Addition Of Pentoxifylline Research Articles

Effects of pentoxifylline treatment before freezing on motility, viability and acrosome status of poor quality human spermatozoa cryopreserved by the liquid nitrogen vapor method

The objective of the present study was to investigate the effects of the direct addition of pentoxifylline (PF) to the ejaculates of men with poor sperm quality before freezing on post-thaw sperm motility, viability, acrosome integrity, and agonist-induced acrosome reaction. Semen specimens from 16 infertile men with impaired sperm count and motility (oligoasthenozoospermia) were divided into two equal aliquots: one received no treatment (control) while the other was incubated with 5 mM PF (treated). Both aliquots were cryopreserved by the liquid nitrogen vapor method. Motility was assessed according to WHO criteria. Acrosome integrity and spontaneous and calcium ionophore-induced acrosome reactions were assessed with fluorescein isothiocyanate-conjugated peanut agglutinin combined with a supra-vital dye (Hoechst-33258). Cryopreservation impaired sperm motility (percentage reduction: 87.4 (interquartile range, IQ: 70.3-92.9) vs 89.1 (IQ: 72.7-96.0%)), viability (25.9 (IQ: 22.2-29.7) vs 25.6 (IQ: 19.7-40.3%)) and acrosome integrity (18.9 (IQ: 5.4-38.9) vs 26.8 (IQ: 0.0-45.2%)) to the same extent in both treated and control aliquots. However, PF treatment before freezing improved the acrosome reaction to ionophore challenge test scores in cryopreserved spermatozoa (9.7 (IQ: 6.6-19.7) vs 4.8 (IQ: 0.5-6.8%); P = 0.002). These data show that pre-freeze treatment of poor quality human sperm with pentoxifylline did not improve post-thaw motility or viability nor did it prevent acrosomal loss during the freeze-thaw process. However, PF, as used, improved the ability of thawed spermatozoa to undergo the acrosome reaction in response to calcium ionophore. The present data indicate that treatment of poor quality human sperm with PF may enhance post-thaw sperm fertilizing ability.

Pentoxifylline

The aim was to evaluate effects of addition of pentoxifylline to skimmed milk semen extender on uterine inflammatory response. Thirty-six estrous cycles of 15 mares were randomly divided into five groups for artificial insemination (AI): Control: mimicking the AI procedure (n = 7); Extender: deposition of skimmed milk based extender (n = 7); Extender + PTX: skimmed milk based extender plus pentoxifylline (7.18 mM; n = 8); Semen: semen diluted with extender without pentoxifylline (n = 7), and Semen + PTX: semen diluted with extender containing pentoxifylline (n = 7). Mares in estrus were examined by trans-rectal palpation and using ultrasonography, and ovulation was induced. Uterine hemodynamics were assessed immediately before ovulation induction (T-30), immediately before AI (T0), 2 (T2), 6 (T6), 12 (T12), 24 (T24) and 48 (T48) h after AI. Endometrial samples were collected 6 h after AI, and slides were stained and examined to determine percentage of PMN. Pentoxifylline had no additional effect on vascular perfusion. There was a major inflammatory response with pentoxifylline treatment that was greater than that of the control group. In the group treated with Extender + PTX, there were more PMN (57.98 ± 9.42%) than in the group treated with Extender (20.20 ± 6.63%) and in the Semen + PTX group more PMN (82.84 ± 5.71%) than in the Semen-treated group (47.83 ± 10.61%). These findings indicate the addition of pentoxifylline does not stimulate blood flow; however, it induces a greater immune defense response because more neutrophils migrate to the uterine lumen.

Oral Pentoxifylline Combined with Pentavalent Antimony: A Randomized Trial for Mucosal Leishmaniasis

Mucosal leishmaniasis is associated with intense tissue damage and high tumor necrosis factor-alpha production. Therapeutic failure occurs in up to 42% of cases; patients who experience treatment failure will require >1 pentavalent antimony (Sb(v)) course or alternative drugs to achieve a cure. We previously showed that an inhibitor of tumor necrosis factor-alpha (pentoxifylline) combined with Sb(v) cured 90% patients refractory to monotherapy with Sb(v). A double-blind, placebo-controlled trial involving 23 patients with mucosal leishmaniasis evaluated the efficacy of pentoxifylline when administered in association with Sb(v), compared with Sb(v) treatment alone. Eleven patients were randomized to receive Sb(v) plus oral pentoxifylline for 30 days, and 12 patients received Sb(v) plus oral placebo. The criterion for cure was a complete healing of lesions. All patients in the pentoxifylline group experienced a cure with 1 course of Sb(v), whereas 5 (41.6%) of 12 patients in the placebo group required a second course of Sb(v) (P=.037). The healing time +/- standard deviation in the pentoxifylline group was 83+/-36 days, compared with 145+/-99 days in the placebo group (P=.049). No relapses were documented in either group at the 2-year follow-up visit. The addition of pentoxifylline to Sb(v) in mucosal leishmaniasis reduces the healing time significantly and prevents the need for further courses of Sb(v).

Precision-cut fibrotic rat liver slices as a new model to test the effects of anti-fibrotic drugs in vitro

Current cell culture models contributed significantly to the study of liver fibrosis and the testing of anti-fibrotic drugs but mimic the complex in vivo milieu poorly. Therefore, we evaluated fibrotic rat liver slices as a new, more physiologic in vitro model to test anti-fibrotic compounds. Precision-cut slices (8 mm diameter, 250 microm thickness) were prepared from fibrotic rat livers three weeks after bile-duct ligation and incubated for 0-48 h, during which viability and progression of the fibrotic process was evaluated. In addition, the effects of pentoxifylline, gleevec, and dexamethasone on mRNA expression of markers for fibrosis were determined. Fibrotic liver slices remained viable during 48 h of incubation, with increasing alphaSMA and pro-collagen 1a1 mRNA expression, and alphaSMA and collagen protein content after prolonged incubation. Addition of pentoxifylline, gleevec, or dexamethasone during incubation dose-dependently inhibited pro-collagen-1a1 and alphaSMA mRNA expression after 24h of incubation without influencing slice viability. Fibrotic liver slices are a promising tool to test anti-fibrotic drugs in vitro in a multicellular, fibrotic milieu, which cannot be achieved in vitro using other models. Importantly, this method may provide the opportunity to study anti-fibrotic compounds not only in animal but also in fibrotic human liver tissue.

Effect of Pentoxifylline Containing Human Sperm Cryopreservation Medium on Post-Thaw Motility of Human Spermatozoa and Lipid Peroxidation Status of Human Semen

The process of freeze-thawing impairs sperm motility and membrane integrity and results in an overall loss of sperm fertilizing ability. The damage occurs mostly by the production of reactive oxygen species. Pentoxifylline acts as a potent motility activator by inhibiting the phosphodiesterase activity as well as an antioxidant. The present study was carried out to assess the effect of pentoxifylline containing human sperm cryopreservation medium {egg-yolk, glucose, fructose, glycine containing and glycerol based medium where the effective concentration of glycerol in medium-semen mixture is 7.5% (V/V)} on human sperm motility, forward progression and lipid peroxidation status of frozen thawed semen. Prospective experimental study. A final concentration of 3.6 mM pentoxifylline/L of medium-semen mixture was selected for this study. A comparative study between both the media (the Human Sperm Cryopreservation Medium[HSPM] alone and the HSPM containing 7.2 mM pentoxifylline/L of medium) was carried out in 26 normozoospermic human semen samples from patients attending the University clinic. After preliminary analysis, each semen sample was divided into 2 aliquots, each of 300 μL and one was mixed with the medium (M) alone and the other with the pentoxifylline containing medium (Mp), both in 1: 1 dilution and preserved at -196°C in liquid nitrogen for 1 week. The motility characteristics were assessed and lipid peroxidation status was estimated by malonaldehyde (MDA) formation in both the media preserved spermatozoa on thawing and it was compared with that of pre-freeze ones. The mean percentage (± SD) motility was 66.9 ± 15.2 % in pre-freeze samples; it was 31.3 ± 17.0% (p < 0.005) and 46.2 ± 19.4% (p > 0.07) after thawing in spermatozoa preserved in medium M and Mp respectively. The mean percentage (± SD) of 5% forward progression was 56.6 ± 16.4 % in pre-freeze samples; it declined to 21.8 ± 16.9% (p < 0.005) and 37.3 ± 20.9% (p > 0.01) on thawing in sperm preserved in medium M and Mp, respectively. The lipid peroxidation of whole semen was 22.6 ± 11.9 nM in pre-freeze condition and increased to 43.0 ±11.3 (p < 0.01) in samples preserved in medium M and 30.6 ± 15.8 (p > 0.3) nM of MDA/ml of semen in samples preserved in Mp. The addition of pentoxifylline with sperm cryopreservation medium not only provides a comparatively higher yield of spermatozoa with % motility and forward progression on thawing but also minimizes the lipid peroxidation of sperm membrane on cryopreservation. Hence, pentoxifylline could be used as a supplement in human sperm cryopreservation medium.

275 PENTOXIFYLLINE ADDED TO FREEZING EXTENDER HAS A DELETERIOUS EFFECT ON POST-THAW BOAR SPERM QUALITY AND IN VITRO FERTILIZATION RATE

Pentoxifylline, a methylxanthine derivative, is considered to be a hyperactivation and acrosome reaction-improving agent. The purpose of this study was to test how the addition of pentoxifylline to freezing extender influences post-thaw sperm motility and membrane integrity. The ability of thawed spermatozoa to fertilize in vitro-matured oocytes was also assessed. Pooled ejaculate sperm-rich fractions collected from three fertile boars were frozen in 0.5-mL straws after being diluted in lactose/egg yolk/glycerol/Orvus-ES-Paste extender (0 pentoxifylline = control) or the same extender supplemented with 2, 4, 8, 16, and 32 mM pentoxifylline. To evaluate post-thaw sperm survival, the percentage of total motile spermatozoa and rapid progressive spermatozoa (CASA system) and plasma membrane and acrosome integrity (flow cytometry) were assessed. Data from six replicates were analyzed in a split plot design using a PROMIXED model. The addition of 4, 8, 16, and 32 mM pentoxifylline to freezing extender significantly decreased progressive and total motility (P &lt; 0.001) compared with control (4.5/26.6%, 4.5/24.5%, 2.8/20.5%, 0.6/11.4%, and 13.2/49.7% for the 4, 8, 16, and 32 mM pentoxifylline groups and the control group, respectively). The same was observed for sperm viability; the percentage of viable spermatozoa with intact acrosomes was significantly lower (P &lt; 0.001) in pentoxifylline-treated groups compared with the control group, chiefly in the 16 mm, and 32 mM pentoxifylline groups (54, 11.6, and 6.2% for control, 16 and 32 mM, respectively). To evaluate in vitro fertilization parameters, cumulus-oocyte complexes were matured in BSA-free NCSU23 medium with 10% porcine follicular fluid, 0.1% cysteine, 10 ng EGF, 10 IU/mL eCG, and 10 IU/mL hCG, in a incubator at 39�C and 5% CO2. After 40-44 h of maturation, oocytes (n = 1067, in three replicates) were denuded of cumulus cells, washed, transferred to droplets (30 oocytes in 50 �L) of TBM medium supplemented with 2 mM caffeine and 0.2% BSA, and inseminated (2000 thawed sperm/oocyte). After a co-incubation period of 6 h, oocytes were washed and transferred to droplets (500 �L) of NCSU23 with 0.4% BSA for another 10-14 h, then fixed and stained for 72 h, and examined under a phase-contrast microscope. Data were analyzed as split plot design using a PROMIXED model. The addition of pentoxifylline to the freezing extender reduced significantly (P &lt; 0.001) the penetration rate (51.4, 17.5, 15.8, 17.8, 9.5, and 4.8% for the 0, 2, 4, 8, 16, and 32 mM pentoxifylline groups, respectively) and the efficiency (monospermic oocytes/total inseminated oocytes) of fertilization (34.8, 14.6, 14.7, 15.5, 7.9, and 4.8% for the 0, 2, 4, 8, 16, and 32 mM pentoxifylline groups, respectively) as compared with the control group (the first value in each of these two cases). It is therefore concluded that pentoxifylline added to the freezing extender has a deleterious effect on post-thaw boar sperm quality and on their ability to fertilize the oocytes in vitro. This work was supported by CICYT (AGL05-0471).

Effect of activators and the phosphodiesterase inhibitors Pentoxifylline and Enoximone on the deformability of neutrophils in neonates and adults

Stimulated polymorphonuclear leukocytes (PMN) are extremely rigid compared to resting PMN. They may obstruct narrow vessels and contribute to ischaemic organ injury. Deformability is a prerequisite for both active and passive movement in the microcirculation. The investigation was designed to study whether stimulators and inhibitors of stimulation show different effects on deformability of neonatal and adult PMN. Deformability of PMN was assessed by complete aspiration of a PMN into a micropipette with an internal diameter of 5 microm. Blood samples from 20 neonates and 20 adults were studied before and after stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP), interleukin-8 (IL-8) or tumour necrosis factor-alpha (TNF-alpha). Moreover, effects of the phosphodiesterase inhibitors Pentoxifylline (PTX) and Enoximone on the deformability of stimulated PMN were investigated. fMLP, IL-8 and TNF-alpha significantly delayed aspiration times of PMN in relation to the concentrations of the stimulators. The addition of PTX or Enoximone to stimulated PMN increased the deformability up to 60% depending on the concentration of the inhibitors. No significant differences in the aspiration times were found between neonatal and adult PMN at any of the experimental conditions after activation with the three stimulators and treatment with the two inhibitors. Neonatal and adult PMN show similar reduction of passive deformability when stimulated with either fMLP, IL-8 or TNF-alpha compared to resting PMN and a similar improvement of deformability in response to PTX or Enoximone.

Efeitos da pentoxifilina sobre a viabilidade in vitro dos espermatozóides de eqüinos, após o resfriamento a 5ºC

O objetivo deste trabalho foi avaliar, in vitro, o efeito da adição de 1 mg pentoxifilina por mL de amostras seminais diluídas em meio Kenney, e resfriadas a 5º C, de garanhões normospérmicos, sobre os seguintes parâmetros: taxas de motilidade total e motilidade progressiva, velocidade espermática ao longo da trajetória real, índice retilíneo, taxa de linearidade, velocidade progressiva, taxa de viabilidade e taxa de integridade da membrana plasmática. Foram avaliados 20 ejaculados de quatro garanhões, com o auxílio do Hamilton Thorn Research (Animal Version 12.0 L, EUA), em câmara de Makler. A taxa de viabilidade foi realizada por coloração de eosina e microscopia de contraste e a taxa de integridade de membrana, por coloração com fluorocromos, iodeto de propídio e diacetato de carboxifluoresceina e microscopia de fluorescência. As análises foram realizadas aos 30, 60, e 120 minutos de incubação a 37º C, após 12, 24 e 48 horas de resfriamento a 5ºC. A pentoxifilina incrementou significativamente, em relação ao grupo controle, os parâmetros espermáticos relacionados à motilidade dos espermatozóides e de integridade da membrana plasmática, durante todo o período de incubação, da seguinte forma: taxa de motilidade total em 8,2%; motilidade progressiva em 4,7%; velocidade real em 23,1 mm/s; taxa de espermatozóides com velocidade rápida em 7,4%; taxa de viabilidade em 4,7%; e integridade da membrana plasmática em 3,5 % do tratado. Quanto aos parâmetros índice de retilinidade e linearidade, não foi observada diferença significativa entre os grupos. Os resultados obtidos nas condições deste experimento indicam que a adição de pentoxifilina ao ejaculado resfriado de garanhões, até 48 horas após o resfriamento, pode ser benéfica à qualidade dos espermatozóides para uso na inseminação artificial.

A protocol of electroejaculation and systematic assisted reproductive technology achieved high efficiency and efficacy for pregnancy for anejaculatory men with spinal cord injury

Shieh J-Y, Chen S-U, Wang Y-H, Chang H-C, Ho H-N, Yang Y-S. A protocol of electroejaculation and systematic assisted reproductive technology achieved high efficiency and efficacy for pregnancy for anejaculatory men with spinal cord injury. Arch Phys Med Rehabil 2003;84:535-40. Objective: To help anejaculatory men with spinal cord injury (SCI) to procreate. Design: Prospective, clinical study. Setting: A team of physiatrists, urologists, and gynecologists at a university hospital in Taiwan. Participants: Ten infertile men with SCI seen at our hospital between 1995 and 2001. Interventions: Electroejaculation induced their seminal emission. Depending on semen parameters, the couples were treated with intrauterine insemination (IUI), intracytoplasmic sperm injection (ICSI), surgical retrieval of sperm, cryopreservation of sperm, or donor sperm. Main Outcome Measures: Fertilization and pregnancy. Results: Ten couples underwent assisted reproductive technology (ART). One couple achieved pregnancy after the second cycle of electroejaculation and IUI. Seven couples underwent 8 cycles of ICSI, 4 cycles with fresh electroejaculates, 2 with cryopreserved samples, and 2 with cryopreserved samples with addition of pentoxifylline. Seven (88%) clinical pregnancies were achieved, 2 of which ended with spontaneous abortion. One couple accomplished pregnancy by ICSI with cryopreserved sperm from vasal aspiration. The percentages of fertilization and pregnancy of ICSI cycles using sperm from men with SCI were comparable to men without SCI. One couple attained pregnancy by using donor sperm. The cumulative successful pregnancy rate per couple was 80% (8/10). Conclusion: Electroejaculation and systematic ART are highly efficient for achieving pregnancy with the spouses of men with SCI. The neurologic deficit and electroejaculation did not affect the outcome of ICSI. Using cryopreserved sperm for ICSI may reduce risk from electroejaculation or surgery.

Effect of pentoxifylline on motility and membrane integrity of cryopreserved human spermatozoa.

The purpose of this study was to examine the effects of pentoxifylline used before and after semen cryopreservation-thawing on sperm motility and membrane integrity. Twenty-four semen samples were split into four equal aliquots. Aliquots were incubated at 37 degrees C for 30 min, followed by cryopreservation with TEST-yolk freezing medium using slow programmable freezing protocol. After 2 weeks the sperm samples were thawed, washed twice in Quinn's Sperm Washing Medium (modified HTF with 5.0 mg/mL Human Albumin) and incubated at 37 degrees C for 30 min. Aliquots were treated by adding 3 mmol/L pentoxifylline to: (1) fresh sperm samples during incubation period prior to cryopreservation, (2) sperm samples as a supplement to the cryoprotectant prior to cryopreservation, and (3) thawed sperm samples during incubation period. One aliquot received no treatment (control group). The addition of 3 mmol/L pentoxifylline to fresh semen during incubation period prior to cryopreservation significantly decreased progressive and total motility compared with controls. However, the addition of 3 mmol/L pentoxifylline to cryopreserved semen after thawing significantly increased progressive and total motility compared with controls. After post-thaw, no differences in motion characteristics between sperm samples treated by adding 3 mmol/L pentoxifylline as a supplement to the cryoprotectant and control groups were observed. Post-thaw hypoosmotic swelling (HOS) test scores did not improve with the addition of pentoxifylline compared with the control group. It is concluded that pentoxifylline enhanced post-thaw motility of cryopreserved human spermatozoa when added after thawing. No improvement was found by freezing sperm with pentoxifylline.

Influence of irradiation and pentoxifylline on histone H3 phosphorylation in human tumour cell lines.

Phosphorylation of histone H3 at Ser-10 correlates with chromatin condensation and this amino terminal modification is now recognized as a specific marker of mitosis. We have monitored the appearance of cells showing histone H3 phosphorylation in four human tumour cell lines to identify cell cycle progression after irradiation. In the human melanoma cell lines Be11 and MeWo and in the squamous cell carcinoma lines 4197 and 4451 a dose of 7 Gy of Co-gamma irradiation increases the number of cells binding anti-histone H3-P antibody 1-8-fold in a p53-independent manner. In the p53 mutant cell lines MeWo and 4451 H3-P phosphorylated cells can be detected as early as 30 min and show a maximum 1 h post-irradiation. In the cell lines Be11, 4197 and 4451 the early wave of H3 phosphorylated cells is followed by a second wave, which reaches a maximum 4.5-7 h post-irradiation and then declines. These events are attributed to damage-induced cell cycle blocks in the G1 and G2 phase of the cell cycle. Addition of the dose modifying drug pentoxifylline before irradiation increases the appearance of cells showing early and the late H3 phosphorylation. When pentoxifylline is added 12-24 h post-irradiation when the cell cycle blocks have reached their maximum the appearance of cells with phosphorylated H3 increases 3-5-fold in the p53 mutant cell lines MeWo and 4451. These observations are consistent with the function of the drug as a G2 block abrogator. The large H3 phosphorylation signal in p53 mutant cells is consistent with early entry of a cohort of G2 cells into mitosis. The smaller H3-P signal in p53 wild type cells correlates with the lower proportion of stable G2 populations in G1 blocked cells. These results indicate that pentoxifylline influences the appearance of histone H3 phosphorylated cells in a manner strongly dependent on the number of cells in G2 phase. This suggests that addition of pentoxifylline indeed abrogates the G2 block and thereby facilitates early entry into mitosis.

Effects of Pentoxifylline on Inflammatory Cytokine Expression and Acute Pleuropneumonia in Swine

Pentoxifylline, a methylxanthine derivative and nonspecific type 4 phosphodiesterase inhibitor, has been used to improve survival of animals with sepsis and to attenuate lung injury in acute lung inflammation. The purpose of this study was to examine whether pentoxifylline would inhibit the expression of inflammatory cytokines, particularly tumor necrosis factor alpha (TNF), and thereby decrease the pathophysiology of acute porcine pleuropneumonia. E. coli lipopolysaccharide (LPS) and bacterial extracts of A. pleuropneumoniae--induced elevations in TNF mRNA which were fully abrogated by addition of pentoxifylline in both alveolar macrophage and neutrophil cultures. A 30% reduction in the level of LPS-induced interleukin (IL)-1beta mRNA levels also was achieved in macrophages. Pentoxifylline did not affect either IL-1alpha or IL-8 expression in vitro. Pentoxifylline therapy in vivo significantly reduced the number of band neutrophils in swine but did not reduce the pathology associated with pleuropneumonia, including changes in serum zinc, iron, or haptoglobin. Neither did it alter TNF, IL-1, IL-6, or IL-8 expression. Measurement of pentoxifylline and its metabolites in pig sera suggested that efficacious doses of pentoxifylline were probably not achieved in vivo. However, subcutaneous doses of pentoxifylline higher than 25 mg/kg produced transient diarrhea, vomiting, and tremors. These results suggest that pentoxifylline is an effective pharmacological tool for the dissection of cytokine regulation in vitro, but inhibitory concentrations may not be achievable for in vivo pharmacological use in swine.

Pentoxifylline influences the autocrine function of organ cultured donor corneas and enhances endothelial cell survival

BACKGROUND/AIMSScientific interest in pentoxifylline has been reawakened owing to the recognised effects of this drug on immune functions, particularly its influence on cytokine production. In a previous study, the authors...

Pentoxifylline in Perforated Peritonitis: Results of a Randomised, Placebo Controlled Trial

To evaluate the role of pentoxifylline as an adjuvant to operation and routine antibiotic treatment for perforated peritonitis. Randomised controlled clinical trial. University hospital, India. 36 patients with clinically diagnosed and radiologically confirmed perforated peritonitis. 22 (61%) had typhoid enteric perforations, 11 (31%) had duodenal ulcer perforations while 3 (8%) had perforated gastric ulcers. Laparotomy with closure of perforation and lavage together with routine antibiotic treatment (ciprofloxacin and metronidazole), and random allocation to pentoxifylline 200 mg/day for 3 days in 500 ml of saline over 3-4 hours or saline alone (n = 18 in each group). Hospital stay, APACHE II scores, and the condition of the wound during the postoperative period. The baseline characteristics of the two groups were essentially similar. However, their preoperative APACHE II scores differed significantly (mean (SD) 12 (3) in the pentoxifylline group compared with 10 (2) in the saline group; p <0.01). The outcome was better in the pentoxifylline group in terms of significantly reduced hospital stay (median 8, range 6-17, compared with 11, 7-27, p=0.02) improved postoperative APACHE II scores (mean (SD) 8 (2) compared with 9 (2), p=0.02), and reduced incidence of wound infection (6/18 compared with 12/18, p=0.02). The addition of pentoxifylline to our standard management protocol for patients with perforated peritonitis helped to improve their outcome significantly compared with a placebo-treated group.

Abrogation of G(2)/M-phase block enhances the cytotoxicity of daunorubicin, melphalan and cisplatin in TP53 mutant human tumor cells.

Irradiation of human melanoma (MeWo, Be11) and squamous cell carcinoma (4451, 4197) cells induces cell cycle blocks from which the cells recover to re-enter mitosis after 40-60 h. In the TP53 mutant cell lines, MeWo and 4451, irradiation induces a G(2)-phase block, where the fraction of cells in G(2) phase reaches a maximum after 18-20 h. In the TP53 wild-type cell lines, 4197 and Be11, a G(1)- and G(2)-phase block is reached 12 and 16 h postirradiation, respectively. Addition of pentoxifylline after irradiation at the time when the number of cells in G(2) phase has reached a maximum shortens the normal recovery from G(2)-phase block to approximately 7 h. Addition of daunorubicin, melphalan and cisplatin under these conditions markedly enhanced drug toxicity. In the TP53-mutated cell lines MeWo and 4451, the survival ratio at 7 Gy measured by colony formation was 2.3-2.8, 8.6-85 and 52-74 for daunorubicin, melphalan and cisplatin, respectively. In the TP53 wild-type cell lines, the corresponding survival ratios were found to be 1.3-1.4, 2.3-3.0 and 1.2-2.6, respectively. The survival ratios are for clonogenic survival after 7 Gy and 2 mM pentoxifylline and measure the influence of drug doses that ensure 95% survival in nonirradiated controls. The results indicate that the G(2)-phase block is a crucial event in the damage response that can be manipulated to achieve a significant enhancement of drug toxicity. These effects are particularly pronounced in TP53 mutant cells and are observed at drug doses well below the clinical range.

The use of pentoxifylline to improve motility of cryopreserved equine spermatozoa

Pentoxifylline was evaluated as a method to increase motility of cryopreserved equine spermatozoa. In a preliminary experiment, pentoxifylline (3.5 mM or 7.0 mM) was added to extended semen that was chilled to 4°C. Motility was evaluated at 8-h intervals for 48 h. The addition of 3.5 or 7.0 mM pentoxifylline appeared to increase the motility of chilled spermatozoa compared to controls. Based on these results, similar concentrations of pentoxifylline were added to semen either before or after cryopreservation. The addition of pentoxifylline (3.5 or 7.0 mM) to semen before cryopreservation significantly (P < 0.001) decreased total and progressive motility compared to controls. However, the addition of pentoxifylline (3.5 or 7.0 mM) to cryopreserved semen immediately after thawing significantly (P < 0.01) increased total and progressive motility compared to controls. These results indicate that pentoxifylline enhanced the postthaw motility of cryopreserved equine semen when added after thawing. Further research is required to evaluate the effect of pentoxifylline on the fertility of cryopreserved equine semen.

Influence of the G2 cell cycle block abrogator pentoxifylline on the expression and subcellular location of cyclin B1 and p34cdc2 in HeLa cervical carcinoma cells.

The progression of cells from G2 into mitosis is mainly controlled by formation of the cyclin B1/p34cdc2 complex. The behaviour of this complex in the irradiation-induced G2 cell cycle delay is still unclear. A prior study demonstrated that the expression of the cyclin B1 protein is reduced by irradiation, and restored to control levels by the methylxanthine drug pentoxifylline, which is a potent G2 block abrogator. The present study shows that irradiation, and 2 mM pentoxifylline affect the expression of the cyclin-dependent kinase p34cdc2 in HeLa cells. Irradiation induces p34cdc2 levels to increase and cyclin B1 levels to decrease. Addition of pentoxifylline at the G2 maximum reverses these trends. This is also evident from the cyclin B1/p34cdc2 ratios which decline after irradiation and are rapidly restored to control levels upon addition of pentoxifylline. It is concluded that cyclin BI and p34cdc2 protein expression are important events and act in concert to control the irradiation induced G2 block. Analysis of cyclin B1 expression in whole cells and in isolated nuclei furthermore show that cyclin B1 is translocated from the nucleus into the cytoplasm when the G2 block is abrogated by pentoxifylline.

Cryopreservation of human spermatozoa with pentoxifylline improves the post-thaw agonist-induced acrosome reaction rate.

Cryopreservation causes extensive damage to spermatozoa, thereby impairing their fertilizing ability. The purpose of this study was to determine if the direct addition of pentoxifylline to the seminal plasma before cryopreservation improved sperm motility and acrosome reaction. Semen specimens from 15 healthy volunteers were divided into two aliquots. One aliquot was treated by adding 5 mM pentoxifylline directly to the seminal plasma (treatment group) and the other aliquot received no treatment (control group). Both aliquots were then cryopreserved by using the liquid nitrogen freezing method. The percentage of motile spermatozoa and various motion characteristics were then evaluated by performing computer-assisted semen analysis. The sperm viability was determined with a supra-vital dye, Hoechst-33258, and the acrosome reaction (spontaneous and calcium ionophore-induced) was monitored using fluorescein isothiocyanate-conjugated peanut lectin (FITC-PNA) binding assays. Pentoxifylline treatment significantly increased the sperm motility, the amplitude of lateral head displacement, the hyperactivation status, and the frequency of spontaneous acrosome reactions before freezing (P < 0.05). After post-thaw, no difference in motion characteristics (except percentage motility) between treated and control groups were observed. Acrosome loss due to the freeze-thaw process was less in the pentoxifylline-treated group (P = 0.0003). In addition, the percentage of cryopreserved acrosome-intact spermatozoa that underwent further acrosome reactions in response to calcium-ionophore challenge was significantly higher in the treated group (P = 0.03). Pentoxifylline treatment before freezing improved the acrosome reaction to ionophore challenge in cryopreserved spermatozoa. Treatment with pentoxifylline appears to minimize sperm damage during the freeze-thaw process and may improve fertilization rates with assisted reproductive procedures such as intrauterine insemination or in-vitro fertilization.

Controlled reperfusion and pentoxifylline modulate reperfusion injury after single lung transplantation

Objective: Rodent models have suggested that initial low-pressure reperfusion of transplanted lungs reduces injury after ischemia. We investigated this phenomenon and the use of pentoxifylline in a porcine model of left single lung transplantation. Methods: Donor lungs were preserved with Euro-Collins solution for a mean ischemic time of 18.4 hours. Neutrophil trapping in the graft, pulmonary artery pressure, and gas exchange were assessed over a 12-hour period. Partial occlusion of the contralateral pulmonary artery allowed manipulation of the pulmonary artery pressure in the transplanted lung. Group A ( n = 5) was perfused at a mean pulmonary artery pressure of 20 mm Hg, group B was reperfused at a mean pulmonary artery pressure of 45 mm Hg for 10 minutes before reducing the pressure to the same as group A, and group C was reperfused at a mean pressure of 20 mm Hg for 10 minutes, then increased to a mean of 45 mm Hg for the remainder of the experiment. Group D was reperfused as in group A with the addition of intravenous pentoxifylline. Results: Leukocyte sequestration was observed in the first 10 minutes after reperfusion in groups A, B, and C, with maximal sequestration at 2 minutes. Significantly more sequestration was observed in the first 6 minutes in group B than in groups A and C, which were similar. Pentoxifylline significantly reduced leukocyte sequestration. Pulmonary venous oxygen tension in the allograft lung was worst in group B. Groups A and C were similar, but group D was superior to all other groups ( p < 0.001). Conclusions: Low-pressure reperfusion, even when limited to the first 10 minutes, modulates reperfusion injury possibly through a leukocyte-dependent mechanism. The addition of pentoxifylline in the recipient confers significant additional benefit. (J Thorac Cardiovasc Surg 1998;115:1335-41)

Extracellular SOD: Pathophysiologic importance and modulation of nitric oxide responses: [formula omitted], National Jewish Medical and Research Center, Denver, CO 80206

Shieh J-Y, Chen S-U, Wang Y-H, Chang H-C, Ho H-N, Yang Y-S. A protocol of electroejaculation and systematic assisted reproductive technology achieved high efficiency and efficacy for pregnancy for anejaculatory men with spinal cord injury. Arch Phys Med Rehabil 2003;84:535-40. Objective: To help anejaculatory men with spinal cord injury (SCI) to procreate. Design: Prospective, clinical study. Setting: A team of physiatrists, urologists, and gynecologists at a university hospital in Taiwan. Participants: Ten infertile men with SCI seen at our hospital between 1995 and 2001. Interventions: Electroejaculation induced their seminal emission. Depending on semen parameters, the couples were treated with intrauterine insemination (IUI), intracytoplasmic sperm injection (ICSI), surgical retrieval of sperm, cryopreservation of sperm, or donor sperm. Main Outcome Measures: Fertilization and pregnancy. Results: Ten couples underwent assisted reproductive technology (ART). One couple achieved pregnancy after the second cycle of electroejaculation and IUI. Seven couples underwent 8 cycles of ICSI, 4 cycles with fresh electroejaculates, 2 with cryopreserved samples, and 2 with cryopreserved samples with addition of pentoxifylline. Seven (88%) clinical pregnancies were achieved, 2 of which ended with spontaneous abortion. One couple accomplished pregnancy by ICSI with cryopreserved sperm from vasal aspiration. The percentages of fertilization and pregnancy of ICSI cycles using sperm from men with SCI were comparable to men without SCI. One couple attained pregnancy by using donor sperm. The cumulative successful pregnancy rate per couple was 80% (8/10). Conclusion: Electroejaculation and systematic ART are highly efficient for achieving pregnancy with the spouses of men with SCI. The neurologic deficit and electroejaculation did not affect the outcome of ICSI. Using cryopreserved sperm for ICSI may reduce risk from electroejaculation or surgery.