Nucleus accumbens and dorsal medial striatal dopamine and neural activity are essential for action sequence performance

Separable striatal circuits have unique functions in Pavlovian and instrumental behaviors but how these roles relate to performance of sequences of actions with and without associated cues are less clear. Here, we tested whether dopamine transmission and neural activity more generally in three striatal subdomains are necessary for performance of an action chain leading to reward delivery. Male and female Long-Evans rats were trained to press a series of three spatially distinct levers to receive reward. We assessed the contribution of neural activity or dopamine transmission within each striatal subdomain when progression through the action sequence was explicitly cued and in the absence of cues. Behavior in both task variations was substantially impacted following microinfusion of the dopamine antagonist, flupenthixol, into nucleus accumbens core (NAc) or dorsomedial striatum (DMS), with impairments in sequence timing and numbers of rewards earned after NAc flupenthixol. In contrast, after pharmacological inactivation to suppress overall activity, there was minimal impact on total rewards earned. Instead, inactivation of both NAc and DMS impaired sequence timing and led to sequence errors in the uncued, but not cued task. There was no impact of dopamine antagonism or reversible inactivation of dorsolateral striatum on either cued or uncued action sequence completion. These results highlight an essential contribution of NAc and DMS dopamine systems in motivational and performance aspects of chains of actions, whether cued or internally generated, as well as the impact of intact NAc and DMS function for correct sequence performance.

Contexts facilitate dynamic value encoding in the mesolimbic dopamine system

Adaptive behavior in a dynamic environment often requires rapid revaluation of stimuli that deviates from well-learned associations. The divergence between stable value-encoding and appropriate behavioral output remains a critical test to theories of dopamine's function in learning, motivation, and motor control. Yet how dopamine neurons are involved in the revaluation of cues when the world changes to alter our behavior remains unclear. Here we make use of pharmacology, in vivo electrophysiology, fiber photometry, and optogenetics to resolve the contributions of the mesolimbic dopamine system to the dynamic reorganization of reward-seeking. Male and female rats were trained to discriminate when a conditioned stimulus would be followed by sucrose reward by exploiting the prior, non-overlapping presentation of a separate discrete cue - an occasion setter. Only when the occasion setter's presentation preceded the conditioned stimulus did the conditioned stimulus predict sucrose delivery. As a result, in this task we were able to dissociate the average value of the conditioned stimulus from its immediate expected value on a trial-to-trial basis. Both the activity of ventral tegmental area dopamine neurons and dopamine signaling in the nucleus accumbens were essential for rats to successfully update behavioral responding in response to the occasion setter. Moreover, dopamine release in the nucleus accumbens following the conditioned stimulus only occurred when the occasion setter indicated it would predict reward. Downstream of dopamine release, we found that single neurons in the nucleus accumbens dynamically tracked the value of the conditioned stimulus. Together these results reveal a novel mechanism within the mesolimbic dopamine system for the rapid revaluation of motivation.

Advance directives among community-dwelling stroke survivors

OBJECTIVE

Advance directives (ADs) are integral to health care, allowing patients to specify surrogate decision-makers and treatment preferences in case of loss of capacity. The present study sought to identify determinants of ADs among stroke survivors.

METHODS

In this cross-sectional study (Care Attitudes and Preferences in Stroke Survivors [CAPriSS]), community-dwelling stroke survivors were surveyed on ADs; validated scales were used to query palliative care knowledge and attitudes towards life-sustaining treatments. Logistic regression was used to determine variables associated with ADs.

RESULTS

Among 562 community-dwelling stroke survivors who entered the survey after screening questions confirmed eligibility, 421 (74.9%) completed survey components with relevant variables of interest. The median age was 69 years (IQR 58-75 years); 53.7% were male; and 15.0% were Black. Two hundred and fifty-one (59.6%) respondents had ADs. Compared to stroke survivors without ADs, those with ADs were more likely to be older (median age 72 vs. 61 years; p<0.001), White (91.2% vs. 75.9%, p<0.001), and male (58.6% vs. 46.5%, p = 0.015), and reported higher education (p<0.001) and income (p = 0.011). Ninety-eight (23.3%) participants had "never heard of palliative care". Compared to participants without ADs, participants with ADs had higher Palliative Care Knowledge Scale (PaCKS) scores (median 10 [IQR 5-12] vs. 7 [IQR 0-11], p<0.001), and lower scores on the Attitudes Towards Life-Sustaining Treatments Scale (indicating a more negative attitude towards life-sustaining treatments; median 23 [IQR 18-28] vs. 29 [IQR 24-35], p<0.001). Multivariable logistic regression identified age (OR 1.62 per 10 year increase, 95% CI 1.30-2.02; p<0.001), prior advance care planning discussion with a physician (OR 1.73, 95% CI 1.04-2.86; p = 0.034), PaCKS scores (OR 1.06 per 1 point increase, 95% CI 1.01-1.12; p = 0.018), and Attitudes Towards Life-Sustaining Treatments Scale scores (OR 0.91 per 1 point increase, 95% CI 0.88-0.95; p<0.001) as variables independently associated with ADs.

CONCLUSIONS

Age, prior advance care planning discussion with a physician, palliative care knowledge, and attitudes towards life-sustaining treatments were independently associated with ADs.

[Efficacy and safety of neoadjuvant chemotherapy combined with PD-1 antibody for esophageal squamous cell carcinoma in the real world]

Objective: To evaluate the efficacy and safety of neoadjuvant chemotherapy combined with programmed death-1 (PD-1) antibody in operable, borderline or potentially resectable locally advanced esophageal squamous cell carcinoma(ESCC) in the real world. Methods: The study retrospectively analyzed 28 patients with operable or potentially resectable locally advanced ESCC patients treated with preoperative chemotherapy combined with PD-1 inhibitor in Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School from April 2020 to March 2021. According to the clinical TNM staging system of the 8th edition of the American Joint Committee on Cancer, there were 1, 15, 10, 1 and 1 case of stage Ⅱ, Ⅲ, ⅣA, ⅣB and unknown stage respectively. The treatment was two cycle of dual drug chemotherapy regimen including taxane plus platinum or fluorouracil combined with PD-1 antibody followed by tumor response assessment and surgery if the patient was eligible for resection. Results: Of the 28 patients, 1, 2, 3 and 4 cycles of chemotherapy combined with PD-1 antibody treatment completed in 1, 21, 5, and 1 patient, respectively. Objective response rate (ORR) was 71.4% (20/28), and disease control rate (DCR) was 100% (28/28). The incidence of adverse events exceeding grade 3 levels was 21.4% (6/28), including 3 neutropenia, 1 leukopenia, 1 thrombocytopenia and 1 immune hepatitis. There was no treatment-related death. Of the 23 patients underwent surgery, R0 resection rate was 87.0% (20/23), 13 patients had down staged to the T1-2N0M0 I stage, the pCR rate was 17.3% (4/23), and the pCR rate of primary tumor was 21.7% (5/23). Four patients received definitive chemoradiotherapy. One patient rejected surgery and other treatment after achieved PR response. Conclusion: Neoadjuvant chemotherapy combined PD-1 inhibitor is safe and has high efficacy in operable, borderline or potentially resectable locally advanced ESCC, and it is a promising regimen.

Practice Patterns and Attitudes Among Speech-Language Pathologists Treating Stroke Patients with Dysphagia: A Nationwide Survey

Dysphagia management is a core component of quality stroke care. Speech-Language Pathologists (SLPs) play a key role in the management of post-stroke dysphagia. We sought to elicit perceptions, attitudes, and practice patterns regarding post-stroke dysphagia management among SLPs in the United States. We conducted a survey among SLPs registered with the American Speech-Language-Hearing Association who indicated that they care for acute stroke patients. A total of 336 participants completed the survey. Over half of the participants (58.6%) indicated that they obtain objective swallow testing in ≥ 60% of their post-stroke dysphagia patients. Almost 1 in 5 SLPs indicated that they are often unable to perform objective dysphagia testing due to limited resources (18.8% indicated resource limitations; 78.9% indicated no resources limitations; 2.4% were unsure). SLPs in hospitals without stroke center certification had higher odds of indicating limited resources compared to SLPs in certified stroke centers (OR 2.08, 95% CI 1.11-3.87). Over 75% indicated that percutaneous endoscopic gastrostomy (PEG) tubes after stroke are placed too early. SLPs who obtain objective swallow testing in ≥ 60% of patients had higher odds of indicating that PEG tubes are placed too early (OR 1.70, 95% CI 1.13-2.56). While 19.4% indicated that the optimal timing for PEG after stroke is < 7 days after admission, 25.0% indicated that the optimal timing is > 12 days. Almost 35% indicated that health care system pressures influence their recommendations, and 47.6% indicated that ≥ 25% of PEGs could be avoided if patients were given up to 7 more days for swallowing recovery.

Temporal Trends in Stroke Thrombolysis in the US by Race and Ethnicity, 2009-2018

This study investigates the temporal trend in racial and ethnic differences in use of intravenous thrombolysis for stroke treatment between 2009 and 2018 in a representative sample of US adults.

Geographic and Regional Variability in Racial and Ethnic Disparities in Stroke Thrombolysis in the United States

BACKGROUND AND PURPOSE

Intravenous thrombolysis (IVT) after ischemic stroke is underutilized in racially/ethnically minoritized groups. We aimed to determine the regional and geographic variability in racial/ethnic IVT disparities in the United States.

METHODS

Acute ischemic stroke admissions between 2012 and 2018 were identified in the National Inpatient Sample. Multivariable logistic regression was used to test the association between IVT and race/ethnicity, stratified by geographic region and controlling for demographic, clinical, and hospital characteristics.

RESULTS

Of the 545 509 included cases, 47 031 (8.6%) received IVT. Racially/ethnically minoritized groups had significantly lower adjusted odds of IVT compared with White people in the South Atlantic region (odds ratio [OR], 0.86 [95% CI, 0.82-0.91]), the East North Central region (OR, 0.91 [95% CI, 0.85-0.97]) and the Pacific region (OR, 0.90 [95% CI, 0.85-0.96]). In the South Atlantic region, IVT use in racial/ethnic minority groups was below the national average of all racial/ethnic minority patients (P=0.002). Compared with White patients, Black patients had lower odds of IVT in the Middle Atlantic region (OR, 0.84 [95% CI, 0.78-0.91]), the South Atlantic region (OR, 0.78 [95% CI, 0.74-0.82]), and the East North Central region (OR, 0.86 [95% CI, 0.79-0.93]). In the South Atlantic region, this difference was below the national average for Black people (P<0.001). Hispanic patients had significantly lower use of IVT only in the Pacific region (OR, 0.92 [95% CI, 0.85-0.99]), while Asian/Pacific Islander patients had lower odds of IVT in the Mountain (OR, 0.76 [95% CI, 0.59-0.98]) and Pacific region (OR, 0.89 [95% CI, 0.82-0.97]).

CONCLUSIONS

Racial/ethnic disparities in IVT use in the United States vary by region. Geographic hotspots of lower IVT use in racially/ethnically minoritized groups are the South Atlantic region, driven predominantly by lower use of IVT in Black patients, and the East North Central and Pacific regions.

[Analysis of prognosis-related factors in patients with hepatitis B virus-related acute-on-chronic liver failure]

Objective: To investigate the prognosis-related factors and its predictive value in patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF). Methods: Sixty-three cases with HBV-ACLF were enrolled. According to the prognosis of 4-weeks, patients were divided into survival and death group. Univariate and multivariate analyses were performed on the clinical data of the two groups of patients to screen the risk factors affecting prognosis, evaluate its predictive value, and compare them with the MELD score, CTP score, and CLIFACLF score. The data were analyzed using t-test, Mann-Whitney U test, χ (2) test. Multiple logistic regression analysis was used for multiple risk factors. Results: There were 63 cases with HBV-ACLF, with 16 cases (25.40%) in the 4-week survival group, and 47 cases (74.60%) in the death group. The survival group age was 38.38 ± 14.50 years, which was significantly lower than the age of the death group 52.28 ± 12.51 years (P < 0.001). The survival group alpha-fetoprotein (AFP) level was 91.21 (8.38 ~ 154.10)μg/L, which was significantly higher than the level of the death group [12.60 (5.70 ~ 33.80) μg/L, P = 0.039]. The survival group alanine aminotransferase (ALT) level was 925.65 (523.43 ~ 1 364.80) U/L, which was much higher than that of the death group [371.60 (117.30 ~ 895.30) U/L, P = 0.040]. The survival group serum sodium level was (136.59 ± 4.03) mmol /L, which was significantly higher than the level of the death group [(132.22 ± 6.37) mmol/L, P = 0.013]. The survival group ascites severity level was much lower than that of the death group (P = 0.008). The survival group creatinine level was 56.50(49.43 ~ 86.25) μmol/L, which was much lower than the level of the death group [86.20 (68.00 ~ 143.00) μmol/L, P = 0.003]. Multivariate logistic regression analysis showed that ascites (OR = 0.470, 95% CI: 0.226 ~ 0.977) and age (OR = 0.941, 95% CI: 0.888 ~ 0.996) were risk factors affecting the HBV-ACLF prognosis. The area under the curve predicted liver failure prognostic score for ascites and age was 0.821, and the sensitivity and specificity were 68.8% and 87.2%, which was higher than the area under the curve predicted by the MELD score, CTP score, and CLIFACLF score, respectively. Conclusion: Age and ascites can be used to predict the clinical outcome in patients with HBV-ACLF. Younger patients without ascites have a higher survival rate at 4-weeks, but older patients with ascites are more likely to have a lower survival rate.

Bleeding risk in patients with cardiac disease from ischaemic stroke reperfusion therapy: an update

Background

Intravenous tissue plasminogen activator (rtPA) and arterial endovascular therapy (ET) rapidly restore cerebral perfusion in eligible patients who had an acute ischaemic stroke (AIS). It is unknown whether patients who had an AIS with premorbid cardiac disease respond differently to reperfusion therapies than those without. These patients may have risk factors that worsen outcomes or may represent those who would most benefit from reperfusion therapy.

Objective

To determine whether patients who had an AIS with the most frequently encountered pre-existing cardiac conditions, atrial fibrillation (AF), heart failure (HF), left ventricular assist devices (LVADs), or taking anticoagulation for cardiac indications, are at increased risk for poor outcome, such as symptomatic intracranial haemorrhage (sICH), after reperfusion therapy.

Results

Although AF is an independent risk factor for poor poststroke outcomes, intravenous rtPA is not associated with increased risk of sICH for those not on anticoagulants. Likewise, HF is independently associated with mortality post stroke, yet these patients benefit from reperfusion therapies without increased rates of sICH. Patients with LVADs or who are on anticoagulation should not be given IV rtPA; however, ET remains a viable option in those who meet criteria, even patients with LVAD.

Conclusion

There is no evidence of an increased risk for sICH after intravenous rtPA or ET for those with AF or HF. Intravenous rtPA should not be given to patients on anticoagulation or with LVADs, but ET should be offered to them when eligible. Whenever possible, future AIS reperfusion research should include patients with premorbid cardiac disease as they are frequently excluded, representing a gap in evidence.

Novel Score for Stratifying Risk of Critical Care Needs in Patients With Intracerebral Hemorrhage

OBJECTIVE

To develop a risk prediction score identifying patients with intracerebral hemorrhage (ICH) at low risk for critical care.

METHODS

We retrospectively analyzed data of 451 patients with ICH between 2010 and 2018. The sample was randomly divided into a development and a validation cohort. Logistic regression was used to develop a risk score by weighting independent predictors of intensive care unit (ICU) needs according to strength of association. The risk score was tested in the validation cohort and externally validated in a dataset from another institution.

RESULTS

The rate of ICU interventions was 80.3%. Systolic blood pressure (SBP), Glasgow Coma Scale (GCS) score, intraventricular hemorrhage (IVH), and ICH volume were independent predictors of critical care, resulting in the following point assignments for the Intensive Care Triaging in Spontaneous Intracerebral Hemorrhage (INTRINSIC) score: SBP 160 to 190 mm Hg (1 point), SBP >190 mm Hg (3 points); GCS 8 to 13 (1 point), GCS <8 (3 points); ICH volume 16 to 40 cm3 (1 point), ICH volume >40 cm3 (2 points); and presence of IVH (1 point), with values ranging between 0 and 9. Among patients with a score of 0 and no ICU needs during their emergency department stay, 93.6% remained without critical care needs. In an external validation cohort of patients with ICH, the INTRINSIC score achieved an area under the receiver operating characteristic curve of 0.823 (95% confidence interval 0.782-0.863). A score <2 predicted the absence of critical care needs with 48.5% sensitivity and 88.5% specificity, and a score <3 predicted the absence of critical care needs with 61.7% sensitivity and 83.0% specificity.

CONCLUSION

The INTRINSIC score identifies patients with ICH who are at low risk for critical care interventions.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that the INTRINSIC score identifies patients with ICH at low risk for critical care interventions.

Theoretical studies of the g factors and local structures of the Ni3+ centers in Na2 Zn(SO4 )2 ·4H2 O and K2 Zn(SO4 )2 ·6H2 O crystals

The local structures and the g factors g_i (i = x, y, z) for Ni³⁺ centers in Na₂ Zn(SO₄ )₂ ·4H₂ O (DPPH) and K₂ Zn(SO₄ )₂ ·6H₂ O (PHZS) crystals are theoretically studied by using the perturbation formulas of the g factors for a 3d⁷ ion with low spin (S = 1/2) in orthorhombically compressed octahedra. In these formulas, the contributions to g factors from both the spin-orbit coupling interactions of the central ion and ligands are taken into account, and the required crystal-field parameters are estimated from the superposition model and the local geometry of the systems. Based on the calculations, the Ni-O bonds are found to suffer the axial compression δz (or Δz) of about 0.111 Å (or 0.036 Å) along the z-axis for Ni³⁺ centers in DPPH (or PHZS) crystals. Meanwhile, the Ni-O bonds may experience additional planar bond length variation δx (≈0.015 Å) along x- and y-axes for the orthorhombic Ni³⁺ center in DPPH. The theoretical g factors agree well with the experimental data. The obtained local structural parameters for both Ni³⁺ centers are discussed.

[Clinical investigation in the methods for complete placenta previa labor induction in the second trimester]

Objective: To investigate the appropriate method of labor induction in the second trimester for complete placenta previa patients. Methods: The labor induction outcomes of 85 cases with complete placenta previa in the second trimester were retrospectively analyzed. Twenty patients in group A were treated with cesarean section, 30 patients in group B were treated with ethacridine and mifepristone combined with uterine artery embolization (UAE), and 35 patients in group C were induced by using ethacridine and mifepristone. The clinical features and induction outcomes of three groups were compared. Results: The total duration of labor in group B [(28.7±30.1) hours] was significantly longer than that of group C [(24.3±21.9) hours; P<0.05]. The total amount of blood loss during induction and labor in group B [(302±271) ml] was significantly lower than those of group C [(393±523) ml] and group A [(626±487) ml; P<0.05]. The incidence of fever in group B (13%, 4/30) was significantly higher than those of group C (11%, 4/35) and group A (10%, 2/20; P<0.05). In group C, 13 patients (37%, 13/35) underwent emergency UAE, and 2 patients (6%, 2/35) underwent emergency cesarean section. As to average hemoglobin level and blood transfusion rate, there were no difference among the three groups (all P>0.05). Conclusion: Prophylactic UAE combined with drug induction in patients with complete placenta previa in the second trimester could significantly reduce the amount of bleeding during induction and reduce the risk of emergency procedures.

Colistin and tylosin enhances disaccharidase activities, and improves morphology and permeability of the intestine of broilers

1. The present study focused on the potential effects of antibiotics on intestinal digestion and integrity in broilers in terms of disaccharidase activity, electrophysiological properties and morphology. 2. One-day-old Arbour Acres birds were randomly allocated to one of four treatment groups for 42 days; control, colistin (20 mg/kg), tylosin (55 mg/kg) or chlortetracycline (CTC, 55 mg/kg) groups. Colistin and tylosin supplementation, but not CTC supplementation, caused an increase in body weight gain. 3. Colistin and tylosin elevated the activities of maltase and sucrase in the mucosa of the jejunum on d 42. Age caused a gradual decrease in the short-circuit current (Isc) and conductance (Gt) of the ileum, as a measure of permeability. The Isc and Gt of the ileum were higher in the colistin-supplemented broilers than in the control birds on d 42. Tylosin- and CTC-supplemented birds displayed Isc and Gt values similar to those of the control birds. 4. Colistin supplementation increased the villus area in the jejunum and thinned the muscularis mucosae in the ileum compared with the control group. Tylosin supplementation decreased the thickness of the muscularis mucosae and the depth of crypt in the jejunum. CTC thickened the muscularis mucosae in the jejunum and ileum. 5. Colistin and tylosin exhibited a beneficial effect on intestinal digestion and integrity by enhancing disaccharidase activities and improving gut morphology and permeability.

[The effect and mechanism of 2-methoxyestradiol on human laryngeal papilloma cell line]

Objective:To explore the signal pathway that mediates the effect of 2-methoxyestradiol（2ME2） on human laryngeal papilloma cell line, in terms of cell proliferation and neovascularization. Method:HIF-1α expression of human laryngeal papilloma cell line（Hs840. T） was interfered using siRNA, and the cells were then processed by 2ME2 in two concentrations. RT-PCR and ELISA were performed to detect the difference of HIF-1α in cells with normal or lower HIF-1α mRNA level, with ELISA test of excretory VEGF level and CCK8 test of cell viability. Result:The IC50of 2ME2 in Hs840. T was 0.309 μmol/L in terms of the inhibition effect of cell proliferation（P<0.01）. Baseline level of intracellular HIF-1α was detectable, and procession of Hs840. T cells by 2ME2 of 0.4 μmol/L inhibited the transcription and expression of HIF-1α by（76.8±2.0）% and（68.6±3.5）% [vs blank group（100.0±2.7）% and（100.0±6.9）%, P<0.01]. VEGF excretion decreased to（50.8±2.1） and（28.1±4.0）% [vs blank group（100.0±3.1）%, P<0.01]after procession by 2ME2 of 0.2 μmol/L and 0.4 μmol/L. After the successful interference of HIF-1α by siRNA, the inhibition effect on cell proliferation by 2ME2 of 0.4 μmol/L decreased to（51.5±3.8）% [vs control group（65.7±1.7）%, P<0.01]. siRNA interference of HIF-1α lead to a decrease of HIF-α mRNA and protein level to（16.3±0.9）% and（7.4±0.8）% [vs cells not interfered（76.8±2.0）% vs（68.6±3.5）%, P<0.01]. Secretory VEGF dropped to（41.0±2.9）% [vs cells not interfered（28.1±4.0）%, P<0.05]. Conclusion:2ME2 has a significant inhibitory effect on human laryngeal cell line. The inhibition of cell proliferation was mediated by a lower level of HIF-1α and therefore lower VEGF. 2ME2 might serve as a novel potential therapy for patients of recurrent respiratory papillomatosis.

Li(Cd,Mn)P: a new cadmium based diluted ferromagnetic semiconductor with independent spin & charge doping

We report a new diluted ferromagnetic semiconductor Li_1+y(Cd,Mn)P, wherein carrier is doped via excess Li while spin is doped by isovalence substitution of Mn²⁺ into Cd²⁺. The extended Cd 4d-orbitals lead to more itinerant characters of Li_1+y(Cd,Mn)P than that of analogous Li_1+y(Zn,Mn)P. A higher Curie temperature of 45 K than that for Li_1+y(Zn,Mn)P is obtained in Li_1+y(Cd,Mn)P polycrystalline samples by Arrott plot technique. The p-type carriers are determined by Hall effect measurements. The first principle calculations and X-ray diffraction measurements indicate that occupation of excess Li is at Cd sites rather than the interstitial site. Consequently holes are doped by excess Li substitution. More interestingly Li_1+y(Cd,Mn)P shows a very low coercive field (<100 Oe) and giant negative magnetoresistance (~80%) in ferromagnetic state that will benefit potential spintronics applications.

Efficient unidirectional and broadband vertical-emitting optical coupler assisted by aperture-coupled nanopatch antenna array

Vertical-emitting optical couplers that convert in-plane guided light to out-of-plane emission are crucial elements for future photonic integrated circuits. However, traditional vertical-coupling elements, such as grating couplers, by default radiate light in both upward and downward directions, leading to a significant reduction of device efficiency. In this paper, we propose to solve this problem using a novel nanopatch antenna array, inspired by patch antenna theories commonly deployed in microwave circuits. The proposed nanopatch array features an up-to-down emission directionality up to 12.91 dBc and a wide operating bandwidth of over 400 nm simultaneously. Compared with a typical waveguide grating antenna, our design shows a significantly higher free-space gain of 24.27 dBi. The unidirectional, efficient, and broadband antenna arrays presented here are promising for a range of integrated photonics applications, including inter-chip photonic interconnects, light ranging and detection, optical communications, and biological imaging.

Praseodymium ion doped K+-Na+ thermal ion-exchangeable waveguide-adaptive aluminum germanate glasses

Intense multi-peak red fluorescence and effective near-infrared (NIR) ultra-broadband emission have been observed in Pr³⁺ doped ion-exchangeable aluminum germanate (NMAG) glasses. The maximum emission cross section for P₀3→F₂3 red emission is up to 100.58×10^-21  cm², and the NIR emission corresponding to D₂1→G₄1 transition possesses a full-width at half-maximum (FWHM) of 210 nm. Although the obvious cross-relaxation (CR) process at high concentration causes a decrease of the quantum efficiency, the CR broadens the spectral FWHM effectively from another perspective. The admirable red fluorescence trace and the NIR single-mode transmission confirm that Pr³⁺ doped NMAG glass planar waveguides can support the generation of visible fluorescence and the amplification of infrared signal. For a waveguide channel ion-exchanged in molten KNO₃ for 2 h, the single-mode field diameters at 1.55 μm are identified to be 10.4 μm in the horizontal direction and 6.5 μm in the vertical direction, implying an acceptable overlap with a standard single-mode fiber. Effective red fluorescence and broad NIR emission demonstrate that Pr³⁺ doped NMAG glasses are a promising substrate in developing irradiative luminescence sources and ultra-broadband waveguide amplifiers, especially operating at the entire S-, C-, and L- bands.

Effects of high pressure on the ferromagnetism and in-plane electrical transport of (Ba0.904K0.096)(Zn0.805Mn0.195)2As2 single crystal

Pressure technique is an effective way to modify magnetic properties of diluted magnetic semiconductors (DMS). Based on single crystal, in-plane electrical transport properties of a new generation DMS (Ba_0.904K_0.096)(Zn_0.805Mn_0.195)₂As₂ have been measured with hydrostatic pressure up to 1.8 GPa. Magnetic properties of the single crystal sample are effectively tuned by pressure. Upon compression, the in-plane resistivity initially decreases but then increases when pressure is higher than 1.2 GPa. First principle calculations suggest that decrease of the resistivity is due to enhancement of density of state at Femi energy while increase of the resistivity under higher pressure is caused by distorted MnAs₄ tetrahedra. We reveal that the configuration of the MnAs₄ tetrahedra and strength of interlayer As-As bonding are of importance to ferromagnetic coupling of (Ba,K)(Zn,Mn)₂As₂.

Quick rehabilitation nursing improves the recovery of colon cancer patients after laparoscopy

Colon cancer is a common malignant tumor with particularly high morbidity and mortality. The aim of this study was to compare the effect of quick rehabilitation nursing and routine nursing in postoperative recovery of patients with colon cancer after laparoscopic surgery. Two hundred forty patients with colon cancer were classified into four random groups (A, B, C and D, with 60 patients in each group). All patients underwent surgery to remove the colon tumor by laparoscopy under general anesthesia. Patients in groups A and B received quick rehabilitation nursing for post-surgery recovery. In group C patients, local anesthesia associated with quick rehabilitation nursing for post-surgery recovery was used. Group D was used as control group and the patients were treated based on routine nursing. Time to get out of bed, first bowel movement time and the average time of hospitalisation in group A was lower than group D (p less than 0.05), postoperative leukocyte level as well as the occurrence rate of nausea and vomiting, ankylenteron and pelvic adhesion was decreased in group A compared to group D (p less than 0.05), but the postoperative albumin and total protein level was higher than group D (p less than 0.05). The serum level of C-Reactive Protein (CRP) and interleukin 6 (IL-6) in group A was decreased compared to group D several days after surgery (p less than 0.05); group B had 4 cases of intestinal obstruction after surgery that could be cured through conservative treatment, while group D had 10 cases of intestinal obstruction, 8 of which could be cured through conservative treatment and two needed surgery (p less than 0.05); VAS for pain degree of group C in active state was clearly lower at 1h, 5h, 7h, 15h, 30h and 42h after surgery, and side effects of postoperative analgesia were clearly reduced. Time to get out of bed was obviously decreased, while there was no evident effect on postoperative dosage, chronic pain and complications. Adopting quick rehabilitation nursing can effectively reduce occurrence of complications and postoperative pain, speed up the recovery of gastrointestinal function, shorten the length of stay, and improve patients’ satisfaction.

The emerging role of circular RNAs in transcriptome regulation

Circular RNAs (circRNAs) are a recently discovered form of RNA that has been found to regulate mammalian transcription. CircRNAs are covalently closed, single-stranded transcripts produced from precursor mRNA. While initially circRNAs were considered to be splicing artefacts, next-generation RNA sequencing of non-polyadenylated transcriptomes has recently shown that the expression of circRNAs is widespread and over 20% of expressed genes in examined cells and tissues can produce these transcripts. Until now thousands of circRNAs have been discovered in organisms ranging from Drosophila melanogaster to Homo sapiens. Functional studies indicate that these transcripts regulate expression of protein-coding linear transcripts and thus comprise an important component of gene expression regulation. Here we provide a comprehensive overview on the biology of circRNAs, including the expression patterns and function. Moreover, we discuss current methodologies for the discovery and validation of circular transcripts. Finally, perspectives on the utilization of circRNA as molecular markers of complex diseases are presented.

Factors associated with Staphylococcus aureus nasal carriage and molecular characteristics among the general population at a Medical College Campus in Guangzhou, South China

BACKGROUND

The nasal cavity is the main colonization site of Staphylococcus aureus (S. aureus) in human body. Nasal carriage may be a strong risk factor for some serious infection. There was still limited information about the nasal carriage for S. aureus in south China.

METHODS

Sought to determine the prevalence and molecular characteristics of S. aureus nasal carriage, 295 volunteers residing on a medicine campus were investigated and sampled the nasal cavity swab. Selected S. aureus isolates were carried through molecular analysis, including pulsed-field gel electrophoresis (PFGE), multilocus sequence analysis, staphylococcal cassette chromosome mec (SCCmec) and virulence gene detection.

RESULTS

A total of 73 S. aureus isolates were recovered from separate subjects (24.7%, 73/295), with one methicillin-resistant S. aureus (MRSA) isolate (0.3%, 1/295). Among the 73 isolates, 71 isolates were successfully grouped into 13 pulsotypes by PFGE analysis, with profiles A and L the most prevalent; 12 sequence types (STs) were found among the 23 isolates which had similar drug resistant spectrum. ST59, ST188 and ST1 were the most prevalent, accounting for 17.4, 13.0 and 13.0% of all isolates, respectively. The MRSA isolate presented ST8-SCCmec III. 56.5% of isolates carried both the staphylococcal enterotoxin A (sea) and enterotoxin B (seb) genes. 83.6% of the S. aureus isolates were resistant to penicillin, all isolates were susceptible to quinupristin/dalfopristin, levofloxacin, teicoplanin and vancomycin. The most common risk factors for S. aureus carriage were being male, age ≤30 years, and nasal cavity cleaning habits.

CONCLUSIONS

Colonization by S. aureus was greater among male and young age (20-30 years) students and those with irregularity nasal cleaning. The S. aureus isolates selected were revealed into various sequence types and pulsotypes, indicating molecular heterogeneity among S. aureus isolates from the populations in the medical college in Guangzhou.

Immunohistochemical analysis of T-type calcium channels in acquired melanocytic naevi and melanoma

BACKGROUND

Cutaneous malignant melanoma arises from transformed melanocytes de novo or from congenital or acquired melanocytic naevi. We have recently reported that T-type Ca²⁺ channels (TT-Cs) are upregulated in human melanoma and play an important role in cell proliferation.

OBJECTIVES

To describe for the first time in formalin-fixed paraffin-embedded tissue the immunoexpression of TT-Cs in biopsies of normal skin, acquired melanocytic naevi and melanoma, in order to evaluate their role in melanomagenesis and/or tumour progression, their utility as prognostic markers and their possible use in targeted therapies.

METHODS

Tissue samples from normal skin, melanocytic naevi and melanoma were subjected to immunohistochemistry for two TT-Cs (Cav3.1, Cav3.2); markers of proliferation (Ki67), the cell cycle (cyclin D1), hypoxia (Glut1), vascularization (CD31) and autophagy (LC3); BRAF V600E mutation (VE1) and phosphatase and tensin homologue (PTEN). Immunostaining was evaluated by histoscore. In silico analysis was used to assess the prognostic value of TT-C overexpression.

RESULTS

TT-C immunoexpression increased gradually from normal skin to common naevi, dysplastic naevi and melanoma samples, but with differences in the distribution of both isoforms. Particularly, Cav3.2 expression was significantly higher in metastatic melanoma than in primary melanoma. Statistical correlation showed a linear interaction between PTEN loss/BRAF V600E/Cav3.1/LC3/ Ki67/cyclin D1/Cav3.2/Glut1. Disease-free survival (DFS) and overall survival correlated inversely with overexpression of Cav3.2. DFS also correlated inversely with overexpression of Cav3.1.

CONCLUSIONS

TT-C immunoexpression on melanocytic neoplasms is consistent with our previous in vitro studies and appears to be related to tumour progression. TT-C upregulation can be considered as a prognostic marker using The Cancer Genome Atlas database. The high expression of Cav3.2 in metastatic melanoma encourages the investigation of the use of TT-C blockers in targeted therapies.

Gene expression and enzyme activity of lipoprotein lipase correlate with intramuscular fat content in Guangxi san-huang and Arbor Acres chickens

Lipoprotein lipase (LPL) is a key enzyme in lipid metabolism. This study investigated LPL gene expression, LPL enzyme activity, and the correlation of each with intramuscular fat (IMF) in Chinese Guangxi san-huang (GXSH) and Arbor Acres (AA) chickens. The results showed that age and breed had significant effects on LPL expression and enzyme activity. Correlation analyses showed significant positive correlations between LPL expression levels and IMF contents in the breast and thigh tissues of both GXSH (r = 0.712, P = 0.001; r = 0.792, P < 0.001, respectively) and AA (r = 0.644, P < 0.001; r = 0.545, P < 0.001, respectively) chickens. The results also indicated a significant positive correlation between LPL enzyme activity and IMF contents in the breast and thigh tissues of both GXSH (r = 0.615, P = 0.001; r = 0.685, P < 0.001, respectively) and AA (r = 0.600, P = 0.001; r = 0.528, P = 0.003, respectively) chickens. The results indicated that the LPL gene was significantly correlated with IMF in these two breeds. The results presented here could contribute to knowledge of LPL mRNA developmental expression patterns and enzyme activity, and it could facilitate further research on the molecular mechanisms underlying IMF deposition in chickens.

Analysis of the drug-resistant characteristics of Klebsiella pneumoniae isolated from the respiratory tract and CTX-M ESBL genes

The main aim of this study was to understand the relationship between the drug-resistant characteristics of Klebsiella pneumoniae and CTX-M-type extended spectrum β-lactamases (ESBLs), and to detect the distributions of CTX-M-type ESBLs in clinically isolated strains. CTX-M ESBL genes isolated from the clinical samples were amplified by polymerase chain reaction and identified by sequence analysis; the antibiotic susceptibility of the samples was determined using the Kirby-Bauer disc-diffusion method. One hundred and five strains among the 246 isolated strains of K. pneumoniae tested positive for ESBL production (42.68%); 92 of these produced CTX-M ESBLs. Of the 92 CTX-M ESBL strains, 81 produced CTX-M-1 ESBLs and 11 produced CTX-M-25 ESBLs. Fifty-seven of the CTX-M-1 ESBL- and six of the CTX-M-25 ESBL-producing bacteria had CTX-M ESBL genes that coexisted in the plasmid and chromosome. The Kirby-Bauer antibiotic susceptibility method revealed that CTX-M ESBL-positive strains showed a higher rate of resistance to cefazolin, cefoxitin, cefuroxime, ceftazidime, cefotaxime, aztreonam, levofloxacin, and cotrimoxazole, compared to the CTX-M ESBL-negative strains (P < 0.05). The CTX-M ESBL genes were commonly observed in the K. pneumoniae isolated from respiratory tract samples; these were significantly associated with the drug-resistant characteristics of K. pneumoniae to β-lactam antibiotics.

Infrared radiation properties of Ho³⁺ in multicomponent germanium tellurite glasses

Ho(3+)-doped and Ho(3+)/Yb(3+)-codoped multicomponent germanium tellurite (MGT) glasses with multifarious emission channels in the near-infrared wavelength region have been fabricated and characterized. Judd-Ofelt intensity parameters of Ho(3+)-doped MGT glasses are solved to be Ω2=5.32×10(-20)  cm(2), Ω(4)=2.73×10(-20)  cm(2), and Ω(6)=1.12×10(-20)  cm(2), indicating a higher asymmetric and stronger covalent environment around Ho(3+) ions in MGT glasses. Efficient infrared fluorescences have been observed in MGT glasses, and spontaneous emission probabilities are derived to be 230.4, 79.9, and 138.3  s(-1) for the (5)I(6)→(5)I(8), ((5)F(4),(5)S(2))→(5)I(5), and (5)I(7)→(5)I(8) radiative transitions, respectively. In Ho(3+)/Yb(3+)-codoped MGT glasses, the maximum stimulated emission cross-section of 2.0 μm emission is calculated to be 4.93×10(-21)  cm(2), and the corresponding gain cross-section is derived to be 3.62×10(-21)  cm(2) when the excited state population fraction P reaches 0.8. Multifarious infrared emissions show that Ho(3+) in MGT glasses is a good candidate for optical amplifiers and optoelectronic devices.

Pr3+-doped heavy metal germanium tellurite glasses for irradiative light source in minimally invasive photodynamic therapy surgery

Pr3+-doped medium-low phonon energy heavy metal germanium tellurite (NZPGT) glasses have been fabricated and the intense multi-peak red fluorescence emissions of Pr3+ are exhibited. Judd-Ofelt parameters Ω2 = 3.14 × 10(-20)cm(2), Ω4 = 10.67 × 10(-20)cm(2) and Ω6 = 3.95 × 10(-20)cm(2) indicate a high asymmetrical and covalent environment in the optical glasses. The spontaneous emission probabilities A(ij) corresponding to the 1D2→3H4, 3P0→3H6, and 3P0→3F2 transitions are derived to be 1859.6, 6270.1 and 17276.3s(-1), respectively, and the relevant stimulated emission cross-sections σ(em) are 5.20 × 10(-21), 14.14 × 10(-21) and 126.77 × 10(-21)cm(2), confirming that the effectiveness of the red luminescence in Pr3+-doped NZPGT glasses. Under the commercial blue LED excitation, the radiant flux and the quantum yield for the red fluorescence of Pr3+ are solved to be 219μW and 11.80%, respectively. 85.24% photons of the fluorescence in the visible region are demonstrated to be located in 600-720nm wavelength range, which matches the excitation band of the most photosensitizers (PS), holding great promise for photodynamic therapy (PDT) treatment and clinical trials.

Lower extremity radicular pain after prophylactic intrathecal saline injection through a subarachnoid catheter following accidental dural puncture

We describe a case in which severe lower extremity radicular pain occurred after administration of 0.9% saline into the subarachnoid space through a catheter that had been left for 20 h following inadvertent dural puncture in an obstetric patient. A 42-year-old (G8P7) woman was admitted for repeat cesarean delivery. Accidental dural puncture occurred during epidural placement. Following a slow 10-mL intrathecal injection of 0.9% normal saline an epidural catheter was advanced into the subarachnoid space. Spinal anesthesia was used for cesarean delivery and the subarachnoid catheter was kept in place for 20 h. Before catheter removal, an additional 10 mL of 0.9% saline was slowly administered into the intrathecal space. Almost instantly, the patient complained of back pain that progressed to lower extremity radicular pain and paresthesia; symptoms began to resolve after 10 min. Subsequently, the patient developed a postdural puncture headache that persisted for three days. The patient's radiculitis and paresthesia likely resulted from an acute increase in intrathecal pressure after saline administration or from direct catheter irritation. Although both intrathecal saline administration and subarachnoid catheter placement have been previously proposed as ways to prevent postdural puncture headache, their efficacy remains controversial, and we advise caution with these techniques.

Biodegradation of organic compounds from coking wastewater with UASB reactor

The UASB reactor was applied for biodegradation of organic compounds in coking wastewater. The influent pH ranged between 6.8 and 7.2, and stirring speed and temperature were controlled at 2 r/min and 30±1°C, respectively. The reactor was successfully started up in 133 days. When the influent COD was 2,600 mg/L (VLR was 2.6 kg/m(3) d), the removal rate of COD was about 54% and the effluent VFA was below 400 mg/L. GC/MS analysis indicated that the coking wastewater mainly contained aniline, phenol, o-phenol, p-cresol, benzoic acid, indole, quinoline etc. Twenty four kinds of organic compounds were detected in the influent, and 20 kinds of organic compounds were completely removed in the UASB reactor. The biodegradation of organic compounds followed Grau second-order kinetics. It was proved to be an effective and feasible method for coking wastewater anaerobic treatment.

Selective elimination of alloreactivity from immunotherapeutic T cells by photodynamic cell purging and memory T-cell sorting

Allogeneic stem cell transplantation (alloSCT), especially in the mismatched setting, carries a high risk of life-threatening GvHD because of activation of donor T cells by Ag present on host cells. Removal of mature donor T cells can prevent GvHD but leads to delayed immune reconstitution, and an increased incidence of opportunistic infections and disease relapse. These findings demonstrate the vital role of donor T cells in providing graft-versus-tumor (GvT) and anti-pathogen effects as well as facilitating immune reconstitution. It has been well documented that GvHD can be separated from GvT effects, making it possible potentially to eliminate GvHD while preserving the immunotherapeutic benefits of donor T cells. Over the past decade, major attempts have been made to reduce GvHD incidence without loss of GvT effect, especially in the haplo-identical setting. Novel techniques to deplete host-reactive donor T cells selectively have been explored. This review focuses on the use of the photodynamic cell purging (PDP) process and of sorting memory T cells for the selective elimination of alloreactivity. Minimizing the threat of GvHD while maximizing the beneficial GvT effect would broaden the scope and effectiveness of alloSCT.

A survey of microbial contamination of food contact surfaces at broiler slaughter plants in Taiwan

Microbial contamination levels at broiler slaughter plants were investigated at three major slaughter plants in Taiwan during the summer and winter. The microbial contamination levels in chicken carcasses and on food contact surfaces were examined using the swab method. The results indicated that the bacterial counts were affected by the slaughter processing plant, processes, and season (P < 0.05). The bacterial counts on food contact surfaces of the equipment before operation were not significantly lower than those after processing. Regardless of the bacterial type, bacterial counts of chicken carcasses generally decreased from the scalding step to the washing step before evisceration and then increased. The cleaning procedures for food contact surfaces should be evaluated, and special attention should be given to utensils used during processing, such as gloves, baskets, and hand tools.

T-Cell recovery in adults and children following umbilical cord blood transplantation

T-cell reconstitution following allogeneic stem cell transplantation may involve thymic education of donor-derived precursors or peripheral expansion of mature T cells transferred in the graft. T cell-receptor excision circles (sjTRECs) are generated within the thymus and identify new thymic emigrants and those that have not divided. We measured quantitative and qualitative immunologic reconstitution and sjTREC levels in adult and pediatric recipients of umbilical cord blood transplants (UCBTs). sjTRECs were detected at normal levels in all children, starting 12 months after transplantation. sjTRECs were not detected until 18 months after transplantation in adults, and then only at a 3-fold lower level than expected for age. We used complementarity-determining region 3 (CDR3) spectratyping to measure changes in T cell-receptor diversity occurring with restoration of thymic function. T-cell repertoires were skewed in adults and children at 12 to 18 months after transplantation but recovered to near-normal diversity at 2 to 3 years post-UCBT. T-cell repertoires appeared more diverse earlier in children (at 1 to 2 years post-UCBT) than in adults (at 3 to 4 years post-UCBT). We conclude that early T-cell recovery after UCBT occurs primarily through peripheral expansion of adoptively transferred donor T cells and results in skewing of the T-cell repertoire. The reappearance of sjTREC-containing cells after UCBT is associated with increasing numbers of phenotypicaly naive T cells, improved mitogen and recall antigen responses, and diversification of the T-cell repertoire. The delay in central T-cell recovery in adults relative to children may be due to differences in thymic function resulting from age-related atrophy, graft-versus-host disease, or the pharmacologic effects of prophylaxis and treatment of graft-versus-host disease.

Twenty-one-gauge needles provide more cellular samples than twenty-five-gauge needles in fine-needle aspiration biopsy of the thyroid but may not provide increased diagnostic accuracy

The technique of fine-needle aspiration (FNA) biopsy of the thyroid is important to evaluate malignancy in thyroid nodules. Eighty-five percent of thyroid FNA procedures lead to sufficient cellular material for diagnosis. With more cells aspirated, the chance of sufficiency for diagnosis increases. Large-bore needles lead to more cellular material being aspirated but bloodier specimens that may interfere with cytologic interpretation. Small-bore needles may result in too few cells for diagnosis. We conducted a randomized prospective study contrasting 21-gauge and 25-gauge needles in the evaluation of 50 consecutively enrolled nodules at our institution. In our investigation, 21-gauge needles more frequently provided superior biopsy specimens (50%) than did 25-gauge needles (18%). In the remaining specimens (32%), the 21-gauge and 25-gauge needles provided similar cellular material. The rate of sufficient samples was the same. We conclude that use of 21-gauge needles results in more cellular specimens but may not result in increased diagnostic accuracy.

[Repair and reconstruction of massively damaged wounds]

OBJECTIVE

To report repair and reconstruction of massively damaged wound under unusual condition.

METHODS

One hundred and forty-seven patients with deep tissue defects were admitted from January 1993 to December 2000, among them, 96 cases suffered from electrical injury, 18 cases with hot press injury, 18 cases with deep burns as a result of CO poisoning or epileptic seizure, 6 cases caused by chemical producing necrosis and wound infection, 3 cases with radiation injuries, 2 cases with chemical burn, 2 cases with explosive injury, 2 cases with frostbite. One hundred and seventy five wounds in 147 patients were repaired by transfer of local flap, forearm conversal island skin flap, pectoralis major myocutaneous flap, delto-pectoral skin flap, latissimus dorsi skin flap, gastroecnemius myocutaneous flap, anterior and posterior tibial artery island skin flap, and so on. The wound defect ranged from 1 cm x 1 cm to 20 cm x 28 cm, and the flaps were 1.5 cm x 2.0 cm to 22 cm x 30 cm. The necrotic tendon was replaced with acellular allogenic tendon simultaneously in 7 cases.

RESULTS

One hundred and sixty-nine flaps were survival with first intention, while necrosis of the tip of flap occurred in 6 cases. The transplantation of acellular allogenic tendon in all cases were survival. The function and configuration in 28 cases were satisfactory after 4 months to 8 years follow-up.

CONCLUSION

Various types of flaps are choosen according to the position, defect range and degree of wound, which is an ideal method to restore the function and to improve patients' living condition.

Triptolide, a novel immunosuppressive and anti-inflammatory agent purified from a Chinese herb Tripterygium wilfordii Hook F

Triptolide is a diterpenoid triepoxide purified from a Chinese herb Tripterygium Wilfordii Hook F (TWHF). TWHF has been used in traditional Chinese medicine for more than two thousand years. However, its potential value was recognized by the western medicine only after investigators observed the effectiveness of TWHF in the treatment of leprosy and rheumatoid arthritis. Triptolide has been identified as the major component responsible for the immunosuppressive and anti-inflammatory effects of TWHF. Triptolide inhibits both Ca(2+)-dependent and Ca(2+)-independent pathways and affects T cell activation through inhibition of interleukin-2 transcription at a site different from the target of cyclosporin A. Triptolide also has inhibitory effects on a variety of proinflammatory cytokines and mediators and on the expression of adhesion molecules by endothelial cells. Triptolide is effective for the treatment of a variety of autoimmune diseases and in prevention of allograft rejection and graft-versus-host disease in both animals and humans. Moreover, triptolide possesses antitumor and male anti-fertility effect. However, the toxicities of triptolide may be associated with renal, cardiac, hematopoietic and reproductive systems. Currently available data suggest that triptolide is a promising immunosuppressive and anti-inflammatory agent and should be explored further in autoimmune diseases and transplantation.

Graft-versus-host disease prevention by rapamycin: cellular mechanisms

Understanding the cellular mechanisms that lead to graft-versus-host disease (GVHD) may lead to alternative approaches in the prevention or therapy of this disease process. In this manuscript, we investigated the mechanisms of action of the immunosuppressive drug rapamycin for the prevention of GVHD. GVHD-free long-term survival was achieved in BALB/c (H2d, Mls-2a, Mls-3a) recipients of B10.D2/nSnJ (H-2d, Mls-2a, Mls-3a) bone marrow and spleen cells after a 30-day course of high-dose rapamycin (5 mg/kg per day). Low responses to recipient and third-party cells in a mixed lymphocyte reaction (MLR) were observed as well as decreased mature T-cell numbers in the spleen. This low response was not due to defective interleukin (IL)-2 production, because exogenous IL-2 did not improve the responses in the MLR. However, GVHD-free long-term survival was associated with a large number of infiltrating mononuclear cells in the target organs of GVHD. This observation suggested the possibility that these cells were responsible for suppressing the immune response. Regulatory cells, which could suppress both antirecipient and third-party responses in vitro, were demonstrated to be present in the spleens of these GVHD-free long-term survivors. These results suggest that in addition to impaired cellular immune function, the presence of non-specific regulatory cells (ie, suppression) may contribute to maintenance of GVHD-free long-term survival induced by short-course rapamycin.

Effects of aflatoxin and carotenoids on growth performance and immune response in mule ducklings

The purpose of this study was to investigate if carotenoids could alleviate the adverse effects caused by aflatoxin with respect to growth performance and immune response. In two experiments, a total of 320 mule ducklings were assigned to 5 treatments, i.e. control, aflatoxin B(1) (AFB(1)) 200 ppb, AFB(1) +beta-carotene (BC) 200 ppm, AFB(1)+BC 400 ppm, and AFB(1)+astaxanthin (AS) 200 ppm. In experiment 1, the addition of beta-carotene or astaxanthin in the diet containing AFB(1) 200 ppb resulted in a significant decrease in average daily gain as compared with the control. AFB(1) 200 ppb alone and the addition of BC or AS on top of AFB(1) resulted in a significantly lower daily feed intake than for the control group. There were no significant differences in relative organ weights among treatment groups. Both treatments of BC 400 ppm and AS 200 ppm had significantly more macrophages harvested per duck than the control and AFB(1) 200 ppb treatments. However, there were no significant differences among treatments in percentages of phagocytotic macrophages and number of Candida albican phagocytized by phagocytotic macrophages. In experiment 2, blood biochemical parameters and antibody titers were evaluated. There were no significant differences among treatments in total bilirubin content and alkaline phosphatase activity in the serum or in antibody titers against fowl cholera. However, AFB(1) treatment had the highest activities of AST and ALT in the serum. The addition of BC 400 ppm on top of AFB(1) significantly reduced ALT activity as compared with the AFB(1) 200 ppb treatment. These results suggest that carotenoids could provide a slightly toxic alleviating effect on growth performance, enhance the chemotaxis ability of macrophages, and reduce ALT activity elevated by AFB(1).

Prevention of graft-versus-host disease by a novel immunosuppressant, PG490-88, through inhibition of alloreactive T cell expansion

BACKGROUND

PG490-88 is a water soluble, semisynthetic derivative of a novel compound PG490 (triptolide) purified from the Chinese herb Tripterygium Wilfordii Hook F.

METHODS

PG490-88 was administrated into recipient mice in a model (B10.D2-->BALB/c) of lethal graft-versus-host disease (GVHD) to study the effects of PG490-88 on GVHD and on the various steps involved in the pathological course of GVHD.

RESULTS

Injection of PG490-88 i.p. at a dose of 0.535 mg/kg/day for the first 3 weeks after transplantation protected all the recipients from developing GVHD up to 100 days after transplantation. PG490-88 inhibited in vivo both CD4+Vbeta3+ and CD8+Vbeta3+ T cell (alloreactive T cells in this model) expansion in the spleen by 64.09 and 34.02%, respectively, at the time when Vbeta3+ cell expansion was in the logarithmic phase (day 3 after transplantation). Intracellular cytokine staining without further in vitro activation demonstrated 47.42% inhibition of IL-2 production among CD4+ spleen cells in PG490-88-treated mice as compared to GVHD control on day 3 after transplantation. In contrast, CD25 (alpha chain of interleukin-2 receptor) expression did not differ.

CONCLUSIONS

PG490-88 is highly effective in prevention of murine GVHD. The immunosuppressive effect of PG490-88 is mediated by inhibition of alloreactive T cell expansion through interleukin-2 production.

Chromium-induced glucose uptake, superoxide anion production, and phagocytosis in cultured pulmonary alveolar macrophages of weanling pigs

The dose-dependent effects of chromium chloride (CrCl3) and chromium picolinate (CrPic) were evaluated for their glucose uptake, superoxide anion (O2-) production, activity of glucose-6-phosphate dehydrogenase, and phagocytosis of incubated pulmonary alveolar macrophages in medium containing no or 5 x 10(-8)M insulin. Glucose uptake was found to increase in cells treated with 20 microg/L CrCl3. Incubation with 20 microg/L of CrPic enhanced glucose uptake and O2- production in an insulin-dependent manner. However, the inclusion of CrPic to 100 microg/L in the medium absent of insulin also increased O2- production. The activity of glucose-6-phosphate dehydrogenase was not affected by either the addition of Cr or insulin. The phagocytosis of Escherichia coli by macrophages was enhanced significantly (p < 0.05) in medium containing 10-100 microg/L CrCl3 or 20-100 microg/L CrPic in the presence of insulin. These results suggest that the addition of 10-20 microg/L CrCl3 enhances directly the cellular activity of macrophages, whereas the effect of CrPic requires the cooperative action of insulin in enhancing their glucose uptake and phagocytosis.

Managing an animal health emergency in Taipei China: foot and mouth disease

Taipei China had been free from foot and mouth disease (FMD) over 68 years before the disease occurred in March 1997. The first suspected case was recorded on a pig farm in the Hsinchu Prefecture on 14 March 1997. Based on clinical signs, gross histopathological findings, and results of enzyme-linked immunosorbent assays and reverse-transcriptase polymerase chain reaction tests, diagnosis of FMD was confirmed by the Taiwan Animal Health Research Institute on 19 March 1997 and was reconfirmed by the FMD World Reference Laboratory in Pirbright (United Kingdom), on 25 March 1997. By the end of July 1997, 6,147 pig farms (about a quarter of the pig farms in Taipei China), were affected. The disease was well under control within two months by means of stamping-out and blanket vaccination. The Government purchased 21 million doses of inactivated oil-adjuvant FMD vaccine, which allowed for two injections per pig and one injection of other cloven-hoofed animals. Before the vaccine was used, the stamping-out policy was implemented, ensuring that all pigs in the affected farms were destroyed. After blanket vaccination, a partial stamping-out policy was adopted, i.e. only pigs showing clinical signs were destroyed.

Fresh vs aged benzylpenicillin on non-IgE responses in mice

AIM

To study whether or not the freshly prepared benzylpenicillin could induce different non-IgE antibody response from aged benzylpenicillin.

METHODS

Antibody response was determined by enzyme-linked immunosorbent assay (ELISA). Antigen molecules recognized by antibodies and antigenic cross reactions were tested by hapten inhibition assay.

RESULTS

Isotypes of specific non-IgE antibodies induced by freshly prepared benzylpenicillin were mainly IgM, and then IgG and IgA. Some parts of specific antibodies recognized benzylpenicillin molecule and major parts combined with degraded or transforming products. Isotypes of antibodies responsible for cross reaction were mainly IgG between benzylpenicillin and ampicillin and IgM between benzylpenicillin and piperacillin.

CONCLUSION

Freshly prepared and aged benzylpenicillin induced different non-IgE antibody response.

Acute and subacute toxicity study of water-soluble polyalkylsulfonated C60 in rats

Polyalkylsulfonated C60, or FC4S, a highly water-soluble caged fullerene derivative, is believed to be a free radical remover or an antioxidant in biological systems. A 50 mg/ml aqueous solution was prepared as a master solution and administered to female Sprague-Dawley CD(Crl:CD(SD)BR) rats in a single-dose acute toxicity study or a 12-day subacute toxicity study where rats were given the solution daily. In a study of the median lethal dose (LD50), no rats died after oral administration, and thus FC4S was considered to be nontoxic if administered orally. In an LD50 intraperitoneal injection study, rats died within 30 hr after injection; the LD50 was determined to be approximately 600 mg per kilogram of body weight. Rats injected with the compound intraperitoneally or intravenously immediately eliminated the compound through the kidney; the kidney appeared to be the primary target organ. The compound induced a distinct lysosome-overload nephrosis, a phagolysosomal nephropathy characterized by a tinctorial difference between the outer cortex and the inner cortex and the medulla. The affected outer cortex showed a diffuse degeneration, with the presence of numerous large vacuoles and cytoplasmic aggregates in the tubular epithelium. The phagolysosomal nephropathy was detected in rats after acute exposure as well as in the surviving rats following 1 intraperitoneal injection of 500 mg/kg or intravenous injection of 100 mg/kg. Ultrastructural investigation revealed numerous membranous conglomerates characteristic of phagolysosomal and/or lysosomal inclusions in the cytoplasm of the renal tubular epithelium. These conglomerates were confined to the vacuole, electron-dense, and unevenly stained. They varied in size and shape and were fused or aggregated. Occasional phagolysosomes were also observed in the endothelial cells of the peritubular plexus. A preliminary study of microsomal enzyme activity analysis revealed a suppression effect of liver cytochrome P-450-dependent monooxygenase activities, including cytochrome P-450, cytochrome b5, and benzo(a)pyrene hydroxylase, but an increased level of kidney cytochrome P-450-dependent monooxygenase activities, including NADPH-cytochrome P-450 reductase. The significance of these enzyme alterations was not well determined. Further study is needed to clarify the correlation between the alterations of microsomal enzyme activity and the nephropathy of lysosomal overload-induced changes. These changes may serve as a biological marker in toxicity screening tests for this class of compound.

A noninvasive method in the differential diagnosis of vecuronium-induced and magnesium-induced protracted neuromuscular block in a severely preeclamptic patient

The occurrence of neuromuscular blockade and the resulting potentiation of muscle relaxants during magnesium sulfate (MgSO4) administration is well known. However, a method to differentiate the neuromuscular block induced by magnesium from that induced by curariform nondepolarizing muscle relaxant in the clinical setting has never been reported. We report a case in which the duration of action of 1 mg of vecuronium lasted 4 hours in a patient with severe preeclampsia whose serum magnesium level was in the therapeutic range. We believe this is a remarkable potentiation on record in the literature. We also describe a new, noninvasive method to assess magnesium-induced neuromuscular block when curariform muscle relaxant was given simultaneously.

Circulating clonal lymphocytes in myeloma constitute a minor subpopulation of B cells

The mononuclear cells in the blood of myeloma patients have been reported to contain a high proportion of phenotypically abnormal myeloma B lymphocytes. These cells have been proposed to constitute the drug-resistant proliferative myeloma cell compartment. To determine the extent of B lymphocyte involvement, the proportion of clonotypic cells among the CD19-expressing cells from myeloma patients was estimated by quantitative polymerase chain reaction analysis of the third complementarity determining region (CDR3). The results indicate that the B lymphocytes constitute, on average, 6% of blood mononuclear cells, and that only a minor fraction of these are clonally related to the myeloma cells. While the small number of circulating clonal cells is not incompatible with their proposed role as a reservoir of proliferating myeloma progenitors, the majority of the B cells appear not to be clonally related to the myeloma cells.

Suppression of Escherichia coli alkB mutants by Saccharomyces cerevisiae genes

The alkB gene is one of a group of alkylation-inducible genes in Escherichia coli, and its product protects cells from SN2-type alkylating agents such as methyl methanesulfonate (MMS). However, the precise biochemical function of the AlkB protein remains unknown. Here, we describe the cloning, sequencing, and characterization of three Saccharomyces cerevisiae genes (YFW1, YFW12, and YFW16) that functionally complement E. coli alkB mutant cells. DNA sequence analysis showed that none of the three gene products have any amino acid sequence homology with the AlkB protein. The YFW1 and YFW12 proteins are highly serine and threonine rich, and YFW1 contains a stretch of 28 hydrophobic residues, indicating that it may be a membrane protein. The YFW16 gene turned out to be allelic with the S. cerevisiae STE11 gene. STE11 is a protein kinase known to be involved in pheromone signal transduction in S. cerevisiae; however, the kinase activity is not required for MMS resistance because mutant STE11 proteins lacking kinase activity could still complement E. coli alkB mutants. Despite the fact that YFW1, YFW12, and YFW16/STE11 each confer substantial MMS resistance upon E. coli alkB cells, S. cerevisiae null mutants for each gene were not MMS sensitive. Whether these three genes provide alkylation resistance in E. coli via an alkB-like mechanism remains to be determined, but protection appears to be specific for AlkB-deficient E. coli because none of the genes protect other alkylation-sensitive E. coli strains from killing by MMS.