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Human Populations
Published in Gary S. Moore, Kathleen A. Bell, Living with the Earth, 2018
Gary S. Moore, Kathleen A. Bell
Sterilization has become one of the most popular methods for contraception in the United States among married couples who have achieved their desired level of parenthood. Male sterilization by vasectomy is usually an outpatient procedure accomplished by making an incision on either side of the scrotum and snipping out a piece of the vas deferens. The two ends of the vas are tied off or cauterized. There is some discomfort in this area for about a week. The risks are minimal and effectiveness in preventing unwanted pregnancies in partners is better than 99 percent. Women may be sterilized by tubal ligation, which is a slightly more involved surgical procedure requiring small incisions near the navel and just above the pubic area. The abdomen is inflated with a gas so the physician can easily locate the fallopian tubes with the fiber-optic light on the laparoscope and tie off or cauterize the tubes. This procedure blocks the entry of eggs into uterus, and eggs released from the ovaries dissolve and are reabsorbed into the body. Tubal ligations are largely reversible while vasectomies have generally not met with similar success at being reversed. However, developments in microsurgical techniques have resulted in a reversal approaching 50 percent depending on the elapsed time since the vasectomy and the skill of the surgeon.60
Assisted reproduction: Brazilian heterosexual couples' testimonies on the care of specialists
Published in Tapuya: Latin American Science, Technology and Society, 2020
The couples that provided testimony all appear as heterosexual, married for 8.07 years on average. Treatment had been carried out for an average of 3.94 years. Women’s average age was 38.3 years; men’s average age was not calculated, due to insufficient information. The average age at which pregnancy was achieved was around 38 years old. Infertility causes were described in detail in only 68 of the 294 testimonies, among which the most frequent included vasectomy (or some other male issue), tube obstruction and endometriosis (13 cases of each). Other causes mentioned included myomas, low ovarian reserves, thrombophilia, uterine polyps, ovary loss, tubal ligation, low sperm motility, azoospermia, varicocele, early menopause, ectopic pregnancy, bladder and rectum nodules, ovarian failure, genetic diseases, implantation problems, and other undefined causes. During pregnancy, complications experienced included abortions, internal hemorrhages and tube loss, movement of the gestational sac, physical and emotional stress, weakness, acid reflux, intrauterine growth restriction, preeclampsia, bleeding, anxiety and depression. The number of failed attempts to achieve pregnancy varied significantly but was more than two in the majority of cases. Twin gestation was mentioned in 50 testimonies; gamete donation and egg reception were mentioned 2 and 6 times, respectively.
A model for phthalic acid esters’ biodegradability and biotoxicity multi-effect pharmacophore and its application in molecular modification
Published in Journal of Environmental Science and Health, Part A, 2021
Mengying Zhou, Jiawen Yang, Yu Li
In addition, PAEs are likely to accumulate in the food chain[25] and impact ecological and human health.[26] Suspected as endocrine disrupting chemicals,[27] PAEs can induce multiple hormone disorders and affect the endocrine system, inducing bone changes, male sperm count reduction, reproductive dysfunction, and even a risk of reproductive cancer after long-term exposure.[28] Moreover, they have harmful effects on the reproduction and development of humans, animals, plant algae, plankton, and fish due to their reproductive toxicity, embryonic toxicity, and genotoxicity.[6] Low molecular weight PAEs (e.g., DEP) can irritate the eyes, nose, and throat, while high molecular weight PAEs (e.g., DEHP, di-iso-nonyl phthalate [DINP] and di-iso-decyl phthalate [DIDP]) have carcinogenic effects on the human body, can damage the liver and kidneys, and affect reproductive organ development.[29] Additionally, DINP can induce single-cell leukemia.[30] In previous studies, after high doses of PAEs were given to mature rats in utero or during lactation, the rats’ thyroid and liver tissues were altered slightly, and their testicular weight decreased, accompanied by vasectomy and weight decreases of the epididymis, seminal vesicle, and prostate.[31–33] Moreover, Kim et al.[34] found that exposure to PAEs has a strong pro-atherogenic effect on human macrophages and skin cells. In addition, PAEs can reduce the heart rate of goldfish by acting on the liver,[35] inhibit and reduce prawns’ cellular immune response,[36] inhibit seedling leaves’ antioxidant capacity and antioxidant enzyme activity, and inhibit chlorophyll synthesis.[37] Ma et al.[38] studied DEHP’s enzyme, cellular, and genetic toxicity in earthworms, reporting the promotion in superoxide dismutase activity and all the tested geno-toxicity parameters and a decrease in peroxidase activity with increasing concentration of DEHP. Moreover, other researchers have demonstrated the relationship between PAE structure and their toxicity. In PAEs with straight side chains that are too short or too long, the disordered degree of biotoxicity is relatively low. By contrast, branching and unsaturated side chains increase PAE toxicity.[39,40]