Induction, structural characterization, and genome sequence of Lv1, a prophage from a human vaginal Lactobacillus jensenii strain.

The prophage Lv1, harbored by a vaginal Lactobacillus jensenii isolate, was induced by several different anticancer, antimicrobial, and antiseptic agents, suggesting that they contribute to the adverse vaginal effects associated with their therapeutic use. Of special interest with respect to its novelty was the inducing effect of nonoxynol-9, a non-ionic detergent commonly used as a spermicide. The Lv1 genome consists of a 38,934-bp dsDNA molecule with cohesive ends, in which 48 ORFs were recognized, and is organized into functional modules. Lv1 belongs to the family Siphoviridae and, more precisely, to the proposed Sfi21-like genus. The capsid-tail junction of the Lv1 virions is fragile such that most particles become disrupted, suggesting that the virus is defective and thus unable to generate fertile progeny. However, genome analysis did not provide evidence of the defective nature of the prophage, other than the finding that its genome is shorter than those of other, related, phages. Further analysis indicated that prophage Lv1 suffered deletions in its right half to the extent that it no longer fulfill the minimum packaging limits, thereby generating the observed unstable particles.

Sperm competition: discrimination isn't always bad.

Observing sperm in competition has been limited by our ability to discriminate between males' sperm. Recent work has overcome this obstacle, while another study reports on seminal fluid with very specific spermicidal activity, suggesting discrimination is easy for some.

Simultaneous removal of sperm plasma membrane and acrosome before intracytoplasmic sperm injection improves oocyte activation/embryonic development.

Direct injection of a single spermatozoon into an oocyte (ICSI) can produce apparently normal offspring. Although the production of normal offspring by ICSI has been successful in mice and humans, it has been less successful in many other species. The reason for this is not clear, but could be, in part, due to inconsistent activation of oocytes because of delayed disintegration of sperm plasma membrane within oocytes and incorporation of the acrosome containing a spectrum of hydrolyzing enzymes. In the mouse, the removal of sperm plasma membrane and acrosome was not a prerequisite to produce offspring by ICSI, but it resulted in earlier onset of oocyte activation and better embryonic development. The best result was obtained when spermatozoa were demembranated individually immediately before ICSI by using lysolecithin, a hydrolysis product of membrane phospholipids.

Synthesis and spermicidal activity of a putative nitric oxide-releasing derivative of nonoxynol-9.

OBJECTIVES: We report on the synthesis of a potential nitric oxide releasing derivative of nonoxynol-9 (N9). METHODS: This derivative was synthesised via AgNO3 mediated nitroxylation of a chloride derivative of a N9 which itself was synthesised by thionyl chloride mediated chlorination of N9. In an initial in vitro study the spermicidal efficacy of the nitric oxide derivative and the parent compound (N9) was examined using boar spermatozoa. Sperm motility and viability were examined. RESULTS: The data showed that nitroxylation of N9 did not disrupt spermicidal activity; both sperm motility and viability were comparable between N9 and its nitroxylated derivative. For both compounds, low doses (1-10 microg/mL) were sufficient to induce significant immobilization of sperm after 1 min, whereas concentrations of 10-100 microg/mL were required to achieve significant increase in membrane permeability. CONCLUSION: The results show that a nitric oxide-releasing derivative of N9 retains the spermicidal activity of the parent compound and may have other beneficial effects associated with the release of NO.

Compatibility between the spermicide nonoxynol 9 and mid-cycle human cervical mucus.

The rate of diffusion of [125I]-nonoxynol 9 into mid-cycle human cervical mucus was measured and found to be negligible compared with D-glucose (used as an uncharged small molecule for comparison with nonoxynol 9). These data were confirmed by observation of the lack of inhibition of the movement of spermatozoa in mucus that had been in surface contact, for 3 hours, with a concentration 30 times greater than the ED100 of nonoxynol 9. These results show that the entry of nonoxynol 9 into mucus could be minimal under conditions that would exist in vivo and highlights a limitation of this compound as a vaginal contraceptive.

PIP: Obstetrician-gynecologists and chemists analyzed data on midcycle cervical mucus samples from normally cycling women attending the infertility clinic at the University Hospital of South Manchester, England, to determine the ability of nonoxynol-9 to diffuse into the mucus, thereby testing its spermicidal activity. They used the double diffusion test. They compared diffusion depths of radiolabelled nonoxynol-9 at 120 minutes with those of D-glucose, an uncharged small molecule. They compared the depths of these 2 methods with those of controls containing Tyrode's solution. Migration of spermatozoa in 6 nonoxynol-9 rectangular capillaries was greater than the Tyrode controls, lower in 5 capillaries, and the same in 9 capillaries. Thus, no difference in spermatozoal penetration into midcycle cervical mucus existed between nonoxynol-9 and Tyrode's solution. Further, a 62% concentration of D-glucose was evident in the 1st 5 mm of the cervical mucus column at 2 hours and the concentration fell exponentially. The chemists cold still detect D-glucose at 30 mm at 2 hours. On the other hand, they detected nonoxynol-9 at a 6 times lower concentration than D-glucose in the 1st 5 mm at 2 hours, but could not detect it beyond 5 mm. This meant that, in vivo, only 10% of nonoxynol-9 would be in the interfacial zone of the cervical mucus and not at greater depths. If these results hold true, the ability of nonoxynol-9 to act as a contraceptive and a means to destroy HIV would be limited in the upper genital tract and the cervix. In conclusion, nonoxynol-9's spermicidal activity in midcycle cervical mucus is considerably lower than it is in free solution.

Same day appearance of orally administered, spermicidal 1-substituted imidazoles in dog ejaculates.

Within hours after administration of high oral doses of ketoconazole to males of various species, the intact compound appears in the seminal plasma, leading to immobilization of spermatozoa in ejaculates collected several hours later. The present report describes in vitro and in vivo characterization studies of several new compounds identified from a series of 1-substituted imidazole compounds. Relative rank order of in vitro potencies of the four compounds studied was RS-29984 greater than RS-90847 greater than RS-41353 greater than RS-68287. Oral administration of single doses of these compounds ranging between 10 and 95 mg/kg, followed by ejaculation of the animals at various times after dosing, showed that their relative potencies for decreasing sperm motility were RS-41353 greater than RS-68287 = RS-90847 greater than RS-29984. Four hours after animals were given 30 mg/kg of RS-41353, spermatozoa in the ejaculates had zero forward progression within 30 to 40 minutes after the start of ejaculation. A preliminary metabolic study indicated that the apparently greater potency of RS-68287 in vivo than in vitro was probably not due to metabolic activation. The androgen-suppressing activity of RS-29984 and RS-90847 was shown to be less than that of ketoconazole. These data indicate that orally active inhibitors of sperm motility that exert their effects after ejaculation may be feasible, and suggest that this novel approach to male contraception warrants further investigation.

Bacteriology of cervix in cases of infertility: effect on human sperm.

Microorganisms such as Escherichia coli, Pseudomonas aeruginosa, and Bacillus subtilis isolated from cervices of infertile females possessed spermicidal activity. They also agglutinated the human spermatozoa in vitro and showed tail-to-tail agglutination. Cell-free supernatant of these organisms was found to be spermicidal but did not agglutinate spermatozoa in vitro. Spermicidal activity was increased with increase in age of the culture.

Absorption from the vagina.

PIP: Methods and results are reviewed of research on the permeability of the vagina to a wide variety of compounds including steroids, prostaglandins (PGs), antimicrobials, proteins, antigens, and hormones, nonoxynol-9, methadone, and inorganic compounds. Although the literature indicates that the vagina is capable of absorbing a wide variety of organic and inorganic compounds, quantitative data on the extent of absorption are often lacking. Most steroids were readily absorbed and their bioavailability after intravaginal instillation was greater than after oral administration because of a reduced first-pass effect. Natural and synthetic PGs were absorbed; the extent of absorption ranged from 10-43% of the dose. Penicillin and sulfanilamide exhibited extremely variable absorption from the vagina. In most women neither econazole, miconazole, nor clotrimazole were effectively absorbed. In 1943 it was demonstrated that proteins could be absorbed from the vagina. Data on human absorption of nonoxynol-9 are indirect but are consistent with absorption. Methadone, povidone-iodine, and potassium permanganate have also been shown to be absorbed through the vagina. The stage of the reproductive cycle may alter the extent of vaginal absorption, but this has been clearly demonstrated for only 1 substance in the rat.^ieng

Transvaginal absorption and disposition of nonoxynol-9 in gravid rats.

The placental transfer, maternal tissue distribution and elimination of [14C]-nonoxynol-9 (25 mg/kg) were studied during the first 6 h in 15-day pregnant rats treated intravaginally. Blood concentrations of 14C reached a maximum of 2.0 +/- 0.06 micrograms/ml in 1 h, declining slowly in 3 h, and remaining steady thereafter. At 6 h, the highest levels of 14C were recorded in the maternal urinary bladder, followed by those in the liver, kidney, adrenal and thyroid. The maternal brain showed lowest uptake of 14C among all tissues examined. After 6 h, the 14C concentrations in the uterus or placenta were similar to that of maternal plasma, whereas the mean concentrations of 14C both in the amniotic fluid and fetus were approx. one-third of that of the maternal plasma. About 44% of the administered dose was absorbed from the vagina, and nearly 17% of the per vaginum applied radioactivity was recovered in the urine and feces over 6 h. The results show that nonoxynol-9 (N-9) is rapidly absorbed into the blood stream from the vagina of gravid rat and that the fetal uptake of 14C is much lower than that of the placenta.