Effect of cocaine on ion channels and glutamatergic EPSCs in noradrenergic locus coeruleus neurons

The locus coeruleus (LC) is an important brainstem area involved in cocaine addiction. However, evidence to elucidate how cocaine modulates the activity of LC neurons remains incomplete. Here, we performed whole recordings in brain slices to evaluate the effects of cocaine on the sodium (Na(+)), potassium (K(+)), calcium (Ca(2+)) channels, and glutamatergic synaptic transmission in the locus coeruleus neurons. Local application of cocaine significantly and reversibly reduced the spontaneous firing rate but did not affect action potential amplitude, rising time, decay time, or half width of noradrenergic locus coeruleus neurons. Moreover, cocaine attenuated the sodium current but did not affect potassium and calcium currents. The N-methyl-D-aspartate receptor mediated excitatory postsynaptic currents were reduced by neuropeptide galanin but not cocaine. All those data demonstrate that cocaine has inhibitory effect on the spontaneous activities and sodium current in locus coeruleus neurons. Therefore, neuromodulation of sodium channel in locus coeruleus neurons may play an important role in drug addiction.

Molecular characterization of the pseudorabies virus UL2 gene

A 948-bp sequence of the UL2 gene was amplified from the pseudorabies virus (PRV) Becker strain genome using polymerase chain reaction, and the gene identity was confirmed through further cloning and sequencing. Bioinformatic analysis indicated that the PRV UL2 gene encodes a putative polypeptide with 315-amino acid residues. Its encoding protein, designated UL2, has a conserved uracil-DNA glycosylase (UDG)_F1 domain, which is closely related to the herpesvirus UDG family and is highly conserved among its counterparts encoded by UDG genes. Multiple nucleic acid and amino acid sequence alignments suggested that the product of PRV UL2 has a relatively higher homology with UL2-like proteins of Alphaherpesvirinae than that of other subfamilies of Herpesviridae. In addition, phylogenetic analysis showed that PRV UL2 had a close evolutionary relationship with members of Alphaherpesvirinae, especially members of the genus Varicellovirus of bovine herpesvirus 1 and bovine herpesvirus 5. Antigen prediction indicated the presence of several potential B-cell epitopes in PRV UL2. In addition, secondary structure and 3-dimensional structure prediction revealed that PRV UL2 consisted predominantly of an α-helix. Taken together, these results provide molecular biological insight for the further study of the function and mechanism of UL2 during PRV infection.

Preparation and characterization of an antiserum against truncated UL54 protein of pseudorabies virus

Pseudorabies virus (PRV) early protein UL54 is a homolog of herpes simplex virus 1 immediate-early protein ICP27, which is a multifunctional protein essential for the virus replication. However, the precise role of the PRV UL54 protein in the virus life cycle is still poorly understood. To shed more light on this problem, we considered it essential to have available an antiserum specifically detecting this protein. Since it was known that a full-length UL54 protein is a too big molecule for efficient expression in prokaryotic systems, it was truncated from 1 to 66 N-terminal amino acids, fused to EYFP-His tag and expressed in Escherichia coli through an appropriate expression vector. The truncated protein was purified by Ni-NTA affinity chromatography and used for raising an antiserum in rabbits. Western blot analysis showed that this antiserum specifically recognized the purified truncated as well as full-length UL54 protein in PRV-infected cells. Immunofluorescence assay confirmed the latter finding and also demonstrated localization of this protein first in nucleoli and later in whole nuclei of PRV-infected cells. These results indicate that the prepared antiserum could serve as a valuable tool in further studies of PRV UL54 protein function.

Molecular cloning and characterization of the pseudorabies virus US1 gene

Using polymerase chain reaction, a 1050-bp sequence of the US1 gene was amplified from the pseudorabies virus (PRV) Becker strain genome; identification of the US1 gene was confirmed by further cloning and sequencing. Bioinformatics analysis indicated that the PRV US1 gene encodes a putative polypeptide with 349 amino acids. The encoded protein, designated PICP22, had a conserved Herpes_IE68 domain, which was found to be closely related with the herpes virus immediate early regulatory protein family and is highly conserved among the counterparts encoded by Herpes_IE68 genes. Multiple nucleic acid sequence and amino acid sequence alignments suggested that the product of PRV US1 has a relatively higher homology with ICP22-like proteins of genus Varicellovirus than with those of other genera of Alphaherpesvirinae. In addition, phylogenetic analysis showed that PRV US1 has a close evolutionary relationship with members of the genus Varicellovirus, especially Equid herpes virus 1 (EHV-1), EHV-4 and EHV-9. Antigen prediction indicated that several potential B-cell epitopes are located in PICP22. Also, subcellular localization analysis demonstrated that PICP22 is predominantly located in the cytoplasm, suggesting that it might function as a cytoplasmic-targeted protein.

1.86 W cw single-frequency 1319 nm ring laser pumped at 885 nm

A 1.86 W cw single-frequency 1319 nm laser was produced by using an 885 nm-pumped Nd:YAG crystal with a compact four-mirror ring cavity, for the first time to our knowledge. The Nd:YAG produced a slope efficiency of 21% and an optical-to-optical efficiency of 18% with respect to the absorbed diode pump power. A near-diffraction-limited beam with M(2)=1.2 was achieved under the maximum output power.

Antiserum to the recombinant truncated VP22 protein of herpes simplex virus type 1 that also recognizes full-length VP22

The herpes simplex virus type 1 (HSV-1) tegument protein VP22 encoded by the UL49 gene is essential for HSV-1 infection. However, its precise functions in the virus life cycle are unknown. A relatively important tool for disclosing these functions is an antiserum specifically detecting VP22 in the infected cell. To this end, a recombinant truncated VP22 protein consisting of C-terminal 45 aa fused to EYFP (enhanced yellow fluorescent protein) and His-tag was expressed in Escherichia coli, purified by the Ni2+-NTA affinity chromatography, and used for the preparation of antiserum in rabbits. Western blot and immunofluorescence assay showed that this antiserum specifically detected purified truncated VP22 as well as full-length VP22 in the HSV-1 infected cells. These results indicate that the prepared antiserum could serve as a valuable tool for further studies of VP22 functions.

The prevalence of cardiovascular risk factors in male patients who have lower urinary tract symptoms

OBJECTIVES

To assess the prevalence of cardiovascular risk factors in men presenting with lower urinary tract symptoms, and their possible correlation with the severity of such symptoms.

DESIGN

Retrospective cohort study.

SETTING

Specialty clinic, Hong Kong.

PATIENTS

A total of 617 men presenting with lower urinary tract symptoms between April 2005 and October 2006.

MAIN OUTCOME MEASURES

Presence of cardiovascular risk factors inferred from the prior and current medical and social history as well as physical examination and investigative findings, among patients with International Prostatic Symptom Scores of different severity.

RESULTS

Of 617 patients, 268 (43%) had known hypertension and 318 (52%) had a history of smoking. According to the World Health Organization criteria for Asian populations, 396 (64%) patients were considered to be overweight (body mass index > or =23 kg/m(2)). A total of 178 (29%) patients were either known to have or were diagnosed to have dysglycaemia during workup. For dyslipidaemia and hyperuricaemia, the corresponding figures were 331 (54%) and 191 (31%). In total, 264 (43%) patients were newly diagnosed as having dysglycaemia, dyslipidaemia, or hyperuricaemia. Logistic regression indicated that only hyperuricaemia and a smoking history were significant predictors of moderate-to-severe lower urinary tract symptoms (International Prostatic Symptom Score > or =8), with respective adjusted odds ratios of 2.20 (95% confidence interval, 1.12-4.31; P=0.022) and 2.11 (1.24-3.57, P=0.006). Patients with moderate-to-severe International Prostatic Symptom Scores had a statistically higher chance of having at least one cardiovascular risk factor during assessment (P=0.001).

CONCLUSIONS

Cardiovascular risk factors were prevalent in male patients who had lower urinary tract symptoms; a large portion of these cardiovascular risk factors were not recognised until their urological consultations. Patients with moderate-to-severe lower urinary tract symptoms (International Prostatic Symptom Score > or =8) had statistically higher chances of having more cardiovascular risk factors.

A sub-population of high proliferative potential-quiescent human mesenchymal stem cells is under the reversible control of interferon alpha/beta

Type I interferon (IFN) is shown to control the reversible quiescence of a primitive human bone marrow mesenchymal stem cell (MSC) subpopulation. A 24 h pre-treatment of Stro1+/GlycoA- or CD45-/GlycoA- subpopulations with a monoclonal antibody (mAb) against the IFNAR1 chain of the human type I IFN receptor (64G12), or with a polyclonal anti-IFNalpha antibody, resulted in a marked increase in the number of very large colonies (CFU-F >3000 cells) obtained in the presence of low, but necessary, concentrations of bFGF. Over a 2-month culture period, this short activation promoted a faster and greater amplification of mesenchymal progenitors for adipocytes and osteoblasts. Activation correlated with inhibition of STAT1 and STAT2 phosphorylation and of STAT1 nuclear translocation. A non-neutralizing anti-IFNAR1 mAb was ineffective. We demonstrate that control and activated MSCs express ST3GAL3, a sialyltransferase necessary to produce the embryonic antigens SSEA-3 and -4. Interestingly, activated MSC progeny expressed SSEA-3 and -4 at a higher level than control cultures, but this was not correlated with a significant expression of other embryonic markers. As MSCs represent an essential tool in tissue regeneration, the use of 64G12, which rapidly recruits a higher number of primitive cells, might increase amplification safety for cell therapy.

Adaptive segmentation of cerebrovascular tree in time-of-flight magnetic resonance angiography

Accurate segmentation of the human vasculature is an important prerequisite for a number of clinical procedures, such as diagnosis, image-guided neurosurgery and pre-surgical planning. In this paper, an improved statistical approach to extracting whole cerebrovascular tree in time-of-flight magnetic resonance angiography is proposed. Firstly, in order to get a more accurate segmentation result, a localized observation model is proposed instead of defining the observation model over the entire dataset. Secondly, for the binary segmentation, an improved Iterative Conditional Model (ICM) algorithm is presented to accelerate the segmentation process. The experimental results showed that the proposed algorithm can obtain more satisfactory segmentation results and save more processing time than conventional approaches, simultaneously.

α-Synuclein promoter RsaI T-to-C polymorphism and the risk of Parkinson’s disease

Increased alpha-synuclein expression may be involved in the pathogenesis of Parkinson's disease (PD). We investigated the association of Rep1 microsatellite and RsaI T-to-C substitution in the alpha-synuclein promoter region with the risk of PD by a case-control study. The RsaI C/C genotype and C allele were found less frequently in PD patients than in controls. A reduced risk of the Rep1-RsaI 0-C haplotype (OR = 0.57, 95% CI = 0.36-0.90) with PD was evident. The quantitative real-time PCR study showed that the alpha-synuclein mRNA expression was increased (although not significantly) in PD patients with RsaI T/T genotype or Rep1-RsaI 0-T haplotype as compared to T/C genotype or 0-C haplotype. Reporter constructs containing the RsaI C allele drove significantly lower transcriptional activity compared with the RsaI T allele in both IMR32 and 293 cells. The findings suggest that the RsaI T-to-C substitution may have a functional relevance to the susceptibility to PD.

Optoacoustic imaging with synthetic aperture focusing and coherence weighting

Optoacoustic imaging takes advantage of high optical contrast and low acoustic scattering and has found several biomedical applications. In the common backward mode a laser beam illuminates the image object, and an acoustic transducer located on the same side as the laser beam detects the optoacoustic signal produced by thermoelastic effects. A cross-sectional image is formed by laterally scanning the laser beam and the transducer. Although the laser beam width is generally narrow to provide good lateral resolution, strong optical scattering in tissue broadens the optical illumination pattern and thus degrades the lateral resolution. To solve this problem, a combination of the synthetic aperture focusing technique with coherence weighting is proposed. This method synthesizes a large aperture by summing properly delayed signals received at different positions. The focusing quality is further improved by using the signal coherence as an image quality index. A phantom comprising hair threads in a 1% milk solution was imaged with an optoacoustic imaging system. The results show that the proposed technique improved lateral resolution by 400-800% and the signal-to-noise ratio by 7-23 dB over conventional techniques.

Genetic testing in spinocerebellar ataxia in Taiwan: expansions of trinucleotide repeats in SCA8 and SCA17 are associated with typical Parkinson's disease

DNA tests in normal subjects and patients with ataxia and Parkinson's disease (PD) were carried out to assess the frequency of spinocerebellar ataxia (SCA) and to document the distribution of SCA mutations underlying ethnic Chinese in Taiwan. MJD/SCA3 (46%) was the most common autosomal dominant SCA in the Taiwanese cohort, followed by SCA6 (18%) and SCA1 (3%). No expansions of SCA types 2, 10, 12, or dentatorubropallidoluysian atrophy (DRPLA) were detected. The clinical phenotypes of these affected SCA patients were very heterogeneous. All of them showed clinical symptoms of cerebellar ataxia, with or without other associated features. The frequencies of large normal alleles are closely associated with the prevalence of SCA1, SCA2, MJD/SCA3, SCA6, and DRPLA among Taiwanese, Japanese, and Caucasians. Interestingly, abnormal expansions of SCA8 and SCA17 genes were detected in patients with PD. The clinical presentation for these patients is typical of idiopathic PD with the following characteristics: late onset of disease, resting tremor in the limbs, rigidity, bradykinesia, and a good response to levodopa. This study appears to be the first report describing the PD phenotype in association with an expanded allele in the TATA-binding protein gene and suggests that SCA8 may also be a cause of typical PD.

Hippocampal atrophy and T2-weighted signal changes in familial mesial temporal lobe epilepsy

OBJECTIVE

To correlate the clinical phenotype with hippocampal volumes (HcVs) and signal changes in patients with familial mesial temporal lobe epilepsy (FMTLE).

METHODS

FMTLE was defined when at least two first-degree relatives in a family had a clinical-EEG diagnosis of MTLE. Hippocampal formation measurements were performed using 1- to 3-mm coronal T1-weighted MRIs. The presence of hyperintense T2 signal was evaluated by visual analysis. For statistical analyses, analysis of variance, chi(2) test, and regression analysis were used.

RESULTS

A total of 142 patients from 45 unrelated families were studied: 113 individuals with MTLE (80 with good seizure control) and 29 family members with other seizure types. There were 99 patients (69.7%) with hippocampal atrophy (HA). Sixty-seven of the 99 patients with HA also had a hyperintense T2 signal. Hyperintense T2 signal was associated with more severe HA (p = 0.04). Patients with refractory FMTLE had more frequent HA (p = 0.03) and hyperintense T2 signal (p = 0.004) and more severe atrophy (p < 0.0001). Duration of epilepsy correlated with HcV asymmetry index (r(2) = 0.12, p = 0.00008) and with the more atrophic hippocampi but not with contralateral hippocampi.

CONCLUSION

In familial mesial temporal lobe epilepsy, seizure severity is variable in affected individuals. Hippocampal atrophy was present in 70% of these patients and 69% of these had an associated hyperintense T2 signal. Although hippocampal atrophy associated with abnormal T2 signal was more frequent and more severe in patients with poor seizure control, it was also frequent in affected individuals across families. These observations suggest that one or more genes resulting in familial mesial temporal lobe epilepsy predisposes both to the clinical features of mesial temporal lobe epilepsy and to the development of hippocampal sclerosis.

In vitro anti-influenza virus activity of synthetic humate analogues derived from protocatechuic acid

Two humic-like substances, the oxidative polymer of protocatechuic acid (OP-PCA) and humic acid inhibit the in vitro replication of influenza virus A/WSN/33 (H1N1) in Madin-Darby canine kidney (MDCK) cells at concentrations of no cytotoxicity. The 50% inhibitory concentration (IC50) for OP-PCA was 6.59 +/- 1.02 microg/ml when the compound was added at the stage of viral adsorption. When OP-PCA was added after virus adsorption, the IC50 was 53.27 +/- 8.12 microg/ml. The IC50 for humic acid was 48.61 +/- 7.32 microg/ml and 55.27 +/- 5.46 microg/ml respectively when the compound was added at the stage of viral adsorption or post-adsorption. In spite of structural resemblance of these two compounds, they exhibit different actions of anti-flu. The OP-PCA inhibits virus-induced hemagglutination and low pH-induced cell-cell fusion. Humic acid inhibits the endonuclease activity of viral RNA polymerase. The monomer of PCA shows no inhibition on influenza virus replication.

Iatrogenic pheochromocytomatosis: a previously unreported result of laparoscopic adrenalectomy

BACKGROUND

Laparoscopic adrenalectomy is now regarded as the procedure of choice for treatment of small or benign adrenal tumors, including pheochromocytoma. However, long-term outcomes have not been critically assessed. We report here 3 cases of pheochromocytomatosis recurring 3 to 4 years after laparoscopic adrenalectomy. We postulate laparoscopic-induced seeding of tumor as the mechanism of recurrence.

METHODS

We retrospectively reviewed the cases of 3 patients with documented biochemical and radiolabeled metaiodobenzylguanidine evidence of recurrent pheochromocytoma after prior presumed curative laparoscopic adrenalectomy.

RESULTS

Original pheochromocytomas were 5.5 to 6.5 cm in diameter. At the time of laparoscopic adrenalectomy, tumors were not believed to be malignant, based on clinical or histopathologic data. However, on 3- to 4-year follow-up, each patient developed symptoms, elevated urinary catecholamine levels, and metaiodobenzylguanidine imaging consistent with recurrence. At reoperation, multiple small tumor nodules were found in the adrenal bed near the site of the initial laparoscopic resection. The original operative notes suggested some possible method of local seeding: tumor fragmentation and spillage or excessive tumor manipulation.

CONCLUSIONS

Pheochromocytoma recurrence may occur as a result of local spillage of tumor during laparoscopic adrenalectomy. The relative risk of recurrence between open and laparoscopic resection needs to be assessed. Long-term follow-up will continue to be important, regardless of operative approach.

Elastic properties of tendon measured by two different approaches

Elastic properties of tendon were assessed by two different approaches. Six fresh bovine Achilles tendon specimens were used. The first approach directly measured Young's modulus along the transverse direction (E(perpendicular)) and the longitudinal direction (E(parallel)), using a cyclic compression-relaxation method. Young's moduli were derived based on the measured strain and stress values. The ratio of E(parallel): E(perpendicular) at smaller strains was around 4 and decreased to 0.6 approximately 1.1 at larger strains. The second approach assumed that tendons are transversely isotropic. Three observable second-order elastic stiffness constants (c(11), c(13) and c(33)) were obtained by sound speed measurements along various propagation directions. The measured elastic stiffness constants were also correlated with results from the first approach. It was shown that the transverse isotropy assumption was valid at small strains. However, a significant discrepancy existed between the two approaches. The discrepancy was primarily due to viscoelasticity associated with the first approach.

Cytotoxic 7,20-epoxy ent-kauranoids from Isodon xerophilus

Four 7,20-epoxy ent-kaurane diterpenoids, xerophilusins G (1) and I-K (2-4), were isolated from the leaves of Isodon xerophilus, along with four known ones, enanderianin C (5), rosthorin A (6), longikaurin B (7), and rabdoternin D (8). Their structures were determined primarily using NMR spectroscopic techniques. The structure and stereochemistry of 3 were confirmed by X-ray crystallography. Compounds 4 and 7 exhibited broad cytotoxicity against four kinds of human tumor cells (K562, HL-60, HCT, and MKN-28 cells) in the range of 2.23-15.35 and 0.30-8.61 microg/ml, respectively.

Gastrinoma

Gastrinoma treatment has evolved considerably in the last 20 years. In particular, the advent of effective acid-reducing pharmacologic agents has changed the primary morbidity of this disease entity from one of acid hypersecretion to one of tumor growth and spread. Thus, while symptoms can be temporized using histamine receptor antagonists, proton pump inhibitors, or somatostatin analogs, cure can be effected only by surgical means. Recent advances in operative techniques and pre- and intra-operative imaging studies, including routine duodenotomy, somatostatin-receptor scintigraphy, and intraoperative ultrasound, have allowed for identification and subsequent resection of more than 95% of gastrinoma tumors. Most experts agree that all sporadic cases of localized gastrinoma should be excised. In addition, debulking of metastatic tumor may improve symptoms and survival when cure cannot be ascertained. There is, however, some controversy as to the surgical approach for gastrinoma found in the setting of multiple endocrine neoplasia, type 1. Because of the usual multiplicity and particular indolence of these tumors, two primary strategies have emerged: aggressive approaches have been advocated in an effort to eradicate all present and potential tumor; and less aggressive, or nonoperative, approaches have been suggested because it is unclear whether intervention offers survival or disease-free benefit in this population. We advocate surgical intervention for patients with gastrinoma and multiple endocrine neoplasia, type 1 when tumors exceed 2.5 cm in size. This tumor size has been associated with a higher likelihood of hepatic metastases, which ultimately affects survival. The role of adjuvant therapies for gastrinoma remains limited.

Filter-based synthetic transmit and receive focusing

Most diagnostic ultrasonic imaging systems perform fixed focusing on transmit and dynamic focusing on receive. Such systems suffer from image quality degradation at depths away from the transmit focal zone. Several dynamic transmit focusing techniques have been previously investigated. Among them, a filter-based, retrospective focusing technique was proposed to increase the length of the transmit focal zone. In this paper, the filter-based technique is extended from dynamic receive focusing to fixed receive focusing. It is shown that the filtering technique with fixed receive focusing can achieve an image quality similar to that of dynamic receive focusing with filtering. The performance of the proposed approach is verified using real ultrasound data. It is shown that the proposed approach with fixed receive focusing requires a longer filter than that with dynamic receive focusing. Nonetheless, system complexity is greatly reduced with synthetic transmit and receive focusing because the dynamic receive focusing circuit is no longer needed.

Pharmacological determinants of 9-aminocamptothecin cytotoxicity

The camptothecins are a group of anticancer agents with a unique mechanism of action: poisoning of eukaryotic DNA topoisomerase I. 9-aminocamptothecin (9-AC), a potent water-insoluble derivative of camptothecin, is currently undergoing clinical testing. The kinetics of the active derivative 9-AC lactone in cell culture media was defined, and then 9-AC cytotoxicity against human breast (MCF-7), bladder (MGH-U1), and colon (HT-29) cancer cell lines was studied. The relationship between cytotoxic effects, drug concentration, and exposure time was then explored. For all of the three cell lines, 9-AC cytotoxicity increased with both higher drug concentrations and longer exposure times. However, when the duration of exposure was less than 24 h, cytotoxicity was limited and less than 1 log of cell killing occurred, even with very high drug concentrations. Minimal cell killing was also observed unless 9-AC concentrations exceeded a threshold of 2.7 nM. No fixed relationship between the survival fraction and the area under the drug concentration-time curve could be modeled that would fit all of the three cell lines. However, data for the three cell lines from the multiple exposure time experiments were fitted very well to the pharmacodynamic model C(n)t = k (r2, 0.90-0.99), where C is the drug concentration, n is the drug concentration coefficient, and t is the exposure time. For the three cell lines, to kill 1 log of cells, 0.30 < n < 0.85, which indicated that duration of exposure was more important than concentration. Our data support the use of 9-AC by infusion for 24 h or longer in clinical studies providing target plasma concentrations can be achieved.

Basilar artery aneurysm: an unusual cause of intractable hiccups

A70-year-old retired lorry driver was admitted as an emergency with a 2-day history of moderate amount of haematemesis, nausea, vomiting and intractable hiccups. He was a known hypertensive and 5 years previously had an episode of subarachnoid haemorrhage. Complications required the insertion of a Rickman reservoir shunt. Since the time of the subarachnoid haemorrhage, his hiccups had been almost constant despite taking chlorpromazine tablets 25 mg three times a day.

On examination, he had intractable hiccups. Cardiovascular, respiratory and abdominal examination were normal. Neurological examination revealed a right-sided partial third nerve palsy (with ptosis and pupillary sparing). He also had a right-sided squint operation during childhood. More detailed examination of the cranial nerves revealed mild right-sided glossopharyngeal and hypoglossal nerve palsies. Routine full blood count, blood biochemistry, chest X-ray and abdominal ultrasound scan were normal. Upper gastrointestinal endoscopy revealed a hiatus hernia with mild oesophagitis. He was started on omeprazole.

In view of the neurological findings and past history of subarachnoid bleed, a magnetic resonance imaging brain scan was performed. This revealed a large basilar artery aneurysm with a significant mass effect on the brainstem at the level of the border of fourth ventricle (Figures 1–3).

Alternative drug treatment in the form of nifedipine 10 mg three times a day was initiated instead of chlorpromazine and the hiccups resolved completely. On follow-up in the clinic a few months later, there was no recurrence of the hiccups.

[The regulating mechanism of anti-fungicides on mouse oocyte development]

AIM

To study the mechanism of the effect of gonadotropin-induced oocyte maturation.

METHODS

Mouse oocytes were cultured in HX-medium, and the effects of amphotericin B and ketoconazole on resumption of meiosis of mouse oocyte were examined.

RESULTS

1. FSH(10-200 IU/L) induced a dose-dependent manner of oocytes maturation in CEO. A maximum increase in GVBD was observed with 25-50 IU/L FSH. 2. Amphotericin tericim B (0.025-2.5 micrograms/L) caused significant increases in GVBD in CEO, which mimicked the function of FSH. 3. Ketoconazole (10(-7)-10(-3) mol/L) inhibited the effect of FSH on resumption of meiosis, but no effect on oocyte spontaneous maturation.

CONCLUSION

Amphotericin B and ketoconazole are able to affect mouse oocyte maturation, and indicates that they have a regulation on FSH-induced synthesis of meiosis-activating sterol.

New 7,20:14,20-diepoxy ent-kauranoids from Isodon xerophilus

Three new 7,20:14,20-diepoxy-ent-kaurane diterpenoids, xerophilusins A-C (1-3), together with a known one, macrocalin B (4), were isolated from the leaves of Isodon xerophilus. Their structures were elucidated on the basis of their spectral properties and X-ray crystallographic analysis. Compounds 1, 2, and 4 showed significant cytotoxic activity against K562, HL-60, and MKN-28 cells.