[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.

[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-β1) , tumor necrosis factor-alpha (TNF-α) , interleukin-1beta (IL-1β) 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-β1, TNF-α, IL-1β 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-β1, TNF-α and IL-1β 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.

[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 (β=-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.

[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.

[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.

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.

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.

Grouper interleukin-12, linked by an ancient disulfide-bond architecture, exhibits cytokine and chemokine activities

Interleukin-12 (IL-12) is a pleiotropic cytokine which bridges innate and adaptive immunity in defense against pathogens. IL-12 proved to be an effective and successful adjuvant to enhance both the innate and adaptive immune responses and could be applicable for a rationale vaccine formulation in fish against pathogen infection. We have cloned the p35 and p40 cDNAs of IL-12 from orange-spotted grouper (Epinephelus coioides). Grouper IL-12 most resembles with sea bass orthologues; moderate to low identity with other teleost and mammalian counterparts. The structural model of grouper IL-12 heterodimer revealed NC(141)F three amino acid patch of grouper p35, which is present in teleost p35 but absent in mammalian and avian p35, and is spatially nearby the conserved cysteine residue located at A-helix of p35 to form a disulfide bond when the 14aa peptide located at loop 1 of grouper p35 was aligned with human corresponding exon 4, instead of exon 5. The results indicated that the loss of this 3aa patch during evolution was compensated by the duplication of exon 4 in mammalian p35 to gain another cysteine residue to form a disulfide bond, evidenced by chicken p35 which does not contain NCF corresponding 3-aa patch nor exon 4 duplication. Accordingly, the inter-chain disulfide bond of IL-12 heterodimer is conserved from teleost to mammalian IL-12. A single chain grouper IL-12 (scgIL-12) construct linked by (G4S)3 was successfully expressed in baculovirus-insect cell system; its identity has been confirmed by LC/MS/MS. In addition, the biological activity of recombinant scgIL-12 (rscgIL-12) are demonstrated for its stimulation of PBL proliferation, chemotactic migration, induction of TNF-α gene expression and a plausible adjuvant effect of prolonged protection against parasite infection in fish. We illustrated the first time in lower vertebrate that grouper IL-12 possesses both cytokine and chemokine activities.

Activity and function of rabbit muscle-specific creatine kinase at low temperature by mutation at gly268 to asn268

Carp muscle-specific creatine kinase M1 isoenzyme (M1-CK) seems to have evolved to adapt to synchronized changes in body temperature and intracellular pH. When gly(268) in rabbit muscle-specific creatine kinase was substituted with asn(268) as found in carp M1-CK, the rabbit muscle-specific CK G286N mutant specific activity at pH 8.0 and 10°C was more than 2-fold higher than that in the wild-type rabbit enzyme. Kinetic studies showed that K(m) values of the rabbit CK G268N mutant were similar to those of the wild-type rabbit enzyme, yet circular dichroism spectra showed that the overall secondary structures of the mutant enzyme, at pH 8.0 and 5°C, were almost identical to the carp M1-CK enzyme. The X-ray diffraction pattern of the mutant enzyme crystal revealed that amino acid residues involved in substrate binding are closer to one another than in the rabbit enzyme, and the cysteine283 active site of the mutant enzyme points away from the ADP binding site. At pH 7.4-8.0 and 35-10°C, with a smaller substrate, dADP, specific activities of the mutant enzyme were consistently higher than the wild-type rabbit enzyme and more similar to the carp M1-CK enzyme. Thus, the smaller active site of the RM-CK G268N mutant may be one of the reasons for its improved activity at low temperature.

Tiger shrimp (Penaeus monodon) penaeidin possesses cytokine features to promote integrin-mediated granulocyte and semi-granulocyte adhesion

Recent studies indicated that antimicrobial peptides (AMPs) play multiple roles in both innate and adaptive immune functions. The penaeidin of tiger shrimp Penaeus monodon shows an antimicrobial activity against Gram-positive bacteria and filamentous fungi. To study immunomodulation functions of the penaeidin, we transfected shrimp hemocytes in primary culture with penaeidin-specific small interfering RNA (siRNA-3) and observed a concomitant 20% reduction in adhesive hemocytes compared with mock-transfected cells. The addition of biosynthesized or chemically synthesized penaeidin or penaeidin proline-rich domain (PRD) to the culture medium of penaeidin knock-down hemocytes led to a full recovery in the number of adhesive hemocytes. The effect of penaeidin knock-down on the expression of tiger shrimp cell adhesion-associated molecules was examined using real-time Q-PCR. Results demonstrated 91% and 64% decreases in the expression of integrin-beta and collagen, respectively, and a 396% increase in the expression of collagenase. The addition of chemically synthesized penaeidin after penaeidin knock-down hemocytes normalized the expression of these genes. The addition of the integrin-beta ligand competitor RGDS to mock-transfected hemocytes decreased the number of adhesive hemocytes similar to penaeidin knock-down. In conclusion, penaeidin possesses an integrin-beta-mediated cytokine feature that promotes shrimp granulocyte and semi-granulocyte adhesion. This is the first report about functional shrimp cytokine.

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.

Endosperm-specific hypomethylation, and meiotic inheritance and variation of DNA methylation level and pattern in sorghum (Sorghum bicolor L.) inter-strain hybrids

Understanding dynamics and inheritance of DNA methylation represents important facets for elucidating epigenetic paradigms in plant development and evolution. Using four sets of sorghum (Sorghum bicolor L.) inter-strain hybrids and their inbred parents, the developmental stability and inheritance of cytosine methylation in two tissues, leaf and endosperm, by MSAP analysis were investigated. It was found that in all lines (inbred and hybrid) studied, endosperm exhibited a markedly reduced level of full methylation of the external cytosine or both cytosines at the CCGG sites relative to leaf, which caused a variable reduction in the estimated total methylation level in endosperm by 6.89-19.69% (11.47% on average). For both tissues, a great majority of cytosine methylation profiles transmitted to F1 hybrids, however, from 1.69 to 3.22% of the profiles showed altered patterns in hybrids. Both inherited and altered methylation profiles can be divided into distinct groups, and their frequencies are variable among the cross-combinations, and between the two tissues. The variations in methylation level and pattern detected in the hybrids were not caused by parental heterozygosity, and they could be either non-random or stochastic among hybrid individuals. Homology analysis of isolated bands that showed endosperm-specific hypomethylation or variation in hybrids indicated that diverse sequences were involved, including known-function cellular genes and mobile elements. RT-PCR analysis of six genes representing endosperm-specific hypomethylation in MSAP profiles indicated that all showed higher expression in endosperm than in leaf, suggesting involvement of methylation state in regulating tissue-specific or tissue-biased expression in sorghum. Analysis on leaf-RNA from 5-azacytidine-treated plants further corroborated this possibility.

Endosperm-specific hypomethylation, and meiotic inheritance and variation of DNA methylation level and pattern in sorghum (Sorghum bicolor L.) inter-strain hybrids

Understanding dynamics and inheritance of DNA methylation represents important facets for elucidating epigenetic paradigms in plant development and evolution. Using four sets of sorghum (Sorghum bicolor L.) inter-strain hybrids and their inbred parents, the developmental stability and inheritance of cytosine methylation in two tissues, leaf and endosperm, by MSAP analysis were investigated. It was found that in all lines (inbred and hybrid) studied, endosperm exhibited a markedly reduced level of full methylation of the external cytosine or both cytosines at the CCGG sites relative to leaf, which caused a variable reduction in the estimated total methylation level in endosperm by 6.89-19.69% (11.47% on average). For both tissues, a great majority of cytosine methylation profiles transmitted to F1 hybrids, however, from 1.69 to 3.22% of the profiles showed altered patterns in hybrids. Both inherited and altered methylation profiles can be divided into distinct groups, and their frequencies are variable among the cross-combinations, and between the two tissues. The variations in methylation level and pattern detected in the hybrids were not caused by parental heterozygosity, and they could be either non-random or stochastic among hybrid individuals. Homology analysis of isolated bands that showed endosperm-specific hypomethylation or variation in hybrids indicated that diverse sequences were involved, including known-function cellular genes and mobile elements. RT-PCR analysis of six genes representing endosperm-specific hypomethylation in MSAP profiles indicated that all showed higher expression in endosperm than in leaf, suggesting involvement of methylation state in regulating tissue-specific or tissue-biased expression in sorghum. Analysis on leaf-RNA from 5-azacytidine-treated plants further corroborated this possibility.

The hearing abilities of the prawn Palaemon serratus

The mechanism of sound reception and the hearing abilities of the prawn (Palaemon serratus) have been studied using a combination of anatomical, electron microscopic and electrophysiological approaches, revealing that P. serratus is responsive to sounds ranging in frequency from 100 to 3000 Hz. It is the first time that the Auditory Brainstem Response (ABR) recording technique has been used on invertebrates, and the acquisition of hearing ability data from the present study adds valuable information to the inclusion of an entire sub-phylum of animals when assessing the potential impact of anthropogenic underwater sounds on marine organisms. Auditory evoked potentials were acquired from P. serratus, using two subcutaneous electrodes positioned in the carapace close to the supraesophageal ganglion and the statocyst (a small gravistatic organ located below the eyestalk on the peduncle of the bilateral antennules). The morphology of the statocyst receptors and the otic nerve pathways to the brain have also been studied, and reveal that P. serratus possesses an array of sensory hairs projecting from the floor of the statocyst into a mass of sand granules embedded in a gelatinous substance. It is the purpose of this work to show that the statocyst is responsive to sounds propagated through water from an air mounted transducer. The fundamental measure of the hearing ability of any organism possessing the appropriate receptor mechanism is its audiogram, which presents the lowest level of sound that the species can hear as a function of frequency. The statocyst of P. serratus is shown here to be sensitive to the motion of water particles displaced by low-frequency sounds ranging from 100 Hz up to 3000 Hz, with a hearing acuity similar to that of a generalist fish. Also, recorded neural waveforms were found to be similar in both amplitude and shape to those acquired from fish and higher vertebrates, when stimulated with low-frequency sound, and complete ablation of the electrophysiological response was achieved by removal of the statocyst.

Acoustic communication in two freshwater gobies: the relationship between ambient noise, hearing thresholds and sound spectrum

Two freshwater gobies Padogobius martensii and Gobius nigricans live in shallow (5-70 cm) stony streams, and males of both species produce courtship sounds. A previous study demonstrated high noise levels near waterfalls, a quiet window in the noise around 100 Hz at noisy locations, and extremely short-range propagation of noise and goby signals. To investigate the relationship of this acoustic environment to communication, we determined audiograms for both species and measured parameters of courtship sounds produced in the streams. We also deflated the swimbladder in P. martensii to determine its effect on frequency utilization in sound production and hearing. Both species are maximally sensitive at 100 Hz and produce low-frequency sounds with main energy from 70 to 100-150 Hz. Swimbladder deflation does not affect auditory threshold or dominant frequency of courtship sounds and has no or minor effects on sound amplitude. Therefore, both species utilize frequencies for hearing and sound production that fall within the low-frequency quiet region, and the equivalent relationship between auditory sensitivity and maximum ambient noise levels in both species further suggests that ambient noise shapes hearing sensitivity.

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).

The otic gasbladder as an ancillary auditory structure in a mormyrid fish

Mormyrid fishes use acoustic signals for long-distance communication and a weakly electric field for short-distance interaction. Mormyrids are unique in having an otic gasbladder attached directly to the saccule on each side of the inner ear. Karl von Frisch (1938) hypothesized that the tightly coupled otic gasbladder might aid mormyrid hearing. Using the mormyrid fish (Brienomyrus brachyistius), this study manipulated gas in the otic gasbladder to test this hypothesis and histological sections were made to examine the anatomical relationship between the gasbladder and inner ear. The hearing sensitivity curves (audiograms) were obtained with the auditory brainstem response protocol. Audiograms were obtained from normal fish and from fish in which gas was withdrawn from either one or two otic gasbladders. Removal of gas from one otic gasbladder did not result in a significant change in either hearing ability or acoustically evoked brainwaves as compared to the control fish. Bilateral deflation of the otic gasbladders led to significant threshold changes. Histological sections revealed a particularly close coupling between the otic gasbladder and the saccule chamber. These results support von Frisch's hypothesis that the otic gasbladders of mormyrids assist in underwater sound detection.

Variability in the role of the gasbladder in fish audition

The teleost gasbladder is believed to aid in fish audition by transferring pressure components of incoming sound to the inner ears. This idea is primarily based on both anatomical observations of the mechanical connection between the gasbladder and the ear, followed by physiological experiments by various researchers. The gasbladder movement has been modeled mathematically as a pulsating bubble. This study is extending the previous work on fish with a physical coupling of the gasbladder and ear by investigating hearing in two species (the blue gourami Trichogaster trichopterus, and the oyster toadfish Opsanus tau) without a mechanical linkage. An otophysan specialist (the goldfish Carassius auratus) with mechanical coupling, is used as the control. Audiograms were obtained with acoustically evoked potentials (e.g., auditory brainstem response) from intact fish and from the same individuals with their gasbladders deflated. In blue gourami and oyster toadfish, removal of gas did not significantly change thresholds, and evoked potentials had similar waveforms. In goldfish thresholds increased by 33-55 dB (frequency dependent) after deflation, and major changes in evoked potentials were observed. These results suggest that the gasbladder may not serve an auditory enhancement function in teleost fishes that lack mechanical coupling between the gasbladder and the inner ear.

CDKN2A gene inactivation in epithelial sporadic ovarian cancer

The tumour suppressor gene CDKN2A, located on chromosome 9p21, encodes the cell cycle regulatory protein p16. Inactivation of the CDKN2A gene could lead to uncontrolled cell growth. In order to determine the role of CDKN2A in the development of sporadic ovarian cancer, loss of heterozygosity at 9p21-22, homozygous deletion, mutation and methylation status of the CDKN2A gene as well as CDKN2A expression were examined in a panel of serous papillary ovarian cancer. The frequency of loss of heterozygosity (LOH) for one or more informative markers at 9p21-22 was 65% (15/23). The most common deleted region was located between interferon (IFN)-alpha and D9S171. Homozygous deletions and mutations of the CDKN2A gene were not found. There was no evidence of methylation in exon 1, but methylation in exon 2 of CDKN2A gene was found in 26% (6/23). Absence of CDKN2A gene expression was shown in 27% (6/22) at mRNA level and 21% (4/19) at protein level. These data suggest that the CDKN2A gene is involved in the tumorigenesis of ovarian cancer, but the mechanisms of CDKN2A gene inactivation in serous papillary ovarian cancer remains unclear.

Auditory role of the suprabranchial chamber in gourami fish

Fish hearing specialists (e.g., goldfish, holocentrids, clupeoids, mormyrids) have evolved specialized structures (e.g., Weberian ossicles, swimbladder diverticulae, gas-filled bullae) to enhance their auditory frequency range and threshold sensitivity. The inner ears of anabantoid fish are encased in membranous cranial bones and are protruded into air-filled suprabranchial chambers. This research was intended to test the hypothesis that the gas bubbles inside the suprabranchial chambers may modulate the hearing abilities of anabantoid fish because of their proximity to the membranous bone-encased inner ears. Three species of gourami (blue gourami Trichogaster trichopterus; kissing gourami Helostoma temminckii; dwarf gourami Colisa lalia) were examined. Using the auditory brainstem response recording technique, baseline audiograms tested at 300, 500, 800, 1500, 2500, 4000 Hz were obtained. The air bubbles in the suprabranchial chambers were replaced by water, and the audiograms were remeasured. Thresholds were elevated in all three species. When three blue gouramis were allowed to replenish air into the suprabranchial chambers their hearing abilities returned to baseline levels. These results support the hypothesis that air bubbles in the suprabranchial chambers can affect hearing abilities of gouramis by lowering the thresholds.

Correlation between auditory sensitivity and vocalization in anabantoid fishes

Several anabantoid species produce broadband sounds with high-pitched dominant frequencies (0.8-2.5 kHz), which contrast with generally low-frequency hearing abilities in (perciform) fishes. Utilizing a recently developed auditory brainstem response recording-technique, auditory sensitivities of the gouramis Trichopsis vittata, T. pumila, Colisa lalia, Macropodus opercularis and Trichogaster trichopterus were investigated and compared with the sound characteristics of the respective species. All five species exhibited enhanced sound-detecting abilities and perceived tone bursts up to 5 kHz, which qualifies this group as hearing specialists. All fishes possessed a high-frequency sensitivity maximum between 800 Hz and 1500 Hz. Lowest hearing thresholds were found in T. trichopterus (76 dB re I microPa at 800 Hz). Dominant frequencies of sounds correspond with the best hearing bandwidth in T. vittata (1-2 kHz) and C. lalia (0.8-1 kHz). In the smallest species, T. pumila, dominant frequencies of acoustic signals (1.5-2.5 kHz) do not match lowest thresholds, which were below 1.5 kHz. However, of all species studied, T. pumila had best hearing sensitivity at frequencies above 2 kHz. The association between high-pitched sounds and hearing may be caused by the suprabranchial airbreathing chamber, which, lying close to the hearing and sonic organs, enhances both sound perception and emission at its resonant frequency.

Phosphoinositide 3-kinase in rat liver nuclei

Biochemical and immunochemical data from the present investigation reveal the existence of a p85/p110 phosphoinositide 3-kinase (PI 3-kinase) in rat liver nuclei. 32P-Labeling of membrane phosphoinositides by incubating intact nuclei with [gamma-32P]ATP results in the formation of [32P]phosphatidyl-inositol 3,4, 5-trisphosphate [PtdIns(3,4,5)P3], accompanied by small quantities of [32P]phosphatidylinositol 3-phosphate [PtdIns(3)P]. Studies with subnuclear fractions indicate that the PI 3-kinase is not confined to nuclear membranes. The nuclear soluble fraction also contains PI 3-kinase and an array of inositide-metabolizing enzymes, including phospholipase C (PLC), phosphoinositide phosphatase, and diacylglycerol (DAG) kinase. As a result, exposure of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] to the nuclear extract in the presence of [gamma-32P]ATP generates a series of 32P-labeled D-3 phosphoinositides and phosphatidic acid (PA) in an interdependent manner. On the basis of the immunological reactivity and kinetic behavior, the nuclear PI 3-kinase is analogous, if not identical, to PI 3-kinase alpha, and constitutes about 5% of the total PI 3-kinase in the cell. Moreover, we test the premise that nuclear PI 3-kinase may, in part, be regulated through the control of substrate availability by PtdIns(4,5)P2-binding proteins. Effect of CapG, a nuclear actin-regulatory protein, on PI 3-kinase activity is examined in view of its unique Ca2+-dependent PtdIns(4, 5)P2-binding capability. In vitro data show that the CapG-mediated inhibition of nuclear PI 3-kinase is prompted by PKC phosphorylation of CapG and elevated [Ca2+]. This CapG-dependent regulation provides a plausible link between nuclear PLC and PI 3-kinase pathways for cross-communications. Taken together, these findings provide definite data concerning the presence of an autonomous PI 3-kinase cycle in rat liver nuclei. The nuclear location of PI 3-kinase may lead to a better understanding regarding its functional role in transducing signals from the plasma membrane to the nucleus in response to diverse physiological stimuli.

A comparative study of hearing ability in fishes: the auditory brainstem response approach

Auditory brainstem response (ABR) techniques, an electrophysiological far-field recording method widely used in clinical evaluation of human hearing, were adapted for fishes to overcome the major limitations of traditional behavioral and electrophysiological methods (e.g., invasive surgery, lengthy training of fishes, etc.) used for fish hearing research. Responses to clicks and tone bursts of different frequencies and amplitudes were recorded with cutaneous electrodes. To evaluate the effectiveness of this method, the auditory sensitivity of a hearing specialist (goldfish, Carassius auratus) and a hearing generalist (oscar, Astronotus ocellatus) was investigated and compared to audiograms obtained through psychophysical methods. The ABRs could be obtained between 100 Hz and 2000 Hz (oscar), and up to 5000 Hz (goldfish). The ABR audiograms are similar to those obtained by behavioral methods in both species. The ABR audiogram of curarized (i.e., Flaxedil-treated) goldfish did not differ significantly from two previously published behavioral curves but was lower than that obtained from uncurarized fish. In the oscar, ABR audiometry resulted in lower thresholds and a larger bandwidth than observed in behavioral tests. Comparison between methods revealed the advantages of this technique: rapid evaluation of hearing in untrained fishes, and no limitations on repeated testing of animals.

Pharmacokinetics of bendazac lysine in 10 Chinese young men

AIM

To compare the pharmacokinetics of domestic and imported tablets of bendazao lysine (BL).

METHODS

A single oral dose of 500 mg BL of this 2 kinds of tablets was given to 10 Chinese volunteers of Han nationality in a randomized crossover study. Plasma levels were determined with HPLC-UV method. Data were analyzed automatically by using a CAPP program on microcomputer.

RESULTS

The plasma concentration-time curve was fitted to 2-compartment open model, and the major pharmacokinetic parameters of domestic and imported BL tablets were shown respectively as following: Cmax 66 +/- 16 and 65 +/- 8 mg.L-1; Tmax 0.98 +/- 0.22 and 0.98 +/- 0.21 h; T1/2 beta 6.2 +/- 1.8 and 6.2 +/- 1.7 h; AUC 335 +/- 47 and 337 +/- 58 mg.h.L-1. There was no significant difference between domestic and imported tablets. The bioavailability of the domestic vs that of the imported tablet was 99 +/- 12%. The unchanged BL in urine were about 5.4% and 5.6% respectively of the dosage in 24 h after a single oral dose.

CONCLUSION

The two kinds of tablets had the same biological effects.

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.

Hair cell heterogeneity in the goldfish saccule

A set of cytological studies performed in the utricle and saccule of Astronotus ocellatus (Teleostei, Percomorphi, Cichlidae) identified two basic types of hair cells and others with some intermediate characteristics. This paper reports on applying the same techniques to the saccule of Carassius auratus (Teleostei, Otophysi, Cyprinidae) and demonstrates similar types of hair cells to those found in Astronotus. Since Carassius and Astronotus are species of extreme taxonomic distance within the Euteleostei, two classes of mechanoreceptive hair cells are likely to represent the primitive condition for sensory receptors in the euteleost inner ear and perhaps in all bony fish ears.

Acoustic intensity discrimination by the cichlid fish Astronotus ocellatus (Cuvier)

The acoustic intensity discrimination ability of the oscar (Astronotus ocellatus), a cichlid fish, was investigated using an automated positive reward method. Intensity discrimination thresholds (delta I, in dB) for 7-s continuous pure tone signals were measured both as functions of sound intensity above thresholds, i.e., sensation levels, (SL)(+10 dB, +20 dB and +30 dB) and frequency (200 Hz, 500 Hz, and 800 Hz). delta I at 500 Hz for +10 dB, +20 dB, and +30 dB SLs are 8.9, 5.5, and 3.3 dB, respectively. delta I (at +20 dB SL) for 200 Hz, 500 Hz, and 800 Hz are 4.5, 5.5, and 9.3 dB, respectively. Despite having poor auditory sensitivity (narrow frequency range and high thresholds), the intensity discrimination ability of the oscar follows the general trends of previously studied fish species, however, with higher thresholds.

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.

Auditory sensitivity of the cichlid fish Astronotus ocellatus (Cuvier)

Auditory sensitivity was determined for the oscar, Astronotus ocellatus, a cichlid fish that has no known structural specializations to enhance hearing. Trained A. ocellatus behaviorally responded to sound stimuli from 200 Hz to 800 Hz with best sensitivity of 18 dB (re: 1 mubar) to 21 dB for frequencies between 200 and 400 Hz. This is significantly poorer than hearing sensitivity for fish classified as hearing specialists, but well within the range of hearing capabilities reported for non-specialist teleost species.

Histochemical and immunocytochemical identification of the pituitary cell types in three sciaenid fishes: Atlantic croaker (Micropogonias undulatus), spotted seatrout (Cynoscion nebulosus), and red drum (Sciaenops ocellatus)

The adenohypophysial cell types in three species of sciaenid teleosts were identified using a combination of classical histochemical techniques and immunocytochemistry with antisera raised against piscine and human pituitary hormones. In general greater specificity for the different cell types was observed with antisera to the piscine pituitary hormones than with antisera raised against the human hormones. The distribution of the cell types did not differ significantly among the three species, Atlantic croaker (Micropogonias undulatus), spotted seatrout (Cynoscion nebulosus), and red drum (Sciaenops ocellatus), and was similar to that reported in several other teleosts. A major portion of the rostral pars distalis was composed of acidophilic prolactin cells which showed specific binding to antisera to carp, coho salmon, and chinook salmon prolactins. The acidophilic corticotrops formed cords of cells which bordered the prolactin cells and showed strong immunoreactivity with anti-human ACTH. This antiserum also cross-reacted with the lead hematoxylin-positive cells in the pars intermedia. The acidophilic growth hormone cells were restricted to the dorsal part of the proximal pars distalis in close contact with the neurohypophysis and were specifically bound by anti-carp and anti-chum salmon growth hormone. The basophilic thyrotrops were located in the dorsal-anterior part of the proximal pars distalis and showed strong immunoreactivity to antiserum to the human thyrotropin beta subunit. This antiserum also bound weakly to the basophilic gonadotrops which were concentrated in the ventral part of the proximal pars distalis and also extended posteriorly to form a border around the pars intermedia. Antiserum to croaker maturational gonadotropin, which recognizes two distinct gonadotropins in sciaendis, bound strongly and specifically to the gonadotrops. The gonadotrops were also bound specifically by antisera to the alpha and beta subunits of human luteinizing hormone. Antisera to the beta subunits of two recently isolated coho salmon gonadotropins, GTH-I and GTH-II, failed to bind the gonadotrops strongly or differentially in the three sciaenid species. Consequently, the number of gonadotropin cell types in sciaenid fishes remains unresolved.

Electric organ discharge frequency and plasma sex steroid levels during gonadal recrudescence in a natural population of the weakly electric fish Sternopygus macrurus

1. Sternopygus macrurus were collected in Venezuela during the period of gonadal recrudescence in early or late dry season. Electric organ discharge (EOD) frequencies were recorded, blood samples were taken for analysis of steroid titers, and gonads were taken for determination of reproductive condition. 2. Mean EOD frequencies were significantly lower in males than in females in all samples. EOD frequency was inversely correlated with body length in males in late, but not early, dry season, and these parameters were never correlated in females. 3. Plasma levels of testosterone (T) and 11-ketotestosterone (11-KT), but not estradiol-17 beta (E2), were inversely correlated with EOD frequency in males. No 11-KT was observed in plasma of females, and plasma levels of T and E2 in females were comparable to those of males. Neither T nor E2 were correlated with EOD frequency in females. 4. Testes collected in late dry season were more mature than those from early dry season; androgen levels and EOD frequency were correlated with testicular maturity. Ovaries collected in early dry season were immature, while those from late dry season were more mature. There was no relationship between EOD frequency and stage of ovarian development. 5. These results suggest that plasma androgens modulate EOD frequency in males during the reproductive season and that plasma E2 has little relationship to EOD frequency in either sex.

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.

Ocular and cardiovascular pharmacology of tetramethylpyrazine isolated from Ligusticum wallichii Franch

Tetramethylpyrazine (TMP), the active principle in Ligusticum wallichii, D-timolol, and L-timolol were compared for their effects on retinal and choroidal blood flow (RCBF), blood pressure (BP), and heart rate (HR). TMP (10 mg.kg-1) increased RCBF by 44% and did not affect systemic BP or HR. D-Timolol (4 mg.kg-1 iv) had a tendency to increase RCBF but did not affect systemic BP and HR either. L-Timolol (0.4 mg.kg-1 iv), on the other hand, decreased RCBF by 18% and reduced both systemic BP and HR. In isolated preparations, TMP increased coronary artery blood flow with slight vasodilation, but vasoconstriction in renal, femoral and mesenteric arteries. These results indicate that TMP could be used to prevent or alleviate certain ischemic retinal degenerations without producing significant cardiovascular side effects. The in vitro vasoconstriction actions of TMP (0.2 mg.ml-1) were blocked by propranolol and phenoxybenzamine, indicating that adrenergic mechanism might be involved in TMP action.

Human chorionic gonadotropin-induced shifts in the electrosensory system of the weakly electric fish, Sternopygus

Sternopygus macrurus of both sexes were injected with human chorionic gonadotropin (hCG) or saline. Electric organ discharge (EOD) frequency rose after hCG injections in females and gradually declined to baseline levels over the next few weeks. EOD changes in males were more complex and variable; most males showed an initial minor rise in EOD frequency followed by a larger decrease, or simply a decrease. hCG treatment also resulted in a rise in electroreceptor best frequency and shortened electric organ pulse duration in females, and had the opposite effect on these parameters in males. The saline-injected controls showed no changes in any of these parameters. Levels of testosterone (T) and 11-ketotestosterone, but not estrogen (E), were elevated in males preceding the fall in EOD frequency, whereas neither T nor E changed significantly in females before EOD frequency increases. Saline injections caused a drop in T in the male control group and had no effect in the female control group. We presume that the effect of hCG on the electrosensory system of males is mediated via androgens. Whether the effects of hCG on females are mediated by slight increases in circulating levels of gonadal steroids, the release of hormones other than T or E, or are due to direct effects on the nervous system is not known.

Effects of L-timolol, D-timolol, haloperidol and domperidone on rabbit retinal blood flow measured with laser Doppler method

L-Timolol (0.4 mg/kg) reduced significantly retinal blood flow (17%), systemic blood pressure (18-20%) and heart rate (28%) in the rabbit. D-Timolol (4.0 mg/kg) increased retinal blood flow slightly (9%) and did not significantly affect systemic blood pressure or heart rate. Since D-timolol is effective in reducing intraocular pressure, these results indicate that D-timolol is superior to L-timolol for glaucoma treatment. Haloperidol and domperidone are dopamine antagonists, but, while haloperidol (0.1 mg/kg) suppressed retinal blood flow (16%), domperidone (0.2 mg/kg) increased it (12%). Neither of them affected blood pressure or heart rate significantly. While either of these given topically decreases intraocular pressure significantly, domperidone's ability to increase retinal blood flow makes it more useful than either haloperidol or L-timolol for treating glaucoma.

Effects of antiglaucoma drugs on the blood flow in rabbit eyes

Although it is essential that intraocular pressure (IOP) be reduced in glaucoma treatment, it is also vitally important to provide sufficient blood flow to eye tissues so that healthy visual field is maintained. It is possible for an agent to reduce IOP and blood supply to the eye. In that case, glaucoma appears to be under control since IOP has been reduced to within normal range, yet the disease is actually progressing, causing damage to the retina, optic nerve, and other tissues. The 85Sr-microsphere technique was used to study the effects of several antiglaucoma drugs on blood supply to various eye tissues. It was found that pilocarpine, L-timolol, D-timolol and haloperidol are good drugs to use in treating glaucoma because they do not reduce ocular blood flow. D-timolol is particularly good because it does not cause side effects through beta-adrenergic blockade or cholinergic stimulation. On the other hand, trifluperidol and moperone reduce IOP effectively, but also decrease blood supply.