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PubMed1985

Studies on Genetic Male-Sterile Soybeans : IV. Effect of Male Sterility and Source of Nitrogen Nutrition on Accumulation, Partitioning, and Transport of Nitrogen.

Soybean (Glycine max [L.] Merr.) germplasm, isogenic except for loci controlling male sterility (ms(1)) and nodulation (rj(1)), was used to investigate the effects of reproductive tissue development and source of nitrogen nutrition on accumulation, transport, and partitioning of nitrogen in a greenhouse experiment. Nodulated plants were supplied nitrogen-free nutrient solution, and nonnodulated plants were supplied nutrient solution containing 20 millimolar KNO(3). Plants were sampled from flowering until maturity (77 to 147 days after transplanting).Accumulation rates of nitrogen in whole plants during reproductive growth were not significantly different among the four plant types. Nitrogen accumulation in the sterile, nonnodulated plants, however, ceased 2 weeks earlier than in fertile, nonnodulated or fertile and sterile, nodulated plants. This early cessation in nitrogen accumulation resulted in sterile, nonnodulated plants accumulating significantly less whole plant nitrogen by 133 days after transplanting (DAT) than fertile, nonnodulated plants. Thus, changing the site of nitrogen assimilation from nodules (N(2)-fixing plants) to roots and leaves (NO(3)-fed plants) resulted in similar whole-plant nitrogen accumulation rates in fertile and sterile plants, despite the absence of seed in the latter.Leaflet and stem plus petiole tissues of both types of sterile plants had significantly higher nitrogen concentrations after 119 DAT than both types of fertile plants. Significantly higher concentrations and exudation rates of nonureide, reduced-nitrogen in xylem sap of sterile than of fertile plants after 105 DAT were observed. These latter results indicated possible cycling of nonureide, reduced-nitrogen from the downward phloem translocation stream to the upward xylem translocation stream in roots of sterile plants. Collectively, these results suggest a lack of sinks for nitrogen utilization in the shoots of sterile plants. Hence, comparison of nitrogen accumulation rates for sterile and fertile plants does not provide a definitive test of the hypothesis that reproductive tissue development limits photosynthate availability for support of N(2) fixation and nitrate assimilation in determinate soybeans.Nitrogen assimilation during reproductive growth met a larger proportion of the reproductive-tissue nitrogen requirement of nitrate-dependent plants (73%) than of N(2)-fixing plants (63%). Hence, vegetative-tissue nitrogen mobilization to reproductive tissue was a more prominent process in N(2)-fixing than in nitrate-dependent plants. N(2)-fixing plants partitioned nitrogen to reproductive tissue more efficiently than nitrate-dependent plants as the reproductive tissues of the former and latter contained 65 and 55%, respectively, of the whole-plant nitrogen at the time that nitrogen accumulation in reproductive parts had ceased (133 DAT).

Journal Article↗
PubMed2002

Re-examination of sibling cross-sterility in the ascidian, Ciona intestinalis: genetic background of the self-sterility.

Self-sterility of solitary ascidians is a typical example of the allogeneic recognition, though its molecular mechanism remains an open question. In this paper we analyze the fertility between siblings from selfed and crossed eggs to understand the genetic basis of self-sterility in the ascidian, Ciona intestinalis. First, we show that the self-sterility is strict and stable, and the individuality expressed in gametes is highly diversified in the wild population that we used. Secondly, we show one-way cross-sterility and reciprocal cross-sterility within the siblings that are self-sterile but fertile with non-siblings. Thirdly, we show self-sterility and cross-sterility share some natures and both are closely related to the sperm capacity not to bind to the vitelline coat of the autologous eggs or the eggs sterile to the sperm concerned. In all, this paper shows that the self-sterility is genetically governed by a multiple-locus system, and that most probably individual-specific determinants are haploid expression in sperm and diploid expression in eggs, given they recognize self but not non-self.

Acids↗
PubMed2003

Fertility and reproductive history of sterilized and non-sterilized women in Campinas, São Paulo, Brazil.

This article compares sterilized and non-sterilized women in relation to socio-demographic characteristics, reproductive history, and cohabitation status. Women from 30 to 49 years of age and residing in Campinas, São Paulo State, Brazil, were interviewed with a pre-tested and structured questionnaire: 236 women sterilized at least five years before the interview and 236 non-sterilized women. The sterilized women were significantly more likely to be married or cohabiting, to be younger when they began cohabiting, and to have been in the union longer than the non-sterilized women. They also began childbearing at an earlier age and had a history of more pregnancies and more live births than non-sterilized women. Factors associated with a history of 3 or more live births at the time of the interview were surgical sterilization, younger age at first childbirth, older age at the interview, recognition of fewer contraceptive methods, and lower per capita income. The article concludes that sterilization generally appears to be the consequence of higher fertility in a group of women who initiate childbearing early in life, although its role in preventing these women from having even larger families may also have a demographic impact.

Adult↗
PubMedDate not supplied

Design and use of a novel peracetic acid sterilizer for absolute barrier sterility testing chambers.

Increasing use is being made of absolute barrier chambers in the pharmaceutical industry for sterility testing of sterile pharmaceuticals. Since these barriers are designed to form a microbial-tight enclosure to eliminate laboratory microbial contamination derived from the operator and the environment,it is important that the method used to sterilize these barriers, product containers, and articles used within, provide a high degree of sterility assurance. A major part of incorporating absolute barriers in the sterility testing laboratory at the Upjohn Company was to design an automated sterilization system to facilitate the spraying of a liquid sterilant, e.g., peracetic acid, inside these barriers. This article focuses on general design considerations, specific details of the apparatus, and the operational steps. The sterilization efficacy of this method is also described, with particular emphasis on validation criteria and results. Finally, operational sterility testing results are discussed.

Equipment Contamination↗
PubMed1987

[Sterilization of the female with special reference to laparoscopic tubal sterilization].

Within recent years female sterilization has gained a place of great importance as an effective contraceptive method. Nowadays sterilization is hardly subject to any formal restrictions, but is solely the responsibility of the woman concerned, the couple or the physician. The indications for sterilization may be divided into two main groups, namely for medical indications and family planning. Sterilization is carried out on the uterus or tubes. Today the method of choice is laparoscopic tubal sterilization. The most frequently used procedure and the safest way of tubal occlusion is bipolar electrocoagulation of the entire isthmic tubal portions without additional section of the tubes. The complication rate in laparoscopic tubal sterilization depends on the type of anaesthesia, on the skill of the operator and on patient risk factors such as obesity etc. Minor intraoperative complications are of little importance since they are easily remedied during laparoscopy. Severe complications are rare, but have to be corrected immediately by laparotomy. Pregnancies on account of failure in sterilization procedure may be due to the occlusion technique, the lack of experience of the operator, the timing of sterilization and the observation period. Altogether 2372 laparoscopic tubal sterilizations were performed at the University Department of Obstetrics and Gynaecology in Graz between January 1st, 1975 and December 31st, 1985. During these eleven years a specific technique has been developed, whereby standard methods were simplified and improved. No intrauterine cannula for mobilizing the uterus is applied to avoid infection or perforation. The preferred "single-puncture technique" offers many advantages over the older "double-puncture technique", since fewer instruments are needed and the operation is less time-consuming, eliminating the danger of a second puncture. Moreover, the procedure is easier to perform and the cosmetic result better. In high-risk patients, especially the extremely obese, the laparoscopic technique has been improved by a special method of introducing the trocar.

Female↗
PubMed1992

Sterilization needs in the 1990s: the case for quinacrine nonsurgical female sterilization.

Much evidence suggests that demand for sterilization is a function of supply of surgical sterilization services in less-developed countries. If such services were greatly expanded, the number of procedures performed would grow dramatically. While the prevalence of sterilization is estimated to increase from 23.5% to 28.8% of married women of reproductive age in the 1990s, there will actually be 106,432,000 more couples of reproductive age at the end of this decade than at its beginning who use either no method or a far less effective method with much lower continuation rates than sterilization--nearly a 20% increase. To achieve a mean sterilization prevalence of 47% of married women of reproductive age in the less-developed world, as now seen in the Republic of Korea and Puerto Rico, the number of sterilizations would need to be more than double the current projection for the 1990s: 328,429,000 rather than 159,000,000. The quinacrine pellet method for nonsurgical female sterilization offers hope that this enormous shortfall in sterilization services can be overcome in this decade.

Adult↗