ABSTRACT
Ultrasound is one of the most promising forms of non-invasive contraception and has been studied in several animal models. The objective of the current investigation was to determine the most practical and effective application protocol for dog sterilization. A total of 100 dogs were divided into five equal groups. Group A received 5-min applications three times performed at 48-hr intervals and covering the entire testicular area at frequency of 1 MHz; Group B received 5-min applications three times performed at 48-hr intervals over the dorso-cranial area of the testis at frequency of 3 MHz; Group C received three sequential 5-min applications (at 5-min intervals between applications) covering the entire testicular area at frequency of 1 MHz; Group D received 15-min applications two times performed at 48-hr intervals and covering the entire testicular area at frequency of 1 MHz. The experimental groups' ultrasound had an intensity of 1.5W/cm(2) . The Control Group had the same procedure as Group A, but with the transducer switched-off. Dogs were surgically castrated 40 days following the treatment for histological examination. Azoospermia, testicular volume reduction and apparently irreversible testicular damage were achieved by Group A. No effects were noticed in the other groups. Testosterone levels remained within physiological range with all application protocols. A regimen of three applications of ultrasound at 1 MHz, and 1.5 W/cm(2) , lasting 5 min with an interval of 48 h was effective as permanent sterilization in the dog without hormonal impact.
Subject(s)
Contraception/veterinary , Sterilization, Reproductive/veterinary , Ultrasonics/methods , Animals , Castration/veterinary , Contraception/methods , Dogs , Male , Sperm Count/veterinary , Sterilization, Reproductive/methods , Testis , Testosterone/bloodABSTRACT
Two methods for transcervical cannulation of the goat were evaluated during a contraception study in 15 adult female Nigerian dwarf and African pygmy goats. Twenty-four transcervical cannulation procedures were conducted in which seven females underwent the procedure 2-3 times. Initially, a rigid 4-mm stainless steel cannula and external light source were used in 19 procedures to introduce the contraceptive compound into the uterus. Placement of the cannula was directed by feel or depth assessment. Of seven females that were euthanized following this procedure, four evidenced complications including penetration of the cervix with the cannula and cervical damage. A 2-mm custom-made endoscope with a specially designed cannula was then used for the remaining five procedures. No complications were found. A single animal, that underwent the endoscopic procedure twice, was euthanized for study purposes and no abnormal findings of the reproductive tract were reported. The use of an endoscope resulted in better outcomes because the uterus could be visualized after traversing the cervix.
Subject(s)
Endoscopes/veterinary , Goats/anatomy & histology , Hysteroscopy/veterinary , Uterus/anatomy & histology , Animals , Female , Hysteroscopy/adverse effects , Hysteroscopy/methodsABSTRACT
Four linear polyacetylenic compounds were synthesized. Pentadeca-6,8,10-triynoic acid 1 and octadeca-8,10,12-triynoic acid 2 were synthesized by using acetylene coupling reactions. The syntheses of (Z)-hexadec-11-en-7,9-diynoic acid 3 and (Z)-octadec-12-en-7,9-diynoic acid 4 by using vinylic telluride coupling reactions were accomplished.
Subject(s)
Acetylene/analogs & derivatives , Acetylene/chemical synthesis , Fatty Acids, Unsaturated/chemical synthesis , Plants, Medicinal/chemistry , Polymers/chemical synthesis , Acetylene/isolation & purification , Alkynes , Fatty Acids, Unsaturated/isolation & purification , Indicators and Reagents , Magnoliopsida/chemistry , Medicine, Traditional , Molecular Structure , Phytotherapy , Plant Stems/chemistry , Polymers/isolation & purification , PolyynesABSTRACT
PIP: At least 8 new male contraceptives have emerged and most can be used now, but little promotion of these new methods has occurred. No-scalpel vasectomy developed in China consists of a small puncture instead of an incision through which the health worker either cuts or blocks the vas deferens. This technique is safer and heals faster than the conventional technique. The Association for Voluntary Surgical Contraception has a list of US physicians trained in this technique. Another new male contraceptive is injection of chemicals in the vas deferens thereby blocking sperm movement. It is permanent. Research in China shows the injectable plug in the vas deferens to be an effective, potentially reversible method. Similarly the surgically implanted "shug" performs the same purpose as the injectable plug and has the same potential to be reversible. Another method is injection of a spermicide into the vas deferens which temporarily brings about infertility. Animal trials indicate it is safe and effective. Human trials are now going on in India and will soon be underway in the US. The wet heat method has been known since the 4th century B.C. It involves placing the testes in hot water (116 degrees Fahrenheit) for 45 minutes every night for 3 weeks. This provides protection for 6 months. A similar method is artificial cryptorchidism where men wear special underwear during the day to keep the testes inside the inguinal canal which increases their temperature. Applying ultrasound to the testes for 10 minutes once every 6 months also brings about azoospermia. Ultrasonography requires physician intervention but wet heat and artificial cryptorchidism do not. Funding agencies have not provided monies to male contraception research, claiming men are not committed to contraception, yet vasectomies comprise 12% of global contraceptive use. Another excuse is that new male contraceptives do not prevent HIV transmission but neither does Norplant. Men should familiarize themselves with the new male contraceptives and then pressure authorities to sponsor their research and development.^ieng
