Growth Differentiation Factor-15 as a Predictor of Idiopathic Membranous Nephropathy Progression: A Retrospective Study.

Idiopathic membranous nephropathy (IMN) is a major cause of nephrotic syndrome. No biomarker to predict the long-term prognosis of IMN is currently available. Growth differentiation factor-15 (GDF-15) is a member of the transforming growth factor-ß superfamily and has been associated with chronic inflammatory disease. It has the potential to be a useful prognostic marker in patients with renal diseases, such as diabetic nephropathy and IgA nephropathy. This study examined whether GDF-15 is associated with the clinical parameters in IMN and showed that GDF-15 can predict IMN disease progression. A total of 35 patients with biopsy-proven IMN, treated at Chungnam National University Hospital from January 2010 to December 2015, were included. Patients younger than 18 years, those with secondary membranous nephropathy, and those lost to follow-up before 12 months were excluded. Levels of GDF-15 at the time of biopsy were measured using enzyme-linked immunosorbent assays. Disease progression was defined as a ≥30% decline in estimated glomerular filtration rate (eGFR) or the development of end-stage renal disease. The mean follow-up was 44.1 months (range: 16-72 months). Using receiver operating curve analysis, the best serum GDF-15 cut-off value for predicting disease progression was 2.15 ng/ml (sensitivity: 75.0%, specificity: 82.1%, p = 0.007). GDF-15 was significantly related to age and initial renal function. In the Kaplan-Meier analysis, the risk of disease progression increased in patients with GDF-15 ≥ 2.15 ng/ml when compared with those with GDF-15 < 2.15 ng/ml (50.0% versus 9.7%) (p = 0.012). In the multivariate Cox regression analysis adjusted for potential confounders, only GDF-15 was significantly associated with disease progression in IMN (p = 0.032). In conclusion, the GDF-15 level at the time of diagnosis has a significant negative correlation with initial renal function and is associated with a poor prognosis in IMN. Our results suggest that GDF-15 provides useful prognostic information in patients with IMN.

A Case of Ethylene Glycol intoxication with Acute Renal Injury: Successful Recovery by Fomepizole and Renal Replacement Therapy.

Ethylene glycol is a widely used and readily available substance. Ethylene glycol ingestion does not cause direct toxicity; however, its metabolites are highly toxic and can be fatal even in trace amounts. Poisoning is best diagnosed through inquiry, but as an impaired state of consciousness is observed in most cases, poisoning must be suspected when a significantly elevated osmolar gap or high anion gap metabolic acidosis is found in blood tests. Hemodialysis and alcohol dehydrogenase inhibitors such as ethanol and fomepizole are a part of the basic treatment, and timely diagnosis and treatment are crucial because any delays can lead to death. However, there are few reported cases in Korea, and no report on the use of fomepizole. Herein, we report a case of acute renal failure caused by ethylene glycol poisoning that was treated with fomepizole and hemodialysis and present a literature review.

Promigratory activity of oxytocin on umbilical cord blood-derived mesenchymal stem cells.

Recent studies show that oxytocin has various effects on cellular behaviors. Oxytocin is reported to stimulate cardiomyogenesis of embryonic stem cells and endothelial cell proliferation. Mesenchymal stem cells (MSCs) are widely used for cardiac repair, and we elucidated the effect of oxytocin on umbilical cord derived-MSCs (UCB-MSCs). UCB-MSCs were pretreated with oxytocin (100 nM) and washed with saline prior to experiments. To evaluate their angiogenic potential and migration activity, tube formation assay and Boyden chamber assay were performed. For in vivo study, ischemia-reperfusion was induced in rats, and UCB-MSCs with or without oxytocin pretreatment were injected into the infarcted myocardium to evaluate the engraftment of injected cells. Histological and hemodynamic studies were performed. Oxytocin-treated UCB-MSCs showed a decrease in tube formation but a drastic increase in transwell migration activity. The transcription level of matrix metalloproteinase (MMP)-2 was increased in oxytocin-treated UCB-MSCs. Knock-down of MMP-2 by use of siRNA restored the tube formation, while reducing transmigration activity. In rats injected with oxytocin-treated UCB-MSCs, cardiac fibrosis and CD68 infiltration in the peri-infarct zone were reduced, whereas cell engraftment and connexin43 expression were greater than in rats injected with untreated UCB-MSCs. By contrast, angiogenesis did not differ significantly between the two groups. Cardiac contractility was higher in the group injected with oxytocin-treated UCB-MSCs than in the group injected with phosphate-buffered saline alone. Collectively, oxytocin is an effective priming reagent for stem cells for application to damaged heart tissue.

Role of FAK phosphorylation in hypoxia-induced hMSCS migration: involvement of VEGF as well as MAPKS and eNOS pathways.

Here we show that the effect of hypoxia on human umbilical cord blood mesenchymal stem cell (hMSC) migration is via the modulation of focal adhesion kinase (FAK) and its related signaling pathways. Hypoxia increased hMSC migration and cell viability, whereas lactate dehydrogenase (LDH) release was not affected for up to 48 h (data not shown). In addition, hypoxia increased the level of reactive oxygen species (ROS) generation in a time-dependent manner. Hypoxia-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) and stress-activated protein kinase/c-Jun NH(2)-terminal kinase (SAPK/JNK) were inhibited by the antioxidant (N-acetylcysteine, NAC, 10(-6) M) and (taurine, 4x10(-6) M). Hypoxia-induced endothelial nitric oxide synthase (eNOS) phosphorylation was regulated by p38 MAPK and SAPK/JNK activation. In addition, hypoxia increased the level of hypoxia inducible factor (HIF)-1alpha expression, which was blocked by inhibition of eNOS. Also, hypoxia-induced expression of Flk-1, vascular endothelial growth factor (VEGF), and its secreted form were inhibited by HIF-1alpha small interfering RNA (siRNA). In this hypoxic condition, FAK and Src phosphorylation were increased in a time-dependent manner. Inhibition of Src with specific inhibitor (PP2, 10(-8) M) blocked hypoxia-induced FAK activation. Subsequently, hypoxia-induced FAK phosphorylation was blocked by VEGF siRNA. Finally, hypoxia-induced increase of hMSC migration was inhibited by FAK siRNA. The results indicate that hypoxia increases migration of hMSCs via VEGF-mediated FAK phospholylation and involves the cooperative activity of the ROS, MAPK, eNOS and HIF-1alpha pathways.

Role of HIF-1alpha and VEGF in human mesenchymal stem cell proliferation by 17beta-estradiol: involvement of PKC, PI3K/Akt, and MAPKs.

17beta-Estradiol (E(2)) is a steroid hormone well known for its roles in the regulation of various cell functions. However, the precise role that E(2) plays in the proliferation of human mesenchymal stem cells (hMSCs) has not been completely elucidated. In the present study, we examined the effects of E(2) on cell proliferation and the related signaling pathways using hMSCs. We showed that E(2), at > or =10(-9) M, significantly increased [3H]thymidine incorporation after 24 h of incubation, and E(2) also increased [3H]thymidine incorporation at >6 h. Also, E(2) significantly increased the percentage of the cell population in the S phase based on FACS analysis. Moreover, E(2) increased estrogen receptor (ER), PKC, phosphatidylinositol 3-kinase (PI3K)/Akt, and MAPK phosphorylation. Subsequently, these signaling molecules were involved in an E(2)-induced increase of [3H]thymidine incorporation. E(2) also increased hypoxia-inducible factor (HIF)-1alpha and VEGF protein levels. These levels of protein expression were inhibited by ICI-182,780 (10(-6) M, an ER antagonist), staurosporine and bisindolylmaleimide I (10(-6) M, a PKC inhibitor), LY-294002 (10(-6) M, a PI3K inhibitor), Akt inhibitor (10(-5) M), SP-600125 (10(-6) M, a SAPK/JNK inhibitor), and PD-98059 (10(-5) M, a p44/42 MAPKs inhibitor). In addition, HIF-1alpha small interfering (si)RNA and ICI-182,780 inhibited E(2)-induced VEGF expression and cell proliferation. VEGF siRNA also significantly inhibited E(2)-induced cell proliferation. In conclusion, E(2) partially stimulated hMSC proliferation via HIF-1alpha activation and VEGF expression through PKC, PI3K/Akt, and MAPK pathways.

Linoleic acid stimulates gluconeogenesis via Ca2+/PLC, cPLA2, and PPAR pathways through GPR40 in primary cultured chicken hepatocytes.

Fatty acids serve vital functions as sources of energy, building materials for cellular structures, and modulators of physiological responses. Therefore, this study examined the effect of linoleic acid on glucose production and its related signal pathways in primary cultured chicken hepatocytes. Linoleic acid (double-unsaturated, long chain) increased glucose production in a dose (> or =10(-4) M)- and time (> or =8 h)-dependent manner. Both oleic acid (monounsaturated, long chain) and palmitic acid (saturated, long chain) also increased glucose production, whereas caproic acid (saturated, short chain) failed to increase glucose production. Linoleic acid increased G protein-coupled receptor 40 (GPR40; also known as free fatty acid receptor-1) protein expression and glucose production that was blocked by GPR40-specific small interfering RNA. Linoleic acid increased intracellular calcium concentration, which was blocked by EGTA (extracellular calcium chelator)/BAPTA-AM (intracellular calcium chelator), U-73122 (phospholipase C inhibitor), nifedipine, or methoxyverapamil (L-type calcium channel blockers). Linoleic acid increased cytosolic phospholipase A(2) (cPLA(2)) phosphorylation and the release of [(3)H]-labeled arachidonic acid. Moreover, linoleic acid increased the level of cyclooxygenase-2 (COX-2) protein expression, which stimulated the synthesis of prostaglandin E(2) (PGE(2)). The increase in PGE(2) production subsequently stimulated peroxisome proliferator-activated receptor (PPAR) expression, and MK-886 (PPAR-alpha antagonist) and GW-9662 (PPAR-delta antagonist) inhibited glucose-6-phosphatase and phosphoenolpyruvate carboxykinase. In addition, linoleic acid-induced glucose production was blocked by inhibition of extracellular and intracellular calcium, cPLA(2), COX-2, or PPAR pathways. In conclusion, linoleic acid promoted glucose production via Ca(2+)/PLC, cPLA(2)/COX-2, and PPAR pathways through GPR40 in primary cultured chicken hepatocytes.

Mastoid obliteration using a hyaluronic acid gel to deliver a mesenchymal stem cells-loaded demineralized bone matrix: an experimental study.

BACKGROUND AND OBJECTIVE: The aim of this study was to evaluate whether a combination of expanded human mesenchymal stem cells (hMSCs) with hyaluronic acid gel in human demineralized bone matrix (hDBM) can promote osteogenesis in a mastoid obliteration procedure, with using the guinea pig as an animal model. MATERIALS AND METHODS: Fourteen male guinea pigs were used for the experiment. Bulla obliteration using 6-diamidino-2-phenylindole (DAPI)-labeled hMSCs (2x10(6)) loaded into hDBM with hyaluronic acid hydrogel was performed in the experimental group (n=7). The control group was obliterated using hDBM only (n=7). The histologic findings and microCT images were obtained from each bulla at 3 and 7 weeks postsurgery. RESULTS: The increased soft tissue intensity caused by chondrogenic differentiation around the implanted hMSCs-loaded hDBM was identified, as compared to the hMSCs-free hDBM group. All the hMSCs-loaded hDBM at 7 weeks post-implantation displayed greater amounts of bone filling the bulla space, as compared to the hMSCs-free hDBM implanted group. In the hMSCs-free hDBM group, microCT shows incomplete new bone formation, as compared to the hyaluronic acid gel-hMSCs treated group. CONCLUSION: The successful formation of bone using allogeneic hMSCs loaded onto hDBM and hyaluronic acid hydrogel to repair critically sized bulla defects in the guinea pig model was accompanied with the absence of any local response to the foreign cells. The use of hMSCs-loaded hDBM and hyaluronic acid hydrogel is appropriate for performing clinical mastoid obliteration.

Autologous bone marrow plasma injection after arthroscopic debridement for elbow tendinosis.

INTRODUCTION: The treatment of tendinosis of elbow can be challenging, yet rewarding. Nevertheless, for the patients who failed conservative management and develop persistent recalcitrant symptoms, surgical intervention should be considered. The hypothesis of this study is iliac bone marrow plasma injection after arthroscopic debridement of degenerative tissue will bring along biological cure. Thus, it will not only reduce pain but also improve function in patients with resistant elbow tendonitis. MATERIALS AND METHODS: Twenty-four patients (26 elbows) with significant persistent pain for a mean of 15 months, despite of standard rehabilitation protocol and a variety of other nonsurgical modalities were treated arthroscopically. We applied autologous iliac bone marrow plasma injection following arthroscopic debridement. This material is produced by centrifugation of iliac bone marrow blood at 1,800 rpm for 20 to 30 minutes. Patients were allowed full range of motion (ROM) exercise after 2 to 3 days. Cytokine analyses for this injective material were done. Outcome was rated by postoperative sonography, visual analog pain scores (VAS) and Mayo elbow performance scores (MEPS) at 8 weeks and 6 months follow-up. Informed consent had been obtained from the subjects, and the study protocol was approved by the ethics committee of Chosun University Hospital, Korea. RESULTS: All patients in this study noted improvement both in their VAS and MEPS. No complication occurred in any patient. Evidence of tendon healing was observed in postoperative sonographic examination. Predominant cytokines of this study were interleukin-12 (IL-12), interferon-gamma-inducible protein-10 (IP-10) and RANTES. CONCLUSION: Biologic treatments in orthopaedics are just beginning to evolve. In the present investigation, the injection of iliac bone marrow plasma after arthroscopic debridement in severe elbow tendinosis demonstrated early recovery of daily activities and clear improvement.

In vivo bioluminescence imaging of cord blood derived mesenchymal stem cell transplantation into rat myocardium.

OBJECTIVE: The conventional method for the analysis of myocardial cell transplantation depends on postmortem histology. Here, we have sought to demonstrate the feasibility of a longitudinal monitoring of transplanted cell survival in living animals, accomplished with optical imaging techniques and pharmacological interventions. METHODS: Human cord blood (50 ml) was donated with parental consent. After getting cord blood derived mesenchymal stem cells (CBMSCs), cells were transfected (MOI = 100) overnight with adenovirus encoding firefly luciferase gene (Ad-CMV-Fluc). Our experimental Sprague-Dawley rats (n = 12) were given intramyocardial injections containing 1 x 10(6) CBMSCs, which had been made to express the firefly luciferase (Fluc) reporter gene. Optical bioluminescence imaging was then conducted using a cooled charged-coupled device (CCD) camera (Xenogen), beginning on the day after the transplantation (day 1). Groups of mice were intraperitoneally injected with cyclosporine (5 mg/kg) or tacrolimus (1 mg/kg), in an attempt to determine the degree to which cell survival had been prolonged, and these values were then compared with the cell survival values of the negative control group. The presence of transplanted CBMSCs on in vivo images confirmed by in situ hybridization for human specific Alu in the myocardium. RESULTS: Cardiac bioluminescence signals were determined to be present for 6 days after transplantation: day 1 (97000 +/- 9100 x 10(5) p/s/cm2/sr), day 3 (9600 +/- 1110 p/s/cm2/sr), and day 5 (3200 +/- 550 p/s/cm2/sr). The six mice that received either cyclosporine or tacrolimus displayed cardiac bioluminescence signals for a period of 8 days after transplantation. We observed significant differences between the treated group and the non-treated group, beginning on day 3 (tacrolimus; 26500 +/- 4340 p/s/cm2/sr, cyclosporine; 27200 +/- 3340 p/s/cm2/sr, non-treated; 9630 +/- 1180 p/s/cm2/sr, p < 0.01), and persisting until day 7 (tacrolimus; 12500 +/- 2946 p/s/cm2/sr, cyclosporine; 7310 +/- 1258 p/s/cm2/sr, non-treated; 2460 +/- 160 p/s/cm2/sr, p < 0.01). The human-derived CBMSCs were detected in the myocardium 3 days after transplantation by in situ hybridization. CONCLUSIONS: The locations, magnitude, and survival duration of the CBMSCs were noninvasively monitored with a bioluminescence optical imaging system. We determined that optical molecular imaging expedites the fast throughput screening of pharmaceutical agents, allowing for the noninvasive tracking of cell survival within animals. In rat cardiac CBMSC transplant models, transient immunosuppressive treatment with tacrolimus or cyclosporine was shown to improve donor cell survival.

Topical vancomycin for chronic suppurative otitis media with methicillin-resistant Staphylococcus aureus otorrhoea.

There has been a steady increase in the number of cases of methicillin-resistant Staphylococcus aureus (MRSA) otorrhoea; this is a growing concern. The purpose of this study was to evaluate the efficacy of topical vancomycin treatment in patients with MRSA otorrhoea. Fifty-five patients with MRSA otorrhoea were prospectively enrolled into the study. Thirty-five patients were treated with vancomycin eardrops as outpatients. The concentration of the locally prepared vancomycin solution was 25 mg/ml. The dose of vancomycin was two drops three times daily for 10 days. As a control group, 20 patients were treated with gentamicin 0.3% solution. Data were analysed by the Mann-Whitney U test to compare the efficacy of vancomycin eardrops and gentamicin eardrops. In the vancomycin group, the otorrhoea was significantly reduced in 33 ears (94%); in the gentamicin group, in four ears (20 per cent); this reduction was statistically significant (P < 0.03). The use of topical vancomycin treatment was effective for patients with MRSA otorrhoea refractory to conventional antibiotic treatment.

Effect of Ga-as laser on the regeneration of injured sciatic nerves in the rat.

Laser irradiation is one of the therapeutic methods for the recovery of degenerated peripheral nerves. The aim of the present study was to determine if low-power laser treatment stimulates the regeneration process of damaged nerves. A standardized crush to the sciatic nerve was applied to cause extensive axonal degeneration. After this procedure, low-power infrared laser irradiation was administered transcutaneously to the injured sciatic nerve, 3 minutes daily to each of four treatment groups for 1, 3, 5 and 7 weeks, respectively. A nerve conduction study was done, and a morphological assessment was performed using both light and electron microscopy. With trauma of the nerve, both amplitude of compound motor action potential and nerve conduction velocity decreased significantly compared to the pre-trauma state. Morphologically, the numbers of myelinated axons and degenerated axons were decreased and increased, respectively, compared with the control. Typical aspects were of onion skin-type lamellation, fragmentation, edematous swelling and rarefaction in the myelin sheath. All these parameters recovered almost to the level of the pre-trauma state with laser irradiation, in direct proportion to the time spent for treatment. These results suggest that low-power infrared laser irradiation can relieve the mechanical damage of sciatic nerves and stimulate the regeneration of peripheral nerves.

Asian pear pectin administration during presensitization inhibits allergic response to ovalbumin in BALB/c mice.

OBJECTIVE: A type of respiratory disorder resembling some aspects of human allergic asthma can be induced in mice using ovalbumin. The factors that influence the etiology of asthma are poorly understood even though cytokines are known to play a pivotal role. The purpose of this study was to test the hypothesis whether an administration of Asian pear pectin during presensitization could suppress allergic response to ovalbumin in BALB/c mice. DESIGN: High-dose (100 microg) of pectin-sol was used and values were compared to those from the control. Ovalbumin and aluminum hydroxide were utilized for sensitization while ovalbumin aerosol was used for provocation 2 weeks later. The bronchoalveolar lavage (BAL) and assessment of tracheal smooth muscle responsiveness to electrical field stimulation or acetylcholine were performed 1 day after ovalbumin provocation. Two main cytokines of interferon (IFN)-gamma and interleukin (IL)-5, and serum immunoglobulin E (IgE) were assayed. SETTINGS: Laboratory of the Chosun University Medical School SUBJECT: Male BALB/c mice RESULTS: Antigen dose of 5 microg for sensitization generated TH1 type cytokines in the lungs with a high level of IFN-gamma and a low level of IL-5. In contrast, TH2 type cytokines were produced in splenocytes including a high level of IL-5 and a low level of IFN-gamma. Asian pear pectin-sol administration during presensitization significantly inhibited (p < 0.05) sensitivity of airway smooth muscle to electrical field stimulation and acetylcholine. Further, IFN-gamma production significantly decreased (p < 0.05) in BAL fluids while it significantly increased (p < 0.05) in splenic cells. On the other hand, IL-5 production significantly increased (p < 0.05) in BAL fluids while it was a significant decrease (p < 0.05) in splenic cells. For the histopathologic changes in the lung, pear pectin-sol recovered ovalbumin (OVA)-induced abnormal signs to an almost normal state. As a correlate, IgE production significantly decreased (p < 0.05) in pectin-sol-treated animals compared to the control. CONCLUSIONS: It is possible from these data that BALB/c mice have different susceptibilities to different doses of OVA regulated by pulmonary TH1 and TH2 type cytokines, independent of splenic TH1 and TH2 type cytokines production. These results also indicate that administration of Asian pear pectin-sol in presensitized mice suppresses allergic asthmatic reaction.

Influence of suction tube noise on hearing in pediatric patients who received ventilation tube insertion.

BACKGROUND: Myringotomy with ventilation tube insertion is the most frequently used surgical procedure performed on children to treat otitis media with effusion. The risk of acoustic trauma caused by the suctioning noise during the procedure has not been clearly understood. The objective of this study was to investigate whether the suctioning noise during ventilation tube placement procedure damaged children's hearing. METHODS: The study was conducted in a prospective manner. The ventilation tube placement procedures were performed on a series of 30 consecutive patients (60 ears). The electro-acoustic signals of the suctioning noises during the procedure were analyzed using a high quality digital tape recording system. The hearing threshold was measured using pure tone audiometry before and after the procedures. RESULTS: The peak intensity of the suctioning noise ranged from 4 kHz to 10 kHz in frequency. The mean intensities of the suctioning noise were 86.4 +/- 9.6 dB for serous effusion and 96.4 +/- 9.6 dB for mucoid effusion, respectively. No noise-induced sensori-neural hearing loss was observed in this cohort. CONCLUSIONS: Even though the peak intensity of the suctioning noise may reach a level of more than 90 dB, it is not likely that the suctioning noise during the ventilation tube placement procedure causes noise-induced sensori-neural hearing loss.

Electro-acupuncture reverses nerve growth factor abundance in experimental polycystic ovaries in the rat.

Polycystic ovary syndrome (PCOS) remains one of the most common causes of anovulation in women of reproductive age. There is some evidence that nerve growth factor (NGF) is involved in the pathogenesis of PCOS. Therefore, seeking the pathogenesis of PCOS is important for controlling fertility. In traditional Oriental Medicine, acupuncture has been used for the function of ovaries. The present study was designed to determine whether electro-acupuncture (EA) could affect experimentally induced polycystic ovary (PCO) in the rat. The two acupoints Sp-6 and E-128 were stimulated to test for efficacy in the protein expression of NGF. Polycystic ovaries were induced by a single injection of estradiol valerate (4 mg i.m.). During the experimental period of 8 weeks, some of the rats were treated with EA twice weekly; this group was compared with a vehicle-treated control group and an estradiol-injected group not subjected to EA. At day 60, the protein expression of NGF was examined by immunohistochemistry in the ovaries, the adrenal glands and some parts of the brain. The estradiol treatment induced a clear PCO appearance, and was associated with a robust increase in NGF expression in the ovaries, the adrenal glands and the brain. EA treatment partly reversed the NGF abundance, particularly in the ovaries, but not in the brain. Our data show that EA affects the NGF involvement in ovarian dysfunction.

Development of a radioreceptor assay for measuring an oxytocin antagonist in blood.

The purpose of the present study was to develop a radioreceptor assay to monitor the pharmacokinetics of the oxytocin antagonist, TT-235, in the blood of the pregnant rat and baboon. The receptors used for this assay were prepared from the pregnant rat uterus at delivery. The assay using blood from pregnant rats and baboons was performed on filter plates and analyzed for radioactivity in a gamma counter. The assay was sensitive to 10 pg/well with a range from 10 to 1,000 pg. The average recovery was 86%. A new radioreceptor assay was developed for the oxytocin antagonist, TT-235. TT-235 had a much longer half-life than oxytocin in the pregnant rat and baboon. This longer half-life may partially explain the prolonged in vivo tocolytic activity of TT-235 in these animals.

Effect of exposure to mitomycin C on cultured tympanic membrane fibroblasts.

OBJECTIVE: Recently, attempts have been made to prolong the patency of myringotomy site with topical use of mitomycin C (MMC). It has been shown that MMC inhibits mitosis and proliferation of ocular fibroblasts, however, there are no studies of MMC's effect on tympanic membrane fibroblasts. To investigate the effects of MMC on cultured human tympanic membrane fibroblasts and understand the cellular basis of MMC for maintain myringotomy patency, cultured fibroblasts were exposed to various concentrations of MMC for periods of 5-10 min. METHODS: Effect of MMC on cultured fibroblasts was assessed by microscopic observation and cell viability test. RESULTS: Dose-, time- dependent relationship of MMC on cultured fibroblasts was revealed. There was a significant difference between the inhibition effects of MMC at concentrations of 0.4 mg/ml and control following 5 and 10 min exposure intervals. Phase-contrast microscopy showed consistency with the antiproliferative effect of MMC at higher concentration. CONCLUSIONS: Therefore, it would appear that intraoperative use of MMC could be effective in delaying the healing of the myringotomy site and extending the period of time for myringotomy patency.

Extrauterine incubation of fetal goats applying the extracorporeal membrane oxygenation via umbilical artery and vein.

The fetus is an unstable subject for an isolated physiological and biochemical study. To study the fetus in a controlled and stable environment, a trial was done using 12 goat fetuses. Extrauterine incubation system was devised using an extracorporeal membrane oxygenation system. The system consisted of a venous reservoir with a servo-controlled roller pump and a membrane oxygenator. The extra-corporeal circuit and membrane oxygenator were primed with the maternal whole blood of 200 mL. Fetal umbilical cords was exposed by Cesarean section. Fetal umbilical arterial blood was drained via the drainage cannula. The drained blood was perfused to the oxygenator by the roller pump. The highly oxygenated and decarboxylated blood was returned to an umbilical vein via the perfusion catheter. The blood flow rate was controlled manually using a roller pump. Fetal heart rate, blood pressure, and electrocardiogram were continuously recorded. Gas analysis of drained and perfused blood was performed hourly. With this system, the fetuses were able to survive under fairly stable physiological condition for periods of up to 34 hr. The extrauterine incubation system used in this study could therefore be a encouraging future experimental model in researching the artificial placenta for premature fetuses.

Comparison of oxytocin and oxytocin antagonist metabolism in the plasma of pregnant humans and baboons.

Oxytocin antagonists may be useful in inhibiting the uterine contractions of preterm labor. One such compound is TT-235 (previously referred to as Antag III). The purpose of this study was to compare the resistance of TT-235 and oxytocin to enzymatic degradation by oxytocinase in the blood of humans and baboons during their 3rd trimester of pregnancy. Blood samples from pregnant women and baboons not in labor were incubated in vitro with known amounts of oxytocin and TT-235. Samples were collected at 0, 15, 30, 45, and 60 min for oxytocin analysis and at 0, 10, 60, and 360 min for TT-235 analysis. Oxytocin was analyzed by radioimmunoassay after extraction, while TT-235 was analyzed by radioreceptor assay. In human blood, oxytocin was readily metabolized with >83% disappearance over the 60-min incubation period. In contrast, TT-235 was stable up to 360 min of incubation. In the baboon, oxytocin did not diminish over the 60-min incubation period. The level of TT-235 was similar to that in human blood without change over 360 min of incubation. This study suggests (1) that in contrast to blood from pregnant humans, blood from pregnant baboons lacks oxytocinase at least in vitro and (2) that TT-235 is resistant to enzymatic degradation by human blood, implying that this oxytocin antagonist may have a prolonged activity in vivo in humans.