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Biomedical subjects

A Steinleitner

Publications and source records attributed to A Steinleitner.

At least 19 recordsLinked to original sources

Successful treatment of immunologic abortion with low-dose intravenous immunoglobulin.

OBJECTIVE: To evaluate the efficacy of low-dose intravenous immunoglobulin (IVIG) treatment in older women with immunologic abnormalities and recurrent spontaneous abortion (RSA), a condition referred to as immunologic abortion. DESIGN: Prospective clinical trial. SETTING: Outpatient referral practice. PATIENT(S): Forty-seven women were enrolled in the study. The mean age of the women was 37 years (range, 28-45 years), and the mean number of prior miscarriages was 3.7. Immunologic abnormalities included antiphospholipid antibodies (32%), antithyroid antibodies (53%), antinuclear antibodies (28%), antiovarian antibodies (2%), increased natural killer cells (40%), increased immunoglobulin (Ig)M level (28%), and increased CD4/CD8 T-cell ratio (15%). One patient had IgA deficiency, and three women had endometriosis. Thirty-one of the 47 patients (66%) had more than one immunologic abnormality. INTERVENTION(S): Treatment with IVIG at a dose of 0.2 g/kg within 2 weeks of attempted conception. Once conception was achieved, IVIG treatment was continued on a monthly basis at the same dose through 26-30 weeks of gestation. MAIN OUTCOME MEASURE(S): Successful pregnancy or recurrent abortion. RESULT(S): Of the 47 women, 36 received initial IVIG treatment, and 24 subsequently became pregnant. Of these women, 20 continued IVIG treatment through 26-30 weeks of gestation, and 19 (95%) had a successful term pregnancy. Four women discontinued IVIG therapy after 10-12 weeks of gestation, and 3 (75%) had a successful pregnancy outcome. Of the 11 women who refused IVIG therapy, 7 became pregnant, and all 7 miscarried. The difference in pregnancy success rate between the IVIG-treated and untreated groups was significant (P=.001). Three women had adverse reactions during the low-dose IVIG infusion, and these reactions resolved when the IVIG brand was changed. Fetal abnormalities were not observed. CONCLUSION(S): Low-dose IVIG therapy is beneficial for older women with immunologic abortion. The optimum duration of IVIG treatment in these women requires further study.

Abortion, Habitual↗

Detection of human leukocyte antigen class I messenger ribonucleic acid transcripts in human spermatozoa via reverse transcription-polymerase chain reaction.

OBJECTIVE: To determine by reverse transcription-polymerase chain reaction (PCR) whether human leukocyte antigen (HLA) class I messenger RNA (mRNA) is present in mature human spermatozoa. DESIGN: Mature human spermatozoa was isolated from donor semen using a swim-up technique. Total RNA was extracted via guanidinium isothiocyanate-cesium chloride ultracentrifugation. By the method previously validated in our laboratory, reverse transcription-PCR was performed using primers specific for HLA class I transcripts. Positive control cells included a choriocarcinoma cell line (JEG) and human fetal tissue. Transformed peripheral blood lymphocytes (PBL) were used as a negative control for somatic cellular contamination. RESULTS: Human spermatozoa were positive for HLA class I (-G and -B) mRNA by reverse transcription-PCR, consistent with the positive controls. We did not detect any mRNA for beta-actin, retinoblastoma (RB), CD4, or kappa light chain genes in the sperm complementary DNA samples, verifying that the class I mRNA detected was not due to somatic cellular contamination of the purified sperm samples. CONCLUSION: These experiments provide the first evidence that mRNA for HLA class I molecules are present in mature human spermatozoa. The physiological role of these transcripts is unknown at present. Further experiments characterizing the expression of HLA class I (-G and -B) mRNA in oocytes and preimplantation embryos are in progress.

Actins↗

New modalities under development for adhesion prevention: immunomodulatory agents and poloxamer barrier materials.

Obviously, no single modality will prove to be universally applicable or completely effective at preventing postoperative adhesion formation. Increasing understanding of the pathophysiology of peritoneal healing provides the intellectual basis for the development of specific interventions at critical points along the adhesion formation cascade. We believe that multimodality therapy, including the use of pharmacologic adjuvants such as immunomodulatory drugs and fibrinolytic/anticoagulant agents in conjunction with a barrier material tailored to the specific operative procedure may provide optimal results. Hopefully, developments in the 1990's will provide reproductive surgeons with the means to help patients derive maximal benefit from their reconstructive procedures.

Adjuvants, Immunologic↗

Enhanced gamete interaction in the sperm penetration assay after coincubation with pentoxifylline and human follicular fluid.

OBJECTIVE: To evaluate the effect of pentoxifylline and heat-inactivated human follicular fluid (FF) on performance in the sperm penetration assay (SPA) as a paradigm for the effect of these agents on human sperm-egg interaction in vivo and in vitro fertilization. DESIGN: Semen specimens from men undergoing SPA testing for evaluation of suspected male factor infertility were coincubated with neat medium or media supplemented with pentoxifylline or human FF in a nonblinded manner. PARTICIPANTS: Twenty male factor infertility patients. INTERVENTIONS: Semen specimens were preincubated with: [1] pentoxifylline 0.25 mg/mL; [2] 10% human FF; [3] pentoxifylline+human FF; and [4] neat Biggers, Whitten, and Whittingham medium. MAIN OUTCOME MEASURES: Differences in the rate of penetration of zona-free hamster oocytes. RESULTS: Preincubation with either human FF or pentoxifylline produced a significant improvement in hamster egg penetration rates. Coincubation with a combination of human FF and pentoxifylline resulted in a significant enhancement of penetration as compared with single agent treatment. CONCLUSIONS: Coincubation of sperm with human FF and pentoxifylline may provide a means of enhancing sperm activity for insemination and assisted reproduction.

Animals↗

Reduction of primary posttraumatic adhesion formation with the prostacyclin analog iloprost in a rodent model.

Recent evidence suggests that inhibition of postsurgical adhesion formation may be effected by modulation of the activities of inflammatory cells contributing to mesothelial repair. Iloprost, a stable analog of prostacyclin, has been shown to exert vasodilatory, antiinflammatory, fibrinolytic, and antithrombotic influences. To determine whether these properties of iloprost might protect mesothelial surfaces from perioperative damage and hence prevent adhesion formation, we evaluated the effect of iloprost on peritoneal healing in a hamster model for primary pelvic injury. Perioperative iloprost therapy significantly reduced posttraumatic adhesion formation when compared with that in vehicle-treated controls. Dose-response studies demonstrate adhesion prevention with doses ranging from 0.04 to 4 mg/kg per 8 hours given subcutaneously over the course of 3 days. These data demonstrate that iloprost is a potent positive modulator of peritoneal healing after pelvic trauma. Further studies to characterize the potential application of iloprost as an adjuvant in reproductive surgery are indicated.

Animals↗

Immunomodulation in the treatment of endometriosis-associated subfertility: use of pentoxifylline to reverse the inhibition of fertilization by surgically induced endometriosis in a rodent model.

OBJECTIVE: To determine the effect of pentoxifylline on early reproductive performance in an animal model for endometriosis. DESIGN: Preclinical blinded study in a rodent model. SETTING: Animal research laboratory. PARTICIPANTS: Sexually mature female golden hamsters. INTERVENTIONS: At laparotomy, groups of hamsters were subjected to: (1) excision of the right uterine horn and (2) excision of the right uterine horn with explantation of four 2-cm2 uterine fragments onto the left uterine mesentery. Six weeks later, surgically treated hamsters and nonsurgically treated controls were subjected to ovulation induction with pregnant mare serum gonadotropin and human chorionic gonadotropin; subsequently, hamsters were divided into groups for periovulatory treatment with either pentoxifylline (2.5 mg/kg) or vehicle given subcutaneously every 8 hours. All hamsters were mated with proven males and killed after 48 hours. MAIN OUTCOME MEASURES: Numbers of unfertilized oocytes and embryos recovered from the left uterine horn at 48 hours after mating. RESULTS: Fertilization rates in surgical and nonsurgical control groups exceeded 90%. Fertilization was significantly impaired in saline-treated animals bearing uterine explants (mean of 2.3% +/- 1.9%). Administration of pentoxifylline dramatically reversed this effect (99.0% +/- 0.7% mean fertilization rate). CONCLUSION: These data suggest that periovulatory treatment with pentoxifylline abrogated the adverse influence of endometrial explants on fertilization in the rodent model. Periovulatory administration of nonteratogenic immunomodulatory agents may provide an alternative to conventional treatment for endometriosis.

Adjuvants, Immunologic↗

Poloxamer 407 as an intraperitoneal barrier material for the prevention of postsurgical adhesion formation and reformation in rodent models for reproductive surgery.

Comtemporary adhesion-prevention regimens for infertility surgery emphasize the use of barrier materials to effect physical separation of injured surfaces before reperitonealization. Poloxamer 407 is a biocompatible polymer that displays reverse thermal gelation characteristics; that is, the material exists as a liquid at room temperature and as a solid at body temperature. These properties make it an ideal material for use in laparoscopic surgery. The antiadhesion properties of poloxamer 407 were evaluated in two models. In the first experiment, Golden hamsters were subjected to a standardized adhesion-producing lesion in the left uterine horn. Poloxamer solutions in concentrations ranging from 15-35% were applied to the injured horn. Location, thickness, and extent of adhesion formation were assessed 14 days later. Significant reduction in post-traumatic adhesion formation was observed following treatment with the 30-35% solutions. The second experiment was designed as a paradigm of the typical situation encountered in infertility surgery: prevention of adhesion reformation after lysis of established adhesions. New Zealand White rabbits were subjected to three laparotomies at 14-day intervals for placement of the adhesion-producing lesion, evaluation (prescore) and surgical lysis of induced adhesions, and subsequent evaluation of adhesion reformation (post-score). The effect of applying poloxamer 407 after adhesiotomy was compared with controls (no treatment). Adhesion reformation (post-score) was markedly reduced by poloxamer-407 treatment. Further trials of this material in the clinical setting are indicated.

Animals↗

Immunomodulation with pentoxifylline abrogates macrophage-mediated infertility in an in vivo model: a paradigm for a novel approach to the treatment of endometriosis-associated subfertility.

Although present consensus holds that endometriosis-associated subfertility is the result of an adverse effect of hyperactivated macrophages on early reproductive events, most treatments for endometriosis are directed at the suppression of endometriotic implants. We hypothesized that periovulatory immunomodulation of macrophage activation and inflammatory mediator production might be a more effective approach to this problem. In this experiment, heterologous transfer of activated peritoneal inflammatory cells within a syngeneic strain of mice was used as an in vivo model for the peritoneal inflammatory environment of the endometriosis patient. Intraperitoneal transfer of hyperactivated macrophages, but not basal state macrophages, significantly inhibited fertilization. This activity was reversed by periovulatory pentoxifylline treatment. Immunomodulation of peritoneal inflammatory cell hyperactivation with pentoxifylline may represent a new modality for the treatment of endometriosis-associated subfertility.

Adjuvants, Immunologic↗

Periovulatory calcium channel blockade enhances reproductive performance in an animal model for endometriosis-associated subfertility.

Current evidence suggests that peritoneal inflammatory cell hyperactivation may be the essential pathologic abnormality in patients with endometriosis-associated subfertility. In these experiments we utilized an animal model to evaluate the use of an immunomodulatory agent as an alternative treatment for endometriosis-associated subfertility. The right uterine horn of 12 golden hamsters was resected and 2 x 2 mm squares were explanted onto the left uterine mesentery. Controls included hamsters undergoing uterine horn resection without endometrial explantation (n = 6) and nonsurgically treated animals (n = 6). Ovulation induction was initiated 6 weeks postoperatively with 40 IU of pregnant mare's serum gonadotropin on day 1 and 40 IU of human chorionic gonadotropin on day 3. Groups of six explant-bearing hamsters and six nonsurgical control hamsters were treated with verapamil (250 micrograms/kg every 8 hours subcutaneously), a calcium channel-blocking agent known to inhibit macrophage activation, from day 1 to 48 hours after administration of human chorionic gonadotropin. Animals were then killed and the number of embryos and oocytes in left tube counted as a reflection of reproductive performance. Fertilization was completely inhibited in animals bearing uterine explants. Treatment with verapamil dramatically reversed this effect. These data suggest that periovulatory treatment with an immunomodulatory agent such as verapamil may be an effective alternative to conventional treatment for endometriosis-associated subfertility.

Animals↗

Reduction of primary postoperative adhesion formation under calcium channel blockade in the rabbit.

Preliminary studies in a hamster model have demonstrated calcium channel blocking agents to be potent inhibitors of primary post-traumatic peritoneal adhesion formation. The present investigation was designed to extend these observations to an extensively studied model, the rabbit, and to evaluate the optimal route of administration of these drugs for intraabdominal surgery. Rabbits were subjected to a standardized traumatic lesion of the left uterine horn. Subsequently, animals were divided into the following treatment groups: subcutaneous vehicle control (n = 7), intraperitoneal (ip) vehicle control (n = 8), subcutaneous verapamil treatment (n = 6), low-dose (2.5 micrograms/kg/hr) ip verapamil treatment (n = 10), and high-dose ip (25 micrograms/kg/hr) verapamil treatment (n = 6). All animals were reexplored at 1 week postop for evaluation of adhesion formation (scale: 0 to 4+). Calcium channel blockade-treated animals formed significantly fewer adhesions (0.45) than controls (3.93) (P less than 0.01). There was no significant difference between animals treated with sc with verapamil sc and those treated with low- or high-dose verapamil ip (0.33 vs 0.20 vs 1.0). These data confirm our preliminary results, suggesting that calcium channel blockade potently modulates peritoneal healing and regeneration. Furthermore, intraperitoneal delivery and systemic administration appear equipotent in this model. Further study of these agents as potential adjuvants for intraperitoneal surgery is indicated.

Abdomen↗

Peritoneal fluid from endometriosis patients affects reproductive outcome in an in vivo model.

The cause and importance of endometriosis-associated subfertility are a subject of dispute in reproductive endocrinology. To further study this phenomenon, we have established a model to test the effect of peritoneal fluid (PF) from endometriosis patients on early reproductive events in vivo. Sexually mature female golden hamsters were subjected to an ovarian hyperstimulation protocol and divided into groups that received the following intraperitoneal injections: (1) saline, (2) human serum albumin (HSA), (3) PF from fertile controls, and (4) PF from stage I/II endometriosis patients. Animals were killed on days 4 and 17; reproductive performance was assessed by the number of oocytes and embryos recovered on day 4 and the number of uterine swellings counted on day 17. Reproductive performance was significantly impaired by PF from endometriosis patients; animals treated with control PF and HSA did not differ from control. These data demonstrate a marked impairment of early in vivo reproductive performance under the influence of endometriosis PF. These results support a role for a soluble PF component as a mediator in the pathogenesis of endometriosis-associated subfertility.

Animals↗

Heterologous transplantation of activated murine peritoneal macrophages inhibits gamete interaction in vivo: a paradigm for endometriosis-associated subfertility.

Macrophage hyperactivation has been postulated to be the pathologic aberration in patients suffering from endometriosis-associated subfertility. In this report an in vivo model for macrophage-mediated infertility is described. Populations of macrophages were obtained from an inbred strain of mice (Balb/C) as follows: (1) in vivo hyperactivated macrophages (harvested from donor mice treated with intraperitoneal thioglycolate); (2) hyperactivated macrophages deactivated ex vivo with the protein synthesis inhibitor emetine; and (3) basal state (nonactivated) macrophages obtained from untreated mice. Recipient mice underwent ovarian hyperstimulation with pregnant mare serum gonadotropins; 2 x 10(6) macrophages were transferred on the afternoon of stimulation day 3 before injection of human chorionic gonadotropin (hCG) and mating. Unfertilized oocytes and 4-cell embryos were counted on day hCG +2 as a reflection of reproductive performance. Heterologous transfer of in vivo hyperactivated macrophages, but not basal state macrophages, significantly inhibited fertilization. This effect was largely reversed by pretreatment with emetine. These experiments confirm the relevance of macrophage-mediated interference with early reproductive performance and provide a model for the development of alternative therapies (e.g., immunomodulation of the peritoneal fluid environment) for endometriosis-associated subfertility.

Animals↗

Effect of interleukin-1 on gamete interaction and mouse embryo development.

Early stages of endometriosis have been shown to be associated with infertility. The pathophysiology of this relationship is unclear. To determine if interleukin-1 (IL-1), a peritoneal macrophage product, has any effect on gamete interaction and early embryo development, human recombinant IL-1 was added to the coincubation of gametes in the sperm penetration assay (SPA), human zona pellucida assay (ZPPA) and culture medium (Ham's F-10) used for processing semen samples with the layering method, with analysis of velocity and motility after 24 hours. IL-1 was also added to mouse embryos (two cells) cultured for 72 hours. The results showed that IL-1 caused impairment of SPA and ZPPA when compared to control medium, without significant alterations in sperm velocity and motility. Also, IL-1 demonstrated significant inhibition of mouse embryo development. These results help explain subfertility associated with early stages of endometriosis.

Animals↗

Pentoxifylline, a methylxanthine derivative, prevents postsurgical adhesion reformation in rabbits.

Previous studies from our laboratory have demonstrated pentoxifylline to be a potent inhibitor of primary post-traumatic adhesion formation in a rodent model. To evaluate pentoxifylline in a situation more closely mimicking the events encountered in infertility surgery, we developed a model for adhesion reformation after lysis of pelvic adhesions. New Zealand White rabbits received a standardized primary traumatic lesion to the left uterine horn. One week later, a laparotomy was performed for evaluation (prescore) and subsequent lysis of adhesions. After closure, the animals were randomized to treatment with vehicle or subcutaneous pentoxifylline, 2.5 mg/kg, administered at 12-hour intervals for six doses. Seven days later, the rabbits were sacrificed and evaluated in a blinded manner to quantify adhesion reformation (postscore). Using a scoring scale from 0 = no adhesions to 4+ = most severe, the mean prescore was not different between pentoxifylline-treated and control rabbits (3.8 versus 3.9, respectively). However, the mean postscore (0.7 versus 3.7, respectively) was markedly reduced by pentoxifylline (P less than .001). These data demonstrate a marked inhibition of adhesion reformation after lysis of pelvic adhesions under the influence of pentoxifylline in rabbits.

Animals↗

Decreased in vitro production of 6-keto-prostaglandin F1 alpha by uterine arteries from postmenopausal women.

Cessation of ovarian function is associated with a marked increased in morbidity and mortality secondary to ischemic heart disease. Estrogen replacement has been shown to impart protection against ischemic heart disease. We hypothesized that estrogen may influence vascular production of vasodilators such as prostacyclin. To investigate this relationship we have measured the production of 6-keto-prostaglandin F1 alpha, and thromboxane B2 by superfused uterine arteries from pre- and postmenopausal women. Arterial specimens from healthy normotensive premenopausal (n = 5) and postmenopausal women (n = 5) were superfused for 5 hours. Production of 6-keto-prostaglandin F1 alpha reached steady state levels by 120 minutes and remained linear for the length of the experiment. Indomethacin (4 x 10(-5) mol/L) added at 120 minutes significantly decreased prostanoid production. In subsequent experiments, 17 beta-estradiol in concentrations of 10, 100, 1000 ng/ml was added to the superfusion media at 120 minutes. Total production of 6-keto-prostaglandin F1 alpha by premenopausal arteries superfused with neat media during the steady state interval (3 hours) was significantly greater than that of postmenopausal specimens (1.25 versus 0.27 ng/mg dry tissue, p less than 0.05). Thromboxane B2 levels were undetectable in spent media. However, the addition of 17 beta-estradiol did not alter production of 6-keto-prostaglandin F1 alpha. These data suggest that arterial production of prostacyclin is significantly decreased in uterine arteries from postmenopausal women, but in this in vitro model system estrogens did not affect vascular prostanoid production.

6-Ketoprostaglandin F1 alpha↗