Exploring the outer limits of polyplexes

Histidine-containing polymers show promise in their transport of nucleic acids in vitro and in vivo. In addition to the pH-buffering histidine component, the polymer often contains a protonated component at physiological pH, such as lysine. These polyplexes usually accumulate in the tumor by enhanced permeability and retention, which has proved disappointing in clinical trials. We presently compare two histidine-lysine (HK) peptide polyplexes for their neuropilin-1-mediated transport of plasmids in vivo. While the polymerized HK (H2KC-48) polyplex was markedly better than the monomeric HK (H2K) polyplex in vitro, both HK polyplexes were effective in transfecting tumor xenografts over a wide range of peptide and plasmid ratios. Nevertheless, polyplexes of low peptide/DNA ratios gave higher tumor transfection and specificity than those of higher ratios. Surprisingly, there was minimal to no gel retardation of polyplexes made from these low ratios during electrophoresis. These results demonstrate that loosely packed HK polyplexes effectively transfected tumors in vivo.

[A comparative analysis of the clinical symptoms of benign paroxysmal positional vertigo between older and young and middle-aged patients]

Objective: To compare the differences in clinical symptoms and the time required for diagnosis of benign paroxysmal positional vertigo (BPPV) between older patients and young and middle-aged patients in the structured inquiry of dizziness history. Methods: The medical records of 6 807 patients diagnosed with BPPV from the Vertigo Database of Vertigo Clinical Diagnosis, Treatment, and Research Center of Beijing Tiantan Hospital, Capital Medical University, between January 2019 and October 2021 were retrospectively analyzed. The data included basic demographic information, clinical symptoms in a structured medical history questionnaire, and the time interval from the appearance of BPPV symptoms to diagnosis consultation. The patients were divided into the young and middle-aged group (<65 years old) and the older group (≥65 years old). The differences in clinical symptoms and consultation time were compared between these two groups. Categorical variables were represented by numbers (%), and compared using Chi-squared tests or Fisher's exact probability test for analysis; whereas, continuous variables conforming to normal distribution were represented by mean±standard deviation. Both data groups were compared and analyzed by Student's t-test. Results: The mean age of the older group was 65-92 (71±5) years, while the mean age of the middle-aged group was 18-64 (49±12) years. The incidence of vertigo (42.5% vs. 49.1%, χ²=23.69, P<0.001); vertigo triggered by changes in position of the head or body (52.4% vs. 58.7%, χ²=22.31, P<0.001); and autonomic symptoms (10.1% vs. 12.4%, χ²=7.09, P=0.008) were lower, but hearing loss (11.8% vs. 7.8%, χ²=27.36, P<0.001) and sleep disorders (18.5% vs. 15.2%, χ²=11.13, P=0.001) were higher in the older group than in the young and middle-aged group. The time from the appearance of dizziness to diagnosis was commonly longer in the older patient group than the other group (55.0% vs. 38.5%, χ²=55.95, P<0.001). Conclusions: Older patients with BPPV have more atypical symptoms and complex concomitant symptoms than young and middle-aged patients. For older patients with dizziness, positional testing is needed to confirm the possibility of BPPV even if the clinical symptoms are atypical.

Biparametric MRI-based radiomics classifiers for the detection of prostate cancer in patients with PSA serum levels of 4∼10 ng/mL

Purpose

To investigate the predictive performance of the combined model by integrating clinical variables and radiomic features for the accurate detection of prostate cancer (PCa) in patients with prostate-specific antigen (PSA) serum levels of 4-10 ng/mL.

Methods

A retrospective study of 136 males (mean age, 67.3 ± 8.4 years) with Prostate Imaging-Reporting and Data System (PI-RADS) v2.1 category ≤3 lesions and PSA serum levels of 4-10 ng/mL were performed. All patients underwent multiparametric MRI at 3.0T and transrectal ultrasound-guided systematic prostate biopsy in their clinical workup. Radiomic features were extracted from axial T2-weighted images (T2WI) and apparent diffusion coefficient (ADC) maps of each patient using PyRadiomics. Pearson correlation coefficient (PCC) and recursive feature elimination (RFE) were implemented to identify the most significant radiomic features. Independent clinic-radiological factors were identified via univariate and multivariate regression analyses. Seven machine-learning algorithms were compared to construct a single-layered radiomic score (ie, radscore) and multivariate regression analysis was applied to construct the fusion radscore. Finally, the radiomic nomogram was further developed by integrating useful clinic-radiological factors and fusion radscore using multivariate regression analysis. The discriminative power of the nomogram was evaluated by area under the curve (AUC), DeLong test, calibration curve, decision curve analysis (DCA), and clinical impact curve (CIC).

Results

The transitional zone-specific antigen density was identified as the only independent clinic-radiological factor, which yielded an AUC of 0.592 (95% confidence interval [CI]: 0.527-0.657). The ADC radscore based on six features and Naive Bayes achieved an AUC of 0.779 (95%CI: 0.730-0.828); the T2WI radscore based on 13 features and Support Vector Machine yielded an AUC of 0.808 (95%CI: 0.761-0.855). The fusion radscore obtained an improved AUC of 0.844 (95%CI: 0.801-0.887), which was higher than the single-layered radscores (both P<0.05). The radiomic nomogram achieved the highest value among all models (all P<0.05), with an AUC of 0.872 (95%CI: 0.835-0.909). Calibration curve showed good agreement and DCA together with CIC confirmed the clinical benefits of the radiomic nomogram.

Conclusion

The radiomic nomogram holds the potential for accurate and noninvasive identification of PCa in patients with PI-RADS ≤3 lesions and PSA of 4-10 ng/mL, which could reduce unnecessary biopsy.

Comparison of intravesical instillation of hyaluronic acid with intradetrusor botulinum toxin A injection or cystoscopic hydrodistention for ketamine-associated cystitis

OBJECTIVE

This study aimed to compare the therapeutic effect of intravesical instillation hyaluronic acid with intradetrusor botulinum toxin A (BTX-A) injection or cystoscopic hydrodistention for ketamine-associated cystitis.

METHODS

Thirty-six patients were evenly randomly divided into the BTX-A group or the hydrodistention group. Patients received 200 U BTX-A detrusor injections in the BTX-A group and cystoscopic hydrodistention in the hydrodistention group. Intravesical instillation of hyaluronic acid was administrated in both groups for eight times. Patients with involuntary detrusor contraction were divided into the persistent involuntary detrusor contraction group and resolved involuntary detrusor contraction group after treatment in 6 months. The predictors of persistent involuntary detrusor contraction were analyzed.

RESULTS

Twelve months after treatment, the daytime frequency, Interstitial Cystitis Symptom Index, maximal capacity, and maximal cystometric capacity in the BTX-A group were significantly better than those in the hydrodistention group. Patients with resolution of involuntary detrusor contraction had a significantly shorter duration of ketamine, lower amount of fibrosis in pathology, and higher maximal capacity than those with persistent involuntary detrusor contraction 6 months after therapy.

CONCLUSION

Intravesical instillation of hyaluronic acid with intradetrusor BTX-A injection appears to be a preferable option for long-term effectiveness compared with cystoscopic hydrodistention.

GTSE1 promotes prostate cancer cell proliferation via the SP1/FOXM1 signaling pathway

G2 and S phase-expressed-1 (GTSE1) has been implicated in the pathogenesis of several malignant tumors. However, its specific role in prostate cancer (PCa) remains unclear. In this study, RNA-Seq data from patients with PCa and controls were downloaded from the FIREBROWSE database, and it was found that the GTSE1 mRNA level was significantly upregulated in PCa. Moreover, patients with higher GTSE1 mRNA levels had higher Gleason scores (P < 0.001), a more advanced pT stage (P = 0.011), and a more advanced pN stage (P = 0.006) as well as a shorter time to biochemical recurrence (P = 0.005). In addition, overexpression of GTSE1 could promote proliferation in LNCaP cells, whereas silencing GTSE1 could inhibit the growth of C4-2 cells in vitro and in vivo. Mechanistically, GTSE1 enhanced the expression of FOXM1 by upregulating the SP1 protein level, a transcription factor of FOXM1, which ultimately promoted PCa cell proliferation. In summary, GTSE1 is a new candidate oncogene in the development and progression of PCa, and it can promote PCa cell proliferation via the SP1/FOXM1 signaling pathway.

Microstructures of the spermatic cord with three-dimensional reconstruction of sections of the cord and application to varicocele

The aim of the study was to investigate the micro-structures of the spermatic cord using histological examination with three-dimensional (3D) reconstruction of the serial tissue sections of the cord for clinical application in microscopic varicocelectomy. Human spermatic cord specimens obtained from 13 adult male cadavers were used to prepare serial transverse sections. The sections were stained to allow observation of the spermatic cord microstructures. The 3D reconstruction was performed with digitized serial sections by Mimics software. The microscopic varicocelectomy was performed based on the anatomical results of 3D reconstruction of the spermatic cord. The results showed the number of small spermatic veins, large spermatic veins, arteries, lymphatics or nerves were not markedly different between the subinguinal and inguinal regions or between the right and left sperm cord. The number of medium spermatic veins in the subinguinal region was obviously higher than at the inguinal level. The internal spermatic vessels and the vas deferens together with other associated vessels within the cremaster were separately enclosed by two thin and translucent sheaths, the internal spermatic fascia and the vas deferens fascia. We conclude that internal spermatic vessels and the vas deferens together with the associated neurovascular vessels are wrapped by two distinct sheaths separating them from the surrounding tissues. Microscopic varicocelectomy based on the anatomical results of 3D reconstruction of the spermatic cord is feasible.

ABBREVIATIONS

3D: three-dimensional; ISF: internal spermatic fascia; ESF: external spermatic fascia; MHIV: High inguinal microsurgical varicocelectomy; MSIV: subinguinal microsurgical varicocelectomy; CAAD: computer-assisted anatomic dissection; HE: hematoxylin-eosin.

[Video endosopic inguinal lymphadenectomy for penile cancer]

Inguinal lymph node metastasis is one of the important factors affecting the prognosis of penile cancer. Conventional open inguinal lymphadenectomy, with a high rate of complications, seriously affects the effect of surgery and the patient's quality of life, and therefore is rarely employed nowadays as a treatment option. Video endosopic inguinal lymphadenectomy (VEIL), however, can significantly reduce the incidence rate of surgery-related complications, achieve a desirable control of the tumor, and markedly improve the prognosis. This review focuses on the application, development, indications, effectiveness and complications of VEIL in the treatment of penile cancer.

MicroRNA-488 inhibits proliferation and glycolysis in human prostate cancer cells by regulating PFKFB3

Prostate cancer (PCa) remains the second leading cause of cancer‐related death among men in the United States, and its molecular mechanism remains to be elucidated. Recent studies have suggested that microRNAs may play an important role in cancer development and progression. By analyzing the Gene Expression Omnibus dataset, we found lower expression for miR‐488 in PCa than in normal tissues. Moreover, CCK‐8, EdU, glucose uptake, and lactate secrete assays revealed that overexpression of miR‐488 in PCa cell lines PC3 and DU145 resulted in inhibition of proliferation and glycolysis. In contrast, downregulation of miR‐488 expression promoted proliferation and glycolysis in PCa cells. Using a bioinformatic approach and dual‐luciferase reporter assays, we identified 6‐phosphofructo‐2‐kinase/fructose‐2,6‐bisphosphatase, isoform3 (PFKFB3), as a direct target of miR‐488. Inhibition of PFKFB3 also suppressed PCa cell glycolysis and proliferation. Our study suggests that miR‐488 inhibits PCa cell proliferation and glycolysis by targeting PFKFB3, and thus, miR‐488 may be a novel therapeutic candidate for PCa.

IL-37 inhibits IL-4/IL-13-induced CCL11 production and lung eosinophilia in murine allergic asthma

BACKGROUND

IL-37 is emerging as an anti-inflammatory cytokine, particularly in innate inflammation. However, the role of IL-37 in Th2-mediated allergic lung inflammation remains uncertain. We sought to determine the role and the underlying mechanisms of IL-37 in the development of house dust mites (HDM)-induced murine asthma model.

METHODS

We examined the effect of IL-37 administration during the sensitization or challenge phase on Th2-mediated allergic asthma induced by inhaled HDM. Cellular source of CCL11 and distribution of IL-37 receptors, IL-18Rα and IL-1R8, were determined in HDM-exposed lungs. Finally, we examined the effect of IL-37 on CCL11 production and STAT6 activation in different primary lung structural cell types upon IL-4/IL-13 stimulation.

RESULTS

IL-37 had no effect on HDM sensitization, but when administrated during the challenge phase, significantly attenuated pulmonary eosinophilia, CCL11 production, and airway hyper-reactivity (AHR). Interestingly, IL-37 treatment had no significant effects on lung infiltrating T cells and Th2 cytokine production. Intranasal co-administration of CCL11 reversed the inhibiting effect of IL-37 on HDM-induced pulmonary eosinophilia and AHR. Furthermore, we demonstrated that CCL11 was primarily expressed by fibroblasts and airway smooth muscle cells (AMSC), while IL-37 receptors by tracheobronchial epithelial cells (TEC). In vitro study showed that IL-37 inhibited IL-4/IL-13-induced STAT6 activation and CCL11 production by fibroblasts and AMSC, which was dependent on its direct action on TEC. Moreover, cell contact was required for the inhibitory effect of IL-37-treated TEC.

CONCLUSIONS

IL-37 attenuates HDM-induced asthma, possibly by inhibiting IL-4/IL-13-induced CCL11 production by fibroblasts and AMSC via its direct act on TEC.

Hyperglycaemia-induced miR-301a promotes cell proliferation by repressing p21 and Smad4 in prostate cancer

Hyperglycaemia promotes the development of Prostate cancer (PCa). However, the roles of miRNAs in this disease process and the underlying mechanisms are largely unknown. In this study, we recruited 391 PCa patients in China and found that PCa patients with high level blood glucose (≥100 mg/dL) trended to have high Gleason score (GS ≥ 7). miRNA-301a levels were significantly higher in prostate cancer than that in normal prostate tissues. Hyperglycaemia or high glucose treatment induced miR-301a expression in prostate tissues or PCa cell lines. miR-301a suppressed the expression of p21 and Smad4, and subsequently promoted G1/S cell cycle transition and cell proliferation in vitro and xenograft growth in nude mice in vivo. Furthermore, knockdown of p21 and Smad4 mimicked the effects of miR-301a overexpression. Restoration of p21 and smad4 could interrupt the effects of miR-301a overexpression. Importantly, inhibition of miR-301a severely blocked high glucose-induced PCa cell growth both in vitro and in vivo. These results revealed a novel molecular link between hyperglycaemia and PCa. The miR-301a plays an important role in the hyperglycaemia-associated cancer growth, and represents a novel therapeutic target for PCa.

Epidemiological link between exposure to poultry and all influenza A(H7N9) confirmed cases in Huzhou city, China, March to May 2013

We analysed the association between influenza A(H7N9) confirmed cases and exposure to poultry in Huzhou city, China. All cases (n=12) had a history of direct exposure to poultry or live poultry markets. We detected A(H7N9)-positive poultry samples from each site that was epidemiologically associated with cases. None of the cases’ close contacts tested positive. After closure of the markets, no new cases were identified, suggesting an epidemiological link between poultry exposure and A(H7N9) virus infection.

Epidemiological link between exposure to poultry and all influenza A(H7N9) confirmed cases in Huzhou city, China, March to May 2013

Binary file ES_Abstracts_Final_ECDC.txt matches

Selective modification of HK peptides enhances siRNA silencing of tumor targets in vivo

Our research has focused on systemic delivery of small interference RNA (siRNA) by branched peptides composed of histidine and lysine. After studying several histidine-lysine (HK) peptides, one four-branched peptide, H3K(+H)4b, with a predominant repeating pattern of -HHHK-, was found to be an effective carrier of siRNA. Although the unmodified H3K(+H)4b carrier of siRNA targeting an oncogene was previously shown to have promise in a tumor-bearing mouse model, we sought to develop a more effective HK carrier of siRNA in this study. Our primary goal was to determine whether different ligand (cyclic RGD)-pegylation patterns on the H3K(+H)4b peptide affect siRNA delivery in vitro and in vivo. We compared the unmodified H3K(+H)4b with two modified H3K(+H)4b peptides for their ability to deliver siRNA in a tumor-bearing mouse model; one modified HK peptide, (RGD-PEG)(4)-H3K(+H)4b, had four cyclic RGD-polyethylene glycol (cRGD-PEG) conjugates per molecule, whereas the other peptide, (RGD-PEG)-H3K(+H)4b, had one cRGD-PEG per molecule. Although the modified HK peptides by themselves did not form stable nanoplexes with siRNA, combination of a highly charged unmodified HK peptide, H2K4b, with either of the modified HK peptides did form stable siRNA nanoparticles. For in vitro experiments with MDA-MB-435 cells that expressed luciferase (Luc), the H3K(+H)4b siRNA nanoplexes targeting Luc decreased its activity by 90% compared with negligible downregulation by the modified H3K(+H)4b nanoplexes (P<0.01). In contrast, the two modified H3K(+H)4b siRNA nanoplexes administered intravenously were more effective than the H3K(+H)4b nanoplexes in silencing Luc in a tumor xenograft model. The Luc activity in tumor lysates of mice administered H3K(+H)4b, (RGD-PEG)-H3K(+H)4b and (RGD-PEG)(4)-H3K(+H)4b nanoplexes decreased by 18, 35 and 75%, respectively. Thus, the siRNA nanoplex incorporating the highly modified peptide, (RGD-PEG)(4)-H3K(+H)4b, was the most effective at silencing its target in vivo (P<0.01). These studies demonstrate that selectively modified HK polymers are promising candidates for targeting oncogenes with siRNA.

Peptide-based Antifungal Therapies against Emerging Infections

Acquired drug resistance to mycotic infections is rapidly emerging as a major medical problem. Opportunistic fungal infections create therapeutic challenges, particularly in high risk immunocompromised patients with AIDS, cancer, and those undergoing transplantation. Higher mortality and/or morbidity rates due to invasive mycosis have been increasing over the last 20 years, and in light of growing resistance to commonly used antibiotics, novel antifungal drugs and approaches are required. Currently there is considerable interest in antifungal peptides that are ubiquitous in plant and animal kingdoms. These small cationic peptides may have specific targets or may be multifunctional in their mechanism of action. On the basis of recent advances in protein engineering and solid phase syntheses, the utility and potential of selected peptides as efficient antifungal drugs with acceptable toxicity profiles are being realized. This review will discuss recent advances in peptide therapy for opportunistic fungal infections.

Systemic delivery of HK Raf-1 siRNA polyplexes inhibits MDA-MB-435 xenografts

Our past research has focused on identifying an effective carrier composed of histidine and lysine for delivery of nucleic acid into cells. For this purpose, we developed histidine-lysine-rich (HK) polymers with specific sequences and branching. We have found that branched HK polymers in complex with Raf-1 siRNA markedly decreased Raf-1 mRNA and induced apoptosis in cell lines in vitro. The primary focus of the present study was to determine an effective carrier to deliver siRNA systemically to tumor xenografts. After comparing HK:Raf-1 polyplexes for their in-vivo efficacy, we investigated in greater detail whether one of these polymers, H3K(+H)4b, in complex with Raf-1 siRNA, inhibited the growth of MDA-MB-435 xenografts. H3K(+H)4b is a four-branched HK peptide whose predominant repeating sequence within the terminal arm is -HHHK-. After the first tail-vein injection in a mouse model, there was a statistically significant reduction in tumor size between the H3K(+H)4b:Raf-1 siRNA-treated and the control groups (P<0.01). By the third injection, there was nearly a 50% reduction in the Raf-1 siRNA-treated group compared to the control siRNA-treated or -untreated group. Consistent with a significant effect of the HK:Raf-1 polyplex on the tumor, there were marked histological changes, increased apoptosis and fewer vessels in the Raf-1 siRNA-treated group. Raf-1 protein within the tumor was significantly decreased after treatment with the HK:Raf-1 siRNA polyplex compared to the control treatment groups. Despite the striking effect on the tumor by the HK Raf-1 siRNA, there was little evidence of toxicity in normal tissues with this therapy. By harnessing the ability to modify the amino-acid sequence and branching of HK polymers, we expect continued development of HK polymers as in-vivo carriers of siRNA.

Maxi-K channels contribute to urinary potassium excretion in the ROMK-deficient mouse model of Type II Bartter's syndrome and in adaptation to a high-K diet

Type II Bartter's syndrome is a hereditary hypokalemic renal salt-wasting disorder caused by mutations in the ROMK channel (Kir1.1; Kcnj1), mediating potassium recycling in the thick ascending limb of Henle's loop (TAL) and potassium secretion in the distal tubule and cortical collecting duct (CCT). Newborns with Type II Bartter are transiently hyperkalemic, consistent with loss of ROMK channel function in potassium secretion in distal convoluted tubule and CCT. Yet, these infants rapidly develop persistent hypokalemia owing to increased renal potassium excretion mediated by unknown mechanisms. Here, we used free-flow micropuncture and stationary microperfusion of the late distal tubule to explore the mechanism of renal potassium wasting in the Romk-deficient, Type II Bartter's mouse. We show that potassium absorption in the loop of Henle is reduced in Romk-deficient mice and can account for a significant fraction of renal potassium loss. In addition, we show that iberiotoxin (IBTX)-sensitive, flow-stimulated maxi-K channels account for sustained potassium secretion in the late distal tubule, despite loss of ROMK function. IBTX-sensitive potassium secretion is also increased in high-potassium-adapted wild-type mice. Thus, renal potassium wasting in Type II Bartter is due to both reduced reabsorption in the TAL and K secretion by max-K channels in the late distal tubule.

Beyond self and nonself: fuzzy recognition of the immune system

Self-nonself discrimination of the immune system is a widely accepted principle of immunology; however, abundant existing and physiologic functions of harmless autoimmunity as well as degeneracy of antigen recognition expose the over-simplification of the two-valued doctrine. Here, based on infinite-value fuzzy logic, we propose that the immune repertoire, as a consequence of central tolerance, is able to recognize both self and nonself antigens to a certain degree, compensating for the inadequacy of the two-valued self-nonself doctrine. Subthreshold recognition of self antigens is necessary for the generation of regulatory T cells, survival of both naive and memory T cells and other physiologic functions. The kind and magnitude of the immune response depend on the affinity between the antigen (self and foreign) and the T-cell receptor, and microenvironmental and cellular threshold. The outcome of self-nonself discrimination is influenced fundamentally by central tolerance and further dynamic regulation of threshold molecules both in time and space. Understanding the fuzzy feature of the immune system may shed light on mechanisms of autoimmune diseases, cancers and other chronic diseases, and lead to the design of novel vaccines or immunotherapies.

Helminths, human immunodeficiency virus and tuberculosis

Helminth infections affect over a quarter of the world's population, especially in the developing countries. These long-lasting parasitic infections cause widespread immune activation and dysregulation, a dominant Th2 cytokine immune profile and an immune hyporesponsiveness state. Considering these profound immune changes and the similar geographic distributions of helminthic infections, HIV and tuberculosis (TB), we suggest that helminthic infections play a major role in the pathogenesis of AIDS and TB. They apparently make the host more susceptible to infection by HIV and Mycobacterium tuberculosis, and impair his/her ability to generate protective immunity against both infections. The implication of these ideas is that without eradication of helminth infections and/or modulation of the immune changes that they cause, HIV and TB vaccines may fail to confer protection against their respective infections in helminth-endemic areas.

Immune activation correlates better than HIV plasma viral load with CD4 T-cell decline during HIV infection

This study addressed the role of T-cell immune activation in determining HIV-1 plasma viral load and CD4+ T-cell blood levels during HIV-1 infection. A decrease of blood CD4 levels and CD4/CD8 ratios and an increase of CD8 levels in both treated (n = 35) and untreated (n = 19) HIV-positive individuals were more strongly correlated to immune activation (log percentage of HLA-DR+CD3+ cells; R = -0.78, R = -0.77, and R = 0.58, respectively; p <.0001) than to CD4 T-cell proliferation (log percentage of Ki-67+CD4+ cells; R = -0.57 [p <.0001], R = -0.48 [p <.001], and R = 0.37 [p <.01], respectively) or to viral load (R = -0.36 [p <.01], R = -0.23 [p =.09], R = 0.13 [p =.35], respectively). Because almost half of the Ki-67+CD4+ cells were also positive for CTLA-4 (a marker for activated nonproliferating cells), the correlation of CD4 levels to Ki-67 expression is only partially related to cell proliferation and more likely represents mainly immune activation of the cells without proliferation. Taken together, these results suggest that immune activation is the major determinant of CD4 decline and should therefore be considered central for the monitoring of HIV infection and its outcome after antiviral treatment.

Chronic immune activation associated with intestinal helminth infections results in impaired signal transduction and anergy

Helminthic parasites cause widespread, persistent infections in humans. The immigration of Ethiopians to Israel (a group denoted here by "Eth."), many of them infested with helminths and in a chronic immune-activation state, enabled us to investigate the effects of such immune activation on immune responses. We studied the immune profile and immune functions of 190 Eth. and Israeli non-Eth. (Isr.) highly, partially, or non-immune-activated individuals. Immune cells from highly immune-activated individuals were defective in several signaling responses, all of which were restored gradually following anti-helminthic treatment. These cells showed poor transmembrane signaling, as seen by the phosphorylation of various tyrosine kinases and of the MAPK kinases, ERK1/2 and p38; deficient degradation of phosphorylated IkappaBalpha; increased expression of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), which appears to block proliferative responses in these cells; decreased beta-chemokine secretion by CD8(+) cells after stimulation; and reduced proliferation to recall antigen stimulation. Highly immune-activated individuals also showed decreased delayed-type skin hypersensitivity responses to recall antigen before deworming. These findings support the notion that chronic helminthic infections cause persistent immune activation that results in hyporesponsiveness and anergy. Such impaired immune functions may diminish the capacity of these individuals to cope with infections and to generate cellular protective immunity after vaccination.

Co-expression of calcium-dependent protein kinase with the inward rectified guard cell K+ channel KAT1 alters current parameters in Xenopus laevis oocytes

Increased guard cell cytosolic [Ca2+] is known to be involved in signal transduction pathways leading to stomatal closure, and inhibit the inward rectifying guard cell K+ channel KAT1. Guard cell calcium-dependent protein kinase (CDPK) has been shown to phosphorylate KAT1; such phosphorylation is known to modulate other K+ channels involved in signal transduction cascades. The work reported here focused on demonstrating CDPK-dependent inhibition of KAT1 currents. A cDNA encoding soybean CDPK was generated and it's translation product was shown to be functional; demonstrating Ca2+-dependent autophosphorylation and phosphorylation of a target protein. Ion currents were monitored using voltage clamp techniques upon expression of KAT1 in Xenopus laevis oocytes. Coexpression of recombinant CDPK with KAT1 in oocytes altered the kinetics and magnitude of induced K+ currents; at a given hyperpolarizing command voltage, the magnitude of KAT1 currents was reduced and the half-time for channel activation was increased. This finding supports a model of Ca2+-dependent ABA inhibition of inward K+ currents in guard cells as being mediated by CDPK phosphorylation of KAT1.

[The efficacy of antiviral antibiotic 17997 on treatment of HSV-1 infected guinea pig skin infection]

OBJECTIVE

To study the treatment efficacy of antiviral antibiotic 17997 against HSVl infected guinea pig skin infection.

METHODS

Guinea pig skin was infected by HSV1. 24hrs or 48hrs of post infection local treatment of 0.3% 17997 cream was started, tid for five days. In the mean time, acyclovir treatment, cream treatment and virus control were included.

RESULTS

Local treatment of 0.3% 17997 cream showed therapeutic effects, it reduced the average scores of skin lesion, accelerated crusting-time and healing-time.

CONCLUSIONS

0.3% 17997 cream showed significant treatment efficacy when compared with cream and virus controls by reducing skin lesion scores and healing-time. The treatment efficacy of 3.0% acyclovir cream was a little bit better than 0.3% 17997 cream.

Cloning and first functional characterization of a plant cyclic nucleotide-gated cation channel

Cyclic nucleotide-gated (cng) non-selective cation channels have been cloned from a number of animal systems. These channels are characterized by direct gating upon cAMP or cGMP binding to the intracellular portion of the channel protein, which leads to an increase in channel conductance. Animal cng channels are involved in signal transduction systems; they translate stimulus-induced changes in cytosolic cyclic nucleotide into altered cell membrane potential and/or cation flux as part of a signal cascade pathway. Putative plant homologs of animal cng channels have been identified. However, functional characterization (i.e. demonstration of cyclic-nucleotide-dependent ion currents) of a plant cng channel has not yet been accomplished. We report the cloning and first functional characterization of a plant member of this family of ion channels. The Arabidopsis cDNA AtCNGC2 encodes a polypeptide with deduced homology to the alpha-subunit of animal channels, and facilitates cyclic nucleotide-dependent cation currents upon expression in a number of heterologous systems. AtCNGC2 expression in a yeast mutant lacking a low-affinity K(+) uptake system complements growth inhibition only when lipophilic cyclic nucleotides are present in the culture medium. Voltage clamp analysis indicates that Xenopus laevis oocytes injected with AtCNGC2 cRNA demonstrate cyclic-nucleotide-dependent, inward-rectifying K(+) currents. Human embryonic kidney cells (HEK293) transfected with AtCNGC2 cDNA demonstrate increased permeability to Ca(2+) only in the presence of lipophilic cyclic nucleotides. The evidence presented here supports the functional classification of AtCNGC2 as a cyclic-nucleotide-gated cation channel, and presents the first direct evidence (to our knowledge) identifying a plant member of this ion channel family.

Increased CCR5 expression with decreased beta chemokine secretion in Ethiopians: relevance to AIDS in Africa

OBJECTIVE

This study was undertaken to determine the contribution of HIV co-receptors and beta chemokine secretion to the increased susceptibility for human immunodeficiency virus (HIV) infection of peripheral blood mononuclear cells (PBMC) obtained from HIV-seronegative Ethiopian immigrants in Israel (ETH).

STUDY DESIGN

Immune activation markers and HIV co-receptor expression on lymphocytes and monocytes, and beta chemokine secretion by CD8+ cells, were compared between ETH and non-Ethiopian Israeli (IS) HIV-negative individuals.

RESULTS

The percentage of lymphocytes and monocytes expressing CCR5 was 1.6 and 3.0 times higher in ETH (n = 83) than in IS (n = 45), respectively (P < .001), whereas RANTES and MIP-1alpha secretion was 0.5 and 0.7 times lower (P < .01 and P < .05). The percentage of CCR5-expressing cells and RANTES secretion were inversely correlated (r = -0.7; P < .002). No differences were found in the proportion of CXCR4-expressing cells. No correlation between CCR5 expression and cell activation profile in the whole ETH population was found. However, in highly activated individuals (HLA-DR/CD3 > 7%), a significant decrease in CCR5 expression was observed.

CONCLUSIONS

An increased proportion of CCR5-expressing cells with decreased beta chemokine secretion observed in ETH may account for the increased susceptibility to HIV infection of cells obtained from this group. These findings may partly explain the higher susceptibility for HIV infection in Africa and thus the rapid spread of acquired immunodeficiency syndrome (AIDS) in that continent.

[Establishment of a microbial assay for screening anti-human immunodeficiency virus type-1 protease inhibitors]

OBJECTIVE

This study was to establish a microbial assay of human immunodeficiency virus type-1 protease (HIV-1 PR) activity for screening anti-HIV PR inhibitors.

METHODS

A 24 bp synthetic oligonucleotide fragment that encodes the HIV-1 PR recognition sequence was inserted into the tetr gene of pBR322 (mtetr). Escherichia coli containing HIV-1 PR expression vector-pPOLO was transformed with pACYC184M containing modified mtetr gene. The transformant could express both HIV-1 PR and the modified Tet protein.

RESULTS

The growth of engineered E. coli was prevented in the presence of tetracycline because the resistance Tet protein was degraded by HIV-1 PR. However inhibition of the HIV-1 PR restored tetracycline resistance. 31 chemical synthetic compounds were tested by the microbial assay.

CONCLUSIONS

A microbial assay method of HIV-1 PR activity was established through a engineered E. coli. 5 mumol/L saqunavir-a special HIV-1 PR inhibitor showed inhibitory effect on the engineered E. coli. That means this model could be used as a initial screening model for anti-HIV PR agents.

[Pharmacognostical studies on radix Glehniae (Glehnia littoralis)]

OBJECT

To identify the roots of Glehnia littoralis Fr. Schmidt ex Miq., and compare the chemical constituents of the root skin and the roots with no skin.

METHODS

The roots were identified by morphological and microscopic identification and TLC.

RESULTS

The characteristics of the secretory canal, ray and starch grain can be used to identify the histology and powder of the roots. The chemical constituents of the root skin and the roots with no skin are similar.

CONCLUSION

The characteristics of the morphology, histology and powder can be used to identify the roots of Glehnia littoralis (Radix Glehniae).