Bioactive Wound Healing 3D Structure Based on Chitosan Hydrogel Loaded with Naringin/Cyclodextrin Inclusion Nanocomplex

The current assay aimed to fabricate and analyze a potent wound healing structure based on a naringin (Nar)/β-cyclodextrin (β-CD)-loaded chitosan hydrogel. Using the simulation studies, we assessed the interactions among the Nar, β-CD, and the formation of the inclusion complex. Then, the formation of the hydrogel nanocomplex was simulated and evaluated using the in silico methods. The results showed that after optimization of the structures by DMol3 based on DFT-D, the total energies of Nar, GP, CD, and β-CD were calculated at -2100.159, -912.192, -3778.370, and -4273.078 Ha, respectively. The encapsulation energy of Nar on β-CD in the solvent phase was calculated at -93.626 kcal/mol, and the Nar structure was located inside β-CD in solution. The negative interaction energy value for the encapsulation of Nar on β-CD suggests the exothermic adsorption process and a stable structure between Nar and β-CD. Monte Carlo method was applied to obtain adsorption of CS/GP on Nar/β-CD. Its value of the obtained interaction energy was calculated at -1.423 × 103 kcal/mol. The characterization confirmed the formation of a Nar/β-CD inclusion complex. The Zeta potential of the pristine β-CD changed from -4.60 ± 1.1 to -17.60 ± 2.34 mV after interaction with Nar, and the heightened surface negativity can be attributed to the existence of electron-rich naringin molecules, as well as the orientation of the hydroxyl (OH) group of the β-CD toward the surface in an aqueous solution. The porosity of the fabricated hydrogels was in the range of 70-90% and during 14 days around 47.0 ± 3.1% of the pure hydrogel and around 56.4 ± 5.1 of hydrogel nanocomposite was degraded. The MTT assay showed that the hydrogels were biocompatible, and the wound contraction measurement (in an animal model) showed that the closure of the induced wound in the hydrogel nanocomposite treatment was faster than that of the control group (wound without treatment). The results of this study indicate that the developed bioactive wound healing 3D structure, which is composed of a chitosan hydrogel containing a Nar/β-CD inclusion nanocomplex, has potential as an effective material for wound dressing applications.

Effectiveness of Platelet-Rich Plasma in the Treatment of Androgenic Alopecia: A Meta-Analysis

BACKGROUND

Androgenetic alopecia (AGA) is a common yet difficult-to-treat condition, which is an important psychosocial problem. Platelet-rich plasma (PRP) therapy has been considered as a promising treatment for AGA. However, the current evidence on the efficacy of PRP for treating AGA is still controversial. This study evaluated the efficacy of PRP monotherapy in the treatment of AGA.

METHODS

We searched PubMed, Embase, Cochrane Library and Web of Science to collect randomized controlled trials on use of PRP in AGA for a meta-analysis.

RESULTS

Ten trials with a total 555 treatment units were identified. The hair density in PRP group was significantly higher than control group [MD = 25.09, 95%CI: 9.03-41.15, p = 0.002], but there was no significant difference in hair diameter between two groups [SMD = 0.57, 95%CI: - 0.23 to 1.38, p = 0.16]. Subgroup analyses indicated that hair density was significantly higher among the male-only trials than in the mixed-sex samples (p = 0.02). In addition, neither the split-head design nor the year of publication affected hair density (p = 0.05, p = 0.06). However, hair density was significantly higher in trials with a sample size less than 30 (p = 0.0004).

CONCLUSIONS

PRP treatment increased hair density in participants with AGA, but not hair diameter. In terms of hair density, PRP elicits stronger effects in male patients. There was a trend toward differed treatment effect by gender with PRP injection, which warrants further investigation. Especially in the case of female.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors https://www.springer.com/00266 .

Relationship between Social Support, Sarcopenia, and Cognitive Impairment in Chinese Community-Dwelling Older Adults

BACKGROUND

Cognitive impairment and sarcopenia have become important challenges for the growing aging population. Social support has been shown to protect against cognitive impairment, but its impact on sarcopenia remains unknown. The purpose of this study was to explore the correlation between social support, sarcopenia, and cognitive impairment in Chinese older adults.

METHOD

A multi-stage whole group sampling method was used to conduct a cross-sectional survey of 720 community-dwelling older people in Shanghai. The definition of sarcopenia was in accordance with the criteria of the Asian Working Group for Sarcopenia (AWGS) 2019. Cognitive impairment was evaluated using a computerized neuropsychological assessment device that had been previously validated. Social support was assessed using the Social Support Rate Scale. Logistic regression analyses were conducted to explore the relationship between social support cognitive impairment and sarcopenia, fully adjusting for all potential confounding factors.

RESULTS

Our study found that 230 (31.94%) of the participants had cognitive impairment and 97 (13.47%) of the participants had sarcopenia. The mean social support score was 35.10 ± 7.54. Besides, the results showed that cognitive impairment was associated with sarcopenia (OR:1.650, 95% CI: 1.048, 2.596, P=0.030) after adjusting for confounding factors. Older adults with high level social support had the lowest risk of cognitive impairment (OR: 0.297, 95% CI: 0.115, 0.680, P=0.021) and sarcopenia (OR: 0.113, 95% CI: 0.031, 0.407, P=0.001), respectively.

CONCLUSION

Our analysis revealed that high level social support was negatively associated with sarcopenia and cognitive impairment. These findings provide strong support for the health promotion effect of social networks against sarcopenia and cognitive impairment in Chinese community-dwelling older adults, with important implications for healthcare policy makers.

The application of mesenchymal stromal cells (MSCs) and their derivative exosome in skin wound healing: a comprehensive review

Recently, mesenchymal stromal cells (MSCs) and also their exosome has become a game-changing tool in the context of tissue engineering and regenerative medicine. MSCs due to their competencies to establish skin cells, such as fibroblast and keratinocyte, and also their unique attribute to suppress inflammation in wound site has attracted increasing attention among scholars. In addition, MSC's other capabilities to induce angiogenesis as a result of secretion of pro-angiogenic factors accompanied with marked anti-fibrotic activities, which mainly mediated by the releases matrix metalloproteinase (MMPs), make them a rational and effective strategy to accelerate wound healing with a small scar. Since the chief healing properties of the MSCs depend on their paracrine effects, it appears that MSCs-derived exosomes also can be an alternative option to support wound healing and skin regeneration as an innovative cell-free approach. Such exosomes convey functional cargos (e.g., growth factor, cytokine, miRNA, etc.) from MSCs to target cells, thereby affecting the recipient skin cells' biological events, such as migration, proliferation, and also secretion of ECM components (e.g., collagen). The main superiorities of exosome therapy over parental MSCs are the diminished risk of tumor formation and also lower immunogenicity. Herein, we deliver an overview of recent in vivo reports rendering the therapeutic benefits of the MSCs-based therapies to ease skin wound healing, and so improving quality of life among patients suffering from such conditions.

p75NTR silencing inhibits proliferation, migration, and extracellular matrix deposition of hypertrophic scar fibroblasts by activating autophagy through inhibiting the PI3K/Akt/mTOR pathway

Hypertrophic scar (HS) results from abnormal wound healing, accompanied by excessive hypercellularity, migration, and extracellular matrix (ECM) deposition. Autophagy dysregulation plays crucial roles during HS formation. The overexpressed p75 neurotrophin receptor (p75NTR) in injured skin tissue after wound healing becomes a factor aggravating scar. This study was designed to investigate the role of p75NTR and p75NTR-mediated autophagy in the process of HS. The results revealed that p75NTR expression was significantly upregulated while that of autophagy proteins was downregulated in cicatrix at 3 and 6 months after a burn, which was recovered at 12 months. p75NTR silencing inhibited proliferation, migration, and ECM deposition of hypertrophic scar fibroblasts (HSF), whereas p75NTR overexpression presented the opposite results. Silencing of p75NTR reduced the expression of PI3K/Akt/mTOR signaling molecules while enhancing that of autophagy proteins. Importantly, PI3K agonist (IGF-1) intervention notably decreased the levels of LC3B II/I and Beclin-1 and restored the inhibitory effects of p75NTR silencing on proliferation, migration, and ECM deposition of HSF. Concurrently, autophagy inhibitor 3-methyladenine (3-MA) treatment exhibited the same variation trends with IGF-1. Taken together, these findings demonstrated that p75NTR silencing inhibits proliferation, migration, and ECM deposition of HSF by activating autophagy by inhibiting the PI3K/Akt/mTOR pathway.

Long non-coding RNA GAS5 inhibits tumorigenesis via miR-137 in melanoma

Melanoma is the leading cause of death in patients with skin cancer. In the present study, we aimed to prove the functions and molecular mechanisms of lncRNA-GAS5 in melanoma. Herein, we found that the expression of GAS5 was down-regulated in melanoma tissues compared to adjacent normal tissues. GAS5 was significantly associated with distal metastasis and TNM stage in melanoma. Furthermore, we found that GAS5 suppressed melanoma cell proliferation, migration and invasion. Then, we found thatmiR-137 was decreased in melanoma tissues compared to adjacent normal tissues and was correlated with GAS5. Using a luciferase reporter gene assay, we also demonstrated that GAS5 positively regulated miR-137 transcription. Finally, we suggested that GAS5 inhibited the growth of melanoma through miR-137 in vivo. Therefore, our research demonstrated that the GAS5/miR-137 axis could be a potential therapeutic target for the treatment of melanoma.

The long non-coding RNA NKILA inhibits the invasion-metastasis cascade of malignant melanoma via the regulation of NF-ĸB

The long non-coding RNA (lncRNA) NKILA has been reported to participate in the development of human cancers. The purpose of this study was to explore the potential role of lncRNA-NKILA, which acts through NF-ĸB, in the process of melanoma development. Real-time PCR (qRT-PCR) showed that NKILA was expressed at low levels in human melanoma tissues. The area under the ROC curve of NKILA was 0.875, which indicated that NKILA may be a potential diagnostic biomarker of melanoma. Our results also indicated that NKILA inhibited the progression of cell proliferation, migration, and invasion, and promoted apoptosis of melanoma cells. Furthermore, qRT-PCR showed that NF-κB, which was negatively correlated with NKILA, was highly expressed in human melanoma tissues. Moreover, our results indicated that NKILA inhibited the carcinogenesis of melanoma cells through the inhibition of NF-ĸB in vitro. More importantly, we found that NKILA suppressed the growth of melanoma tumors via NF-ĸB in vivo. In conclusion, NKILA suppressed the development of malignant melanoma via the regulation of NF-ĸB and may be a potential therapeutic target in patients with melanoma.

THE DECADE OF THE RABiT (2005-15)

The RABiT (Rapid Automated Biodosimetry Tool) is a dedicated Robotic platform for the automation of cytogenetics-based biodosimetry assays. The RABiT was developed to fulfill the critical requirement for triage following a mass radiological or nuclear event. Starting from well-characterized and accepted assays we developed a custom robotic platform to automate them. We present here a brief historical overview of the RABiT program at Columbia University from its inception in 2005 until the RABiT was dismantled at the end of 2015. The main focus of this paper is to demonstrate how the biological assays drove development of the custom robotic systems and in turn new advances in commercial robotic platforms inspired small modifications in the assays to allow replacing customized robotics with 'off the shelf' systems. Currently, a second-generation, RABiT II, system at Columbia University, consisting of a PerkinElmer cell::explorer, was programmed to perform the RABiT assays and is undergoing testing and optimization studies.

Design of a Virtual Reality System for Affect Analysis in Facial Expressions (VR-SAAFE); Application to Schizophrenia

Schizophrenia is a life-long, debilitating psychotic disorder with poor outcome that affects about 1% of the population. Although pharmacotherapy can alleviate some of the acute psychotic symptoms, residual social impairments present a significant barrier that prevents successful rehabilitation. With limited resources and access to social skills training opportunities, innovative technology has emerged as a potentially powerful tool for intervention. In this paper, we present a novel virtual reality (VR)-based system for understanding facial emotion processing impairments that may lead to poor social outcome in schizophrenia. We henceforth call it a VR System for Affect Analysis in Facial Expressions (VR-SAAFE). This system integrates a VR-based task presentation platform that can minutely control facial expressions of an avatar with or without accompanying verbal interaction, with an eye-tracker to quantitatively measure a participants real-time gaze and a set of physiological sensors to infer his/her affective states to allow in-depth understanding of the emotion recognition mechanism of patients with schizophrenia based on quantitative metrics. A usability study with 12 patients with schizophrenia and 12 healthy controls was conducted to examine processing of the emotional faces. Preliminary results indicated that there were significant differences in the way patients with schizophrenia processed and responded towards the emotional faces presented in the VR environment compared with healthy control participants. The preliminary results underscore the utility of such a VR-based system that enables precise and quantitative assessment of social skill deficits in patients with schizophrenia.

The G12/13-RhoA signaling pathway contributes to efficient lysophosphatidic acid-stimulated cell migration

The membrane redistribution and phosphorylation of focal adhesion kinase (FAK) have been reported to be important for cell migration. We previously showed that Lysophosphatidic acid (LPA) induced FAK membrane redistribution and autophosphorylation in ovarian cancer SK-OV3 cells and the signaling pathway consisting of Gi-Ras-MEKK1 mediated LPA-induced FAK membrane redistribution but not FAK autophosphorylation. We also showed that the disruption of the Gi-Ras-MEKK1 pathway led to a significant reduction in LPA-stimulated cell migration. These findings raised the question of whether LPA-induced FAK autophosphorylation was required for LPA-stimulated cell migration and what signaling mechanism was involved in LPA-induced FAK autophosphorylation. In this study, we expressed the membrane anchored wild-type FAK (CD2-FAK) in SK-OV3 cells and found that the expression of CD2-FAK greatly rescued LPA-stimulated cell migration in Gi or Ras-inhibited cells. However, Gi inhibitor pertussis toxin or dominant-negative H-Ras still significantly inhibited LPA-stimulated cell migration in cells expressing the membrane anchored FAK containing a mutation in the autophosphorylation site [CD2-FAK(Y397A)]. These results suggest that FAK autophosphorylation plays a role in LPA-stimulated cell migration. With the aid of p115RhoGEF-RGS, G12 and G13 minigenes to inhibit G12/13, we found that the G12/13 pathway was required for LPA-induced FAK autophosphorylation and efficient cell migration. Moreover, LPA activated RhoA and Rho kinase (ROCK) in a G12/13-dependent manner and their activities were required for LPA-induced FAK autophosphorylation. However, Rho or ROCK inhibitors displayed no effect on LPA-induced FAK membrane redistribution although they abolished LPA-induced cytoskeleton reorganization. Our studies show that the G12/13-RhoA-ROCK signaling pathway mediates LPA-induced FAK autophosphorylation and contributes to LPA-stimulated cell migration.

Antagonism of delta(2)-opioid receptors by naltrindole-5'-isothiocyanate attenuates heroin self-administration but not antinociception in rats

delta-Opioid receptors have been implicated in reinforcement processes and antagonists are available that produce long-lasting and selective antagonism of delta-opioid receptors in vivo. This experiment assessed the contribution of delta-opioid receptors to the antinociceptive and reinforcing properties of heroin. The effects of the irreversible delta-antagonist naltrindole-5'-isothiocyanate (5'-NTII) were evaluated on heroin self-administration and hot-plate antinociception in rats. 5'-NTII (10 nmol i.c.v.) shifted the dose-response curve for heroin self-administration downward, increasing the A(50) values on the ascending and descending limbs by approximately 0.5 log units and decreasing the maximum by 33%. 5'-NTII (40 nmol i.c.v.) shifted both limbs of the heroin self-administration dose-effect curve 1.2 log units to the right and decreased the maximum by 90%. Heroin self-administration gradually returned to baseline levels over 7 or 17 days after administration of 10 or 40 nmol 5'-NTII, respectively. 5'-NTII (40 nmol i.c.v.) decreased the self-administration of 0.17 mg/infusion cocaine by 40% while having no effect on responding maintained by 0.33 or 0.67 mg/infusion. 5'-NTII attenuated the antinociceptive effects of deltorphin (delta(2)) in a dose-dependent manner while having no effect on antinociception elicited after i.c. v. administration of [D-Pen(2),D-Pen(5)]-enkephalin (delta(1)) or [D-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin (mu). In addition, the antinociceptive effects of heroin were not significantly affected by 5'-NTII (40 nmol i.c.v.). Therefore, 5'-NTII can attenuate the reinforcing effects of heroin at doses that do not affect its antinociceptive effects. Long-acting delta(2)-opioid antagonists may be beneficial in the treatment of heroin dependence or as adjuncts to reduce the abuse liability of opioid analgesics.

Extraterritorial neuropathic pain correlates with multisegmental elevation of spinal dynorphin in nerve-injured rats

Neuropathic pain is often associated with the appearance of pain in regions not related to the injured nerve. One mechanism that may underlie neuropathic pain is abnormal, spontaneous afferent drive which may contribute to NMDA-mediated central sensitization by the actions of glutamate and by the non-opioid actions of spinal dynorphin. In the present study, injuries to lumbar or sacral spinal nerves elicited elevation in spinal dynorphin content which correlated temporally and spatially with signs of neuropathic pain. The increase in spinal dynorphin content was coincident with the onset of tactile allodynia and thermal hyperalgesia. Injury to the lumbar (L(5)/L(6)) spinal nerves produced elevated spinal dynorphin content in the ipsilateral dorsal spinal quadrant at the L(5) and L(6) spinal segments and in the segments immediately adjacent. Lumbar nerve injury elicited ipsilateral tactile allodynia and thermal hyperalgesia of the hindpaw. In contrast, S(2) spinal nerve ligation elicited elevated dynorphin content in sacral spinal segments and bilaterally in the caudal lumbar spinal cord. The behavioral consequences of S(2) spinal nerve ligation were also bilateral, with tactile allodynia and thermal hyperalgesia seen in both hindpaws. Application of lidocaine to the site of S(2) ligation blocked thermal hyperalgesia and tactile allodynia of the hindpaws suggesting that afferent drive was critical to maintenance of the pain state. Spinal injection of antiserum to dynorphin A((1-17)) and of MK-801 both blocked thermal hyperalgesia, but not tactile allodynia, of the hindpaw after S(2) ligation. These data suggest that the elevated spinal dynorphin content consequent to peripheral nerve injury may drive sensitization of the spinal cord, in part through dynorphin acting directly or indirectly on the NMDA receptor complex. Furthermore, extrasegmental increases in spinal dynorphin content may partly underlie the development of extraterritorial neuropathic pain.

Selective opioid delta agonists elicit antinociceptive supraspinal/spinal synergy in the rat

A multiplicative antinociceptive interaction of morphine activity at supraspinal and spinal sites has been clearly established and is thought to be responsible, in part, for the clinical utility of this compound in normal dose-ranges. While synergistic actions of mu-opioid receptor agonists have been shown, it is unclear whether a similar interaction exists for opioid agonists acting via delta-opioid receptors. Responses to acute nociception were determined with the 52 degrees C hot plate, 52 degrees C warm-water tail-flick and the Hargreaves paw-withdrawal tests. The peptidic opioid delta(1) agonist [D-Pen(2),D-Pen(5)]enkephalin (DPDPE) or delta(2) agonist [D-Ala(2),Glu(4)]deltorphin (DELT) were given into the rostral-ventral medulla (RVM), intrathecally (i.th.) or simultaneously into both the RVM and i.th. (1:1 fixed ratio). Both of the opioid delta agonists produced dose-dependent antinociception in all tests. With the exception of DPDPE in the hot plate test, isobolographic analysis revealed that the supraspinal/spinal antinociceptive interaction for both DPDPE and DELT were synergistic in all nociceptive tests. These data suggest that opioid delta agonists exert a multiplicative antinociceptive interaction between supraspinal and spinal sites to acute noxious stimuli and suggest possibility that compounds acting through delta-opioid receptors may have sufficient potency for eventual clinical application.

A comparison of the potential role of the tetrodotoxin-insensitive sodium channels, PN3/SNS and NaN/SNS2, in rat models of chronic pain

Alterations in sodium channel expression and function have been suggested as a key molecular event underlying the abnormal processing of pain after peripheral nerve or tissue injury. Although the relative contribution of individual sodium channel subtypes to this process is unclear, the biophysical properties of the tetrodotoxin-resistant current, mediated, at least in part, by the sodium channel PN3 (SNS), suggests that it may play a specialized, pathophysiological role in the sustained, repetitive firing of the peripheral neuron after injury. Moreover, this hypothesis is supported by evidence demonstrating that selective "knock-down" of PN3 protein in the dorsal root ganglion with specific antisense oligodeoxynucleotides prevents hyperalgesia and allodynia caused by either chronic nerve or tissue injury. In contrast, knock-down of NaN/SNS2 protein, a sodium channel that may be a second possible candidate for the tetrodotoxin-resistant current, appears to have no effect on nerve injury-induced behavioral responses. These data suggest that relief from chronic inflammatory or neuropathic pain might be achieved by selective blockade or inhibition of PN3 expression. In light of the restricted distribution of PN3 to sensory neurons, such an approach might offer effective pain relief without a significant side-effect liability.

Loss of antiallodynic and antinociceptive spinal/supraspinal morphine synergy in nerve-injured rats: restoration by MK-801 or dynorphin antiserum

The co-administration of morphine at spinal (i.th.) and supraspinal (i.c.v.) sites to the same rat produces antinociceptive synergy, a phenomenon which may underlie the clinical analgesic utility of this drug. In animals with peripheral nerve injury, however, the antinociceptive potency and efficacy of i.th. morphine is significantly decreased. Here, the possible loss of spinal/supraspinal morphine antinociceptive synergy and relationship to elevation of spinal dynorphin content was studied. Ligation of lumbar spinal nerves resulted in elevated dynorphin in the ipsilateral lumbar and sacral spinal cord. In sham-operated rats supraspinal/spinal co-administration of morphine produced synergistic antinociception which was unaffected by i.th. MK-801 or dynorphin A((1-17)) antiserum. In nerve-injured rats, i.th. morphine was inactive against tactile allodynia and showed diminished in potency against acute nociception without supraspinal/spinal antinociceptive synergy. Antiserum to dynorphin A((1-17)) or the non-competitive NMDA antagonist MK-801 increased the antinociceptive potency of i.th. morphine, restored supraspinal/spinal morphine antinociceptive synergy and elicited a dose-related i.th. morphine antiallodynic action. These agents did not demonstrate antinociceptive or antiallodynic activity alone and did not alter morphine actions in sham-operated animals. The loss of spinal/supraspinal antinociceptive synergy and lack of antiallodynic activity of spinal morphine appear to be due to the elevation across multiple spinal segments of dynorphin following nerve injury. Pathological actions of elevated dynorphin may directly or indirectly modulate the NMDA receptor, result in a loss of supraspinal/spinal morphine synergy and may thus account for the decreased clinical analgesic efficacy of morphine in peripheral neuropathies.

Characterization of antiallodynic actions of ALE-0540, a novel nerve growth factor receptor antagonist, in the rat

There is growing evidence that nerve growth factor (NGF) may function as a mediator of persistent pain states. We have identified a novel nonpeptidic molecule, ALE-0540, that inhibits the binding of NGF to tyrosine kinase (Trk) A or both p75 and TrkA (IC50 5.88 +/- 1. 87 microM, 3.72 +/- 1.3 microM, respectively), as well as signal transduction and biological responses mediated by TrkA receptors. ALE-0540 was tested in models of neuropathic pain and thermally-induced inflammatory pain, using two routes of administration, a systemic i.p. and a spinal intrathecal (i.th.) route. Morphine was also tested for comparison in the antiallodynia model using mechanical stimuli. We show that either i.p. or i.th. administration of ALE-0540 in rats produced antiallodynia in the L5/L6 ligation model of neuropathic pain. The calculated A50 values (and 95% confidence intervals) for ALE-0540 administered i.p. and i. th. were 38 (17.5-83) mg/kg and 34.6 (17.3-69.4) microgram, respectively. ALE-0540 given i.th., at doses of 30 and 60 microgram, also blocked tactile allodynia in the thermal sensitization model. Although morphine displayed greater potency [A50 value of 7.1 (5.6-8. 8) mg/kg] than ALE-0540 in anti-allodynic effect when given i.p. to L5/L6-ligated rats, it was not active when administered i.th. These data suggest that a blockade of NGF bioactivity using a NGF receptor antagonist is capable of blocking neuropathic and inflammatory pain and further support the hypothesis that NGF is involved in signaling pathways associated with these pain states. ALE-0540 represents a nonpeptidic small molecule which can be used to examine mechanisms leading to the development of agents for the treatment of pain.

Lack of involvement of capsaicin-sensitive primary afferents in nerve-ligation injury induced tactile allodynia in rats

Tactile allodynia and thermal hyperalgesia, two robust signs of neuropathic pain associated with experimental nerve injury, have been hypothesized to be mechanistically distinguished based on (a) fiber types which may be involved in the afferent input, (b) participation of spinal and supraspinal circuitry in these responses, and (c) sensitivity of these endpoints to pharmacological agents. Here, the possibility that nerve-injury induced tactile allodynia and thermal hyperalgesia may be mediated via different afferent fiber input was tested by evaluating these responses in sham-operated or nerve-injured (L5/L6) rats before or after a single systemic injection of resiniferatoxin (RTX), an ultrapotent analogue of the C-fiber specific neurotoxin, capsaicin. Tactile allodynia, and three measures of thermal nociception, tail-flick, paw-flick and hot-plate responses, were determined before and at various intervals for at least 40 days after RTX injection. Nerve-injured, but not sham-operated, rats showed a long-lasting tactile allodynia and thermal hyperalgesia (paw-flick) within 2-3 days after surgery; responses to other noxious thermal stimuli (i.e., tail-flick and hot-plate tests) did not distinguish the two groups at the stimulus intensities employed. RTX treatment resulted in a significant and long-lasting (i.e. essentially irreversible) decrease in sensitivity to thermal noxious stimuli in both sham-operated and nerve-injured rats; thermal hyperalgesia was abolished and antinociception produced by RTX. In contrast, RTX treatment did not affect the tactile allodynia seen in the same nerve-injured rats. These data support the concept that thermal hyperalgesia seen after nerve ligation, as well as noxious thermal stimuli, are likely to be mediated by capsaicin-sensitive C-fiber afferents. In contrast, nerve-injury related tactile allodynia is insensitive to RTX treatment which clearly desensitizes C-fibers and, therefore such responses are not likely to be mediated through C-fiber afferents. The hypothesis that tactile allodynia may be due to inputs from large (i.e. A beta) afferents offers a mechanistic basis for the observed insensitivity of this endpoint to intrathecal morphine in this nerve-injury model. Further, these data suggest that clinical treatment of neuropathic pains with C-fiber specific agents such as capsaicin are unlikely to offer significant therapeutic benefit against mechanical allodynia.

Spinal opioid mu receptor expression in lumbar spinal cord of rats following nerve injury

Previous studies in rats have shown that spinal morphine loses potency and efficacy to suppress an acute nociceptive stimulus applied to the tail or the paw following injury to peripheral nerves by tight ligation of the L5/L6 spinal nerves. Additionally, intrathecal (i.th.) morphine is ineffective in suppressing tactile allodynia at fully antinociceptive doses in these animals. The molecular basis for this loss of morphine potency and efficacy in nerve injury states is not known. One possible explanation for this phenomenon is a generalized, multi-segmental loss of opioid mu (mu) receptors in the dorsal horn of the spinal cord after nerve injury. This hypothesis was tested here by determining whether nerve injury produces (a) a decrease in mu receptors in the lumbar spinal cord; (b) a decrease in the affinity of ligand-receptor interaction, (c) a decrease in the fraction of high-affinity state of the mu receptors and (d) a reduced ability of morphine to activate G-proteins via mu receptors. Lumbar spinal cord tissues were examined 7 days after the nerve injury, a time when stable allodynia was observed. At this point, no differences were observed in the receptor density or affinity of [3H]DAMGO (mu selective agonist) or [3H]CTAP (mu selective antagonist) in the dorsal quadrant of lumbar spinal cord ipsilateral to nerve injury. Additionally, no change in morphine's potency and efficacy in activating G-proteins was observed. In contrast, staining for mu opioid receptors using mu-selective antibodies revealed a discrete loss of mu opioid receptors localized ipsilateral to the nerve injury and specific for sections taken at the L6 level. At these spinal segments, mu opioid receptors were decreased in laminae I and II. The data indicate that the loss of mu opioid receptors are highly localized and may contribute to the loss of morphine activity involving input at these spinal segments (e.g., foot-flick response). On the other hand, the lack of a generalized loss of opioid mu receptors across spinal segments makes it unlikely that this is the primary cause for the loss of potency and efficacy of mu opioids to suppress multi-segmental reflexes, such as the tail-flick response.

Tactile allodynia, but not thermal hyperalgesia, of the hindlimbs is blocked by spinal transection in rats with nerve injury

Spinal nerve ligation produces signs of neuropathic pain in rats. Different neuronal pathways may underlie the abnormal sensory responses to thermal and tactile stimuli. Here, the possibility that local circuitry in the spinal cord and/or spinal-supraspinal loops might be involved in tactile allodynia and thermal hyperalgesia of the hindpaws was investigated by transecting the spinal cord of sham-operated or L5/L6 nerve ligated rats. Spinal transection completely abolished tactile allodynia in ligated rats. Thermal nocifensive responses were present after transection in ligated and sham-operated rats. Thermal hyperalgesia of the hindpaws was not evident in spinal transected, ligated rats. Tail-withdrawal responses to tactile probing were very robust after spinal transection in both groups, demonstrating loss of descending inhibition. These observations suggest that thermal hyperalgesia of the paw seen after nerve injury involves both spinal and supraspinal circuits, while tactile allodynia depends on a supraspinal loop. This difference may reflect afferent inputs associated with different fiber types.

Differential activities of intrathecal MK-801 or morphine to alter responses to thermal and mechanical stimuli in normal or nerve-injured rats

Nerve ligation injury in rats results in reduced nociceptive and non-nociceptive thresholds, similar to some aspects of clinical conditions of neuropathic pain. Since underlying mechanisms of hyperalgesia and allodynia may differ, the present study investigated the pharmacology of morphine and MK-801 in rats subjected to a tight ligation of the L5 and L6 nerve roots or to a sham-operation procedure. Response to acute nociception was measured by (a) withdrawal of a hindpaw from a radiant heat source, (b) withdrawal of the tail from a radiant heat source or (c) the latency to a rapid flick of the tail following immersion in water at different noxious temperatures. Mechanical thresholds were determined by measuring response threshold to probing the hindpaw with von Frey filaments. Nerve ligation produced a significant, stable and long-lasting decrease in threshold to mechanical stimulation (i.e., tactile allodynia) when compared to sham-operated controls. Standardization of the diameter of the filaments (to that of the largest filament) did not alter the response threshold in nerve-injured animals. Nerve ligation produced decreased response latency of the ipsilateral paw (i.e., hyperalgesia) when compared to that of sham-operated rats. Tail-flick latencies to thermal stimuli induced by water at constant temperatures (48 degrees, 52 degrees or 55 degrees C) or by radiant heat were not significantly different between nerve-injured and sham-operated groups. At doses which were not behaviorally toxic, MK-801 had no effect on tactile allodynia. At these doses, MK-801 blocked decreased paw withdrawal latency to radiant heat in nerve-injured rats, but did not significantly elevate the response threshold of sham-operated rats. Systemic (i.p.) or intracerebroventricular (i.c.v.) doses of morphine previously shown to be antiallodynic in nerve-ligated rats did not affect the response to probing with von Frey filaments in sham-operated controls. Intrathecal (i.t.) morphine did not change paw withdrawal thresholds elicited by von Frey filaments of either nerve-ligated rats (as previously reported) or of sham-operated rats at doses maximally effective against thermal stimuli applied to the tail or foot. Spinal morphine produced dose-dependent antinociception in both nerve-injured and sham-operated groups in the foot-flick test but was less potent in the nerve-injured group. Presuppression of hyperalgesia of the foot with i.t. MK-801 in nerve-injured animals did not alter the potency of i.t. morphine. I.t. morphine was also active in the tail-flick tests with decreased potency in nerve-injured animals and, at some stimulus intensities, with a decreased efficacy as well. These data emphasize the distinction between the inactivity of morphine to suppress mechanical withdrawal thresholds (as elicited by von Frey filaments) and the activity of this compound to block the response to an acute thermal nociceptive stimulus in sham-operated or nerve-injured rats. It appears that nerve ligation injury produces a thermal allodynia/hyperalgesia which is likely dependent upon opioid-sensitive small-diameter primary afferent fibers and a mechanical allodynia which may be largely independent of small-fiber input.

Synergistic antinociceptive interactions of morphine and clonidine in rats with nerve-ligation injury

BACKGROUND

Ligation injury of the L5/L6 nerve roots in rats produces behavioral signs representative of clinical conditions of neuropathic pain, including tactile allodynia and thermal and mechanical hyperalgesia. In this model, intrathecal morphine shows no antiallodynic activity, as well as decreased antinociceptive potency and efficacy. This study was designed to explore the antinociceptive activity of intrathecal clonidine alone or in combination with intrathecal morphine (1:3 fixed ratio) in nerve-injured rats. The aims, with this study, were to use nerve-injured animals to determine: (1) whether the antinociceptive potency and efficacy of intrathecal clonidine was altered, and (2) whether the combination of intrathecal morphine and clonidine would act synergistically to produce antinociception.

METHODS

Unilateral nerve injury was produced by ligation of the L5 and L6 spinal roots of male Sprague-Dawley rats. Sham-operated rats underwent a similar surgical procedure but without nerve ligation. Morphine and clonidine were given intrathecally through implanted catheters alone or in a 1:3 fixed ratio. Nociceptive responses were measured by recording tail withdrawal latency from a 55 degrees C water bath, and data were calculated as % maximal possible effect (%MPE).

RESULTS

Morphine produced a dose-dependent antinociceptive effect in both sham-operated and nerve-injured rats. The doses calculated to produce a 50 %MPE (i.e., A50) (+/-95% confidence intervals [CI]) were 15 +/- 4.9 micrograms and 30 +/- 18 micrograms, respectively. Though morphine was able to produce a maximal response (100%) in sham-operated rats, the maximal response achieved in nerve-injured animals was only 69 +/- 21.9 %MPE. Clonidine produced a dose-dependent effect, with an A50 (+/-95% CI) of 120 +/- 24 micrograms in sham-operated rats. In nerve-ligated rats, clonidine produced a maximal effect that reached a plateau of 55 +/- 10.9 %MPE and 49 +/- 10.2 %MPE at 100 and 200 micrograms, respectively, preventing the calculation of an A50. In sham-operated rats, a morphine-clonidine mixture produced maximal efficacy, with an A50 (+/-95% CI) of 15 +/- 9.2 micrograms (total dose), significantly less than the theoretical additive A50 of 44 +/- 10 micrograms. In L5/L6 nerve-ligated rats, the morphine-clonidine combination produced maximal efficacy, with an A50 (+/-95% CI) of 11 +/- 5.4 micrograms (total dose), which was significantly less than the theoretical additive A50 of 118 +/- 73 micrograms, indicating a synergistic antinociceptive interaction. The intrathecal injection of [D-Ala2, NMePhe4, Gly-ol]enkephalin (DAMGO) produced A50 values of 0.23 microgram (range, 0.09-0.6) and 0.97 microgram (range, 0.34-2.7) in sham-operated and ligated rats, respectively. Phentolamine (4 mg/kg, intraperitoneally) produced no antinociceptive effect alone and attenuated, rather than enhanced, the effect of morphine in both groups of rats.

CONCLUSIONS

These data show that: (1) clonidine, like morphine, loses antinociceptive potency and efficacy after nerve ligation injury, and (2) strongly suggest that a spinal combination of morphine and clonidine synergize under conditions of nerve injury to elicit a significant antinociceptive action when either drug alone may be lacking in efficacy. It is unlikely that the synergy of morphine with clonidine is due to an attenuation of spinal sympathetic outflow by clonidine, because the sympatholytic agent phentolamine produced an opposing effect on morphine antinociception. The data suggest that combinations of morphine and clonidine may prove useful in controlling pain in patients with neuropathic conditions.

[The measurement of natural killer cell activity in peripheral blood and peritoneal fluid of patients with endometriosis]

OBJECTIVE

To investigate the role of natural killer (NK) cell activity in the development of endometriosis.

METHODS

The NK cell activity in peripheral blood (PB) and in peritoneal fluid (PF) of 72 patients with endometriosis was studied by means of MTT-assay and compared with that of infertile women and fertile controls.

RESULTS

The NK cell activity in PB and in PF of patients with endometriosis was lower than that in those of infertile and fertile controls, and decreased as the stage of endometriosis increased. Follow-up of 8 patients with stage II/N endometriosis demonstrated that the NK cell activity in PB had a moderate increase shortly after excision of endometriotic lesions, but decreased again to the preoperative level 6-9 months later.

CONCLUSIONS

Patients with endometriosis have a primary defect in their NK cell function, and the defect may be related to the pathogenesis of the disease.

Antiallodynic effects of a CCKB antagonist in rats with nerve ligation injury: role of endogenous enkephalins

Cholecystokinin (CCK) may act as an endogenous anti-opioid and blockade of CCK receptors can enhance the potency and efficacy of morphine. This effect is blocked by opioid delta (delta) receptor antagonists, suggesting a tonic inhibitory action of CCK to diminish the release and/or availability of endogenous enkephalins. The present studies have further evaluated this possibility by studying the antiallodynic actions of a CCKB antagonist (L365,260) alone, or in the presence of thiorphan (a neutral endopeptidase inhibitor) in a model of peripheral neuropathy. Animals subjected to nerve injury, but not sham controls, exhibited long lasting, stable mechanical allodynia. Intrathecal (i.t.) administration of L365,260 or thiorphan alone did not alter allodynia. However, co-administration of these compounds produced a significant antiallodynic action which was antagonized by receptor selective doses of naltrindole, an opioid delta receptor antagonist. In addition, antisera to [Leu5]enkephalin, but not to [Met5]enkephalin, also blocked the antiallodynic action of thiorphan plus L365,260. These data suggest that blockade of CCKB receptors may enhance the actions or availability of endogenous [Leu5]enkephalin or a like substance which can elicit a significant antiallodynic action via opioid delta receptors when its degradation is by inhibited by thiorphan. The data suggest that delta opioids are involved in regulation of some aspects of nerve-injury induced pain.

Experimental study on the mechanism of cisplatin resistance and its reversion in human ovarian cancer

OBJECTIVE

To explore the mechanism of cisplatin resistance and its reversion in human ovarian cancer.

MATERIALS AND METHODS

A cisplatin resistant cell subline of SKOV3, SKOV3/cp, was established, and a xenograft mice model of human ovarian cancer was established by microencapsulation technology. Various biochemical changes and the effects of modulators on the resistance in the model were observed.

RESULTS

The intracellular platinum accumulation. Pt-DNA adducts and interstrand cross links of DNA (ISC) in SKOV3 was 5.1, 2.4 and 4.8 times respectively of those in SKOV3/cp cell line. Amphotericin B (AmB) and Novobiocin (NVB) could raise platinum accumulation and Pt-DNA adducts concentration in SKOV3/cp and this resulted in reversion of cisplatin resistance.

CONCLUSIONS

The primary factors resulting in SKOV3/cp resistance to cisplatin are the reduction of intracellular drugs and the augmentation of the ability to remove Pt-DNA adducts. AmB and NVB can reverse cisplatin resistance in SKOV3/cp cells.

[Experimental study on the mechanism of cisplatin resistance and its reversion in human ovarian cancer]

OBJECTIVE

To explore the mechanism of cisplatin resistance and its reversion in human ovarian cancer.

METHODS

A xenografted cisplatin resistant mice model of human ovarian cancer, SKOV3/cp, was developed by the microencapsulated technique. The multiple changes of bio-chemical markers in the model were determined, and various modulators for reversion were tested.

RESULTS

Intracellular platinum accumulation in SKOV3 was 5.1 times, Pt-DNA adducts 2.4 times and interstrand cross link of DNA (ISC) 4.8 times of those in cisplatin-resistant cell line, SKOV3/cp. These changes in SKOV3/cp could not be reversed by verapamil. Amphotercin B (AmB) and Novobiocin (NVB) could raise the concentrations of platinum and Pt-DNA adducts in SKOV3/cp, resulting in complete or partial reversion of cisplatin-resistance of SKOV3/cp. There were no differences in total glutathione (GSH) level and in sensitivity to CdCl2 between SKOV3 and SKOV3/cp.

CONCLUSIONS

It is suggested that the primary factor causing SKOV3/cp resistance to cisplatin is the reduction of intracellular platinum accumulation and the augmentation of the ability to remove Pt-DNA adducts. The resistance is not considered to be associated with the multidrug resistant, GSH, metallothionein systems. AmB and NVB can overcome cisplatin resistance of SKOV3/cp in vitro and in vivo.

Regulation of morphine antiallodynic efficacy by cholecystokinin in a model of neuropathic pain in rats

Neuropathic pains have often been classified as opioid-resistant. Here, spinal (intrathecal) actions of morphine and nonmorphine opioids have been studied in a nerve ligation model of neuropathic pain in rats. Mechanical allodynia was evaluated using von Frey filaments. Nerve-injured animals exhibited allodynia that was stable for up to 6 weeks after the surgery. Morphine did not alter allodynia at doses up to 300 nmol (100 micrograms). In contrast, [D-Ala2, NMPhe4, Gly-ol]enkephalin (DAMGO), a high-efficacy mu opioid agonist, produced a significant, dose-related antiallodynic action. [D-Ala2, Glu4]deltorphin (delta agonist) produced a significant antiallodynic effect only at 300 nmol, reaching approximately 70% of the maximum. Coadministration of morphine with a dose of [D-Ala2, Glu4]deltorphin, which was inactive alone, produced a significant and long-lasting antiallodynic action that was antagonized by NTI (delta receptor antagonist); NTI alone had no effect. Although blockade of cholecystokinin-B (CCKB) receptors with L365,260 did not produce effects alone, a significant antiallodynic action was observed when coadministered with morphine; this elevation of nociceptive threshold was abolished by NTI. The finding that DAMGO, but not very large doses of morphine, produced antiallodynic actions suggests that the ability of mu opioids to alleviate the allodynia is related, in part, to efficacy at postsynaptic mu receptors. At an inactive dose, a delta agonist or a CCKB antagonist enhanced morphine antiallodynic efficacy in an NTI-sensitive fashion. CCKB receptor blockade may enhance endogenous enkephalin actions, resulting in enhancement of morphine efficacy through a mu-delta receptor interaction.

Characterization of the antiallodynic efficacy of morphine in a model of neuropathic pain in rats

Neuropathic pains have often been classified as opioid resistant. Here, the ability of systemic (i.p.), intracerebroventricular (i.c.v.) and intrathecal (i.th.) morphine to inhibit mechanical allodynia were studied in a nerve ligation (L5, L6 nerve roots) model of neuropathic pain in rats. Morphine administered i.p. or i.c.v. produced dose-dependent antiallodynia which was readily antagonized by naloxone (5 mg kg-1, i.p. at -10 min). In contrast, i.th. morphine at doses up to 100 micrograms was without effect. These data suggest that the failure of i.th. morphine to produce antiallodynic effects may be due, in part, to the lack of available functional spinal opioid mu-receptors which may occur following nerve injury. In contrast, the antiallodynic actions of i.p. or i.c.v. morphine appear to depend on supraspinal activation of opioid (mu?) receptors and subsequent activation of descending modulatory systems. The inconsistent data seen clinically with morphine in neuropathic pains may be related to the lack of supraspinal/spinal synergy that is normally associated with morphine efficacy in conditions of acute pain.

Inhibition by spinal morphine of the tail-flick response is attenuated in rats with nerve ligation injury

Nerve ligation injury in rats produces increased sensitivity and exaggerated responses to nociceptive stimuli (hyperalgesia) as well as nociceptive responses to normally innocuous stimuli (allodynia) analogous to clinical conditions of neuropathic pain. However, the effect of nerve injury on acute nociception has not been extensively studied. Nerve ligation injury was produced by unilateral ligation of the L5 and L6 spinal roots of the sciatic nerve of male Sprague-Dawley rats. Intrathecal (i.th.) catheters were inserted for spinal drug administration. Response to acute nociception was measured by determining the latency to a rapid flick of the tail (TF) after immersion into a 55 degrees C water bath before (control) and after i.th. morphine administration. No change in baseline response to the nociceptive stimulus was observed in either sham-operated or nerve-injured rats. In sham-operated rats, morphine produced dose-dependent antinociception with a 97 +/- 2.3% maximal possible effect (MPE) at a 60 microgram dose; in these controls A50 (95% CL) was 22 micrograms (17-30 micrograms). Morphine administered to rats with nerve injury also produced dose-dependent increase in TF latency, but an MPE of only 60 +/- 17% was obtained at 100 micrograms; higher doses elicited signs of behavioral toxicity. While it was not possible to produce a proper dose-response curve with i.th. morphine in animals with nerve injury, an estimation of the A50 showed approximately a four-fold loss of potency compared to sham-operated controls. Antinociception was readily reversed by naloxone (5 mg/kg, i.p.) in both groups. These data indicate that nerve ligation injury reduces the potency and efficacy of i.th. morphine. While the reasons for this loss of morphine activity in nerve injured animals are unknown, it is possible to speculate that (a) degeneration of primary afferents subsequent to nerve ligation injury might result in a loss of presynaptic opioid (mu?) receptors in the dorsal horn, thereby reducing the antinociceptive activity of morphine at the spinal level; (b) changes in the efficiency of post-receptor transduction may occur following nerve injury which can reduce opioid efficacy; (c) changes in levels of spinal neurotransmitters (e.g., cholecystokinin) may act to diminish opioid action; or (d) sustained afferent input from the site of the injury may be important in limiting the activity of opioids.

The loss of antinociceptive efficacy of spinal morphine in rats with nerve ligation injury is prevented by reducing spinal afferent drive

Nerve ligation injury in rats may represent a useful model of some clinical neuropathic pains. Activation of N-methyl-D-aspartate (NMDA) receptors may maintain central sensitivity and contribute to neuropathic pain. Here, nerve injury was produced by unilateral ligation of the L5 and L6 spinal roots of the sciatic nerve of rats. Catheters were inserted for intrathecal (i.th.) or local delivery of drugs at the site of nerve ligation. Acute nociception was measured by the 55 degrees C water tail flick test in sham-operated and nerve-injured rats, and allodynia was determined by measuring response to von Frey filaments. In sham-operated rats, morphine (30 micrograms, i.th.) produced a 60 +/- 14.4% MPE (maximal possible effect). MK-801 pretreatment did not alter tail-flick latency or morphine antinociception in sham-operated rats. In nerve-injured rats, morphine (30 micrograms, i.th.) produced a significantly lower antinociceptive effect than in controls (34 +/- 6.3% MPE). While MK-801 alone did not alter tail-flick latency in nerve-injured rats, it significantly enhanced the antinociceptive effect of morphine to 84 +/- 16.0% MPE. Bupivacaine (0.2 ml, 0.75% w/v) at the site of injury also significantly increased the efficacy of morphine (100 +/- 0% MPE) without affecting tail flick latency alone. Bupivacaine administered at the site of injury also produced a significant antiallodynic effect of 94 +/- 7.4% MPE. The reduction in antinociceptive efficacy of i.th. morphine in nerve injured rats may be due, in part, to an ongoing spontaneous activity initiated by ectopic foci at the site of injury, and possible NMDA receptor-mediated activity of spinal neurons.

[Suppressive effects of adenosine on nonspecific and humoral immunities in mice]

Adenosine (Ade) 1.3, 13, 130 mg.kg-1 ip inhibited the ability of peripheral leukocytes and peritoneal macrophages in phagocytosing the Staphylococcus albus with [3H]TdR incorporation in mice, declined the hemolytic ability of plaque-forming cells and the production of antibody in mice immunized by sheep erythrocytes. Ade 13, 130 mg.kg-1 ip decreased the mouse serum muramidase (lysozyme) concentration. Dipyridamole (Dip) 10 mg.kg-1 ip attenuated the effects of Ade 130 mg.kg-1 on humoral immunity reaction, but the nonspecific immunity was not attenuated. These results showed that the uptake of Ade may play an important role in the effects of Ade on humoral immunity reaction. Aminophylline (Ami) 100 mg.kg-1 ip attenuated the effects of Ade 130 mg.kg-1 on hemolytic ability of plaque-forming cells and the ability of peripheral leukocytes in phagocytosing Staphylococcus albus. These results suggested that the effects of Ade on murine humoral and nonspecific immunity reaction were mediated by Ade A2 receptor (A2DR).

[Suppressive effects of safflower yellow on immune functions]

Safflower yellow (SY) extracted from Carthamus tinctorius L contained chalconoid compounds, 75% of which was safflomin A. SY ip 50-450 mg.kg-1.d-1 x 6-8 d in mice decreased serum lysozyme concentration and phagocytosing functions of both peritoneal macrophages and peripheral leukocytes; diminished the production of plaque forming cells, specific rosette forming cells, and antibody; inhibited delayed type hypersensitivity reaction and the activation of T suppressor cells elicited by supraoptimal immunization. Experiments in vitro showed inhibitory effects on [3H]TdR incorporation during human peripheral T- and B-lymphocyte proliferation by SY 0.03-3.0, 0.1-2.0 mg.ml-1 respectively, murine mixed lymphocyte culture response and the production of interleukin-2 by SY 0.1-2.5 mg.ml-1. In conclusion, SY produced declines in both nonspecific and specific immune functions.

[Influence of aminophylline on immune function of mice]

The effects of aminophylline (Ami) on immune systems in normal NIH mice were studied. Ami ig 25, 50 and 100 mg/(kg.d) x 8-10 d increased hemolytic ability of plaque forming cells and antibody concentration while it decreased the delayed type hypersensitivity (DTH) reaction and peripheral white blood cells phagocytosing function. Ami 1, 5, 10 micrograms/ml also promoted lymphocyte transformation of [methyl-3H] TdR incorporation induced by PHA in vitro.