[Clinical evaluation of ventricular septal defect occlusion device for the treatment of postoperative bronchopleural fistula].

Bronchopleural fistula is an abnormal sinus tract that forms between the bronchus and the thoracic cavity. It is most commonly caused by thoracic surgery. Patients often have severe pulmonary and thoracic infections, which seriously affect the quality of life and survival rate. Most of these patients do not have a second operation chance, so the bronchopleural fistula becomes a thorny problem in the clinical practice. The clinical data of 9 patients with postoperative bronchopleural fistula admitted to Anhui Provincial Chest Hospital were reviewed and analyzed. We analyzed and summarized the clinical experience of successful occlusion with a ventricular septal defect(VSD) device, which provided a potentially effective treatment for postoperative bronchopleural fistula.

Therapeutic effect of ginsenoside Rg1 on mastitis experimentally induced by lipopolysaccharide in lactating goats.

Escherichia coli is a cause of subclinical and clinical mastitis in dairy cattle and goats, and sometimes causes severe clinical disease that may result in death of the animal. Previous investigation showed that ginsenoside Rg1 extracted from Panax ginseng C.A. Meyer (Araliaceae) has an anti-inflammatory effect on the sepsis induced by E. coli lipopolysaccharide via competitive binding to toll-like receptor 4. We hypothesized that intravenous injection of Rg1 had therapeutic effect on mastitis experimentally induced by intramammary infusion of lipopolysaccharide in lactating goats. In this study, 9 lactating goats were randomly assigned to 1 of the 3 groups: (1) lipopolysaccharide intramammary infusion + saline intravenous injection, (2) lipopolysaccharide intramammary infusion + Rg1 intravenous injection, and (3) saline intramammary administration + saline intravenous injection. Because no adverse clinical signs were observed after intramammary infusion of saline and intravenous injection of Rg1 in a preliminary experiment, and available qualified goats were limited in this study, this treatment was not included in this study. One udder half of each goat received intramammary infusion of lipopolysaccharide (50 µg/kg of body weight; groups 1 and 2) or saline solution (group 3), and the other half was infused with 2 mL of saline solution at h 0. Afterward, intravenous injections of saline solution (groups 1 and 3) or Rg1 (2.5 mg/kg of body weight; group 2) were administered at h 2 and 4 post-lipopolysaccharide challenge. Blood and milk samples were collected 3, 6, 9, 12, 15, 18, 21, 24, 48, and 72 h post-lipopolysaccharide challenge, and clinical signs were monitored hourly after lipopolysaccharide challenge within the first 10 h and at the same time points as blood samples. The results showed that Rg1 treatment downregulated rectal temperature, udder skin temperature, udder girth, milk somatic cell count, and N-acetyl-ß-d-glucosaminidase and upregulated milk production, lactose, and recovered blood components, such as white blood cells, neutrophils, lymphocytes, total proteins, albumin, and globulin. Considering the positive therapeutic effect on lipopolysaccharide-induced mastitis in goats presented in this study as well as the anti-inflammatory activity found previously, the botanical Rg1 deserves further study as a therapeutic agent in the treatment of E. coli mastitis in dairy animals.

Ginsenoside Rg1 enhanced immune responses to infectious bursal disease vaccine in chickens with oxidative stress induced by cyclophosphamide.

This study was designed to evaluate the effect of oral administration of ginsenoside Rg1 on oxidative stress induced by cyclophosphamide in chickens. Ninety-six chickens were randomly divided into 4 groups, each consisting of 24 birds. Groups 2 and 3 received intramuscular injection of cyclophosphamide at 100 mg/kg body weight for 3 d to induce oxidative stress and immune suppression. Groups 1 and 4 were injected with saline in the same way as groups 2 and 3. Then chickens in group 3 were orally administrated Rg1 of 1 mg/kg body weight in drinking water for 7 d. After that, groups 1 to 3 were orally vaccinated with attenuated infectious bursal disease vaccine (Strain B87). Blood samples were collected for determination of infectious bursal disease virus-specific antibodies, cytokines, and oxidative parameters. Splenocytes were prepared for lymphocyte proliferation assay. The results showed that oral administration of ginsenoside Rg1 significantly enhanced specific antibody, IFN-γ, and IL-6 responses, and lymphocyte proliferation induced by concanavalin A and lipopolysaccharide in chickens injected with cyclophosphamide. Antioxidant activity of ginsenoside Rg1 was also observed in chickens by increased total antioxidant capacity, total superoxide dismutase, catalase, glutathione peroxidase, glutathione, ascorbic acid, and α-tocopherol, as well as decreased malondialdehyde and protein carbonyl. Therefore, oral administration of Rg1 was shown to improve the immune responses to infectious bursal disease vaccine in chickens suffering from oxidative stress.

TRIM59 is a key regulator of growth and migration inrenal cell carcinoma.

Renal cell carcinoma (RCC) is the most common renal neoplasms and metastatic is common. Previous data have shown that the tripartite motif (TRIM) family proteinswere implicated in human tumoriogenesis. In this study, we aimed to investigate the role of TRIM59 in the cell growth and migration in RCC. The expression of TRIM59 in human RCC tissues was initially examined by qRT-PCR. Alentivirus-based shRNA against TRIM59 (Lv-shTRIM59) was constructed. The effects of TRIM59 knockdown on cell proliferation were examined by in vitro MTT assay, colony formation assay and in vivo a mouse xenograft model of RCC. Cell migration and invasion after knockdown of TRIM59 were also examined by transwell assay. Our data showed that the mRNA level of TRIM59 in cancerous tissues was 2-fold increased as compared with non-cancerous tissues. Knockdown of TRIM59 in a RCC cell line 786-O significantly slowed down cell proliferative rate and decreased both the colony number and sizes. In the mouse model, knockdown of TRIM59 consistently inhibited tumor growth in vivo. Moreover, it was shown that cell migration and invasion were suppressed by 68% and 50%, respectively in TRIM59-depleted 786-O cells. Our data suggest that TRIM59 may serve as a pro-oncogenic protein in promoting the progression of RCC. Knockdown of TRIM59 may be a promising strategy concerning the early detection and treatment of RCC.

miR-760 mediates chemoresistance through inhibition of epithelial mesenchymal transition in breast cancer cells.

OBJECTIVE: Therapeutic resistance has been a great obstacle for successful treatment of breast cancer. Our study aimed to explore the role of microRNA-760 (miR-760) in chemoresistant breast cancer cells. MATERIALS AND METHODS: Real-time PCR was performed to measure the mRNA expression of miR-760 and Nanog. Western blot was used to determine the protein expression of Nanog and mesenchymal and epithelial markers. Cell viability was measured by the CCK-8 assay. RESULTS: Our results showed that the expression of miR-760 was significantly reduced the doxorubicin (DOX)-resistant MCF-7/DOX cells and chemoresistant breast cancer tissues. Moreover, up-regulation of miR-760 sensitized breast cancer cells to the anti-cancer agents. The MCF-7/DOX cells exhibited increased expression of Snail, a mesenchymal marker, and decreased levels of E-Cadherin, an epithelial marker. In addition, overexpression of miR-760 suppressed the expression of Nanog, a transcriptional factor involved in chemoresistance, and resulted in the reversal of EMT in breast cancer cells. CONCLUSIONS: Our study demonstrated that miR-760 modulated chemoresistance through the epithelial-mesenchymal transition in breast cancer cells, providing a potential therapeutic target for treatment of drug-resistant breast cancer.

Relationship between donor sperm parameters and pregnancy outcome after intrauterine insemination: analysis of 2821 cycles in 1355 couples.

The aim of this study was to investigate whether sperm parameters can affect the pregnancy outcome of artificial intrauterine insemination with cryopreserved donor spermatozoon (AID). A total of 1355 couples received 2821 AID treatment cycles in the Reproductive Medicine Center of the Tongji Medical College between January 2010 and December 2013, and the data were collected and retrospectively analysed. The relationship between pre-freezing, post-thawing as well as optimised sperm parameters and AID pregnancy outcome was investigated. Clinical pregnancy rate and cumulated pregnancy rate were also calculated. A total of 728 cycles from 2821 treatment cycles achieved pregnancies, and cumulated pregnancy rate was 25.81%. Pre-freezing progressive sperm motility in pregnant cycles was higher than that in nonpregnant cycles (P = 0.001); logistic regression analysis also indicated that pre-freezing progressive sperm motility was the only parameter affecting pregnancy outcome (P = 0.0001). Our study also showed that the cumulated pregnancy rate increased progressively and reached a plateau after the fifth cycle. In conclusion, pre-freezing progressive sperm motility should be a valuable predictor for AID pregnancy outcome. Female fertility factors should be considered, or IVF/ICSI should be recommended when couples received more than 5 AID cycles without pregnancy.

Pioglitazone ameliorates intracerebral insulin resistance and tau-protein hyperphosphorylation in rats with type 2 diabetes.

OBJECTIVE: To investigate intracerebral insulin resistance and its relationship with tau-protein hyperphosphorylation. METHODS: A rat model of type 2 diabetes (T2D) was established with streptozotocin (STZ). Diabetic rats received intragastric administration of pioglitazone (PIO group) or normal saline (T2D group) for 4 weeks. As a control, non-diabetic rats received intragastric normal saline (CTL group). The insulin concentrations in cerebrospinal fluid (CSF) and blood were determined with radioimmunoassay, and blood glucose concentration was determined using a glucose oxidation technique. Total and phosphorylated levels of protein kinase B (AKT), glycogen synthase kinase-3ß (GSK-3ß) and tau-protein in the hippocampus were analyzed using western blotting. RESULTS: The plasma insulin level in the T2D group was higher, and the CSF insulin level in the T2D group lower than in the CTL group. Hippocampal phosphorylated AKT and phosphorylated GSK-3ß levels were significantly lower in the T2D group than in the CTL group. Hippocampal tau-protein in the T2D group was hyperphosphorylated at Ser199 and Ser396. Plasma insulin levels in the PIO group were lower than in the T2D group, with no differences in CSF insulin levels. Phosphorylated AKT and phosphorylated GSK-3ß levels in the PIO group were significantly higher than in the T2D group Hippocampal phosphorylated tau-protein (Ser199/Ser396) was lower in the PIO group than in the T2D group. CONCLUSION: Hyperphosphorylation of tau-protein in pioglitazone-treated rats with T2D was improved. Rats with T2D have both cerebral insulin resistance and cerebral hypoinsulinism. Pioglitazone can ameliorate intracerebral insulin resistance and decrease tau-protein hyperphosphorylation, but cannot increase intracerebral insulin levels.

Serum prolactin levels and the acute-phase efficacy in drug-naïve schizophrenia treated with ziprasidone and olanzapine (translated version).

OBJECTIVES. To study the efficacy and associated serum prolactin levels of ziprasidone and olanzapine treatment in drug-naïve schizophrenia patients. METHODS. All 78 inpatients with drug-naïve schizophrenia were recruited from the Department of Psychology, The Third Affiliated Hospital of Sun Yat-sen University. They were divided into either olanzapine group (n = 49 [24 men, 25 women]; mean [standard deviation] age, 24 [6] years) or ziprasidone group (n = 29 [14 men, 15 women]; mean [standard deviation] age, 23 [7] years), all of whom were treated for 4 weeks. The serum prolactin level, the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression-Severity (CGI-S), and Clinical Global Impression-Improvement scores were measured before and at the end of treatment. RESULTS. In the olanzapine group, the respective mean (standard deviation) PANSS and CGI-S scores after the treatment (62 ± 15 and 3 ± 1) were significantly lower than those before the treatment (104 ± 14 and 6 ± 1) [p < 0.01]. In the ziprasidone group, the corresponding scores after the treatment (75 ± 20 and 4 ± 1) were also significantly lower than those before the treatment (104 ± 17 and 6 ± 1) [p < 0.01]. The decreases in mean (standard deviation) PANSS total (42 ± 17) and PANSS positive scores (12 ± 6) in the olanzapine group were significantly higher than those in the ziprasidone group (29 ± 12 and 6 ± 4, respectively) [p < 0.01]. The increase of serum prolactin in the ziprasidone female group (47 ± 51 µg/L) was significantly higher than that in the ziprasidone male group (17 ± 11 µg/L), the olanzapine male group (5 ± 16 µg/L), and the olanzapine female group (21 ± 34 µg/L) [p < 0.05]. CONCLUSIONS. Both ziprasidone and olanzapine are effective for treating drug-naïve acute schizophrenia, but olanzapine was superior to ziprasidone in terms of positive and general psychopathological symptoms. In women, ziprasidone was associated with greater changes in prolactin level than olanzapine.

Repetitive transcranial magnetic stimulation-induced seizure of a patient with adolescent-onset depression: a case report and literature review.

Repetitive transcranial magnetic stimulation (rTMS) has been used as an investigative and therapeutic tool in neuropsychiatry and is advocated as a therapy for the treatment of psychiatric disorders, particularly adult depression. The therapeutic efficacy of current antidepressants applied to children or adolescents is unsatisfactory; thus innovative treatments such as rTMS are in demand. Large-scale clinical studies are required to determine the safety of rTMS for this age group. The present case report describes a 15-year-old female with depression who had seizure and hypomania during the first session of rTMS concomitant to sertraline 100 mg/day orally. The patient continued on this regimen of sertraline therapy but rTMS was not repeated. Subsequent electroencephalogram (EEG) examination detected no abnormalities and no long-term complications were observed. We suggest that rTMS should be used cautiously to treat adolescents with depressive disorders, particularly when used concomitant to antidepressant treatment.

Haemodynamic brain response to visual sexual stimuli is different between homosexual and heterosexual men.

The underlying neurobiological factors involved in sexual orientation are largely unknown. This study investigated whether neural circuits or different cognitive processes accounted for differences in brain activation in 14 heterosexual and 14 homosexual males. Brain scans were undertaken in each subject using functional magnetic resonance imaging while they viewed different sexual stimuli, i.e. heterosexual couple stimuli (HCS), gay couple stimuli (GCS), lesbian couple stimuli (LCS) and neutral stimuli (NS). Ratings of sexual attractiveness of the stimuli were assessed. Subjective sexual arousal was induced by HCS and GCS in heterosexual and homosexual men, respectively. Sexual disgust was induced by GCS and LCS in heterosexual and homosexual men, respectively. Compared with viewing NS, viewing sexual stimuli induced significantly different brain activations, most of which had the characteristics of cognitive processes. These observations suggest that different cognitive patterns may be the major cause of different subjective responses to sexual stimuli between heterosexual and homosexual men.

Synthesis of nanocarriers with remote magnetic drug release control and enhanced drug delivery for intracellular targeting of cancer cells.

Nanotherapeutic strategy is well recognized as the therapeutic approach of the future. Numerous reports have demonstrated the use of nanoparticulate drug carriers for the development of targeted nanotherapeutics by, for instance, incorporation of a moiety that specifically targets certain diseased cells. However, systematic investigation of this aspect has been inadequate, especially with regard to nanosystems with remotely controlled drug delivery. The authors previously designed a magnetic-responsive core-shell drug delivery nanosystem which proved to be technically feasible in vitro. In the present study, this nanosystem is modified for targeted delivery of an anticancer agent (encapsulated camptothecin (CPT)) to cancer cells overexpressing epithelial growth factor receptor (EGFR) with accurate intracellular drug release. The endocytosis of the nanocarriers by cancer cells, the pathway of cellular uptake and the subsequent intracellular controlled drug delivery were systematically investigated. It was found that the modified nanocarriers showed reasonably high drug load efficiency for CPT and a high uptake rate by cancer cells overexpressing EGFR through clathrin-mediated endocytosis. The intracellular release of the CPT molecules via an external magnetic stimulus proved to be technically successful and ensured much higher therapeutic efficacy than that obtained with the free drug. This study employs multiple functions for nanotherapeutic treatment of specific target cells, i.e. cell-specific targeting, controlled cellular endocytosis and magnetic-responsive intracellular drug release.

Enhancement of immune responses to infectious bursal disease vaccine by supplement of an extract made from Momordica cochinchinensis (Lour.) Spreng. seeds.

The immunological effect of an extract from Momordica cochinchinensis seed (ECMS) on immune responses against infectious bursal disease (IBD) in chickens was evaluated. Fifty-two birds were equally divided into 4 groups and immunized with inactivated IBD vaccine alone (controls) or IBD vaccine emulsified with ECMS (20, 40, and 80 microg). Serum IgG antibody levels against IBD and BW were measured on 0, 7, 14, 21, 28, and 35 d after immunization. The ELISA results revealed that the chickens that received 20 microg of ECMS had significantly enhanced antibody levels on 14, 21, 28, and 35 d when compared with controls (P<0.05). A significant increase in mitogenic stimulated lymphocyte proliferation was also recorded in all ECMS groups as compared with controls (P<0.05; P<0.01). No adverse effect of ECMS was noted on growth performance, although average weight gain was significantly higher in 20 microg (7, 14, 21, 28, and 35 d) and 40 or 80 microg (14 d) of ECMS groups as compared with controls (P<0.05; P<0.01). Further studies are suggested for the investigation of immunological effects of ECMS.

Genetic analysis of haemophilia A in Taiwan.

Haemophilia A (HA) is an X-linked bleeding disorder caused by mutations in the factor VIII (FVIII) gene. Identification of these mutations is becoming increasingly important in a variety of clinical settings. The purpose of this report is to describe our experience of FVIII gene mutation analysis in the largest cohort of patients in Taiwan including the discovery of 21 novel mutations. We tested 115 HA patients from 91 unrelated families, including 79 severe, 15 moderate and 21 mild types starting with an assay for the intron 22 inversion by long range-PCR followed if necessary by additional genetic studies. Intron 22 inversion accounted for 27.8% of the total and 36.7% of severe HA patients respectively while intron 1 inversion comprised 7.6% of severe patients. These were clearly different from the known data in caucasian populations. Of 75 patients without intron 22 or 1 inversion, 70 from 62 unrelated families revealed 56 different mutations by denaturing high-performance liquid chromatography (DHPLC), of which 21 were novel. Also, the only female patient with severe HA was found to have heterozygous non-sense mutation (c.6683G>A) of exon 24. Seven patients, including five without amplified PCR product and two without encoded DNA defect turned out to have exon(s) deletion or insertion by reverse transcript PCR (RT-PCR). In our study, the combination of various molecular techniques including LR-PCR, multiplex PCR, DHPLC and RT-PCR analysis enabled definitive detection of the causative FVIII gene defects in 112 of 113 (99%) HA patients.

A selected review of recent biological psychiatric research in China (translated version).

This review highlights significant biological psychiatric research published by Chinese researchers in recent years. Chinese periodicals with full-text database (Chinese National Knowledge Infrastructure) and English periodicals with PubMed, published from 2003 to 2009 on schizophrenia, depression, bipolar affective disorder, obsessive-compulsive disorder, anxiety disorder and Alzheimer's disease, were reviewed. Articles studying the above-mentioned psychiatric disorders focusing in the area of molecular genetics, neuroendocrine immunology, electrophysiology and psychopharmacology applied to animal models or clinical populations were included. The findings suggest that biological psychiatric research is being developed at a rapid pace and covers a wide perspective from disease mechanisms to clinical interventions.

Patterns of brain activation during visually evoked sexual arousal differ between homosexual and heterosexual men.

BACKGROUND AND PURPOSE: Nowadays the mechanism of homosexuality is little known. Few studies have been carried out to explore the brain functional changes of homosexual men during sexual arousal. We used functional MR imaging (fMRI) to determine whether the patterns of brain activation in homosexual and heterosexual men differed during visually evoked sexual arousal. MATERIALS AND METHODS: To all the subjects (10 homosexual and 10 heterosexual), real-time visual stimulation was provided by 3-minute exposure to 3 types of erotic film: heterosexual couples (F-M), male homosexual couples (M-M), and female homosexual couples (F-F) engaged in sexual activity, during which time fMRI was used to determine the patterns of brain activation. Self-reports of level of sexual arousal were collected immediately afterward. RESULTS: Statistical parametric mapping showed that viewing erotic film excerpts that induced sexual arousal was associated, in both groups, with activation of the middle prefrontal gyrus, bilateral temporal lobe and postcentral gyrus, thalamus, insula, vermis, left precuneus, occipital cortex, parietal cortex, and cerebellum. In homosexual men, the left angular gyrus, left caudate nucleus, and right pallidum were activated; in contrast, heterosexual men showed no activation in these regions. However, heterosexual men showed activation in the bilateral lingual gyrus, right hippocampus, and right parahippocampal gyrus, areas not activated in homosexual men. In both groups, region-of-interest analysis revealed no correlation between the magnitude of amygdala or thalamus activation and the reported level of sexual arousal. CONCLUSION: Our findings indicate that different neural circuits are active during sexual arousal in homosexual and heterosexual men and may contribute to a better understanding of the neural basis of male sexual orientation.

Prevalence of von Willebrand disease in women with iron deficiency anaemia and menorrhagia in Taiwan.

Iron deficiency anaemia (IDA) is a frequently encountered disease, which can be attributed to menorrhagia. Most female patients with von Willebrand disease (VWD) have menorrhagia. The aim of this study was to investigate the prevalence of VWD in women with both IDA and menorrhagia in Taiwan. From January to December 2005 and November 2006 to January 2007, 56 consecutive patients with both IDA and menorrhagia were enrolled in this study. Their median age was 41 years (range 18-53). IDA was diagnosed by anaemia plus either low ferritin or transferrin saturation. Menorrhagia was evaluated by patient's menses history. Both von Willebrand factor antigen (VWF:Ag) and ristocetin cofactor activity (VWF:RCo) were measured for each patient. Bleeding time (BT) and platelet function analyser (PFA)-100 assay were determined as ancillary tests. The VWD diagnosis was established if: (i) both VWF:Ag (<50%) and VWF:RCo (<50%) were low; (ii) either VWF:Ag or VWF:RCo was low plus prolonged BT or prolonged PFA closure times. VWF multimer analysis was performed for subtype confirmation of VWD. Nine of the 56 (16.1%) patients were identified to have VWD. VWD patients with menorrhagia might develop IDA at younger age (34.3 vs. 39.7, P = 0.09) and had more IDA recurrence (75% vs. 16%, P = 0.03) than those patients without VWD. Of the eight VWD patients with VWF multimer analyses, all were revealed to have type I VWD. Our study demonstrates that VWD was not uncommon in women with both IDA and menorrhagia in Taiwan.

The effect of dietary l-carnitine supplementation on pulmonary hypertension syndrome mortality in broilers exposed to low temperatures.

Oxidative stress is involved in the development of pulmonary hypertension syndrome (PHS) in broilers. l-Carnitine has an antiperoxidative effect and supplemental l-carnitine has been revealed to increase broiler heart weight. The present study was conducted to evaluate the effect of an addition of 100 mg/kg l-carnitine to the basal diets on PHS mortality in cold-exposed broilers. Two-hundred and forty mixed-sex broilers were equally assigned to three groups. The control group was reared in normal temperatures throughout the experiment. Starting on day 14 continuing until the end of the experiment, the other two groups were subjected to a step-down temperature programme (by lowering the temperature 1-2 degrees C per day down to 12-14 degrees C) with or without l-carnitine added to the basal diets. Cold exposure increased the right/total ventricle ratio (RV/TV) and plasma malondialdehyde (MDA), reduced superoxide dismutase (SOD) and led to pulmonary vascular remodelling in birds without feeding additional l-carnitine. Supplemental l-carnitine reduced plasma MDA, increased SOD, inhibited remodelling and postponed the occurrence of PHS for 1 week in cold-exposed broilers; nevertheless, it did not significantly influence the cumulative PHS mortality (p > 0.05). On days 24 and 32, birds fed supplemental l-carnitine had lower RV/TV and higher total ventricle/body weight (p < 0.05) but unchanged right ventricle/body weight ratios (p > 0.05) compared to their cold-exposed counterparts, indicating an increase in left ventricle weight. However, from day 39 on, their RV/TV ratios were suddenly increased (p < 0.05). It was suggested that the l-carnitine-induced increase in left heart weight might partially account for the postponed occurrence of pulmonary hypertension in the early stage by elevating cardiac output, which might, in turn, lead to the resulting increase in pulmonary pressure. In view of its complex effects on cardiopulmonary haemodynamics, l-carnitine supplementation may be impractical for reducing PHS.

Persistence of oxytetracycline residues in milk after the intrauterine treatment of lactating cows for endometritis.

Milk samples were collected at one day intervals after the last dose from 31 cows that had received an intrauterine infusion of oxytetracycline once daily between one and five times. The tetrazolium chloride assay was used to determine whether there were significant residues of the antibiotic in the samples. A single treatment resulted in residues for between one and eight days, and the period tended to be longer in the cows that had received more than one dose. Of the 31 cows, six remained tetracycline-positive for more than five days after their last dose of the drug.

Efficacy of nisin in treatment of clinical mastitis in lactating dairy cows.

Nisin is an antimicrobial polypeptide produced by Lactococcus lactis and is believed nontoxic to humans. The objective of this study was to evaluate a nisin-based formulation for the treatment of bovine clinical mastitis in lactating dairy cattle. A total of 92 cows with 107 clinically mastitic quarters were randomly assigned to nisin- (48 cows with 51 quarters) and gentamicin (GM)-treated (44 cows with 56 quarters) groups. In the nisin-treated group, cows received an intramammary infusion of nisin at a dose of 2,500,000 IU; in the GM-treated group, intramammary infusion of GM was administered at a dose of 0.8 g. Results indicated that nisin offered a clinical cure rate similar to GM (90.2 vs. 91.1%) and no difference in bacteriological cure rate than GM-treated group (60.8 vs. 44.6%, respectively). Proportion of the quarters with milk somatic cell counts <500,000 cells/mL was not different in the nisin-treated group (50.0 and 47.8%) compared with the GM-treated group (33.3 and 37.3%) 1 and 2 wk after treatment. Of 17 Staphylococcus aureus isolates, 82.5% were resistant to penicillin, and 35.3% to GM, but none of them to nisin. Nisin therapy eliminated 54.5% (6 of 11) of S. aureus IMI, whereas GM eliminated 33.3% (2 of 6). Nisin in milk (4.5 +/- 0.8 IU/mL) was detected only at 12 h following intramammary infusion, which was much lower than the upper limit (500 mg/mL) allowed as preservative in milk by the China authority. Because of its efficacy in the treatment of bovine clinical mastitis, especially resistant Staph. aureus-caused IMI, as well as its safety in humans, nisin deserves further study to clarify its effects on mastitis caused by different mastitis pathogens on a larger scale.