Electrically tunable graphene-based multi-band terahertz metamaterial filters

In this study, we have designed an electrically tunable multi-band terahertz (THz) metamaterial filter based on graphene and multiple-square-loop structures. The structure contains multiple metal square loops, and these loops with different sizes correspond to different THz frequencies, achieving our expected efficacy of a multiband wave filter. Furthermore, by sweeping external voltages, we could change graphene's Fermi levels, and thus the high-sensitivity THz filter's capability from single-band to multi-band filtering can be modulated. We expect that this study of a hybrid THz wave filter would be promising for the development of selecting channels in THz and 6 G communications.

Differential effects of glucose and N-acetylglucosamine on genome instability

Aberrant sugar metabolism is linked to an increased risk of pancreatic cancer. Previously, we found that high glucose induces genome instability and de novo oncogenic KRAS mutation preferentially in pancreatic cells through dysregulation of O-GlcNAcylation. Increasing O-GlcNAcylation by extrinsically supplying N-acetyl-D-glucosamine (GlcNAc) causes genome instability in all kinds of cell types regardless of pancreatic origin. Since many people consume excessive amount of sugar (glucose, fructose, and sucrose) in daily life, whether high sugar consumption directly causes genome instability in animals remains to be elucidated. In this communication, we show that excess sugar in the daily drink increases DNA damage and protein O-GlcNAcylation preferentially in pancreatic tissue but not in other kinds of tissue of mice. The effect of high sugar on the pancreatic tissue may be attributed to the intrinsic ratio of GFAT and PFK activity, a limiting factor that dictates UDP-GlcNAc levels. On the other hand, GlcNAc universally induces DNA damage in all six organs examined. Either inhibiting O-GlcNAcylation or supplementing dNTP pool diminishes the induced DNA damage in these organs, indicating that the mechanism of action is similar to that of high glucose treatment in pancreatic cells. Taken together, these results suggest the potential hazards of high sugar drinks and high glucosamine intake to genomic instability and possibly cancer initiation.

Disruption of DNA Repair and Survival Pathways through Heat Shock Protein inhibition by Onalespib to Sensitize Malignant Gliomas to Chemoradiation therapy

PURPOSE

Proficient DNA repair by homologous recombination (HR) facilitates resistance to chemo-radiation in glioma stem cells (GSCs). We evaluated whether compromising HR by targeting HSP90, a molecular chaperone required for the function of key HR proteins, using onalespib, a long-acting, brain-penetrant HSP90 inhibitor, would sensitize high-grade gliomas to chemo-radiation in vitro and in vivo Experimental Design: The ability of onalespib to deplete HR client proteins, impair HR repair capacity, and sensitize GBM to chemo-radiation was evaluated in vitro in GSCs, and in vivo using zebrafish and mouse intracranial glioma xenograft models. The effects of HSP90 inhibition on the transcriptome and cytoplasmic proteins was assessed in GSCs and in ex vivo organotypic human glioma slice cultures.

RESULTS

Treatment with onalespib depleted CHK1 and RAD51, two key proteins of the HR pathway, and attenuated HR repair, sensitizing GSCs to the combination of radiation and temozolomide (TMZ). HSP90 inhibition reprogrammed the transcriptome of GSCs and broadly altered expression of cytoplasmic proteins including known and novel client proteins relevant to GSCs. The combination of onalespib with radiation and TMZ extended survival in a zebra fish and a mouse xenograft model of GBM compared to the standard of care (radiation and TMZ) or onalespib with radiation.

CONCLUSIONS

The results of this study demonstrate that targeting HR by HSP90 inhibition sensitizes GSCs to radiation and chemotherapy and extends survival in zebrafish and mouse intracranial models of GBM. These results provide a preclinical rationale for assessment of HSP90 inhibitors in combination with chemoradiation in GBM patients.

Reducing the discomfort in viewing 3D video with a prism device modified eye convergence

A prism device is utilized in this study for modifying the eye convergence to reduce eye accommodation and enhance the comfort in viewing 3D video. Without changing the contents of 3D films, it aims to apply the myosis, convergence, and accommodation visual triad of eyeballs viewing near distance to not change the eyeball pupillary distance when viewing 3D films. Without convergence, the discomfort caused by intraocular muscle contraction when viewing near distance is reduced. Such an effect of a small prism lens is also proven in this study. When viewing 3D films with 1.0△ lenses, the physiological accommodation reaction of eyes would reduce (the right eye decreases 65% and the left eye decreases 70%), revealing the decreasing tension of intraocular muscle. The subjective psychological evaluation result also shows that viewing 3D images with small prism lenses could enhance the comfort. The evaluation of optical simulation, physiological reaction, and mental fatigue proves that the small prism lens proposed in this study could actually improve the comfort in viewing 3D films.

Hydrolyzed Chicken Extract (ProBeptigen®) on Cognitive Function in Healthy Middle-Aged People: A Randomized Double-Blind Trial

Cognitive decline is an important issue of global public health. Cognitive aging might begin at middle adulthood, the period particularly vulnerable to stress in lifespan. Essence of chicken (EOC) has consistently demonstrated its beneficial effects on various cognitive domains as nutritional supplementation. This study primarily aimed to examine the cognitive enhancement effects of ProBeptigen^® (previously named CMI-168), hydrolyzed peptides extracted from EOC, in healthy middle-aged people under mild stress. Ninety healthy subjects were randomly assigned into the ProBeptigen^® or placebo group for eight weeks. Neurocognitive assessment, event-related potentials (ERPs), and blood tests were conducted before, during, and after the treatment. The ProBeptigen^® group outperformed placebo group on Logical Memory subtests of Wechsler Memory Scale-third edition (WMS-III) and Spatial Working Memory task in the Cambridge Neuropsychological Test Automated Battery (CANTAB). The anti-inflammatory effects of ProBeptigen^® in humans were also confirmed, with progressively declining high-sensitivity C-reactive protein (hs-CRP) levels. Regular dietary supplementation of ProBeptigen^® is suggested to improve verbal short- and long-term memory as well as spatial working memory, and reduce inflammation in middle-aged healthy individuals with stress. The effects of ProBeptigen^® on cognition warrant further investigation. (NCT03612752)

Adhesive stem cell coatings for enhanced retention in the heart tissue

Injection into the heart tissue is a direct route for optimally placing mesenchymal stem cells (MSC) to regulate local inflammation following a heart attack. The retention of MSCs at the injection site is severely limited by the fluid flows that rapidly wash cells away and minimize their capacity to modulate cardiac inflammation. To prevent this loss of MSCs and their function, antibody coatings were designed for the surface of MSCs to enhance their adhesion to the inflamed tissue. MSCs were biotinylated, and biotinylated antibodies against intercellular cell adhesion molecules were conjugated to the cell surface through an intermediate layer of streptavidin. MSC surfaces were modified with ~7,000 biotin/μm² and ~23 antibodies/μm². The heart tissue injection of antibody-coated MSCs offered a 3-fold increase of cell retention in an infarcted heart over the injection of uncoated MSCs. We supported the mechanism of adhesion through analysis of MSC adhesion to inflamed endothelial cells and also surfaces of purified adhesion molecules on glass under microfluidic shear flow.

Impaired neuronal sodium channels cause intranodal conduction failure and reentrant arrhythmias in human sinoatrial node

Mechanisms for human sinoatrial node (SAN) dysfunction are poorly understood and whether human SAN excitability requires voltage-gated sodium channels (Nav) remains controversial. Here, we report that neuronal (n)Nav blockade and selective nNav1.6 blockade during high-resolution optical mapping in explanted human hearts depress intranodal SAN conduction, which worsens during autonomic stimulation and overdrive suppression to conduction failure. Partial cardiac (c)Nav blockade further impairs automaticity and intranodal conduction, leading to beat-to-beat variability and reentry. Multiple nNav transcripts are higher in SAN vs atria; heterogeneous alterations of several isoforms, specifically nNav1.6, are associated with heart failure and chronic alcohol consumption. In silico simulations of Nav distributions suggest that I_Na is essential for SAN conduction, especially in fibrotic failing hearts. Our results reveal that not only cNav but nNav are also integral for preventing disease-induced failure in human SAN intranodal conduction. Disease-impaired nNav may underlie patient-specific SAN dysfunctions and should be considered to treat arrhythmias.

The role of of voltage-gated sodium channels (Nav) in pacemaking and conduction of the human sinoatrial node is unclear. Here, the authors investigate existence and function of neuronal and cardiac Nav in human sinoatrial nodes, and demonstrate their alterations in explanted human diseased hearts.

Detection of proteoglycan loss from articular cartilage using Brillouin microscopy, with applications to osteoarthritis

The degeneration of articular cartilage (AC) occurs in osteoarthritis (OA), which is a leading cause of pain and disability in middle-aged and older people. The early disease-related changes in cartilage extra-cellular matrix (ECM) start with depletion of proteoglycan (PG), leading to an increase in tissue hydration and permeability. These early compositional changes are small (<10%) and hence difficult to register with conventional non-invasive imaging technologies (magnetic resonance and ultrasound imaging). Here we apply Brillouin microscopy for detecting changes in the mechanical properties and composition of porcine AC. OA-like degradation is mimicked by enzymatic tissue digestion, and we compare Brillouin microscopy measurements against histological staining of PG depletion over varying digestion times and enzyme concentrations. The non-destructive nature of Brillouin imaging technology opens new avenues for creating minimally invasive arthroscopic devices for OA diagnostics and therapeutic monitoring.

Coatings on mammalian cells: interfacing cells with their environment

The research community is intent on harnessing increasingly complex biological building blocks. At present, cells represent a highly functional component for integration into higher order systems. In this review, we discuss the current application space for cellular coating technologies and emphasize the relationship between the target application and coating design. We also discuss how the cell and the coating interact in common analytical techniques, and where caution must be exercised in the interpretation of results. Finally, we look ahead at emerging application areas that are ideal for innovation in cellular coatings. In all, cellular coatings leverage the machinery unique to specific cell types, and the opportunities derived from these hybrid assemblies have yet to be fully realized.

Optimal expression and purification of sapelovirus A structural protein VP1, and its immunogenicity in mice

Sapelovirus A (SV-A) is a positive-sense single-stranded RNA virus which is associated with acute diarrhea, pneumonia and reproductive disorders. The virus capsid is composed of four proteins, and the functions of the structural proteins are unclear. In this study, we expressed SV-A structural protein VP1 and studied its antigenicity and immunogenicity. SDS-PAGE analysis revealed that the target gene was expressed at high levels at 0.6 mM concentration of IPTG for 24 h. The mouse polyclonal antibody against SV-A VP1 protein was produced and reached a high antiserum titer (1: 2,048,000). Immunized mice sera with the recombinant SV-A VP1 protein showed specific recognition of purified VP1 protein by western blot assay and could recognize native SV-A VP1 protein in PK-15 cells infected with SV-A by indirect immunofluorescence assay. The successfully purified recombinant protein was able to preserve its antigenic determinants and the generated mouse anti-SV-A VP1 antibodies could recognize native SV-A, which may have the potential to be used to detect SV-A infection in pigs.

[Comparison of molluscicidal cost and effectiveness between 5% niclosamide ethanolamine salt granules and 26% suspension concentrate of metalaldehyde and niclosamide ethanolamine salt]

OBJECTIVE

To compare the molluscicidal effects and cost-effectiveness of 5% niclosamide ethanolamine salt granules (NEG) and 26% suspension concentrate of metalaldehyde and niclosamide ethanolamine salt (MNSC) .

METHODS

Two plots with high Oncomelania hupensis snail density were selected as research areas in Nanjing Chemical Industry Zone, and 5% NEG (40 g/m²) and 26% MNSC (40 g/m²) were used by the spraying method for snail control in the two plots, and their molluscicidal effects and cost-effectiveness were investigated and statistically analyzed.

RESULTS

There was no significant difference between 5% NEG and 26% MNSC in the molluscicidal effects. The cost of 5% NEG was 1.25 times higher than that of 26% MN-SC per ten thousand square meters in snail control.

CONCLUSIONS

The cost of 5% NEG is higher than that of 26% MNSC per ten thousand square meters in snail control. Their molluscicidal effects are similar.

Development of small intestinal enzyme activities and their relationship with some gut regulatory peptides in grazing sheep

Growth depends on an animal's capacity to digest and assimilate ingested nutrients, and insufficient supply and impairment will constrain lamb growth. Eight groups of Alpine Finewool lambs were harvested on 0, 3, 7, 14, 21, 28, 42, and 56 d to measure pH and enzymatic activities in the duodenum, proximal jejunum, middle jejunum, distal jejunum, and ileum mucosa or digesta. From the duodenum to the ileum the pH of intestinal mucosa and digesta increased, whereas pH changed very little with age. The trypsin, chymotrypsin, lipase, lactase, and α-amylase activities observed at birth decreased by d 3, followed by a nonuniform enzymatic response in the small intestine. The trypsin activity increased from d 3 to peak, at d 21, followed by a decline. Chymotrypsin activity followed the same general trend but with smaller responses in activities. Trypsin demonstrated greater enzymatic activity than chymotrypsin at the same age. The lipase activity of small intestinal mucosa and digesta changed little with age. The lactase activity was high at birth, decreased by d 3, and then increased, followed by a decrease as lambs approached weaning. α-Amylase activity was similar in the small intestinal mucosa and digesta at birth but increased with age for the duodenum and proximal jejunum. Plasma concentrations of cholecystokinin (CCK), secretin, and gastrin were positively correlated ( < 0.05) with ileal mucosa lipase activity. Plasma concentration of CCK, secretin, gastrin, and gastric inhibitory polypeptide (GIP) were positively correlated ( < 0.05) with ileal mucosa lactase activity. Plasma concentration of pancreatic polypeptide (PP) was negatively correlated ( < 0.05) with lactase activity in the middle jejunum and ileal mucosa. Plasma concentrations of CCK, secretin, gastrin, and GIP were positively correlated ( < 0.05) with α-amylase activity in the ileal mucosa but negatively correlated ( < 0.05) with duodenum, prejejunum, and middle jejunum. Plasma PP concentrations were positively correlated ( < 0.01) with α-amylase activity of duodenum, middle jejunum, and postjejunum mucosa but not with the enzyme activity of postjejunum and ileal mucosa ( > 0.05). Small intestinal enzymatic activities exist and may be sufficient to enhance lamb growth via appropriate nutrient supplementation.

Hydrogel Patches on Live Cells through Surface-Mediated Polymerization

Many naturally occurring cells possess an intrinsic ability to cross biological barriers that block conventional drug delivery, and these cells offer a possible mode of active transport across the blood-brain barrier or into the core of tumor masses. While many technologies for the formation of complete, nanoparticle-loaded coatings on cells exist, a complete coating on the cell surface would disrupt the interaction of cells with their environments. To address this issue, cell surface patches that partially cover cell surfaces might provide a superior approach for cell-mediated therapeutic delivery. The goal of this study is to establish a simplified approach to producing polymeric patches of arbitrary shapes on a live cell via surface-mediated photopolymerization. Cell surfaces were nonspecifically labeled with eosin, and polyethylene (glycol) diacrylate (PEGDA) coatings were directed to specific sites using 530 nm irradiation through a chrome-coated photomask. These coatings may entrap drug-loaded or imaging particles. The extent of nonspecific formation of PEGDA hydrogel coatings increased with irradiation time, light intensity, and initiating species; 40 mW/cm² irradiation for 5 min delivered high-resolution patterns on the surface of A549 cells, and these cells remained viable for 48 h postpatterning with fluorescent nanoparticle-loaded coatings. This work first demonstrated the feasibility of photopatterning polymer patches directly on the surface of cells.

Developmental changes in fatty acid-binding protein (H-FABP) mRNA expression and intramuscular fat (IMF) content in Oula sheep

Increasing meat consumption by Chinese people has created a focus for improving meat quality for increasing quality of life. Twenty-five Male Oula sheep were selected at 2, 21, 56, 84, and 112 d to investigate the developmental changes associated with age on the intramuscular fat (IMF) content of heart fatty acid-binding protein (H-FABP) mRNA expression in muscle. Longissimus dorsal muscle and biceps femoris muscle were sampled to measure IMF concentrations and total mRNA was extracted to measure H-FABP mRNA expression using real-time polymerase chain reaction (PCR). Growing male Oula sheep demonstrated that the IMF concentrations continuously increased with age and significant differences (P < 0.05) were detected among the age groups; 2. The IMF concentrations among tissues were different; 3. The development changes in H-FABP mRNA expression in longissimus dorsal muscle and biceps femoris muscle were similar with a decrease from 2 to 21 d, followed by continuously increasing concentrations being significant different (P < 0.05) among age groups; 4. The H-FABP mRNA expression in the longissimus dorsal muscle tissue was significantly (P < 0.05) higher compared to the biceps femoris muscle; 5. The muscle H-FABP mRNA expression concentration was positively correlated with IMF concentrations from d 21 to 112; 6. The correlation coefficients were significantly (P < 0.01)different between H-FABP gene mRNA expression in the longissimus dorsal muscle and IMF concentration of 0.815 compared to the biceps femoris muscle and IMF concentration of 0.787,which indicated that the H-FABP gene may be affecting the IMF concentrations in the early developmental stages of Oula sheep. These results support the hypothesis that H-FABP gene and its expression in muscle tissue is related to the IMF concentration of meat.

Deletion of the Inflammasome Sensor Aim2 Mitigates Aβ Deposition and Microglial Activation but Increases Inflammatory Cytokine Expression in an Alzheimer Disease Mouse Model

OBJECTIVE

Inflammation is clearly associated with Alzheimer disease (AD). Knockout of Nlrp3, a gene encoding an inflammasome sensor, has been shown to ameliorate AD pathology in a mouse model. Because AIM2 is the most dominant inflammasome sensor expressed in mouse brains, here we investigate whether Aim2 deletion also influences the phenotype of a 5XFAD AD mouse model.

METHODS

Quantitative RT-PCR, immunostaining, immunoblotting, and behavioral analyses were applied to compare wild-type, Aim2-/-, 5XFAD, and Aim2-/-;5XFAD mice.

RESULTS

We found that Aim2 knockout mitigates Aβ deposition in the cerebral cortex and hippocampus of 5XFAD mice. The activation of microglial cells is also reduced in Aim2-/-;5XFAD brains compared with 5XFAD brains. However, Aim2 knockout does not improve memory and anxiety phenotypes of 5XFAD mice in an open field, cued Y-maze, or Barnes maze. Compared with 5XFAD mice, Il-1 expression levels are not reduced in Aim2-/-;5XFAD mice. Unexpectedly, Il-6 and Il-18 expression levels in 5XFAD brains were further increased when Aim2 was deleted. Thus, inflammatory cytokine expression in 5XFAD brains is upregulated by Aim2 deletion through an unknown mechanism.

CONCLUSION

Although Aim2 knockout mitigates Aβ deposition and microglial activation, Aim2 deletion does not have a beneficial effect on the spatial memory or cytokine expression of 5XFAD mice. Our findings suggest that Aβ aggregation and microglial activation may not always be correlated with the expression of inflammatory cytokines or cognitive function of 5XFAD mice. Our study also implies that different inflammasomes likely perform distinct roles in different physiological and/or pathological events.

AIM 2 inflammasomes regulate neuronal morphology and influence anxiety and memory in mice

Inflammasomes are the protein assemblies that consist of inflammasome sensors, adaptor apoptosis-associated speck-like proteins containing a CARD (ASC) and inflammasome caspase. Inflammasomes sense multiple danger signals via various inflammasome sensors and consequently use caspase to trigger proteolytic processing and secretion of IL-1β cytokines. Recent studies have suggested that neurons use their own innate immune system to detect danger signals and regulate neuronal morphology. Here, we investigate whether inflammasomes, the critical components of innate immunity, participate in regulation of neuronal morphology and function. Among various sensors, Absent in melanoma 2 (Aim2) expression in neurons is most prominent. Adding synthetic double-stranded DNA (dsDNA) to cultured neurons induces IL-1β secretion in an AIM2-dependent manner and consequently downregulates dendritic growth but enhances axon extension. The results of Aim2 knockout and knockdown show that AIM2 acts cell-autonomously to regulate neuronal morphology. Behavioral analyses further reveal that Aim2-/- mice exhibit lower locomotor activity, increased anxious behaviors and reduced auditory fear memory. In conclusion, our study suggests that AIM2 inflammasomes regulate neuronal morphology and influence mouse behaviors.

Point-of-care universal screening for meticillin-resistant Staphylococcus aureus: a cluster-randomized cross-over trial

BACKGROUND

Meticillin-resistant Staphylococcus aureus (MRSA) is frequently endemic in healthcare settings and may be transmitted by person-to-person spread. Asymptomatic MRSA carriers are potential, unsuspected sources for transmission and some of them may be identified by admission screening.

AIM

To assess whether rapid point-of-care screening (POCS) for MRSA at hospital admission may be associated with a reduction in MRSA acquisition rates when compared with slower laboratory-based methods.

METHODS

A cluster-randomized cross-over trial was conducted in four admission wards of an acute London tertiary care hospital. Polymerase chain reaction-based POCS screening was compared with conventional culture screening. Patients were screened on ward admission and discharge, and the MRSA acquisition rate on the admission wards was calculated as the primary outcome measure.

RESULTS

In all, 10,017 patients were included; 4978 in the control arm, 5039 in the POCS arm. The MRSA carriage rate on admission was 1.7%. POCS reduced the median reporting time from 40.4 to 3.7 h (P < 0.001). MRSA was acquired on the admission wards by 23 (0.46%) patients in the control arm and by 24 (0.48%) in the intervention arm, acquisition rates of 5.39 and 4.60 per 1000 days respectively. After taking account of predefined confounding factors, the adjusted incidence rate ratio (IRR) for change in trend for MRSA acquisition was 0.961 (95% confidence interval: 0.766-1.206). The adjusted IRR for step change for MRSA acquisition was 0.98 (0.304-3.162).

CONCLUSION

POCS produces a significantly faster result but has no effect on MRSA acquisition on admission wards compared with culture screening. Where compliance with infection prevention and control is high and MRSA carriage is low, POCS has no additional impact on MRSA acquisition rates over the first one to four days of admission compared with conventional culture screening.

Effectiveness of Essence of Chicken in Improving Cognitive Function in Young People Under Work-Related Stress: A Randomized Double-Blind Trial

Work-related stress (WS) can result in considerable and extensive changes in physiological and psychological performance. WS beyond the optimal levels induces anxiety, confusion, exhaustion, and burnout. Chronic WS affects neurocognitive performance, particularly attention and visuospatial memory. Essence of chicken (EC) has been reported to improve neurocognitive function after mental stress.To investigate the beneficial effects of EC in improving neurocognitive performance under WS, we conducted a randomized, double blind trial. Total 102 young workers in New Taipei City with high WS, evaluated using the Individual Subjective Perception Job Stress Scale scores (>36 for job leaders and 33 for nonleaders) were recruited. Fifty-one participants received 70 mL of EC and 51 received a placebo daily for 2 weeks. Blood tests and neurocognitive assessment were performed before treatment, at the end of treatment, and 2 weeks after treatment.EC improved the performance of participants with high depression scores in the form-color associative memory test, used for assessing short-term memory. Although creatinine and glutamic-pyruvic transaminase (GPT) levels increased in week 2, but the levels returned to the baseline in week 4. Blood urea nitrogen (BUN) levels decreased in week 4.EC significantly improved short-term memory in participants with high WS and concomitant depressive mood, although it slightly increased GPT and creatinine levels and reduced BUN levels. The long-term treatment effects of EC warrant further investigation.

Near-infrared spectroscopy system for determining brain hemoglobin level

Traumatic brain injury (TBI) usually results from brain shaking or impact. It can affect the normal function of the brain and even cause people become disabled and death. However, there is lack of studies for the physiological changes of humans or animals under brain injury. In order to obtain the information of physiological state change, we designed and enforced a non-invasive, wireless multi-channel near-infrared spectroscopy (NIRS) for monitoring the concentration change of oxy-hemoglobin (HbO2), deoxy-hemoglobin (HbR) and total-hemoglobin (HbT) continuously during and after TBI. The experimental results indicated that the concentration change of HbO2 and HbT is significantly related to the impact strength and infarction volume. Thus, this system is easily used and stable for TBI study.

Access site complications following transfemoral coronary procedures: comparison between traditional compression and angioseal vascular closure devices for haemostasis

BACKGROUND

Vascular closure devices such as angioseal are used as alternatives to traditional compression haemostasis. Although the safety and efficacy of angioseal are confirmed, their use remains controversial because of the potential complications of these devices compared with those of traditional compression haemostasis. The aim of this study was to compare the access site complication rate, the predictive factors for these complications, and patient comfort levels after coronary procedures with traditional compression or angioseal haemostasis.

METHODS

Data were collected from a cardiac unit in a medical center in northern Taiwan. A total of 130 adult patients were recruited and equally divided into two groups according to the method of haemostasis used after the coronary procedure: a traditional compression group and an angioseal group. We observed the incidence of access site complications, including bleeding, oozing, haematoma formation, and arteriovenous fistula formation. In addition, we used a 0-10 numeric rating scale to assess soreness, numbness, and back and groin access site pain after 1 h of catheter removal and immediately before getting out of bed.

RESULTS

The overall incidence of complications was 3.8 % (n = 5), which was not significantly different between the two groups (p = .06). The propensity score--adjusted multivariate analyses revealed that the only independent predictor for access site complications was an age of >70 years (OR, 10.44; 95 % CI, 1.81-60.06; p = .009). Comfort levels were higher in the angioseal group than in the traditional compression group.

CONCLUSIONS

Angioseal used after coronary procedures did not increase the incidence of complications relative to that associated with traditional compression haemostasis; however, it increased patient comfort levels. Health personnel should pay special attention to the predictive factor for access site complications after coronary procedures, such as age >70 years.

Speckle reduction by combination of digital filter and optical suppression in a modified Gerchberg-Saxton algorithm computer-generated hologram

A speckleless illuminated modified-Gerchberg-Saxton-algorithm-type computer-generated hologram, which adopts a lower frequency of the iterative algorithm and calculation time, is proposed to code a hologram with two signals and position a multiplexing phase-only function, which can reconstruct the left and the right viewing holograms on the pupillary-distance position after the decryption and still maintain the content with high contrast and definition. The reconstructed image quality presents root mean square error of 0.03, with a diffraction efficiency of 87%, and signal-to-noise ratio of 8 dB after the analysis. Furthermore, two denoising techniques for the digital filter and optical suppression are combined, in which the speckle suppression with pseudorandom phase modulation and a rotating diffuser are utilized for successfully reducing the speckle contrast, which was reduced to below 4%. The goal was to reduce visual fatigue for the viewers.

Deltex1 promotes protein kinase Cθ degradation and sustains Casitas B-lineage lymphoma expression

The generation of T cell anergy is associated with upregulation of ubiquitin E3 ligases including Casitas B-lineage lymphoma (Cbl-b), Itch, gene related to anergy in lymphocyte, and deltex1 (DTX1). These E3 ligases attenuate T cell activation by targeting to signaling molecules. For example, Cbl-b and Itch promote the degradation of protein kinase Cθ (PKCθ) and phospholipase C-γ1 (PLC-γ1) in anergic Th1 cells. How these anergy-associated E3 ligases coordinate during T cell anergy remains largely unknown. In the current study, we found that PKCθ and PLC-γ1 are also downregulated by DTX1. DTX1 interacted with PKCθ and PLC-γ1 and stimulated the degradation of PKCθ and PLC-γ1. T cell anergy-induced proteolysis of PKCθ was prevented in Dtx1(-/-) T cells, supporting the essential role of DTX1 in PKCθ downregulation. Similar to Cbl-b and Itch, DTX1 promoted monoubiquitination of PKCθ. Proteasome inhibitor did not inhibit DTX1-directed PKCθ degradation, but instead DTX1 directed the relocalization of PKCθ into the lysosomal pathway. In addition, DTX1 interacted with Cbl-b and increased the protein levels of Cbl-b. We further demonstrated the possibility that, through the downregulation of PKCθ, DTX1 prevented PKCθ-induced Cbl-b degradation and increased Cbl-b protein stability. Our results suggest the coordination between E3 ligases during T cell anergy; DTX1 acts with Cbl-b to assure a more extensive silencing of PKCθ, whereas DTX1-mediated PKCθ degradation further stabilizes Cbl-b.

A hybrid temporal and spatial speckle-suppression method for laser displays

We propose a system that reduces laser display speckles by vibrating the light pipe. A small displacement of the light pipe appears to allow the total reflection of the laser, thereby resulting in a homogenized speckle field that changes with time. In this case, the speckle interference generated by the pattern projected by the laser through the light pipe destroys the spatial homogenization of the laser beams when the light pipe is vibrated. Moreover, when the light pipe begins the sequential vibration, the phases and paths of the beams are changed after the beams traverse the light pipe. Consequently, temporal speckle wavefront superposition can homogenize the luminous intensity distribution of the speckle pattern. This process reduces the speckle contrast to less than 4% while maintaining a luminous intensity of greater than 70%.

Ubiquitin E3 ligase deltex1 promotes PKCθ degradation for full T cell anergy (P1109)

The generation of T cell anergy is associated with upregulation of ubiquitin E3 ligases including Cbl-b, Itch, and GRAIL. Both Cbl-b and Itch contribute to the downregulation of PKCθ in anergic T cells. Recently, we identified deltex1 (DTX1) as another E3 ligase that is upregulated in T cell anergy. DTX1-deficiency prevents T cell anergy production and leads to autoimmunity. In the present study, we found that DTX1 also targeted to PKCθ for degradation. DTX1 overexpression stimulated the degradation of PKCθ. There was a direct interaction between DTX1 and PKCθ. Because DTX1 also promotes Cbl-b expression, we showed that Cbl-b knockdown did not affect the ability of DTX1 to downregulate PKCθ, excluding an involvement of Cbl-b in DTX1-mediated PKCθ degradation. We also found that DTX1-induced PKCθ degradation was not prevented by proteasome inhibitor. Instead, DTX1 directed PKCθ into lysosomal pathway for degradation. In addition, T cell anergy-induced proteolysis of PKCθ was prevented in Dtx1-/- T cells, supporting the essential role of DTX1 in PKCθ downregulation. Our results suggest that DTX1 acts together with Cbl-b and Itch to assure a complete silencing of PKCθ for T cell anergy and immune tolerance.

The profile and familiality of personality traits in mood disorder families

OBJECTIVE

Personality traits have impacts on individuals' response to stress and mood expression. The current study aimed to investigate the profile of personality traits in patients with bipolar disorders and major depressive disorder (MDD). Familial aggregation of personality traits in mood disorder families was also evaluated.

METHODS

We recruited 260 clinical patients of MDD (92), bipolar disorder-I and II (BP-I=111, BP-II=57), 190 first-degree relatives, and 180 controls. Four personality traits were assessed using the Eysenck and Tridimensional Personality Questionnaires, including Extraversion (E), Neuroticism (N), Harm Avoidance (HA), and Novelty Seeking (NS). The magnitude of familiality of personality traits in mood disorder families was evaluated by mixed models and intra-class correlation coefficients (ICC).

RESULTS

Patients with mood disorders had lower E, and higher N, HA and NS than controls. Unaffected relatives were not differed from controls in the four personality traits. BP-I had higher E, NS and lower N, HA than MDD patients (p<0.01). The scale N further distinguished BP-I from BP-II (p=0.02) with lower N among BP-I patients. There exhibited moderate familiality in E (ICC=0.184-0.239) and HA (ICC=0.355) in bipolar disorder families.

LIMITATION

Personality traits were accessed cross-sectionally without quantitatively controlled severity of mood symptoms.

CONCLUSION

Different patterns of personality traits distinguish patients from unaffected individuals as well as separate diagnoses of mood disorders, indicating the usage of more comprehensive evaluation of personality traits in clinical settings. Familiality of extraversion and harm avoidance in bipolar disorder families provides insights for further investigating correlates of comorbid behavioral problems in bipolar disorders.

Study of carbon nanotube modified biosensor for monitoring total cholesterol in blood

A carbon nanotube modified biosensor for monitoring total cholesterol in blood was studied. This sensor consists of a carbon working electrode and a reference electrode screen-printed on a polycarbonate substrate. Cholesterol esterase, cholesterol oxidase, peroxidase and potassium ferrocyanide were immobilized on the screen-printed carbon electrodes. Multi-walled carbon nanotubes (MWCN) were added to prompt electron transfer. Experimental results show that the carbon nanotube modified biosensor offers a reliable calibration profile and stable electrochemical properties.

Unusual thickness-dependent heat-capacity anomalies in free-standing hexatic liquid-crystal films

High-resolution heat-capacity and optical-reflectivity measurements have been conducted near the smectic-A to hexatic-B transition in thin free-standing films of the liquid-crystal compound 64COOBC. We find an unexpected dependence on film thickness of the integrated magnitude of the heat-capacity anomalies as the films undergo layer-by-layer transitions. We measure the penetration depths of the ordering from the surface and next-to-surface layers which are pertinent to the highly correlated thermal behavior.

Unusual thickness-dependent thermal behavior and anticlinic coupling in chiral smectic free-standing liquid-crystal films

We observe, in free-standing films of a chiral smectic liquid crystal, a series of discrete transitions in the relative orientation of the tilt of the interior and surface layers. These transitions include a remarkable reentrant synclinic-anticlinic-synclinic ordering sequence of the film surfaces in the presence of an electric field upon cooling. The profiles of the associated heat-capacity anomalies are found to be strongly thickness dependent and exhibit a novel crossover behavior in reduced dimensions. We measure the anticlinic coupling between tilted surface layers in the smectic- A phase.

Hematology values from clinically healthy Peromyscus leucopus

Reported herein are hematocrit and total and differential WBCs obtained from 132 clinically healthy male and female white-footed mice (Peromyscus leucopus) of four different age groups: 4, 5-8, 9-20, and >32 wk old. Minimal differences were identified between the age groups. The number and percentage of neutrophils in the 4-wk-old mice were significantly higher than those in the other groups; the relative percentage of lymphocytes in the 4-wk-old mice was significantly lower than in the 9-20-wk-old mice. The only significant gender effects identified were higher numbers of WBCs and lymphocytes in females of the 4-wk-old group and higher hematocrits in males of the 5-8- and >32-wk-old groups.

Immunological, hematological, and biochemical responses in immature white-footed mice following maternal Aroclor 1254 exposure: A possible bioindicator

A number of hematological, immunological, and biochemical parameters were measured in Peromyscus leucopus pups born from dams exposed to a single dose (300 mg/kg body weight) of Aroclor 1254. To increase the chances of uncovering even modest consequences of the exposure, in one protocol the pups were weaned at 3 weeks and examined at 6 weeks of age, while in a second protocol the pups were kept with their mother for 4 weeks, at which time they were examined. The older pups showed significant decreases in body weight, ratio of spleen weight to body weight, numbers of peripheral white blood cells and lymphocytes, and number and percentage of monocytes. They also showed significant increases in the stimulation index in response to the mitogen phytohemagglutinin (PHA), percentage of peripheral blood neutrophils and liver EROD induction. Pups sacrificed at 4 weeks of age showed even more significant differences. Their body and liver weights, percentage and number of peripheral blood lymphocytes, and serum antibody titers were significantly lower than those of their controls, while spleen to body weight ratios, percent of neutrophils in their peripheral blood, and liver EROD, PROD, and BROD levels were significantly higher than those of the controls. The primary implication of this work is that white-footed mouse pups could be used as biomonitors of contaminated sites. Females could be captured at the sites and bred in captivity with normal males. The vulnerable parameters identified in this study could then be measured in the resulting offspring and compared with a database collected from normal pups.

Calcium influx inhibition: possible mechanism of the negative effect of tetrahydropalmatine on left ventricular pressure in isolated rat heart

The active ingredient dl-tetrahydropalmatine (THP) isolated from the traditional Chinese herb Corydalis racemosa has been found to have antihypertensive effects. However, severe cardiac and neurological toxic effects were reported from using this herb for the treatment of pain. In an isolated perfused rat heart model, THP at the concentration of 100 microM was found to have a negative effect (-45%) on left ventricular pressure and this effect was produced concentration-dependently from concentrations lower than 50 microM. In isolated cardiomyocytes, radioactive calcium influx was also inhibited significantly by THP at the concentration of 100 microM and this effect was also in a concentration-dependent manner (-39%). In a patient with latent heart disease, the use of Corydalis should probably be detrimental, the toxic effect was probably due to calcium influx inhibition.

A conventional myosin motor drives neurite outgrowth

Neuritic outgrowth is a striking example of directed motility, powered through the actions of molecular motors. Members of the myosin superfamily of actin-associated motors have been implicated in this complex process. Although conventional myosin II is known to be present in neurons, where it is localized at the leading edge of growth cones and in the cell cortex close to the plasma membrane, its functional involvement in growth cone motility has remained unproven. Here, we show that antisense oligodeoxyribonucleotides, complementary to a specific isoform of conventional myosin (myosin IIB), attenuate filopodial extension whereas sense and scrambled control oligodeoxyribonucleotides have no effect. Attenuation is shown to be reversible, neurite outgrowth being restored after cessation of the antisense regimen. Myosin IIB mRNA was present during active neurite extension, but levels were minimal in phenotypically rounded cells before neurite outgrowth and message levels decreased during antisense treatment. By contrast, the myosin IIA isoform is shown to be expressed constitutively both before and during neurite outgrowth and throughout exposure to myosin IIB antisense oligodeoxyribonucleotides. These results provide direct evidence that a conventional two-headed myosin is required for growth cone motility and is responsible, at least in part, for driving neuritic process outgrowth.

Mechanisms of hyperproduction of TEM-1 beta-lactamase by clinical isolates of Escherichia coli

The mechanisms of hyperproduction (defined as > or = 200 nmoles nitrocefin hydrolysed per minute per mg of protein) of TEM-1 beta-lactamase by 38 isolates of Escherichia coli were investigated. The copy numbers of TEM-encoding plasmids were determined for the hyperproducing isolates and for 39 TEM-1-producing isolates that did not hyperproduce the enzyme. Allele-specific PCR was used to determine if the promoter region of the TEM-1 gene was of the TEM-1 or TEM-2 type. Twenty three of the 38 hyperproducers had the TEM-1-type promoter but 15 had the more efficient TEM-2-type promoter; in contrast, 37 of the 39 isolates with lower activities had the TEM-1-type promoter and only two had the TEM-2-type promoter. Many of the TEM-1-hyperproducing isolates possessed small plasmids (< or = 20 MDal) with high copy numbers, in some cases together with large, low copy number plasmids; the average total copy number of TEM-encoding plasmids was 14; if only isolates with the TEM-1-type promoter were included, average total copy number was 22. Hyperproduction was attributed to high copy number (> or = 10) plasmids in 11 isolates; another seven had plasmids with moderately high copy numbers (4-9). The average total copy number for isolates that produced relatively small amounts of TEM-1 beta-lactamase (< or = 100 nmoles/min/mg protein) was 2.2, and for the 12 isolates with TEM-1 activities of 101-200 nmoles/min/mg protein it was 6.8. We conclude that both high copy number plasmids and a more efficient promoter are common causes of hyperproduction of TEM-1.

Incidence and mechanisms of resistance to the combination of amoxicillin and clavulanic acid in Escherichia coli

Among Escherichia coli organisms isolated at St. Thomas's Hospital during the years 1990 to 1994, the frequency of resistance to amoxicillin-clavulanic acid (tested by disk diffusion in a ratio of 2:1) remained constant at about 5% of patient isolates (10 to 15% of the 41 to 45% that were amoxicillin resistant). Mechanisms of increased resistance were determined for 72 consecutively collected such amoxicillin-clavulanic acid-resistant isolates. MICs of the combination were 16-8 micrograms/ml for 51 (71%) of these and > or = 32-16 micrograms/ml for the remainder. The predominant mechanism was hyperproduction of enzymes isoelectrically cofocusing with TEM-1 (beta-lactamase activities, > 200 nmol of nitrocefin hydrolyzed per min per mg of protein) which was found in 44 isolates (61%); two isolates produced smaller amounts (approximately 150 nmol/min/mg) of such enzymes, and two isolates hyperproduced enzymes cofocusing with TEM-2. Eleven isolates produced enzymes cofocusing with OXA-1 beta-lactamase, which has previously been associated with resistance to amoxicillin-clavulanic acid. Ten isolates produced increased amounts of chromosomal beta-lactamase, and four of these additionally produced TEM-1 or TEM-2. Three isolates produced inhibitor-resistant TEM-group enzymes. In one of the enzymes (pI, 5.4), the amino acid sequence change was Met-67-->Val, and thus the enzyme is identical to TEM-34. Another (pI, 5.4) had the substitution Met-67-->Ile and is identical to IRT-I67, which we propose now be given the designation TEM-40. The third (pI, 5.2) had the substitution Arg-241-->Thr; this enzyme has not been reported previously and should be called TEM-41. The rarity and diversity of inhibitor-resistant TEM-group enzymes suggest that they are the result of spontaneous mutations that have not yet spread.

Effect of hyperproduction of TEM-1 beta-lactamase on in vitro susceptibility of Escherichia coli to beta-lactam antibiotics

The susceptibility of 173 TEM-1-producing isolates of Escherichia coli was assessed by determination of MICs by the agar dilution method. MICs of amoxicillin, mezlocillin, cephaloridine, and, to a smaller extent, amoxicillin-clavulanic acid (but not cephalexin, cefuroxime, cefotaxime, ceftazidime, or imipenem) were higher for isolates that produced large amounts of beta-lactamase than for isolates that produced smaller amounts. The effect of fixed concentrations of clavulanic acid on resistance to amoxicillin was assessed for 34 selected TEM-1-producing isolates. Low concentrations of the inhibitor (0.5 to 1 microgram/ml) reduced the amoxicillin MICs substantially for almost all the isolates, although the reductions were not sufficient to render any of the isolates amoxicillin susceptible. Higher concentrations of clavulanic acid had progressively greater effects on amoxicillin MICs, but even at 8 micrograms/ml some of the isolates with high beta-lactamase activities remained resistant or only moderately susceptible to amoxicillin. All the isolates were inhibited by clavulanic acid (in the absence of amoxicillin) at concentrations of 16 to 32 micrograms/ml. TEM-1 beta-lactamase activity was inhibited in vitro by clavulanic acid, but not totally, with approximately 2% of the initial activity remaining at 2 micrograms/ml and 0.4% remaining at 8 micrograms/ml. These findings suggest that the amount of beta-lactamase activity is a major determinant of the degree of resistance to several beta-lactam antibiotics and can make the difference between susceptibility and resistance to some compounds, notably the combination of amoxicillin with clavulanic acid.

Developmental toxicity and teratogenicity of trichosanthin, a ribosome-inactivating protein, in mice

The embryotoxic and teratogenic effects of trichosanthin (TCS), a protein isolated from tubers of Trichosanthes kirilowii (family Cucurbitaceae), were studied both in vivo and in vitro. The protein was administered i.p. to ICR mice on day 8.0 of pregnancy, and the animals were sacrificed 1 day before parturition. The fetuses were fixed and subsequently sectioned. At the highest TCS dose employed (7.5 mg/kg body weight), the viability of fetuses declined to 70.2%, compared with 96.5% in the saline-treated control group. The number of resorbed fetuses increased, and the crown-rump length of the surviving fetuses was reduced. At the doses of 5.0 and 7.5 mg TCS/kg body weight, 2.3% and 9.0%, respectively, of the surviving fetuses were found to be abnormal. The abnormalities observed included exencephaly, micromelia, and short tail. When mouse embryos at the early organogenesis stage were cultured with TCS at a dose of 200 micrograms/ml or above, a significantly larger number of embryos were found to be abnormal as compared with the controls. The abnormalities were observed in the head, trunk, and limb regions. Hence, TCS produced adverse effects on prenatal development both in vivo and in vitro.

Susceptibility of Porphyromonas gingivalis and P. asaccharolytica to the non-oxidative killing mechanisms of human neutrophils

Neutrophils are essential for host defence against bacterial dental plaque and the pathogenic bacterial species within it, but in anaerobic environments such as the gingival crevice neutrophils can kill bacteria only with non-oxidative microbicidal compounds stored in their granules. Porphyromonas gingivalis W83, a pathogenic plaque species, and the avirulent non-oral type-strain P. asaccharolytica were incubated anaerobically with intact neutrophils and with compounds extracted from normal human neutrophil granules. The killing of bacteria and the inactivation of lysozyme, cathepsin G, elastase, bacterial-permeability increasing factor and defensins by culture supernatants were assayed. P. asaccharolytica but not P. gingivalis was killed under anaerobic conditions by intact neutrophils. P. gingivalis was also resistant to neutrophil granule compounds, its viability being reduced from a mean of 3.3 x 10(6) to 6.1 x 10(4) c.f.u/ml in 60 min by 400 micrograms/ml neutrophil granule extract, as compared to a reduction from 4.4 x 10(6) to 2.3 x 10(3) c.f.u/ml for P. asaccharolytica. P. gingivalis culture supernatant inactivated cathepsin G, elastase, bacterial-permeability increasing factor and defensins. Resistance to neutrophil non-oxidative killing mechanisms may be an important virulence factor for P. gingivalis.

Response of chemostat cultures of Pseudomonas aeruginosa to carbapenems and other beta-lactams

Cultures of Pseudomonas aeruginosa were grown at different rates in a chemostat and challenged continuously or intermittently with ceftazidime, imipenem, meropenem or piperacillin. The killing rate was related to the bacterial growth rate; fast-growing cells being killed more rapidly than slow-growing ones. Mutants that were stably derepressed (i.e. constitutive) for chromosomal beta-lactamase expression were selected when a beta-lactamase inducible (i.e. typical) strain was challenged with ceftazidime or piperacillin. Addition of the beta-lactamase inhibitor tazobactam to piperacillin did not prevent selection. There was a lag of c. 24-48 h post-challenge before totally derepressed mutants were detectable. Once selected, the derepressed organisms were stable and were not outgrown by inducible cells if these were readded in the absence of selective antibiotics. Selection of resistant mutants was not observed with imipenem, despite the known tendency of this drug to select carbapenem-impermeable mutants of P. aeruginosa in vivo. Imipenem, but not ceftazidime or meropenem, caused a significant post-antibiotic effect after single or repeated dosage.

Biochemical characterization of a beta-lactamase that hydrolyzes penems and carbapenems from two Serratia marcescens isolates

Reexamination of Serratia marcescens isolates obtained in 1982 revealed two organisms that were resistant to the penem FCE 22101 (MIC, 512 micrograms/ml) and imipenem (MIC, 16 micrograms/ml) and that had slightly reduced susceptibilities to meropenem (MIC, 0.12 micrograms/ml). MICs of these agents for typical S. marcescens isolates were 1 to 8, 0.25 to 0.5, and 0.03 micrograms/ml, respectively. The two isolates were fully susceptible to broad-spectrum cephalosporins, and only one was highly resistant to ampicillin and carbenicillin (MICs, greater than 1,024 micrograms/ml). Both isolates had beta-lactamases that focused at pIs 8.2 and 9.7. The penicillin-resistant isolate additionally produced the TEM-1 enzyme. The enzymes with pIs of 8.2 and 9.7 were separated by cation-exchange chromatography. The pI 8.2 beta-lactamase was a class I enzyme of the type found in most S. marcescens isolates. It was almost inactive against carbapenems and penems, as was the class I enzyme from another S. marcescens strain. The pI 9.7 enzyme hydrolyzed penems and carbapenems rapidly: kcat (turnover number) values for FCE 22101, imipenem, and meropenem were 3.4, 26, and 1% of the kcat value for cephaloridine, respectively; kcat/Km values were 140, 915, and 150% of the kcat/Km value for cephaloridine, respectively. Otherwise, the pI 9.7 enzyme had predominantly penicillinase activity. It was inhibited more readily by clavulanate than by tazobactam and was inactivated by the chelating agents EDTA and ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid. Expression of the pI 9.7 enzyme was not associated with any plasmid, and production was not transferred to Escherichia coli K-12 recipients, even after the mobilizing plasmid pUZ8 was inserted into the S. marcecens donor strains.

Clavulanate and beta-lactamase induction

Concern has been expressed that clavulanate can antagonize ticarcillin against enterobacteria and pseudomonads that have inducible expression of chromosomal 'Class I' beta-lactamases. It is suggested that clavulanate-induced enzyme inactivates ticarcillin, which itself is a feeble inducer. We confirmed that this mechanism applied, showing that antagonism was abolished in beta-lactamase-basal mutants of inducible strains. Antagonism has been reported in double disc tests with strains of Pseudomonas aeruginosa, Enterobacter cloacae, Citrobacter freundii, Serratia spp. and indole-positive Proteeae. Only with some strains of Ent. cloacae and Morganella morganii, however, did the presence of 1-32 mg/l clavulanate elevate the MIC of ticarcillin by more than one or two dilutions in chequerboard studies. Clavulanate was synergistic with ticarcillin against Proteus vulgaris strains, being a potent inhibitor of the unusual Class I enzyme of this species. Induction-determined antagonism was not reduced in Ent. cloacae transconjugants that produced the plasmid-mediated TEM-1 beta-lactamase, despite the ability of this enzyme to bind clavulanate. Our results suggest that Ent. cloacae and M. morganii strains should be confirmed not to be more sensitive to ticarcillin alone than to ticarcillin/clavulanate, before the latter combination is used clinically. Otherwise, it appears that beta-lactamase induction is unlikely to cause significant antagonism. It is emphasized that induction is reversible, causing, at worst, a transient resistance. It should not be confused with the selection of stably-derepressed mutants that can occur, for example, in the clinical use of newer cephalosporins.

[The penetration of cephalosporins across the blood-brain barrier and its clinical significance]

The penetration of Cefuroxime (CXM), Ceftazidime (CTZ), Cefotaxime (CTX), Ceftizoxime (CZX), and Ceftriaxone (CTRX) across the blood-brain barrier was studied in 119 patients with or without meningitis after an intravenous injection of 2 grams. Cephalosporins were undetectable or their concentrations very low in the cerebrospinal fluid (CSF), when there was no inflammation in the meninges. On the contrary, the mean CSF concentrations of cephalosporins were 2.21-5.36 micrograms/ml and the CSF/serum ratios 3.73-31.80% in acute stage of purulent meningitis. The CSF levels of all the five cephalosporins were much higher than the mean MICs of the common pathogens of bacterial meningitis as well as that of Enterobacteriaceae. It is thus shown that these five new cephalosporins are useful for treatment of meningitis including those caused by gram-negative bacilli.