[Application value of questionnaires in the screening obstructive sleep apnea syndrome in pregnancy across trimesters].

Objective: To evaluate the clinical utility value of questionnaires of Berlin, STOP, STOP-Bang (SBQ), Epworth Sleepiness Scale (ESS) in screening obstructive sleep apnea syndrome (OSAS) in pregnant women of different trimesters. Methods: Consecutive pregnant women at high risk for OSAS were enrolled from January, 2021 to April, 2022 at the obstetric clinic of Peking University People's Hospital. They completed questionnaires of Berlin, STOP, SBQ, ESS and also underwent an overnight polysomnography (PSG). To evaluate the accuracy of questionnaires of Berlin, STOP, SBQ, ESS, sensitivity, specificity, positive predictive values, negative predictive values and the area under the receiver operating characteristics (ROC) curve of these questionnaires in pregnancy across trimesters (Pregnancy 1-15 weeks was the first stage, pregnancy 16-27 weeks was the second stage, and pregnancy 28-40 weeks was the third stage) were calculated. Results: A total of 100 pregnant women [(34.5±4.3) years old (26-46 years old)] were included in this study, including 20, 35 and 45 pregnant women in the first, second and third trimester of pregnancy, respectively. Based on PSG results, 45 (45%) of 100 pregnant women were diagnosed with OSAS. The overall predictive values of the four questionnaires were not good, area under[AUC(95%CI)] the ROC curve ESS, Berlin questionnaire STOP and SBQ were 0.54(0.43, 0.66), 0.59 (0.47, 0.70), 0.62(0.51, 0.73) and 0.61 (0.49, 0.72), respectively, sensitivity was 35.6%, 65.9%, 48.9%, 28.9%, specificity was 71.7%, 52.5%, 73.6%, 92.5%. When categorized according to trimesters, the predicted values of the four questionnaires increased in the first trimester, the AUC (95%CI) of STOP questionnaire was 0.81 (0.61, 1.00), sensitivity was 75.0%, specificity was 87.5%. Conclusion: The overall predictive power of the four screening questionnaires is limited in pregnant women. But predictive value of STOP questionnaire is acceptable in the first trimester.

Inflammation-induced GluA1 trafficking and membrane insertion of Ca2+ permeable AMPA receptors in dorsal horn neurons is dependent on spinal tumor necrosis factor, PI3 kinase and protein kinase A.

Peripheral inflammation induces sensitization of nociceptive spinal cord neurons. Both spinal tumor necrosis factor (TNF) and neuronal membrane insertion of Ca2+ permeable AMPA receptor (AMPAr) contribute to spinal sensitization and resultant pain behavior, molecular mechanisms connecting these two events have not been studied in detail. Intrathecal (i.t.) injection of TNF-blockers attenuated paw carrageenan-induced mechanical and thermal hypersensitivity. Levels of GluA1 and GluA4 from dorsal spinal membrane fractions increased in carrageenan-injected rats compared to controls. In the same tissue, GluA2 levels were not altered. Inflammation-induced increases in membrane GluA1 were prevented by i.t. pre-treatment with antagonists to TNF, PI3K, PKA and NMDA. Interestingly, administration of TNF or PI3K inhibitors followed by carrageenan caused a marked reduction in plasma membrane GluA2 levels, despite the fact that membrane GluA2 levels were stable following inhibitor administration in the absence of carrageenan. TNF pre-incubation induced increased numbers of Co2+ labeled dorsal horn neurons, indicating more neurons with Ca2+ permeable AMPAr. In parallel to Western blot results, this increase was blocked by antagonism of PI3K and PKA. In addition, spinal slices from GluA1 transgenic mice, which had a single alanine replacement at GluA1 ser 845 or ser 831 that prevented phosphorylation, were resistant to TNF-induced increases in Co2+ labeling. However, behavioral responses following intraplantar carrageenan and formalin in the mutant mice were no different from littermate controls, suggesting a more complex regulation of nociception. Co-localization of GluA1, GluA2 and GluA4 with synaptophysin on identified spinoparabrachial neurons and their relative ratios were used to assess inflammation-induced trafficking of AMPAr to synapses. Inflammation induced an increase in synaptic GluA1, but not GluA2. Although total GluA4 also increased with inflammation, co-localization of GluA4 with synaptophysin, fell short of significance. Taken together these data suggest that peripheral inflammation induces a PI3K and PKA dependent TNFR1 activated pathway that culminates with trafficking of calcium permeable AMPAr into synapses of nociceptive dorsal horn projection neurons.

Identification of commonly dysregulated genes in colorectal cancer by integrating analysis of RNA-Seq data and qRT-PCR validation.

The progression of colorectal cancer (CRC) is a multistep process and metastatic CRC is always incurable; consequently, CRC is the leading cause of cancer-related deaths. There is therefore an urgent need for identifying useful biomarkers with enough sensitivity and specificity to detect this disease at early stages, which will significantly reduce the mortality for this malignancy. In this study, we performed an integrating analysis of different RNA-Seq data sets to find new candidate biomarkers for diagnosis, prognosis and as therapeutic targets for this malignancy, as well as to elucidate the molecular mechanisms of CRC carcinogenesis. We identified 883 differentially expressed genes (DEGs) across the studies between CRC and normal control (NC) tissues by combining five RNA-Seq data sets. Gene function analysis revealed high correlation with carcinogenesis. The top 10 most significantly DEGs were further evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) in both rectal cancer (RC) and colon cancer (CC), and the results matched well with integrating data, suggesting that the method of integrating analysis of different RNA-seq data sets is acceptable. Therefore, integrating analysis of different RNA-seq data sets may be a useful way to overcome the limitation of small sample size in a single RNA-seq study. In addition, our study showed that some genes, such as SIM2, ADAMTS6, FOXD4L4 and DNAH5, may have an important role in the development of CRC, which could be applied for diagnosis, prognosis and as therapy for this malignancy. Our findings would also help to understand the pathology of CRC.

Electrophysiological characteristics of primary afferent fibers after systemic administration of anti-GD2 ganglioside antibody.

An animal model showing mechanical allodynia following systemic bolus injection of a human/mouse chimeric monoclonal antibody to the GD2 ganglioside (ch14.18) has been established (e.g. pain behavior generated by a light tactile stimulus). This is of clinical relevance since ch14.18 is a promising experimental treatment for pediatric neuroblastoma. The present study examined the hypothesis that allodynic effects of the anti-GD2 antibody are mediated by actions on cutaneous nerve fibers. After determining the basal magnitude of the mechanical stimulus required to produce withdrawal, ch14.18, a murine form of the anti-GD2 antibody of IgG2a isotype (14G2a), a control murine anti-melanoma antibody of IgG2a isotype (9.2.27) or saline was injected through a previously implanted jugular cannula. The experimenter was blinded to the syringe contents. Withdrawal threshold was tested at 15 min intervals for 1 h. After administration of either ch14.18 or 14G2a mechanical allodynia typically started within the first 15 min and persisted throughout the hour of behavioral testing. In the control antibody group, a modest change in tactile withdrawal threshold was observed at the 60 min time point only. Rats were then anesthetized with pentobarbital and prepared for single fiber recordings from the sural nerve. Fibers were classified based on conduction velocity, as A beta (> 25 m/s), A delta (2-25 m/s) or C (< 2 m/s). Background activity (BA) was observed in a significant number of A delta (12/61) and C (32/42) fibers in both anti-GD2 treated groups compared to the anti-melanoma antibody (1/17 A delta and 2/10 C fibers) and saline (0/26 A delta and 0/19 C fibers) treated groups. Mean mechanical threshold for A delta fibers in all three antibody treated groups was significantly reduced compared to the saline control; this was not observed for C-fibers in any group. Intravenous bolus injection (15 mg/kg) and infusion of lidocaine (plasma level 0.3-2.2 micrograms/ml) both reduced anti-GD2 associated BA. These data demonstrate that mechanical-allodynia could be produced by action(s) of the anti-GD2 antibody (direct or indirect) on peripheral nerves and suggest intravenous lidocaine as part of the analgesic regimen accompanying anti-GD2 antibody treatment.

Tumour necrosis factor-alpha induces ectopic activity in nociceptive primary afferent fibres.

Tumour necrosis factor-alpha, a pro-inflammatory cytokine, is expressed endoneurially following a variety of local and systemic pathophysiological insults which give rise to pain. We administered tumour necrosis factor-alpha to pentobarbital-anaesthetized rats, either topically along a restricted portion of the sciatic nerve or injected subcutaneously within the distribution of the sural nerve. Single nociceptive primary afferent fibres were assessed for ectopic discharge and receptor sensitization. Low concentrations (0.001-0.01 ng/ml) of tumour necrosis factor-alpha applied along the nerve elicited a dose-dependent, rapid onset (1-3 min) increase in discharge; higher concentrations led to reduced firing rates. C-fibres developed higher mean firing frequencies than A delta-fibres. Bursting frequency in both fibre types reached several (6) Hz. No change in mechanical threshold was observed. Intradermal injection (50 pg in 50 microliters) led to ectopic discharge and a decrease in mechanical threshold; these effects developed at different rates, suggesting multiple actions of the cytokine. Our data suggest that acute application of tumour necrosis factor-alpha to the axon can lead to aberrant electrophysiologic activity independent of peripheral receptor involvement. This low level of ectopic firing of nociceptive axons may produce wind-up in dorsal horn neurons or may, by itself, be interpreted as pain.

Upregulation of vascular endothelial growth factor (VEGF) in the retinas of transgenic mice overexpressing interleukin-1beta (IL-1beta) in the lens and mice undergoing retinal degeneration.

IL-1beta is a pro-inflammatory agent associated with angiogenesis and increased vascular permeability. To determine whether IL-1beta elicits these responses through an upregulation of VEGF, transgenic mice that overexpress IL-1beta in the lens were evaluated at various time points for the localization of VEGF, the location and extent of blood-retinal barrier (BRB) breakdown, and the origin and extent of neovascularization (NV). In homozygous and heterozygous transgenic mice, but not controls, intense VEGF immunoreactivity was scattered throughout the retina at postnatal days 5-7 (P5-7), just after the onset of inflammatory cell infiltration. VEGF staining in the retina remained widespread, but weak from P9-15. Beginning at P15, the intensity of VEGF immunoreactivity achieved a second peak, which it maintained through adulthood. This peak coincided with significant retinal destruction due to massive inflammation. The onset of BRB breakdown coincided with the upregulation of VEGF (P5-7) and widespread BRB breakdown was demonstrated from about P9. From P9-12, aggregates of cells positive for Griffonia simplicifolia isolectin-B4, a marker for vascular endothelial cells, formed on the retinal surface. These cells migrated into the retina at P12-15 with the more superficial cells forming a network of vessels and the deeper cells remaining in small clusters, thus demonstrating that NV occurs much later than BRB breakdown. Non-transgenic FVB/N mice, which undergo retinal degeneration beginning at about P9, also demonstrate the latter peak of VEGF upregulation and the accompanying BRB breakdown, but not the early upregulation. VEGF immunostaining of transgenic and non-transgenic mouse retinas was eliminated by pre-incubation of the VEGF antibodies with VEGF peptide. The data suggest that the early peak of VEGF upregulation (P5-7) and its accompanying BRB breakdown is due to IL-1beta expression and is likely to be dependent on inflammatory cell infiltration. The latter peak appears to be related to retinal destruction.

Magnesium suppresses neuropathic pain responses in rats via a spinal site of action.

We tested the ability of Mg2+ therapy to block the heat-hyperalgesia, mechano-allodynia and mechano-hyperalgesia that are seen in rats with an experimental painful peripheral neuropathy (the CCI model of Bennett and Xie). Systemic Mg2+ (magnesium sulfate, 600 mg/kg, s.c.) significantly reduced heat-hyperalgesia and mechano-allodynia for 2-24 h post-injection, but had no effect on mechano-hyperalgesia. Intrathecal (i.t.) injections of Mg2+ (185-750 micrograms) at the level of the lumbar spinal cord significantly reduced heat-hyperalgesia, but perineural application (750 and 7,000 micrograms) to the site of nerve injury had no effect. Neither s.c. nor i.t. Mg2+ had any effect on the responses from the control, sham-operated side. We conclude that Mg2+ has a spinal site of action. Mg2+ therapy may be of limited use in the treatment of human painful peripheral neuropathy.

Unlabelled iododeoxyuridine increases the cytotoxicity and incorporation of [1251]-iododeoxyuridine in two human glioblastoma cell lines.

Iododeoxyuridine (IUdR), labelled with radioiodines emitting Auger, alpha or beta- radiation, has been proposed as a therapeutic tool in the treatment of cancer. However, the low per cent incorporation in tumour cells and limited cytotoxicity are major obstacles for such an application. Using unlabelled IUdR as a modulator, we have studied the in vitro cytotoxicity of [125I]-IUdR in two human glioblastoma cell lines. Surprisingly, an enhanced cytotoxicity of [125I]-IUdR was observed in the presence of 0.3-10 microM concentrations of unlabelled IUdR in U251 glioblastoma cells and to a lesser extent in LN229 cells. The presence of unlabelled IUdR unexpectedly increased the incorporation of [125I]-IUdR in both cell lines. Thymidine competitively blocked the cytotoxic effects of combined unlabelled and [125I]-labelled IUdR in these cells and DNA-incorporation of radiolabelled IUdR.

Study on cytomegaloviral infection in acute leukemia patients by polymerase chain reaction.

Polymerase chain reaction (PCR) and blot hybridization by probe labelled with digoxin were used to detect human cytomegalovirus (HCMV) DNA in 31 patients with acute leukemia and 20 controls. The positive rate detected by PCR in acute leukemia was 74.2% and 15.0% in the controls. The difference was statistically significant. The results suggest that acute leukemia patients are the high risk population with high infection rate of HCMV. The positive rate detected by digoxin method in acute leukemia was 58.1%. Six patients showed negative results by digoxin method, but positive by PCR. It was demonstrated that PCR was superior to digoxin method in sensitivity. Anti-HCMV IgM in serum of patients was detected at the same time, the positive rate was 16.1%. Only 6 of the 23 PCR positive patients showed positive anti-HCMV IgM. It suggests that the immune response is weak in acute leukemia patients and HCMV recently infected could not be excluded in the anti-HCMV IgM negative cases.

Detection of HCV infection by cPCR in patients with acute leukemia.

HCV RNA and anti-HCV were detected respectively by complemented DNA polymerases chain reaction (cPCR) and ELISA in the sera of 28 acute leukemia patients with repeated blood transfusion and changes in liver function. HCV RNA positive rate was 78.6%. Anti-HCV positive rate was 60.7%. 25 subjects showed positive results in HCV RNA or anti-HCV, or in both of them. By combined assessment, the HCV infection rate was 89.3%. Acute leukemia patients were the high risk group of HCV infection because of the lowered immune function and repeated blood transfusion. By cPCR, HCV RNA can be detected earlier and the sensitivity is higher than by anti-HCV. So cPCR is a sensitive and specific method for early diagnosis of HCV infection. The combination of HCV RNA and anti-HCV detection methods may improve the diagnostic rate of HCV infection.

Inhibitory effect of anisodamine on the neuropathic hyperalgesia following peripheral nerve injury (II).

A peripheral neuropathy with hyperalgesia and allodynia was produced by loosely tying constrictive ligature around the left sciatic nerve of rats, i.v. injection of anisodamine 20 mg/Kg abolished both neuropathic hyperalgesia responses to noxious radiant heat and ectopic discharges generated from the injured region of the nerve. Anisodanime applied either systemically or locally to the damaged area of the nerve not only ceased the spontaneous ectopic discharges recorded from A beta to C fibers but also blocked the afferent ectopic discharge elicited by K+ channel blocker, noradrenaline, Ca2+ or antidromic stimulation of sciatic nerve proximal to the injured nerve area. The experiments indicated that anisodamine probably possessed a calcium channel blocker-like activity and produced selective block of the new channels in the injured area. It is suggested that anisodamine may be a candidate therapeutic agent in relieving hyperalgesia and allodynia following nerve injury.

Electrophysiological evidence for hyperalgesia in the peripheral neuropathy.

A peripheral neuropathy was produced in adult rats by placing loosely constrained ligature around the common sciatic nerve. At the ligature region of the nerve, demyelination developed. The postoperative behavior of these rats indicated that hyperalgesia and allodynia were produced. The electrical activity pattern of the damaged fibers was remarkably different from those of normal nerves: there were some abnormal spontaneous afferent firings from the injured fibers; multi-impulse responses of C-fiber to single shock was recorded; a lasting firing was elicited after the injured region was gently pressed or by oil drops at 40 degrees C; an antidromic electric stimulus to the injured region, stimulations of L5 sympathetic ganglion or systemic administration of noradrenaline, all caused an increase in on-going spontaneous discharges of the injured fibers or brought the silent fibers into firing. Stimulation of the dorsal roots of the sciatic nerve produced no effect on their activities or caused a pause of the on-going discharges of them. Phentolamine, an alpha receptor blocker, ceased the abnormal firing, but did not affect the normal fiber firings. It is hypothesized that noradrenaline released by the sympathetic nerve would be an important factor responsible for both hyperalgesia and allodynia following injury of peripheral nerve.

The relationship between new ion channels and ectopic discharges from a region of nerve injury.

Changes in ectopic discharges from axons in an injured nerve were examined while agents that interact with ion channels were applied to the site of the nerve injury. Tetraethylammonium (TEA) greatly facilitated spontaneous ectopic discharges or evoked ectopic firing in previously silent axons. Tetrodotoxin, an Na+ channel blocker, completely blocked spontaneous discharges. Verapamil, La3+, and Mn2+, agents that interact with Ca2+ channels, blocked spontaneous discharges and depressed the responses evoked by TEA, noradrenaline and high concentration of K+. Increasing Ca2+ levels facilitated ectopic discharges and this effect was blocked by La3+ and Mn2+. Normal axons (from uninjured nerves) were insensitive to all the effects seen in the axons from the injured nerve. These results suggest that following nerve injury the membrane of the regenerating sprout contains new ion channels, particularly Ca2+ channels, and that these channels are responsible for the generation of ectopic discharges.

Mitotoxicity and bortezomib-induced chronic painful peripheral neuropathy.

Many of the most effective anti-cancer drugs induce a dose-limiting peripheral neuropathy that compromises therapy. Evidence from animal models of chemotherapy-induced painful peripheral neuropathy produced by the taxane agent, paclitaxel, and the platinum-complex agent, oxaliplatin, indicate that they produce neuropathy via a common mechanism-a toxic effect on the mitochondria in primary afferent sensory neurons. Bortezomib is from the proteasome-inhibitor class of chemotherapeutics. It also produces a dose-limiting peripheral neuropathy, but its effects on neuronal mitochondria are unknown. To investigate this, we developed a model of bortezomib-induced painful peripheral neuropathy in the rat and assessed mitochondrial function (respiration and ATP production) in sciatic nerve samples harvested at two time points: day 7, which is three days after treatment and before pain appears, and day 35, which is one month post-treatment and the time of peak pain severity. We found significant deficits in Complex I-mediated and Complex II-mediated respiration, and in ATP production at both time points. Prophylactic treatment with acetyl-L-carnitine, which has previously been shown to prevent paclitaxel- and oxaliplatin-induced mitochondrial dysfunction and pain, completely blocked bortezomib's effects on mitochondria and pain. These results suggest that mitotoxicity may be the core pathology for all chemotherapy-induced peripheral neuropathy and that drugs that protect mitochondrial function may be useful chemotherapy adjuncts.

Characterization of oxaliplatin-induced chronic painful peripheral neuropathy in the rat and comparison with the neuropathy induced by paclitaxel.

Anti-neoplastic agents in the platinum-complex, taxane, vinca alkaloid, and proteasome-inhibitor classes induce a dose-limiting, chronic, distal, symmetrical, sensory peripheral neuropathy that is often accompanied by neuropathic pain. Clinical descriptions suggest that these conditions are very similar, but clinical data are insufficient to determine the degree of similarity and to determine if they share common pathophysiological mechanisms. Animal models do not have the limitations of clinical studies and so we have characterized a rat model of chronic painful peripheral neuropathy induced by a platinum-complex agent, oxaliplatin, in order to compare it with a previously characterized model of chronic painful peripheral neuropathy induced by a taxane agent, paclitaxel. The oxaliplatin model evokes mechano-allodynia, mechano-hyperalgesia, and cold-allodynia that have a delayed onset, gradually increasing severity, a distinct delay to peak severity, and duration of about 2.5 months. There is no effect on heat sensitivity. Electron microscopy (EM) analyses found no evidence for axonal degeneration in peripheral nerve, and there is no upregulation of activating transcription factor-3 in the lumbar dorsal root ganglia. There is a statistically significant loss of intraepidermal nerve fibers in the plantar hind paw skin. Oxaliplatin treatment causes a significant increase in the incidence of swollen and vacuolated mitochondria in peripheral nerve axons, but not in their Schwann cells. Nerve conduction studies found significant slowing of sensory axons, but no change in motor axons. Single fiber recordings found an abnormal incidence of A- and C-fibers with irregular, low-frequency spontaneous discharge. Prophylactic dosing with two drugs that are known to protect mitochondria, acetyl-l-carnitine and olesoxime, significantly reduced the development of pain hypersensitivity. Our results are very similar to those obtained previously with paclitaxel, and support the hypothesis that these two agents, and perhaps other chemotherapeutics, produce very similar conditions because they have a mitotoxic effect on primary afferent neurons.

The response of spinal microglia to chemotherapy-evoked painful peripheral neuropathies is distinct from that evoked by traumatic nerve injuries.

Painful peripheral neuropathies produced by nerve trauma are accompanied by substantial axonal degeneration and by a response in spinal cord microglia that is characterized by hypertrophy and increased expression of several intracellular and cell-surface markers, including ionizing calcium-binding adapter molecule 1 (Iba1) and Cd11b (a complement receptor 3 antigen recognized by the OX42 antibody). The microglia response has been hypothesized to be essential for the pathogenesis of the neuropathic pain state. In contrast, the painful peripheral neuropathies produced by low doses of cancer chemotherapeutics do not produce degeneration of axons in the peripheral nerve, although they do cause partial degeneration of the sensory axons' distal-most tips, that is the intraepidermal nerve fibers that form the axons' terminal receptor arbors. The question thus arises as to whether the relatively minor and distal axonal injury characterizing the chemotherapy-evoked neuropathies is sufficient to evoke the microglial response that is seen after traumatic nerve injury. We examined the lumbar spinal cord of rats with painful peripheral neuropathies due to the anti-neoplastic agents, paclitaxel, vincristine, and oxaliplatin, and the anti-retroviral agent, 2',3'-dideoxycytidine (ddC), and compared them to rats with a complete sciatic nerve transection and the partial sciatic nerve injury produced in the chronic constriction injury model (CCI). As expected, microglia hypertrophy and increased expression of Iba1 were pronounced in the nerve transection and CCI animals. However, there was no microglia hypertrophy or increased Iba1 staining in the animals treated with paclitaxel, vincristine, oxaliplatin, or ddC. These results suggest that the mechanisms that produce neuropathic pain after exposure to chemotherapeutics may be fundamentally different than those operating after nerve trauma.

Mitochondrial abnormality in sensory, but not motor, axons in paclitaxel-evoked painful peripheral neuropathy in the rat.

The dose-limiting side effect of the anti-neoplastic agent, paclitaxel, is a chronic distal symmetrical peripheral neuropathy that produces sensory dysfunction (hypoesthesia and neuropathic pain) but little or no distal motor dysfunction. Similar peripheral neuropathies are seen with chemotherapeutics in the vinca alkaloid, platinum-complex, and proteasome inhibitor classes. Studies in rats suggest that the cause is a mitotoxic effect on axonal mitochondria. If so, then the absence of motor dysfunction may be due to mitotoxicity that affects sensory axons but spares motor axons. To investigate this, paclitaxel exposure levels in the dorsal root, ventral root, dorsal root ganglion, peripheral nerve, and spinal cord were measured, and the ultrastructure and the respiratory function of mitochondria in dorsal roots and ventral roots were compared. Sensory and motor axons in the roots and nerve had comparably low exposure to paclitaxel and exposure in the spinal cord was negligible. However, sensory neurons in the dorsal root ganglion had a very high and remarkably persistent (up to 10 days or more after the last injection) exposure to paclitaxel. Paclitaxel evoked a significant increase in the incidence of swollen and vacuolated mitochondria in the myelinated and unmyelinated sensory axons of the dorsal root (as seen previously in the peripheral nerve) but not in the motor axons of the ventral root. Stimulated mitochondrial respiration in the dorsal root was significantly depressed in paclitaxel-treated animals examined 2-4 weeks after the last injection, whereas respiration in the ventral root was normal. We conclude that the absence of motor dysfunction in paclitaxel-evoked peripheral neuropathy may be due to the absence of a mitotoxic effect in motor neuron axons, whereas the sensory dysfunction may be due to a mitotoxic effect resulting from the primary afferent neuron's cell body being exposed to high and persistent levels of paclitaxel.

Synthetic omega-conopeptides applied to the site of nerve injury suppress neuropathic pains in rats.

In patients and animals with painful peripheral neuropathies, spontaneous ectopic discharge from injured primary afferents is hypothesized to maintain a central state of hyperexcitability that underlies hyperalgesia and allodynia. Temporary suppression of this discharge allows the central state to normalize, such that hyperalgesia and allodynia are absent or reduced until the resumption of the discharge rekindles central hyperexcitability. Previous work suggests that Ca++ channels are involved in the genesis of spontaneous discharge from injured afferents. We applied SNX-111 and SNX-124 (0.1-3.0 micrograms), synthetic homologs of omega-conopeptides (MVIIA and GVIA, respectively) and potent blockers of neuronal N-type voltage-sensitive Ca++ channels, to the site of nerve injury via chronically implanted perineural cannulae in rats with an experimental painful peripheral neuropathy (the chronic constriction injury model). Heat-hyperalgesia and mechano-allodynia were reduced for at least 3 hr. Drug application to a normal nerve had no effect on responses to heat or mechanical stimuli. These results suggest that N-type Ca++ channel blockers may be useful in the treatment of the abnormal pains that occur after nerve injury.

Genetic diversity in crucian carp (Carassius auratus).

A survey of restriction fragment polymorphism in mitochondrial DNA of three subspecies of Carassius auratus throughout four provinces in China was undertaken using 17 restriction enzymes. Two carp, Cyprinus carpio rubbrofuscus and Cyprinus carpio carpio, were included as the outgroup. A total of 16 haplotypes was observed: 5 in tetraploids of C. auratus auratus; 8 in hexaploids of C. auratus auratus; and 2 in C. auratus gibelio and C. auratus cuvieri, respectively. The tetraploids and hexaploids share three common haplotypes as I, V, and VI. C. a. Cuvieri may have diverged first among the three subspecies. Interestingly, C. a. auratus and C. a. cuvieri did not form monophyletic clades, which indicated that the classification of Carassius auratus required further studies. The current hypothesis, that hexaploids originated from tetraploids by a polyploidy event, is less favorable, based on the distribution of haplotypes and the lower diversity in tetraploids than in hexaploids. Our data also indicate that divergence of hexaploids and tetraploids might be recent and mtDNA polymorphism existed before the divergence. Meanwhile, genetic isolation exists between the hexaploids and the tetraploids.