients acquiring clarithromycic-resistance. With the triple therapies, the percentages of patients acquiring clarithromycin resistant strains after using a PPI+clarithromycin+amoxycillin or a PPI+clarithromycin+metronidazole were 38.7% (12/31) and 90.0% (9/10), respectively (P<0.01). These data suggest that regimens containing amoxycillin may prevent the selection of secondary clarithromycin resistance.

[Clinical characterization of blaIMP positive gram-negative rods isolated cases]

We detected the metallo-beta-lactamase gene blaIMP positive strains of the gram-negative rods (GNR) isolated in Oita Medical University Hospital between 1993 and 1999 and studied the clinical characteristics of patients infected or colonized with blaIMP positive GNR. 25 strains (20 Pseudomonas aeruginosa and 5 Serratia marcescens) were detected and most of them were isolated from urinary samples after 1997. In the studies of antimicrobial susceptibility, some strains had sensitivity to aztreonum or imipenem although most of the strains showed multidrug resistance. When blaIMP positive GNR were isolated from patients, these strains were thought to have caused infection in 88% of the patients. About half of the patients were over 65 years old and had malignant diseases. Most of the patients had inserted urinary tract catheters, intratracheal tube or intravernous catheters. It was suggested that the insertion of the catheters were related to infection of blaIMP positive GNRs. Two patients were not treated with any antibiotics before the isolation of blaIMP positive GNRs although more than half of the patients were administered carbapenems and cephems. Most of strains were isolated in the same department and showed the same genotype by pulsed field gel electrophoresis.

[A case of ankylosing spondylitis associated with pulmonary aspergillosis and amyloidosis]

A 56-year-old man was admitted because of diarrhea, cough, weight loss, and disturbance of consciousness. He had been diagnosed as having ankylosing spondylitis at 18-years old. The spondylitis progressed until there was complete rigidity of the spine including the neck, hip and knee joints. Human leukocyte antigen (HLA) B27, which has been characteristic of ankylosing spondylitis, was also present in this case. A chest radiograph showed pleural thickness and a cavity in the right upper lobe; and a soft tissue mass and fluid level was found in the cavity. Aspergillus fumigatus was detected in the sputum and pulmonary aspergillosis was diagnosed. Biopsy of the colon revealed that a large interstitial amyloidosis. Despite the treatment of the patient's malnutrition and lung aspergillosis using amphotericin B, the clinical course was rapidly progressive and the patient died of respiratory failure due to lung aspergillosis. It is important to be aware of these rare complications, which are correlated with the prognosis in cases of ankylosing spondylitis.

Comparison of genomic structures and antigenic reactivities of orthologous 29-kilodalton outer membrane proteins of Helicobacter pylori

We purified a 29-kDa Helicobacter pylori outer membrane protein (Omp29 protein) and cloned the gene encoding the protein from H. pylori strain ATCC 43504. The Omp29 gene corresponded to the reported JHP73 and the HP78-79 genes of H. pylori strains. A corresponding nucleotide fragment was detected in all 150 tested H. pylori clinical isolates by PCR or Southern blotting. The amplified Omp29-corresponding fragments were categorized into a ca. 770-bp-long group and a larger-fragment group. Sequence analysis indicated that the larger fragments were likely synthesized from the 770-bp fragments by insertion of an irrelevant fragment via 17-bp-long repeat sequences. Immunoblot analysis implies that the ca. 770-bp fragment is responsible for the protein homologous to Omp29, whereas the larger fragments are not responsible for those proteins or encoding antigenically distinct proteins. We postulate that the H. pylori outer membrane protein Omp29 can alter its antigenicity through gene modifications mediated by nucleotide transfer.

Optical imaging of neural activity in multiple auditory cortical fields of guinea pigs

Neural activity of multiple fields in the auditory cortex of anesthetized guinea pigs in response to pure tones was visualized by optical recording using a voltage-sensitive dye (RH795). Ten auditory fields were identified based on the tonotopic organization and response latency: the core fields consisting of the primary (AI) and secondary (AII) fields and surrounding belt areas consisting of dorso-anterior (DA), dorsal (D), dorso-posterior (DP), posterior (P), ventro-posterior (VP), ventro-medial (VM), ventro-anterior (VA) and ventral (V) fields. Tonotopic organization was observed in all the fields apart from DA, D, DP and V. Spatio-temporal displays suggest that the auditory information spreads from the core fields of AI and AII to belt fields via three distinct (dorsocaudal, caudal and ventrorostral) pathways.

[A case of primary pleural leiomyosarcoma]

A 70-year-old man was admitted to our hospital with complaints of chest pain and exertional dyspnea. Chest radiography and computed tomography (CT) revealed right pleural effusion and pleural thickening on admission. The pleural fluid was bloody. Microbiological and cytologic examinations of the fluid were negative. The chest CT revealed progress of pleural thickening after hospitalization. A thoracoscopic pleural biopsy was performed, and the histological finding of the excised specimen was leiomyosarcoma. Because no organ of origin of the leiomyosarcoma, other than the pleura, was detected, this case was diagnosed as a primary pleural leiomyosarcoma. It is thought that leiomyosarcoma originating from the pleura is rare.

Pretreatment of mice with clindamycin improves survival of endotoxic shock by modulating the release of inflammatory cytokines

Suppression of endotoxin release and subsequent production of inflammatory cytokines is crucial in the treatment of septic shock. We investigated the effect of clindamycin (CLI) on endotoxic shock induced in mice by Escherichia coli lipopolysaccharide (LPS). Mice were treated with CLI (160 to 600 mg/kg) or saline and then injected with E. coli LPS and D-(+)-galactosamine intraperitoneally 0.5 h after CLI administration. Pretreatment with CLI significantly improved survival in a dose-dependent manner (CLI, at 160, 300, and 440 mg/kg) and significantly lowered the peak concentrations of tumor necrosis factor alpha and interleukin-1beta (IL-1beta) in serum. However, the peak concentrations of IL-6 in the sera of CLI-treated mice were higher than in control mice. Our findings suggest that CLI alters LPS-induced inflammatory cytokine production and suppresses endotoxin-induced mortality in this murine model.

Evaluation of prostate-specific antigen (PSA) membrane test for forensic examination of semen

Prostate-specific antigen (PSA) is a glycoprotein produced by the prostatic gland and functions to liquefy the seminal fluid. Recently several PSA membrane test kits utilizing an immunochromatographic assay are commercially available for clinical screening of PSA concentration in serum. In this study, we applied the three PSA test kits to forensic examination of semen, and evaluated the sensitivity and specificity of the PSA test kits. The specificity were the same, but SMITEST PSA Card had the highest sensitivity among the three kits. Furthermore we certified that the SMITEST PSA Card was little affected by heat or contaminants such as other body fluids, reagent of preliminary test for semen stain and spermicides, and the PSA kit was applied to 30 casework samples.

Safety and efficacy of granulocyte and monocyte adsorption apheresis in patients with active ulcerative colitis: a multicenter study

Active ulcerative colitis (UC) is characterized by activation and infiltration of granulocytes and monocytes/macrophages into the colonic mucosa. The infiltrated leukocytes can cause mucosal damage by releasing degradative proteases, reactive oxygen derivatives, and proinflammatory cytokines. The aim of this trial (conducted in 14 specialist centers) was to assess safety and efficacy of granulocyte and monocyte adsorption apheresis in patients with active UC most of whom were refractory to conventional drug therapy. We used a new adsorptive type extracorporeal column (G-1 Adacolumn) filled with cellulose acetate beads (carriers) of 2 mm in diameter, which selectively adsorb granulocytes and monocytes/macrophages. Patients (n = 53) received five apheresis sessions, each of 60 minutes duration, flow rate 30 ml per minute for 5 consecutive weeks in combination with 24.4 +/- 3.60 mg prednisolone (mean +/- SE per patient per day, baseline dose). During 60 minutes apheresis, 26% of granulocytes, 19.5% of monocytes and 2% of lymphocytes adsorbed to the carriers. At week 7, 58.5% of patients had remission or improved, the dose of prednisolone was reduced to 14.2 +/- 2.25 mg (n = 37). The apheresis treatment was fairly safe, only eight non-severe side effects (in 5 patients) were reported. Based on our results, we believe that in patients with active severe UC, patients who are refractory to conventional drugs, granulocyte and monocyte adsorption apheresis is a useful adjunct to conventional therapy. This procedure should have the potential to allow tapering the dose of corticosteroids, shorten the time to remission and delay relapse.

Discovery of novel mesangial cell proliferation inhibitors using a three-dimensional database searching method

A three-dimensional pharmacophore model of mesangial cell (MC) proliferation inhibitors was generated from a training set of 4-(diethoxyphosphoryl)methyl-N-(3-phenyl-[1,2,4]thiadiazol-5-yl)benzamide, 2, and its derivatives using the Catalyst/HIPHOP software program. On the basis of the in vitro MC proliferation inhibitory activity, a pharmacophore model was generated as seven features consisting of two hydrophobic regions, two hydrophobic aromatic regions, and three hydrogen bond acceptors. Using this model as a three-dimensional query to search the Maybridge database, structurally novel 41 compounds were identified. The evaluation of MC proliferation inhibitory activity using available samples from the 41 identified compounds exhibited over 50% inhibitory activity at the 100 nM range. Interestingly, the newly identified compounds by the 3D database searching method exhibited the reduced inhibition of normal proximal tubular epithelial cell proliferation compared to a training set of compounds.