Effects of lipopolysaccharides on TLR4 expression in INS-1 rat insulinoma cells

The aim of the study was to obtain insight into the mechanism of sepsis-induced hyperglycemia, to explore the expression of Toll-like receptor 4 (TLR4) on INS-1 cells, the effects of lipopolysaccharide (LPS) on TLR4 expression and cell viability. The expression of TLR4 on INS-1 was detected by both RT-PCR and Western blot assays. After being intervened by LPS of various concentrations (0.01, 0.1, 1, 5, 10mg/L) for a certain time, the effects of LPS on TLR4 expression and cell viability were detected by quantitative real-time reverse-transcriptase polymerase chain reaction, western blotting and CCK-8 assay. Then INS-1 cells were stimulated by LPS (0.1, 1mg/L) together with anti-TLR4 antibody, cell viability and TLR4 expression were detected again. TLR4 expressed in INS-1 cell line. Its expression was up-regulated by the stimulation of LPS higher than 0.1mg/L for 12h (P<0.05). However, there was a little down-regulation of TLR4 between the LPS treated groups and controls with further LPS treatment for 24 and 48 h (P>0.05). In certain concentrations(0.1~10mg/L), viability of INS-1 cells was inhibited by LPS in a dose dependent manner (P<0.05) These effects could be blocked by anti-TLR4 antibody partially. These results suggest that LPS may act directly on the pancreatic β cells via TLR4 on the β-cell membrane. LPS increased TLR4 expression in the early short period of time and caused injury to INS-1 cells after a certain time. It could be one of the mechanisms that hyperglycemia occurs in the early stage of sepsis.

Differentiation of bone marrow-derived mesenchymal stem cells into hepatocyte-like cells in an alginate scaffold

OBJECTIVES

Alginate scaffolds are the most frequently investigated biomaterials in tissue engineering. Tissue engineering techniques that generate liver tissue have become important for treatment of a number of liver diseases and recent studies indicate that bone marrow-derived stem cells (BMSCs) can differentiate into hepatocyte-like cells. The goal of the study described here, was to examine in vitro hepatic differentiation potential of BMSCs cultured in an alginate scaffold.

MATERIALS AND METHODS

To investigate the potential of BMSCs to differentiate into hepatocyte-like cells, we cultured BMSCs in alginate scaffolds in the presence of specific growth factors including hepatocyte growth factor, epidermal growth factor and fibroblast growth factor-4.

RESULTS

We can demonstrate that alginate scaffolds are compatible for growth of BMSCs and when cultured in alginate scaffolds for several days they display several liver-specific markers and functions. Specifically, they expressed genes encoding alpha-foetoprotein, albumin (ALB), connexin 32 and CYP7A1. In addition, these BMSCs produced both ALB and urea, expressed cytokeratin-18 (CK-18) and were capable of glycogen storage. Percentage of CK-18 positive cells, a marker of hepatocytes, was 56.7%.

CONCLUSIONS

Our three-dimensional alginate scaffolds were highly biocompatible with BMSCs. Furthermore, culturing induced their differentiation into hepatocyte-like cells. Therefore, BMSCs cultured in alginate scaffolds may be applicable for hepatic tissue engineering.

Storage and recall of weak coherent optical pulses with an efficiency of 25%

We demonstrate experimentally an efficient coherent rephasing scheme for the storage and recall of weak coherent light pulses in an inhomogeneously broadened optical transition in a Pr(3+):YSO crystal at 2.1 K. Precise optical pumping using a frequency stable (≈1  kHz linewidth) laser is employed to create a highly controllable atomic frequency comb structure. We report single photon level storage and retrieval efficiencies of 25%, based on coherent photon-echo-type reemission in the forward direction. The high efficiency is mainly a product of our highly controllable and precise ensemble-shaping technique. The coherence property of the quantum memory is proved through interference between a super-Gaussian pulse and the emitted echo.

Prognostic Value of Protease-Activated Receptor 2 Expression in Oesophageal Squamous Cell Carcinoma

Protease-activated receptor-2 (PAR-2) is essential for the initiation and development of tumours, suggesting that the detection of PAR-2 expression might serve as a clinical marker in the prediction or diagnosis of clinical outcomes of malignant neoplasia. Using immunohisto chemical methods, this study investigated whether the detection of PAR-2 protein had clinical implications for patients with oesophageal squamous cell carcinoma (OSCC). PAR-2 protein was present at a high level in primary OSCC sites but at a low level in normal oesophageal tissue. The level of PAR-2 protein in tumours was significantly correlated with the clinical stage and histological grade of disease. Patients with tumours highly positive for PAR-2 protein had a significantly worse prognosis than those with lower PAR-2 levels. Thus, the over-expression of PAR-2 is a characteristic feature of OSCC and suggests that the immuno histochemical detection of raised levels of PAR-2 may be a potentially useful prognostic indicator.

Ulysses radio and plasma wave observations in the jupiter environment

The Unified Radio and Plasma Wave (URAP) experiment has produced new observations of the Jupiter environment, owing to the unique capabilities of the instrument and the traversal of high Jovian latitudes. Broad-band continuum radio emission from Jupiter and in situ plasma waves have proved valuable in delineating the magnetospheric boundaries. Simultaneous measurements of electric and magnetic wave fields have yielded new evidence of whistler-mode radiation within the magnetosphere. Observations of aurorallike hiss provided evidence of a Jovian cusp. The source direction and polarization capabilities of URAP have demonstrated that the outer region of the lo plasma torus supported at least five separate radio sources that reoccurred during successive rotations with a measurable corotation lag. Thermal noise measurements of the lo torus densities yielded values in the densest portion that are similar to models suggested on the basis of Voyager observations of 13 years ago. The URAP measurements also suggest complex beaming and polarization characteristics of Jovian radio components. In addition, a new class of kilometer-wavelength striated Jovian bursts has been observed.

Dose-Dense (dd) Doxorubicin and Cyclophosphamide (AC) Followed by Weekly Paclitaxel (P) with Trastuzumab (T) and Lapatinib (L) in Early Breast Cancer (EBC); Troponin I and C-Reactive Protein as Biomarkers of Cardiotoxicity

BackgroundThe early detection of cardiotoxicity and congestive heart failure (CHF) from anthracyclines and anti-HER2 agents is currently limited to measuring changes in left ventricular ejection fraction (LVEF) at arbitrary time points. This approach has limited sensitivity and specificity and has led to the investigation of putative biomarkers such as cardiac Troponin I (TnI), a highly specific marker of myocardial damage and C-reactive protein (CRP), a sensitive inflammatory marker. In a pre-planned analysis we investigated these as biomarkers of cardiotoxicity within a prospective study testing the feasibility of ddAC- followed by weekly P with T and L.Materials and MethodsPatients (pts) with HER2+ EBC enrolled at MSKCC and DF/HCC and received ddAC (A 60mg/m2 + C 600mg/m2) x 4 → weekly P (80mg/m2) x 12 + T + L (1000mg/day). T+L continued for a total of 1yr. At baseline pts had LVEF ≥50%. Pts with unstable angina, CHF, recent MI, uncontrolled arrhythmia, grade 3 QT prolongation were excluded. LVEF was assessed by MUGA scan at mths 0, 2, 6, 9 and 18. TnI and CRP were measured every 2 wks right before treatment (Rx) during ddAC-PTL, then at mths 6, 9 and 18. TnI was categorized as “undetectable” (&lt; 0.06 ng/ml; MSKCC, &lt;0.04 ng/ml; DF/HCC), “minimally elevated” (&lt;0.31 ng/ml) and “elevated” (&gt;0.31ng/ml). Elevated CRP was defined as (&gt;0.8mg/dl; MSKCC, &gt;0.3mg/dl; DF/HCC). Investigators were blinded to these results until pts completed 18mth follow-up (F/U).ResultsFrom Apr 07- Apr 08, 95 pts were enrolled; 39/95 (41%) withdrew due to PTL toxicities (incl. 3 with asymptomatic LVEF (aLVEF) declines and 3 with CHF). Final biomarker results were available in 84 pts (88%) and 11 pts (12%) continue on study. During Rx, minimal elevations in TnI occurred in 55 pts (65%). One pt had ↑TnI above normal range with AC#4; MUGA 1 wk later was unchanged (LVEF 75%), but she died from sepsis during subsequent Rx without evidence of CHF. Elevations in TnI occurred only during chemoRx and no pt had a ↑TnI during TL or at 18mth F/U. Of 55pts with elevated TnI, 25 (45%) had aLVEF declines (3 ↓ ≥16%, 10 ↓ 10-15%, 12 ↓ 5&lt;10%). Of 29 pts with undetectable TnI, 7 (24%) had aLVEF declines (1 ↓ ≥16%, 4 ↓ 10-15%, 2↓ 5&lt;10%). Elevations in CRP occurred in 61/84 (73%) pts during chemoRx but only in 22 (26%) during TL or at 18mth F/U. Three pts discontinued Rx for aLVEF ↓ at mths 4, 5 and 7 respectively; 2 (66%) had rises in CRP and 2 had minimal elevation in TnI. Three pts developed CHF at mths 3, 6, and 12 respectively, all had rises in CRP; 1 pt had a single ↑TnI of 0.08 ng/ml during chemoRx, and 2pts had no ↑TnIs.ConclusionsIn pts receiving ddAC-PTL fluctuations in TnI and CRP are common but do not persist after chemoRx (during TL). These biomarkers do not appear to predict for CHF. One possibility is that the timing of the drawing of these biomarkers (immediately preceding the specified treatment cycle and after Rx completion) may have been suboptimal. We plan to assess for potential biomarkers by assessing both immediately preceding and following therapy in a planned trial. Updated results will be presented.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3088.

Nonlinear development of shocklike structure in the solar wind

We report first in situ multispacecraft observations of nonlinear steepening of compressional pulses in the solar wind upstream of Earth's bow shock. The magnetic field of a compressional pulse formed at the upstream edge of density holes is shown to suddenly break and steepen into a shocklike structure. During the early phase of development thermalization of ions is insignificant. Substantial thermalization of ions occurs as gyrating ions are observed at the steepened edge. These observations indicate that the mechanisms causing the dissipation of magnetic fields (currents) and ions are different in the early phase of shock development.

Use of BIBW 2992, a novel irreversible EGFR/HER2 tyrosine kinase inhibitor (TKI), to treat patients with HER2-positive metastatic breast cancer after failure of treatment with trastuzumab

1023

Background: BIBW 2992 (Tovok) is an oral, novel, and potent, irreversible dual epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor-2 (HER2) inhibitor, with preclinical activity in trastuzumab-resistant cell lines overexpressing HER2 and phase I clinical activity. A phase II study of BIBW 2992 in patients with HER2-positive breast cancer who have failed treatment with trastuzumab is currently being conducted in the US and the UK. Methods: This is a multi-institutional open label single arm phase II study, planning to recruit 40 patients. Eligibility criteria include stage IIIB or IV HER2-positive metastatic breast cancer, progression following receipt of trastuzumab or intolerance of trastuzumab, measurable disease, Eastern Cooperative Oncology Group (ECOG) performance status of 0–2 and adequate organ function. Patients receive 50 mg BIBW 2992 once daily until disease progression. Tumor assessments are performed every two courses (one course = 28 days). The primary endpoint is objective response rate (RECIST criteria). Safety data are also collected. Results: To date, 40 patients have started treatment on the trial. Patients had received a median of three lines of prior therapy. Nine patients discontinued treatment prior to the first assessment at 8 weeks; four due to disease progression, four due to adverse events and one due to withdrawal of consent. Twenty-one patients have had tumor assessment after 8 weeks of treatment. Of these, four patients had a partial response (PR) and 10 patients had stable disease (SD). The PR has been confirmed at 16 weeks in one patient. The most frequently observed side effects to date are rash (Common Toxicity Criteria for Adverse Events [CTCAE] grade 3 in 4 patients) and diarrhea (CTCAE grade 3 in 8 patients). There were 20 dose reductions in 17 patients. Conclusions: BIBW 2992 at 50 mg/day induced responses and seems promising in HER2-positive breast cancer patients who have failed treatment with trastuzumab. Manageable cutaneous adverse events and diarrhea were the main side effects.

[Table: see text]

Dose-dense (DD) doxorubicin and cyclophosphamide (AC) followed by weekly paclitaxel (P) with trastuzumab (T) and lapatinib (L) in HER2/neu-positive breast cancer is not feasible due to excessive diarrhea: updated results

Abstract #2108

Background: DD q 2 weekly (w) AC → P + T x 1 year (y) has an acceptable safely profile w/ congestive heart failure (CHF) rate of 1/70 pts (Dang, JCO 2008). Lapatinib (L) is effective in HER2 (+) BC. We conducted a pilot study of dd AC → w P + T + L to determine its feasibility and cardiac safety.&#x2028; Methods: Enrolled pts had HER2 (+) BC; LVEF &gt; 50%. Rx consisted of AC at 60/600 mg/m2 x 4 q 2 w (w/ pegfilgrastim 6 mg day 2) → P at 80 mg/m2 x 12 q w + T x 1 y; L (1000 mg daily beginning w/ P + T and continued x 1 y). MUGA is obtained at baseline and at months (mo) 2, 6, 9, and 18. Rx is considered feasible if 1) &gt; 80% pts can complete the PTL phase without a dose delay or reduction and 2) the cardiac event rate (CHF or cardiac death) is &lt; 4%. Pts can remain on-Rx w/ one dose reduction of L (1000 mg → 750 mg) for a G 3 event or &lt; G 3 toxicity (unacceptable).&#x2028; Results: From March 2007 to April 2008, we enrolled 95 pts. Median (med) age was 45 years (range, 28-73). At a med follow-up of 7 months, 90 are evaluable. Of the 90 pts, 34 (37%) withdrew from study during the PTL phase; 29 for a 2nd event of G 3 or unacceptable &lt; G 3 toxicities (15 G 3 diarrhea, 4 G 1/2 diarrhea, 1 G 3 rash, 2 G 2 rash, 1 G 3 dyspnea and also had G 3 diarrhea, 1 G 3 ↑QTc also had G 3 diarrhea, 1 G 3 ↑ALT also had G 3 diarrhea, 1 G 3 paronychia, 1 G 3 pneumonitis, 1 asymptomatic LVEF ↓, 1 myocarditis) and 5 for other reasons (2 personal reason, 1 PCP pneumonia, 1 progression, 1 P hypersensitivity). Overall, 25/90 (27%) pts had G 3 diarrhea and 31/90 (34%) pts required a dose reduction of lapatinib. Med LVEF at baseline is 67% (N=95), at mo 2 is 68% (N=90), at mo 6 is 65% (N=53), and mo 9 is 65% (N=28). To date there are no patient drop-outs due to significant LVEF declines after dd AC; one patient dropped during PTL out due to an asymptomatic LVEF decline.&#x2028; Discussion: L at 1000 mg/day is not feasible combined w/ weekly P and T by protocol stipulation (&gt; 20% pts required L dose reduction) primarily due to excessive G 3 diarrhea. These results have led to the modification of Design 2 (Arm D) of ALTTO. We will report updated results.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2108.

Current status of thalassemia in minority populations in Guangxi, China

Thalassemia is one of the most common monogenic disorders in the world. In order to develop a community-based prevention program, we screened 12,900 individuals for alpha- and beta-thalassemia in Baise City, Guangxi, China, with hematological methods and molecular assays. We found that the frequency of carriers in this area for alpha-thalassemia is 15%. Beta-thalassemia carriers comprise 4.8% of the populations. Five mutations account for 98% of alpha-thalassemia [--SEA 46.7%; -alpha/4.2, 23.9%; -alpha/3.7, 21.7%; hemoglobin (Hb) Constant Spring, 6.5%; Hb Quong Sze, 1.1%]. Seven mutations in the beta-globin gene account for 99% of the mutations [codon (CD) 41/42 (-TCTT) (39.4%), CD 17(A-->T) (32%), CD 71/72 (+A) (7.4%), -28 (A-->G) (5.8%), IVS-2-654 (C-->T) (5.8%), CD26 (Hb E) (4%), IVS-1 (G-->A) (3.7%), and CD 43(G-->T) (1.9%)]. Most individuals with alpha-thalassemia major die in the uterus or shortly after birth. Among 106 patients with beta-thalassemia major followed by our clinic, the majority died before 5 years of age. Knowledge surveys about thalassemia were conducted. Our results show a severe lack of knowledge about thalassemia in both medical professionals and in the general populations. This study shows that thalassemia is a very severe public health issue in minority populations in Baise City, China. Identification of the common mutations will allow us to design cost-effective molecular tests. There is an urgent need to educate the general population and the medical community for a successful community-based prevention program.

Solitary electromagnetic pulses detected with super-Alfvénic flows in Earth's geomagnetic tail

Solitary nonlinear (deltaB/B>>1) electromagnetic pulses have been detected in Earth's geomagnetic tail accompanying plasmas flowing at super-Alfvénic speeds. The pulses in the current sheet had durations of approximately 5 s, were left-hand circularly polarized, and had phase speeds of approximately the Alfvén speed in the plasma frame. These pulses were associated with a field-aligned current J(parallel) and observed in low density (approximately 0.3 cm(-3)), high temperature (T(e) approximately T(i) approximately 3x10(7) K), and beta approximately 10 plasma that included electron and ion beams streaming along B. The wave activity was enhanced from below the ion cyclotron frequency to electron cyclotron and upper hybrid frequencies. The detailed properties suggest the pulses are nonlinearly steepened ion cyclotron or Alfvén waves.

Dendritic plasticity of CA1 pyramidal neurons after transient global ischemia

Dendrites and spines undergo dynamic changes in physiological conditions, such as learning and memory, and in pathological conditions, such as Alzheimer's disease and epilepsy. Long-term dendritic plasticity has also been reported after ischemia/hypoxia, which might be compensatory effects of surviving neurons for the functional recovery after the insults. However, the dendritic changes shortly after ischemia, which might be associated with the pathogenesis of ischemic cell death, remain largely unknown. To reveal the morphological changes of ischemia-vulnerable neurons after ischemia, the present study investigated the alteration of dendritic arborization of CA1 pyramidal neurons in rats after transient cerebral ischemia using intracellular staining technique in vivo. The general appearance of dendritic arborization of CA1 neurons within 48 h after ischemia was similar to that of control neurons. However, a dramatic increase of dendritic disorientation was observed after ischemia with many basal dendrites coursed into the territory of apical dendrites and apical dendrites branched into the region of basal dendrites. In addition, a significant increase of apical dendritic length was found 24 h after ischemia. The increase of dendritic length after ischemia was mainly due to the dendritic sprouting rather than the extension of individual dendrites, which mainly occurred in the middle segment of the apical dendrites. These results reveal a plasticity change in dendritic arborization of CA1 neurons shortly after cerebral ischemia.

Large dose ketamine inhibits lipopolysaccharide-induced acute lung injury in rats

BACKGROUND

Sepsis is associated with the highest risk of progression to acute lung injury or the acute respiratory distress syndrome. Ketamine has been advocated for anesthesia in endotoxemic and other severely ill patients because it is a cardiovascular stimulant. Our study was designed to investigate the effect of ketamine on the endotoxin-induced acute lung injury in vivo.

MATERIALS AND METHODS

Adult male Wistar rats were randomly divided into 6 groups: saline controls; rats challenged with endotoxin (5 mg/kg) and treated with saline; challenged with endotoxin (5 mg/kg) and treated with ketamine (0.5 mg/kg); challenged with endotoxin (5 mg/kg) and treated with ketamine (5 mg/kg); challenged with endotoxin (5 mg/kg) and treated with ketamine (50 mg/kg); saline injected and treated with ketamine (50 mg/kg). TNF-alpha, IL-6 and NF-kappa B were investigated in the tissues of the lung after 2 h. Myeloperoxidase (MPO) activity and wet/dry weight ratio were investigated 6 h later.

RESULTS

We demonstrated that intravenous administration of endotoxin could provoke significant lung injury, which was characterized by increase of MPO activity and wet/dry weight ratio, TNF-alpha and IL-6 expression and NF-kappa B activation. Ketamine (5, 50 mg/kg) inhibited endotoxin-induced NF-kappa B activation. Ketamine only at a dose of 50 mg/kg inhibited TNF-alpha and IL-6 production, and decreased MPO activity and wet/dry weight ratio after endotoxin challenge.

CONCLUSIONS

Ketamine, only at a supra-anesthetic dosage, could inhibit endotoxin-induced pulmonary inflammation in vivo.

Methemoglobinemia misdiagnosed as ruptured ectopic pregnancy

A 22-year-old woman with an initial diagnosis of 'ruptured ectopic pregnancy' and 'hemorrhagic shock' was sent to the operation room for surgical treatment. The mucocutaneous color was deeply cyanosed and the pulse oximeter oxygen saturation (SpO2) was only 86% after tracheal intubation (100% O2). 'Chocolate-brown' blood was observed and methemoglobinemia was considered. Then the arterial blood gas (ABG) sample was obtained, an intravenous infusion of methylene blue and vitamin C followed. The patient recovered quickly, and later two other patients with similar symptoms were treated in the same way. The success was due to a correct diagnosis accompanied with prompt treatment and quick recognition of the etiology.

Temperature dependence of the surface anisotropy of Fe ultrathin films on Cu(001)

We report an experimental approach to separate temperature dependent reversible and irreversible contributions to the perpendicular magnetic anisotropy of Fe films grown at low temperatures on Cu(001) substrates. The surface anisotropy K(S)(T) is found to decrease linearly with temperature, causing a thermally induced spin reorientation into the plane. The irreversible shift of the spin reorientation transition and the coercivity of the iron films are directly correlated to the increasing Fe island size during annealing. The increased coercivity is discussed in terms of domain wall energy inhomogeneities provided by the islands.

The expression of Fas/FasL in peripheral blood lymphocytes and the level of IL-2 in serum of patients with condyloma acuminata

In order to investigate the role of the expression of the Fas/FasL in peripheral blood lymphocytes (PBLC) and the level of IL-2 in serum of patients with condyloma acuminata (CA) in the immune pathogenesis of CA, flow cytometry, indirect immunofluorescence labeling and ELISA were performed to detect the expression of the apoptotic regulatory proteins Fas/FasL in PBLC and the level of IL-2 in serum of 60 patients with different course of CA. The results showed that the expression of Fas/FasL in PBLC of the group of short course in CA was significantly higher than that of the normal controls (P < 0.05); the expression of Fas, FasL in PBLC of the group of long course CA was significantly higher than that of the group of short course and the normal controls (P < 0.05 and P < 0.01, respectively); the level of IL-2 in serum of the group of short and long course CA was significantly lower than that of the group of normal controls (P < 0.01); the negative relation was revealed between the expression of Fas/FasL in PBLC and the level of IL-2 in serum of patients with CA (r = -0.76, P < 0.01). It was suggested that the abnormal apoptosis in PBLC and decreased level of IL-2 in serum of CA might play an important role in the course of CA.

Therapy-related myelodysplastic syndrome after autologous stem cell transplantation for breast cancer

Therapy-related myelodysplastic syndrome and acute myelogenous leukemia (t-MDS/AML) are serious complications of chemotherapy and radiotherapy for cancer. High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) may be associated with an increased incidence of these complications. The frequency of t-MDS/AML after ASCT for breast cancer is uncertain. We reviewed our database of 379 consecutive breast cancer ASCT patients treated with alkylator-based chemotherapy, followed for a median of 1.52 years (range 0-8.97), with a median survival of 6.16 years. Three patients have developed tMDS/AML. The probability of developing this complication at 5 years is 0.032 in our series. We have used pathologic, cytogenetic and molecular methods to evaluate which portions of therapy may have predisposed to the development of this complication. Cytogenetic abnormalities were not found in the stem cell harvests of these patients by metaphase analysis or by fluorescence in situ hybridization (FISH). One patient demonstrated a clonal X chromosome inactivation pattern in her stem cell harvest, indicating pre-transplant chemotherapy may have been responsible for the development of her leukemia. As two of our patients developed this complication at greater than 4 years post-transplant, the number of cases may increase with longer follow-up. While the incidence appears to be low, further prospective and retrospective analysis will be necessary to determine which portions of therapy predispose to the development of t-MDS/AML in patients undergoing ASCT for treatment of breast cancer.

[Studies on the antifertility effect of bis-trichloromethyl sulfone and its reversibility in male rats]

Bis-trichloromethyl sulfone(BTS) given p.o. to male Sprague-Dawley rats at a dose of 10 mg.kg-1.d-1, 6 days a week for 8 weeks(or 30 mg.kg-1.d-1 for 4 weeks), was found to lead to infertility. The density and, in particular, the motility of the spermatozoa in the cauda epididymidis were significantly lower than those of the controls (P < 0.001). The body weight, the sex behavior, the blood testosterone level and the histology of important organs were not significantly different from those of the control rats. Fertility started to recover 4 weeks after cessation of medication and was entirely recovered 2 more weeks later in rats having received BTS for 8 weeks at the dose of 30 mg.kg-1.d-1. In vitro study showed that BTS at a concentration of 0.31 mg.ml-1 would make rat spermatozoa immobile within 20 seconds. These results indicate that BTS has both antifertility effect in male rats and direct inhibitory effect on rat spermatozoa. We conclude that nontoxic doses of BTS can induce reversible infertility in male rats.