[Safety and effectiveness of emergency stenting for acute anterior circulation large artery disease].

Objective: To explore the safety and effectiveness of early stent implantation in patients with acute anterior circulation large artery disease. Methods: Patients were recruited from the RESCUE-RE study (a registration study for Critical Care of Acute Ischemic Stroke After Recanalization). Patients who were diagnosed with acute ischemic stroke within 24 hours of onset and given endovascular treatment after consultation from July 2018 to May 2019 from 18 sub-centers nationwide were retrospectively enrolled. According to whether the stents were placed during the operation, the patients were divided into two groups: stenting group and non-stenting group. The baseline between the two groups was matched by propensity score. The matching variables included age, sex, baseline National Institutes of Health Stroke Scale (NIHSS) score, baseline Glasgow Coma Scale (GCS) score, history of stroke, smoking and onset to hospital time. The primary clinical outcome was 90-day good neurological outcome [defined as modified Rankin score (mRS) 0-2]. Secondary outcomes include 90-day mortality, 24-hour re-occlusion of the responsible artery, and symptomatic intracranial hemorrhage. The differences in clinical endpoints between the two groups were compared. Result: A total of 899 patients with acute anterior circulation artery stenosis or occlusion were included in the study, with a mean age of(66±12)years,and 532(59.18%) were male. There were 193 patients in the stenting group and 706 patients in the non-stenting group. After the baseline data between the two groups were matched by propensity score, 169 patients were enrolled in each of two groups respectively. After matching, the proportion of patients in the stenting group with etiological diagnosis of large atherosclerosis [82.53% (137/166) vs 55.69% (93/167)] and the proportion of patients with previous history of hypertension [63.31% (107/169) vs 47.93% (81/169)] in the stenting group were higher than those in the non-stenting group (both P<0.05). While the proportion of patients in the non-stenting group with cardiogenic embolism [37.73%(63/167) vs 11.45%(19/166)]and the proportion of patients with atrial fibrillation [18.93% (32/169) vs 10.65%(18/169)]was higher(all P<0.05). In the stenting group, the time from onset to recanalization was longer[519 (408, 620)min vs 469 (365, 690)min], and the proportion of general anesthesia [50.89% (86/169) vs 35.50% (60/169)] was higher in the stenting group(both P<0.05). In addition, in the stenting group, the proportion of patients receiving mechanical thrombectomy[67.46% (114/169) vs 88.76% (150/169)] and arterial thrombolysis [2.37% (4/169) vs 18.93% (32/169)] was lower than non-stenting group during the operation, while the proportion of patients receiving balloon dilation [53.85% (91/169) vs 13.61% (23/169)]was higher(both P<0.05). The proportion of patients in stent group receiving antiplatelet drugs before operation was higher [13.46% (21/169) vs 8.70% (14/169)](both P<0.05). In terms of clinical outcome, compared with the non-stenting group, the proportion of patients in the stenting group with good neurological function in 90 days was lower [44.79% (73/169) vs 56.36% (93/169)], and the proportion of death at 90 days was higher[15.98% (27/169) vs 8.88% (15/169)] (both P<0.05). There was no significant difference between the two groups in 24-hour re-occlusion[8.88% (15/169) vs 9.47% (16/169)] and symptomatic intracranial hemorrhage[5.92% (10/169) vs 4.76% (8/169)](both P>0.05). Conclusion: For patients with acute anterior circulation artery disease, early stent therapy may increase the proportion of patients with adverse neurological outcomes.

[Three cases of acute chlorfenapyr poisoning].

This paper reported 3 cases of poisoning caused by chlorfenagyr. Chlorfenapyr poisoning has gradually increased in clinical practice. The early stage after poisoning is digestive tract symptoms, followed by sweating, high fever, changes in consciousness, changes in myocardial enzymology, etc. Its main mechanism of intoxication is uncoupling oxidative phosphorylation. Since there is no specific antidote after poisoning, the fatality rate of chlorfenapyr poisoning remains high. The therapeutic measures are early gastrointestinal decontamination, symptomatic and supportive treatments, and early blood purification may be an effective treatment.

[The association between stress hyperglycemia ratio and outcome of patients with acute ischemic stroke undergoing endovascular treatment].

Objectives: To investigate the correlation between stress hyperglycemia ratio (SHR) and outcomes in patients with acute ischemic stroke treated with endovascular treatment. Methods: In a multicenter registration study for RESCUE-RE (a registration study for critical care of acute ischemic stroke after recanalization), eligible patients with large vessel occlusion stroke within 24 hours after onset who received endovascular treatment between July 2018 and May 2019 were enrolled. SHR was calculated as the fasting glucose concentration divided by the estimated average glucose concentration and then categorized into four groups according to the quartiles (group Q1, group Q2, group Q3 and group Q4). The primary outcome was poor neurological outcomeat day 90 fromstroke onset [defined as modified Rankin scale (mRS) of 3-6]. Secondary outcomes included early neurological deterioration (END), death within 3 months after stroke onset, and symptomatic intracranial hemorrhage.Multivariable logistic and Cox regression modelswere used to assess the correlation between quartiles of SHR and prognosis in patients with endovascular treatment. Results: A total of 592 patients were enrolled in the study, with a mean age of (63±12) years, and 68.07% were male.The median National Institute of Health stroke scale(NIHSS) score on admission was15(11, 20), and the median SHR was 1.23 (1.07, 1.47), with SHR<1.07 in group Q1, 1.07≤SHR<1.23 in group Q2, 1.23≤SHR<1.47 in group Q3 and SHR≥1.47 in group Q4, respectively. The rate of complete recanalization was lower in group Q4 than that of group Q1 (70.27% vs 83.67%, P=0.026). After fully adjusted for potential covariates, the risk of poor neurological outcome at day 90 from stroke onset in group Q4 was 2.38 folds that of group Q1(adjusted OR= 2.38, 95%CI: 1.57-3.57,P=0.003). The risk of death within 3 months of patients in group Q4 was 1.80 times that of the patients in group Q1, but the difference was not statistically significant(adjusted HR=1.80, 95%CI: 0.90-3.62, P=0.098). Conclusion: Higher SHR was correlated with poor neurological outcome at 3 months in large artery occlusion related acute ischemic stroke patients receiving endovascular therapy.

[Association studies between postoperative hypoeosinophilia and hospital stay in patients undergoing hip fracture surgery under different anesthesia].

Objective: To investigate early postoperative changes in eosinophils (EOS) and the relationship of postoperative hospital stay and hypoeosinophilia in patients undergoing hip fracture surgery under general or spinal anesthesia. Methods: The clinical data of patients who underwent hip fracture surgery at Beijing Tiantan Hospital between April 2014 and November 2017 were retrospectively analyzed. Patients were classified according to whether they received general anesthesia or spinal anesthesia. Univariate regression analysis was used to examine a number of covariates potentially contributed to postoperative hospital stay. Multivariate linear regression was used to analyze the relationship between postoperative day 1 EOS counts and postoperative hospital stay. Interaction and stratified analyses were conducted according to anesthesia methods. Results: A total of 149 patients were included in this study. Thirty-four of them underwent general anesthesia and 115 of them underwent spinal anesthesia. The postoperative day 1 EOS of the general anesthesia group was 0 (0,1.8)×107/L, which was lower than that of the spinal anesthesia group 1.0(0,6.0)×107/L (Z=3.095, P<0.01). After adjusting the confounders of age, gender, American Society of Anesthesiologists (ASA) grade, intraoperative blood loss, intraoperative red blood cell (RBC) transfusion, postoperative day 1 hematocrit (HCT) and white blood cell (WBC), postoperative complications, and the interaction terms for ASA, intraoperative blood loss, intraoperative RBC transfusion and postoperative complications, the negative correlation between postoperative hospital stay and postoperative day 1 EOS level was significant (ß=-0.39, 95%CI:-0.74--0.05, P<0.05) in the general anesthesia group. Conclusion: EOS were significantly decreased after surgery in general anesthesia group, and the postoperative hospital stay was negatively correlated with postoperative day 1 hypoeosinophilia.

[Interventional effect of metformin on pulmonary inflammation and pulmonary fibrosis in silicotic rats].

Objective: To investigate the interventional effect of metformin on pulmonary inflammation and pulmonary fibrosis in silicotic rats. Methods: In April 2019, 48 Wistar male rats of SPF grade were randomly divided into negative control group, metformin control group, silicon dioxide (SiO2) model group, low, medium and high dose metformin intervention group according to the random number table method, 8 rats in each group. The SiO2 model group and the low, medium and high dose metformin intervention groups were given 1 ml 50 mg/ml of SiO2 by intratracheal instillation, the negative control group and the metformin control group were given 1 ml normal saline by intratracheal instillation. 24 hours later, the low, medium and high dose metformin intervention groups and the metformin control group were treated with 100, 200, 400 and 400 mg/kg metformin daily, the control and SiO2 model groups received normal saline daily. Then the rats were sacrificed at the 28th day after SiO2 exposure. The changes of rat body weight and pathological examination of rat lung tissue were observed, and the lung organ coefficient, the content of hydroxyproline (HYP) , the expression levels of inflammatory factors transforming growth factor beta1 (TGF-ß1) , tumor necrosis factor-alpha (TNF-α) , interleukin-1beta (IL-1ß) and the protein expression of E-cadherin (E-Cad) , Vimentin, α-SMA were detected. Results: Compared with the negative control group, SiO2 model group had a significant decrease in the body weight of rats (P<0.05) , lung organ coefficient, alveolitis and fibrosis scores, HYP content and the levels of TGF-ß1, TNF-α, IL-1ß were all significantly increased (P<0.05) . Compared with the SiO2 model group, the weights of the rats in the medium and high dose intervention group of metformin increased significantly (P<0.05) . And after intervention with different doses of metformin, the lung organ coefficient, alveolitis and fibrosis scores, HYP content and the levels of TGF-ß1, TNF-α and IL-1ß were significantly decreased (P<0.05) . Immunohistochemistry and Western blotting results showed that compared with the negative control group, the expression of E-Cad of the SiO2 model group was decreased, and the expression levels of Vimentin and α-SMA were significantly increased (P<0.05) . After metformin intervention, the expression of E-Cad was significantly increased, the expression levels of Vimentin and α-SMA were significantly decreased (P<0.05) . Conclusion: Metformin can reduce lung tissue inflammation and fibrosis in rats exposed to SiO2 dust, which may be related to reducing the expression of inflammatory factors in lung tissue and inhibiting the EMT process.

Safety and pharmacodynamic mechanism of ropivacaine lumbar anesthesia in Cesarean section.

Lumbar anesthesia is the preferred anesthetic approach for puerperae undergoing cesarean section in China. To observe the safety of administering different doses of ropivacaine for cesarean section and its pharmacodynamic mechanism, we randomly divided 180 pregnant women undergoing cesarean section into three groups: group A, 10 mg ropivacaine (0.50%); group B, 12 mg ropivacaine (0.50%); and group C, 14 mg ropivacaine (0.50%). Pharmacodynamic index, anesthesia quality and incidence of untoward reactions of each group were observed. Group A performed the poorest and group C the best in evaluation of sensory and motory block (P less than 0.05). With regard to evaluation of hemodynamic index, hemodynamic parameters of the three groups had significant differences after medication; mean arterial pressure (MAP) of patients in group B decreased at time points T1, T2 and T3 and heart rate (HR) became much higher at T1 (P less than 0.05); MAP of the patients in group C decreased at T1, T2, T3 and T4, but HR became higher at T1 and T2 (P less than 0.05); HR of group B was higher than that of group A at T1 (P less than 0.05); MAP of the patients in group C had a significant decrease at T1, T2, T3 and T4, but HR became higher at T2 (P less than 0.05); MAP of patients in group C significantly decreased compared to group B at T1 and T2, but HR became higher at T2 (P less than 0.05). Fluctuation of oxyhemoglobin saturation (SpO2) of all patients was between 95% and 99%. There was no occurrence of myocardial ischemia or arrhythmia. 1-min Apgar score of neonates of the three groups had no significant difference (P0.05). The incidence of adverse reactions of the patients in group C was much higher than that of the patients in the other groups (P less than 0.05). Twelve mg ropivacaine (5%) is the most suitable dose for pregnant women undergoing cesarean section as it can achieve a sound anesthetic effect and high safety and, moreover, has little influence on respiratory and circulatory functions.

A histochemical study on the snout tentacles and snout skin of bristlenose catfish Ancistrus triradiatus.

Histological sections of the tentacles of Ancistrus triradiatus revealed that they contain many goblet cells with granule-like sections distributed along the edge of the tentacles (mean 302 cells mm(-1)). Various histochemical methods were used to characterize the contents of the goblet cells. The results indicated that the contents were periodic acid-Schiff (PAS) positive, glycogen negative and no sulphated mucins could be found. The contents of the goblet cells were acid mucins and O-acetylated sialomucins which had high energy content. The snout skin of the male also contained goblet cells with higher density (mean 755 cells mm(-1)) than that of the tentacles. Snout skin of female A. triradiatus, on the contrary, did not contain any goblet cells. Instead, many minute spines could be found. Based on the acid mucins and O-acetylated sialomucins secretions of goblet cells which are of high nutritional values, it is hypothesized that snout tentacle secretions are used to provide nutrients to fish larvae when they are under paternal care.

The structure and possible functions of the milkfish Chanos chanos adipose eyelid.

Basic histological sections (with different staining methods) and scanning electron microscopy (SEM) examinations showed that there were three distinctive layers in the adipose eyelid of milkfish Chanos chanos, which is found in the cephalie region and covers the entire eye. The outer and inner layers were epithelial tissues and the middle layer was composed of connective tissue formed by type I collagen fibrils. No adipose tissue was found in any of the three layers of the so-called adipose eyelid. Examination by transmission spectrophotometer showed that the adipose tissue could filter out ambient light with a wavelength shorter than 305 nm. A photoretinoscope was used to investigate whether the adipose eyelid influenced the mechanism of eye focusing. Eye diopter values did not differ before or after eyelid removal, which indicated that the adipose eyelid did not play a role in eye focusing. In light of these findings, it is suggested that the adipose eyelid serves to block exposure of harmful ultraviolet light into eyes and may also to offer some protection against impact to the eye in the aquatic environment.

[Transmission electron microscopic observation on gonad of Oncomelania hupensis offspring bred in Weishan Lake areas].

OBJECTIVE: To observe the morphological changes in the testes and ovaries of adult 12th-generation Oncomelania hupensis bred for 12 winters in Weishan Lake areas. METHODS: The offspring of the adult O. hupensis snails bred in the Weishan Lake that were originated from the Yangzhou section of the Yangtze River was defined as the experiment group, while uninfected, adult O. hupensis snails captured from the marshland of the Yangzhou section of the Yangtze River served as the control group. Snails were dissected and intact testicular and ovarian specimens were sampled, routinely fixed, dehydrated, embedded, polymerized in an oven and sliced on an ultramicrotome. The sections were visualized under a transmission electron microscope, and the ultrastructure of the snail gonad was compared between the experiment and control groups. RESULTS: Transmission electron microscopy showed "9 + 2" microtubules on the transverse sections of the tails of sperm cells in the testes of male snails in the control group, with triangular acrosomes and spiral, dense nuclei seen in the tip, while in the experiment group, the "9 + 2" microtubules disappeared on the transverse sections of the tails of sperm cells in the testes of male snails, with low chromatin density found in the tip. Transmission electron microscopy revealed clear nucleolus and nuclear membranes in the ova of female snail ovaries, and displayed yolk body, liposomes and endoplasmic reticulum in the cytoplasm, bilayer twists of nuclear membrane and a uniform nucleolus in the control group, while in the experiment group, smooth nuclear membrane and unclear nucleolus were observed in the ova of female snail ovaries, with few contents seen within cells. CONCLUSIONS: Following breeding for 12 winters in the Weishan Lake, the 12th-generation O. hupensis snails fail to fully adapt to the natural environment in northern China, and the remarkable changes in the ultrastructure of the snail gonad may be a cause of gradual decline and even extinction of O. hupensis in the Weishan Lake areas.

TUG1 promotes diabetic atherosclerosis by regulating proliferation of endothelial cells via Wnt pathway.

OBJECTIVE: To explore the specific role of TUG1 in regulating the occurrence and progression of diabetic atherosclerosis and its underlying mechanism. PATIENTS AND METHODS: TUG1 expressions in coronary artery disease (CAD) tissues, normal arterial tissues, endothelial cells induced by high-dose glucose and tumor necrosis factor-α (TNF-α) were detected by quantitative Real-time polymerase chain reaction (qRT-PCR). The effects of TUG1 on proliferation, migration and cell cycle of human umbilical vein endothelial cells (HUVECs) were detected by cell counting kit-8 (CCK-8), transwell assay and flow cytometry, respectively. Subsequently, protein expressions of proliferation-related genes, cell cycle-related genes and Wnt pathway-related genes were detected by Western blot after altering TUG1 expression in HUVECs. Further rescue experiments were carried out to explore whether TUG1 could regulate diabetic atherosclerosis via Wnt pathway. RESULTS: Overexpressed TUG1 was found in CAD tissues and endothelial cells induced by high-dose glucose and TNF-α compared with those of controls. TUG1 overexpression remarkably promoted proliferation, migration and cell cycle of HUVECs. Protein expressions of ß-catenin and c-Myc were upregulated by overexpression of TUG1. Rescue experiments indicated that XAV-939, the inhibitor of Wnt pathway, could partially reverse the increased proliferative and migratory changes in HUVECs induced by TUG1 overexpression. CONCLUSIONS: We found that overexpressed TUG1 stimulates proliferation and migration of endothelial cells via Wnt pathway, thereby promoting the occurrence and progression of diabetic atherosclerosis.

Expressions of VEGF and miR-21 in tumor tissues of cervical cancer patients with HPV infection and their relationships with prognosis.

OBJECTIVE: To investigate the expressions of vascular endothelial growth factor (VEGF) and micro-ribonucleic acid-21 (miR-21) in cervical cancer patients with human papillomavirus (HPV) infection and determine the potential relationships with prognosis. PATIENTS AND METHODS: Expressions of VEGF in cervical cancer tissues and cancer-adjacent tissues were detected by immunohistochemistry, and the expressions of miR-21 and VEGF in both tissues were quantitatively analyzed using reverse transcription polymerase chain reaction (RT-PCR). Patients with cervical cancer were followed up after operation, and the survival rates of patients with different expression levels of miR-21 and VEGF were compared. RESULTS: VEGF was expressed in both cervical cancer tissues and cancer-adjacent tissues. The positive expression rate of VEGF in cervical cancer tissues (75.69%) was significantly higher than that in cancer-adjacent tissues (10.45%). RT-PCR results showed that the expression levels of miR-21 and VEGF in cervical cancer tissues were significantly higher than those in cancer-adjacent tissues (p<0.05). Correlation analyses revealed that miR-21 expression was significantly positively correlated with VEGF expression in cervical cancer tissues (r2=0.4174, p<0.0001). Prognostic analyses showed that the 5-year survival rate of patients was relatively high when miR-21 and VEGF were lowly expressed. CONCLUSIONS: VEGF and miR-21 are highly expressed in tumor tissues of cervical cancer patients with HPV infection. VEGF expression is significantly positively correlated with miR-21 expression, and the high levels of VEGF and miR-21 predict unfavorable prognosis of cervical cancer. Data provide a theoretical support for clinical treatment of cervical cancer patients with HPV infection.

[Advances of self-healing dental composite resin].

Degradation of composite resin during ageing always produces micro-cracks, the latter could gradually expand, leading to the fracture of tooth restoration. In order to extend the service life of composite resin by repairing cracks intelligently, self-healing microcapsule models have been introduced in resin-based dental materials. This paper will present the concept and classification of self-healing materials, and review the research progresses on self-healing dental resin.

Obesity is an independent risk factor for non-alcoholic fatty liver disease: evidence from a meta-analysis of 21 cohort studies.

BACKGROUND: The association between obesity and nonalcoholic fatty liver disease (NAFLD) has not been fully quantified, and the magnitude of NAFLD risk associated with obesity is still unclear. A meta-analysis of cohort studies was performed to elucidate the NAFLD risk associated with obesity. METHODS: Pubmed, Web of Science and Embase were searched for cohort studies assessing NAFLD risk associated with obesity or increased body mass index (BMI). Relative risks (RRs) with 95% confidence intervals (95%CIs) were pooled using random-effects model of meta-analysis. RESULTS: Twenty-one cohort studies including 13 prospective studies and 8 retrospective studies were finally included. There were a total of 381,655 participants in the meta-analysis. Compared with normal weight, obesity independently led to a 3.5-fold increased risk of developing NAFLD (RR = 3.53, 95%CI 2.48 to 5.03, P < 0.001). Meta-analysis also suggested an obvious dose-dependent relationship between BMI and NAFLD risk (per 1-unit increment in BMI: RR = 1.20, 95%CI 1.14 to 1.26, P < 0.001). Subgroup analyses further identified the robustness of the association above. No obvious risk of publication bias was observed. CONCLUSION: Obese individuals have a 3.5-fold increased risk of developing NAFLD, and there is an obvious dose-dependent relationship between BMI and NAFLD risk. © 2016 World Obesity.

CD44v6 expression in patients with stage II or stage III sporadic colorectal cancer is superior to CD44 expression for predicting progression.

BACKGROUND: Currently, it is difficult to predict the prognosis of patients exhibiting stage II or stage III colorectal cancer (CRC) and to identify those patients most likely to benefit from aggressive treatment. The current study was performed to examine the clinicopathological significance of CD44 and CD44v6 protein expression in these patients. STUDY DESIGN: We retrospectively investigated 187 consecutive patients who underwent surgery with curative intent for stage II to III CRC from 2007 to 2013 in the Beijing Civil Aviation Hospital. CD44 and CD44v6 protein expression levels were determined using immunohistochemistry and compared to the clinicopathological data. RESULTS: Using immunohistochemical detection, CD44 expression was observed in 108 (57.75%) of the CRC patients; and its detection was significantly associated with greater invasion depth, lymph node metastasis, angiolymphatic invasion, and a more advanced pathological tumor-lymph node-metastasis (TNM) stage. CD44v6 expression was observed in 135 (72.19%) of the CRC patients; and its expression was significantly associated with a poorly differentiated histology, greater invasion depth, lymph node metastasis, angiolymphatic invasion, and a more advanced pathological TNM stage. Expression of CD44v6 was higher than that of CD44 in stage II and stage III sporadic CRC. CONCLUSION: CD44v6 is a more useful marker for predicting a poor prognosis in stage II and stage III sporadic CRC as compared to CD44.

Sensory hair cells of a fish ear: evidence of multiple types based on ototoxicity sensitivity.

Sensory hair cells from the striolar region (striolar hair cells) of the utricle and the lagena of the ear of a teleost fish Astronotus ocellatus (Cuvier) ear are sensitive to gentamicin sulphate, an ototoxic drug. In contrast, sensory hair cells from outside the striolar region (extra-striolar hair cells) are not sensitive to gentamicin. These data, combined with results from studies showing different ultrastructural features and different immunoreactivity to a calcium binding protein, S-100, lead to the suggestion that there are distinguishable types of hair cells in these endorgans. These results add to the increasing evidence that classifying the sensory hair cells of fish ears only as the traditional 'vestibular type II' may be inadequate for properly understanding structure and function of the fish ear.

Effects of underwater noise on auditory sensitivity of a cyprinid fish.

The ability of a fish to interpret acoustic information in its environment is crucial for its survival. Thus, it is important to understand how underwater noise affects fish hearing. In this study, the fathead minnow (Pimephales promelas) was used to examine: (1) the immediate effects of white noise exposure (0.3-4.0 kHz, 142 dB re: 1 microPa) on auditory thresholds and (2) recovery after exposure. Audiograms were measured using the auditory brainstem response protocol and compared to baseline audiograms of fathead minnows not exposed to noise. Immediately after exposure to 24 h of white noise, five out of the eight frequencies tested showed a significantly higher threshold compared to the baseline fish. Recovery was found to depend on both duration of noise exposure and auditory frequency. These results support the hypothesis that the auditory threshold of the fathead minnow can be altered by white noise, especially in its most sensitive hearing range (0.8-2.0 kHz), and provide evidence that these effects can be long term (>14 days).

Damage and recovery of hair cells in fish canal (but not superficial) neuromasts after gentamicin exposure.

Recent evidence demonstrating the presence of two types of sensory hair cell in the ear of a teleost fish (Astronotus ocellatus, the oscar) indicates that hair cell heterogeneity may exist not only in amniotic vertebrates but also in anamniotes. Here we report that a similar heterogeneity between hair cell types may also occur in the other mechanosensory organ of the oscar, the lateral line. We exposed oscars to the aminoglycoside (ototoxic) antibiotic gentamicin sulfate and found damaged sensory hair cells in one class of the lateral line receptors, the canal neuromasts, but not in the other class, the superficial neuromasts. This effect was not due to the canal environment. Moreover, new ciliary bundles on hair cells of the canal neuromasts were found after, and during, gentamicin exposure. The pattern of hair cell destruction and recovery in canal neuromasts is similar to that of type I-like hair cells found in the striolar region of the utricle and lagena of the oscar after gentamicin treatment. These results suggest that the hair cells in the canal and superficial neuromasts may be similar to type I-like and type II hair cells, respectively, in the fish ear.

Damage and regeneration of hair cell ciliary bundles in a fish ear following treatment with gentamicin.

Sensory hair cells in the striolar regions of the utricle and lagena of a teleost fish, the oscar (Astronotus ocellatus), were damaged following intramuscular injections of gentamicin sulfate. In order to determine whether fish can regenerate hair cells, the time course of damage and recovery was followed over a period of four weeks by scanning electron microscopy. Maximum loss of ciliary bundles occurred at about day 10 after the first of four daily injections of gentamicin (20 mg/kg) in 4-6 cm long fish. The striolar regions were almost totally denuded of ciliary bundles, and there was evidence of considerable hair cell loss. The time course for damage was longer in larger fish, but the recovery of the ciliary bundles appeared to be complete about 10 days after maximal damage was seen in both the smaller and larger fish. These data indicate that Astronotus is able to repair damage to hair cells for an extended period of time post-embryonically.

[Observation of ultrastructure and drug sensitivity of in vitro cultured exoerythrocytic form of Plasmodium berghei].

The ultrastructure of in vitro cultured exoerythrocytic stage (EE) of Plasmodium berghei (P. b.) was observed under transmission electron microscope (TEM). The drug sensitivity of EE was also measured in vitro. The EE was cultured in monolayer host cell, fixed and embedded in situ. The ultrathin sections were prepared and examined by routine methods. The TEM pictures showed that the fine structure of in vitro cultured EE was similar with that of EE grown in rat hepatocytes in vivo, as described by Meis et al. The parasite was found within a parasitophorous vacuole, with nucleus, mitochondria, endoplasmic reticula and Golgi apparatus were observed inside the parasite. After 24 h cultivation, the EE was incubated for 48 h in medium containing a serial concentrations of primaquine or chloroquine, then examined under light microscope. The percentage of abnormal parasites was calculated. The preliminary results showed that the sensitivity of cultured P. b. EE to primaquine and chloroquine was significantly different. At the same concentration of 1 x 10(-5) mol/L, the percentage of abnormal parasites was 38.5 +/- 3.9% and 5.7 +/- 1.9%, respectively. These results demonstrated that the in vitro cultivation system of P. b. EE would have potential utility in antimalarial drug research. (Figs. 1-6).

[In vitro cultivation of the exoerythrocytic stage of Plasmodium berghei].

This paper reports on an in vitro culture system for the exoerythrocytic (EE) stage of Plasmodium berghei (P.b.) using embryonic lung cells. The system was first developed by our laboratory in China. The embryonic lung cells were isolated by trypsin digestion of a human embryonic lung obtained from a therapeutic abortion case and was designated as cell line Elu 8801. Anopheles stephensi mosquitoes were infected by biting P.b. ANKA strain infected Kunming mice and after 18-21 days were dissected under aseptic conditions for preparation of a sporozoite suspension. This suspension was used to inoculate the monolayer cultures of Elu 8801. Regular examination found that following a cultivation for 48 hours, up to 100 multinuclear EE schizonts of P.b. could be observed on 1 x 1 cm cover slide. Seventy-two hours later mature merozoites were seen among part of the schizonts. An intraperitoneal inoculation of the supernatant culture medium to mice could induce malaria infection which could be transferred to other mice by blood inoculation. When the mice infected with the second generation were allowed to feed A. stephensi, sporozoites developed in the mosquitoes. The results demonstrate that the human embryonic lung cell line Elu 8801 established in our laboratory is susceptible to P.b. ANKA sporozoites and can support the developmental maturation of EE stages, producing potentially infectious merozoites.