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Sterile endophthalmitis following intravitreal injection of triamcinolone acetonide.

PURPOSE: To investigate clinical findings and ocular characteristics of sterile endophthalmitis following intravitreal injection (IVI) of triamcinolone for the treatment of macular edema. METHODS: IVI is an institutional practice at our hospital. From March 2002 to January 2003, a total of 21 IVIs of triamcinolone acetonide were performed on 19 patients with macular edema secondary to various retinal disorders. Cases diagnosed as sterile endophthalmitis after IVI of triamcinolone were selected for the study. Fisher's discriminant linear analysis was used to determine whether a significant correlation existed between specific ocular features and the occurrence of post-injection sterile endophthalmitis. RESULTS: Five of 21 eyes (23.8%) had sterile endophthalmitis with hypopyon formation after the injection. Of the five sterile endophthalmitis patients, three were pseudophakic with impaired posterior capsule and four had a diagnosis of Irvine-Gass syndrome. The rate of sterile endophthalmitis was significantly higher in pseudophakic patients with impaired posterior capsule (p = 0.0075) and in patients with Irvine-Gass syndrome (p = 0.0008). The best-corrected visual acuity (BCVA) in these patients remained unchanged or even improved when the inflammation subsided. CONCLUSION: Pseudophakia with impaired posterior capsule and the diagnosis of cystoid macular edema due to Irvine-Gass syndrome are two risk factors of sterile endophthalmitis following IVI triamcinolone. No loss of BCVA was noted in the patients with post-injection sterile endophthalmitis.

Adult↗

A novel mouse chromosome 17 hybrid sterility locus: implications for the origin of t haplotypes.

The effects of heterospecific combinations of mouse chromosome 17 on male fertility and transmission ratio were investigated through a series of breeding studies. Animals were bred to carry complete chromosome 17 homologs, or portions thereof, from three different sources-Mus domesticus, Mus spretus and t haplotypes. These chromosome 17 combinations were analyzed for fertility within the context of a M. domesticus or M. spretus genetic background. Two new forms of hybrid sterility were identified. First, the heterospecific combination of M. spretus and t haplotype homologs leads to complete male sterility on both M. spretus and M. domesticus genetic backgrounds. This is an example of symmetrical hybrid sterility. Second, the presence of a single M. domesticus chromosome 17 homolog within a M. spretus background causes sterility, however, the same combination of chromosome 17 homologs does not cause sterility within the M. domesticus background. This is a case of asymmetrical hybrid sterility. Through an analysis of recombinant chromosomes, it was possible to map the M. domesticus, M. spretus and t haplotype alleles responsible for these two hybrid sterility phenotypes to the same novel locus (Hybrid sterility-4). Previous structural studies had led to the hypothesis that the ancestral t haplotype originated through an introgression event from M. spretus or a related species. If this were true, one might expect that (1) M. spretus homologs would be transmitted at a non-Mendelian ratio within the M. domesticus background, and (2) t haplotypes would be transmitted at a ratio closer to Mendelian within the M. spretus background.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Genetics of reproductive isolation in the Drosophila simulans clade: DNA marker-assisted mapping and characterization of a hybrid-male sterility gene, Odysseus (Ods).

In this study, we address the question of whether there exist major genes that cause complete male sterility in the interspecific hybrids of Drosophila and, if they do, how these genes may be characterized at the molecular level. Our approach is to introgress small segments of the X chromosome from Drosophila mauritiana (or Drosophila sechellia) into Drosophila simulans by repeated backcrosses for more than 20 generations. The introgressions are monitored by both visible mutations and a series of DNA markers. We compare the extent of introgressions that cause male sterility with those that do not. If a major sterility factor exists, there should be a sharp boundary between these two classes of introgressions and their breakpoints should demarcate such a gene. Furthermore, if male sterility is the only major fitness effect associated with the introgression, recombination analysis should yield a pattern predicted by the classical three-point cross. Both the genetic and molecular analyses suggest the presence of a major sterility factor from D. mauritiana, which we named Odysseus (Ods), in the cytological interval of 16D. We thus formalize three criteria for inferring the existence of a major gene within an introgression: (1) complete penetrance of sterility, (2) complementarity in recombination analysis, and (3) physical demarcation. Introgressions of Ods from D. sechellia do not cause sterility. Twenty-two introgressions in our collection have breakpoints in this interval of about 500 kb, making it possible to delineate Ods more precisely for molecular identification. The recombination analysis also reveals the complexity of the introgressed segments--even relatively short ones may contain a second male sterility factor and partial viability genes and may also interfere with crossovers. The spermatogenic defects associated with Ods and/or a second factor were characterized by phase-contrast microscopy.

Animals↗

Complex epistasis and the genetic basis of hybrid sterility in the Drosophila pseudoobscura Bogota-USA hybridization.

We analyzed the genetic basis of postzygotic isolation between the Bogota and USA subspecies of Drosophila pseudoobscura. These subspecies diverged very recently (perhaps as recently as 155,000 to 230,000 years ago) and are partially reproductively isolated: Bogota and USA show very little prezygotic isolation but form sterile F1 males in one direction of the hybridization. We dissected the basis of this hybrid sterility and reached four main conclusions. First, postzygotic isolation appears to involve a modest number of genes: we found large chromosome regions that have no effect on hybrid fertility. Second, although apparently few in number, the factors causing hybrid sterility show a remarkably complex pattern of epistatic interaction. Hybrids suffer no hybrid sterility until they carry the "right" allele (Bogota vs. USA) at at least four loci. We describe the complete pattern of interactions between all chromosome regions known to affect hybrid fertility. Third, hybrid sterility is caused mainly by X-autosomal incompatibilities. Fourth, hybrid sterility does not involve a maternal effect, despite earlier claims to the contrary. In general, our results suggest that fewer genes are required for the appearance of hybrid sterility than implied by previous studies of older pairs of Drosophila species. Indeed, a maximum likelihood analysis suggests that roughly 15 hybrid male steriles separate the Bogota and USA subspecies. Only a subset of these would act in F1 hybrids.

Animals↗

Optimal life stage for radiation sterilization of Anopheles males and their fitness for release.

Mating by male Anopheles mosquitoes (Diptera: Culicidae) was evaluated in the laboratory to assess fitness effects of radio-sterilization applied during different life stages of the malaria vectors An. stephensi Liston and An. gambiae Giles sensu stricto. After reproductive sterilization by gamma-irradiation (120 Gy), equal proportions of sterile and fertile (unirradiated) male adults were released into cages with virgin females and allowed to compete for matings. Radio-sterilization was applied when the males were pupae aged 0-7 h or 24-32 h, or adults aged <24 h or 24-55 h. After being radio-sterilized in the adult stage, males of both species competed effectively with unirradiated males, whereas those sterilized in the pupal stage obtained significantly fewer matings than unirradiated males from the same cohort. There was no evidence of females obtaining multiple inseminations. These findings emphasize the need to radio-sterilize males as adults in order to minimize the fitness cost. Such males may be intended for sterile insect technique population suppression or for trial releases of transgenic anophelines.

Animals↗

A simple genetic incompatibility causes hybrid male sterility in mimulus.

Much evidence has shown that postzygotic reproductive isolation (hybrid inviability or sterility) evolves by the accumulation of interlocus incompatibilities between diverging populations. Although in theory only a single pair of incompatible loci is needed to isolate species, empirical work in Drosophila has revealed that hybrid fertility problems often are highly polygenic and complex. In this article we investigate the genetic basis of hybrid sterility between two closely related species of monkeyflower, Mimulus guttatus and M. nasutus. In striking contrast to Drosophila systems, we demonstrate that nearly complete hybrid male sterility in Mimulus results from a simple genetic incompatibility between a single pair of heterospecific loci. We have genetically mapped this sterility effect: the M. guttatus allele at the hybrid male sterility 1 (hms1) locus acts dominantly in combination with recessive M. nasutus alleles at the hybrid male sterility 2 (hms2) locus to cause nearly complete hybrid male sterility. In a preliminary screen to find additional small-effect male sterility factors, we identified one additional locus that also contributes to some of the variation in hybrid male fertility. Interestingly, hms1 and hms2 also cause a significant reduction in hybrid female fertility, suggesting that sex-specific hybrid defects might share a common genetic basis. This possibility is supported by our discovery that recombination is reduced dramatically in a cross involving a parent with the hms1-hms2 incompatibility.

Alleles↗

Persistent sterile leukocyturia is associated with impaired renal function in human immunodeficiency virus type 1-infected children treated with indinavir.

BACKGROUND: Prolonged administration of indinavir is associated with the occurrence of a variety of renal complications in adults. These well-documented side effects have restricted the use of this potent protease inhibitor in children. DESIGN: A prospective study to monitor indinavir-related nephrotoxicity in a cohort of 30 human immunodeficiency virus type 1-infected children treated with indinavir. METHODS: Urinary pH, albumin, creatinine, the presence of erythrocytes, leukocytes, bacteria and crystals, and culture were analyzed every 3 months for 96 weeks. Serum creatinine levels were routinely determined at the same time points. Steady-state pharmacokinetics of indinavir were done at week 4 after the initiation of indinavir. RESULTS: The cumulative incidence of persistent sterile leukocyturia (> or =75 cells/ micro L in at least 2 consecutive visits) after 96 weeks was 53%. Persistent sterile leukocyturia was frequently associated with a mild increase in the urine albumin/creatinine ratio and by microscopic hematuria. The cumulative incidence of serum creatinine levels >50% above normal was 33% after 96 weeks. Children with persistent sterile leukocyturia more frequently had serum creatinine levels of 50% above normal than those children without persistent sterile leukocyturia. In children younger than 5.6 years, persistent sterile leukocyturia was significantly more frequent than in older children. A higher cumulative incidence of persistent leukocyturia was found in children with an area under the curve >19 mg/L x h or a peak serum level of indinavir >12 mg/L. In 4 children, indinavir was discontinued because of nephrotoxicity. Subsequently, the serum creatinine levels decreased, the urine albumin/creatinine ratios returned to zero, and the leukocyturia disappeared within 3 months. CONCLUSIONS: Children treated with indinavir have a high cumulative incidence of persistent sterile leukocyturia. Children with persistent sterile leukocyturia more frequently had an increase in serum creatinine levels of >50% above normal. Younger children have an additional risk for renal complications. The impairment of the renal function in these children occurred in the absence of clinical symptoms of nephrolithiasis. Indinavir-associated nephrotoxicity must be monitored closely, especially in children with risk factors such as persistent sterile leukocyturia, age <5.6 years, an area under the curve of indinavir >19 mg/L x h, and a C(max) >12 mg/L.

Child↗

[Recommendation for validation and routine monitoring of sterilization processes with ethylene oxide for medical devices].

The European Medical Device Directives specifically address sterilization issues in a number of instances. The European Standards for sterilization of medical devices, especially EN 550, EN 554, EN 556 regulate the manufacture, installation and operation of sterilizers as well as the validation of sterilization processes, on using ethylene oxide (EN 550) or moist heat (EN 554) for sterilization. This recommendation is intended as a source of information for conducting validation according to EN 550 and concomitantly for ensuring that the medical devices reprocessed (cleaned, disinfected, packed, sterilized, stored) in the hospital setting or in other healthcare establishments are endowed with the same level of safety with respect to sterility as that of industrially produced and marketed sterile medical devices.

Antisepsis↗

[Usefulness of hysteroscopy in diagnosing sterility].

Sterility is a severe social problem. Using hysteroscopy, which is possible thanks to development of medical technology, seems to be an important improvement in diagnostics and therapy of sterility. The aim of this study is evaluation of the usefulness of hysteroscopy in diagnostics of sterility. There was a group of 106 women with diagnosed primary sterility and 82 women with secondary sterility. Wolf and Storz hysteroscopes were used during examinations, whereas the uterine cavity was dilated by CO2 using Wolf Metrometer 2121. During this examination a normal uterine cavity was found in most cases (32.9%). The next findings were: endometrial polyps (27.6%), intrauterine adhesions (23.4%), sub-serous myomas (14.3%), and congenital uterine abnormalities (1.5%). Comparing outcomes of hysteroscopy in both groups of sterile women, the high rate of intrauterine adhesions in the secondary sterility (43.9%) was detected. Performing hysteroscopy in patients with sterility increases considerably the range of informations about reproductive organs. Also the possibility of eye-controlled biopsy, deliberation of intrauterine adhesions or removing of endometrial polyps during endoscopic procedure increases the value of hysteroscopy.

Adult↗

Genetic basis of hybrid male sterility among three closely related species of Drosophila.

The genetic basis of hybrid male sterility among three closely related species, Drosophila bipectinata, D. parabipectinata and D. malerkotliana has been investigated by using backcross analysis methods. The role of Y chromosome, major hybrid sterility (MHS) genes (genetic factors) and cytoplasm (non-genetic factor) have been studied in the hybrids of these three species. In the species pair, bipectinata--parabipectinata, Y chromosome introgression of parabipectinata in the genomic background of bipectinata and the reciprocal Y chromosome introgression were unsuccessful as all males in second backcross generation were sterile. Neither MHS genes nor cytoplasm was found important for sterility. This suggests the involvement of X-Y, X-autosomes or polygenic interactions in hybrid male sterility. In bipectinata--malerkotliana and parabipectinata--malerkotliana species pairs, Y chromosome substitution in reciprocal crosses did not affect male fertility. Backcross analyses also show no involvement of MHS genes or cytoplasm in hybrid male sterility in these two species pairs. Therefore, X- autosome interaction or polygenic interaction is supposed to be involved in hybrid male sterility in these two species pairs. These findings also provide evidence that even in closely related species, genetic interactions underlying hybrid male sterility may vary.

Animals↗

[Male sterility. Experience of an andrologist].

Male sterility is taken as a paradigm for a new approach to andrology. Although known about since Antiquity, responsibility of man in conjugal sterility has only been recognized in the last half century. All the same, even to day, it is not always accepted: although apparently obsolete since women's sexual liberation, this denial often manifests itself in patients behaviour, as well as in their doctor's. Until now, as far as we know, no andrologist has taken into account this strange denial. The aim of this paper is to draw attention to the need for the andrologist to be aware of it in his approach to the sterile man. History of male sterility emphasizes the coexistence, since Antiquity, of two opposite preoccupations, those of doctors thoughtful of proving male sterility existence and those of philosophers, often determined to deny it. Steps of knowledge as well as social structures institutionalizing its dissembling are described. Sexual liberation which claimed to put and end to women's dependence on men is often illusory; acceptance of equality of sexes by men is often more apparent that real. At present, the medicalization of male sterility leads some patients and even some doctors to an activist behaviour which demonstrate their inability to accept even the concept of man sterility. In our opinion, to be an andrologist in the full sense of the word means not only to know the biology of reproduction and the progresses of research in this domain, but also and mainly to be aware of the permanence of prejudices and fantasies infallibly conveyed by the idea of sterility in every one, andrologist included.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗

Chromosomal and genic sterility of hybrid type in mice and men.

Three mouse models of male-limited, hybrid-type sterility are available: the sterility controlled by the T-t genetic complex, the hybrid sterility system including the Hst-1 gene, and the sterility of carriers of various chromosomal anomalies. A large body of experimental evidence has been gathered on the nonrandom attraction between X chromosome and rearranged autosomes in meiosis of carriers of various male-sterile chromosomal rearrangements in mice and men. A hypothesis is evaluated relating the X-autosomal interaction to spermatogenic breakdown. New data on the structure of t haplotypes indicate the presence of chromosomal inversions, and this might point to a chromosomal type of sterility of tx/ty hybrids. Gene hybrid sterility-1 is responsible for different fertility of male hybrids between certain laboratory and wild mice. The availability of wild mice (Mus musculus) derived inbred strains PWB, PWD, and PWK may facilitate further study of the hybrid sterility phenomenon in the mouse.

Animals↗

[Clinical study of children with sterile vesicoureteral reflux].

A clinical study of 5 children (3 boys and 2 girls) with primary sterile vesicoureteral reflux is presented. Their ages ranged from 8 to 11 years old. During the same period, we saw 14 children (6 boys and 8 girls) with primary infected vesicoureteral reflux. Their ages ranged from 1 to 13 years old. There were several distinctions between these two reflux groups. Manifestations of the infected reflux group were mainly fever attacks, while those of the sterile reflux group were hypertension, proteinuria and enuresis. The duration from onset to diagnosis was longer in the sterile reflux group because their manifestations did not appear to be severe especially in cases of enuresis. The grade of reflux tended to be more advanced in sterile reflux group. The renal scarrings were identified in all involved kidneys in the sterile reflux, while in 65.2% in the infected reflux group. It is difficult to detect sterile reflux early because the manifestations are not related with urinary tract infection. Recently, reflux nephropathy is a subject of frequent discussion and end stage of reflux nephropathy has been sporadically reported. Therefore, an effort should be made for early detection of sterile reflux. Based on our experiences as well as review of the literature, possible clues to detect sterile reflux are abnormal voiding patterns, such as nocturnal enuresis, incontinence, frequency and so on.

Adolescent↗

Duration of sterility induced in males of the tropical house mosquito, Culex pipiens fatigans Wiedemann, by the chemosterilants apholate and tepa.

Various alkylating and non-alkylating agents are known to induce sterility in Culex pipiens fatigans, but the duration of the sterilizing effect they produce had not so far been studied for this species. The authors therefore investigated the duration of sterility induced by the alkylating chemosterilants apholate and tepa in C. p. fatigans, second-instar larvae being exposed to 10 ppm apholate or pupae to 3570 ppm tepa. They found that, in experiments in which treated males were mated once only, both apholate and tepa induced sterility lasting at least 48 days. However, in experiments in which males were mated once weekly for 6 weeks apholate-treated males showed a slight recovery from the early sterilizing effect. On the other hand, tepa was found to be very effective in inducing lasting sterility throughout the 6 successive matings. The probable reasons for the recovery from sterility of apholate-treated males and the more lasting sterility of tepa-treated males are discussed.

Alkylating Agents↗

Field attempt to assess the mating competitiveness of sterile males produced by crossing 2 member species of the Anopheles gambiae complex.

In laboratory experiments sterile males produced by crossing member species of the Anopheles gambiae complex competed very successfully with normal males for normal females and the latter when mated with sterile males laid sterile eggs.A field trial was arranged in a small isolated village near Bobo-Dioulasso, Upper Volta; the trial took place at the end of the rainy season against a declining population of species A. Sterile males were produced from the cross between species B males and An. melas females; this cross yielded an F(1) generation mainly composed of sterile males with a sporadic occurrence of a sometimes significant proportion of females which were reproductively normal.The F(1) generation was reared to pupae and these were released into existing breeding places and later from artificial containers.Some 300 000 pupae were so released over a period of 2 months and adult collections were made periodically from inside houses and from outside shelters after releases started. Of the males caught, 75% proved to be sterile while nearly 6% of normal-looking ovipositions failed to hatch. However 2.5% of them proved to be from hybrid females and not from species A females. In control villages, 1.35% of normal-looking ovipositions did not hatch.It was concluded from this field trial that the sterile males were not mating on any significant scale with the natural species A females. This could have been due to a number of factors but the most important is considered to be an ethological one-a mating barrier preventing mating between introduced sterile males and natural females. This is strongly expressed under natural conditions but not operative in the limited confines of a cage. The use of a cross between two species against a third species may well have enhanced this barrier.

Animals↗

Tubal sterilization. Characteristics of women most affected by the option of reversibility.

In order to determine the types of women whose sterilization decisions would be most affected by the option of reversibility, responses from 1074 randomly selected ob-gyn patients, concerning eventual intention to undergo permanent and hypothetically reversible procedures, were analyzed. Cross-tabulation of the dependent variables with a wide array of socio-demographic and attitudinal characteristics was followed by discriminant function analysis in order to determine which variables had the greatest independent impact on sterilization decisions. Particular attention was given to the shift from initial rejection of sterilization, when permanent, to its acceptance, when reversible. Intention to eventually undergo permanent sterilization is most significantly associated with intention to have no more children, Friends with positive experience with tubal sterilization and educational level other than a Bachelor's degree. Response change among initial rejectors of permanent sterilization is most strongly associated with mixed feelings regarding abortion, age under 35, and dissatisfaction with or ambivalence toward last contraceptive method used. Response change, using the total sample as a base, is most significantly associated with mixed feelings toward abortion, age under 35, and intention to have or unsure about having more children. These variables suggest that reversible sterilization, although important to all sub-groups, is likely to become a solution for women who are ambivalent toward abortion and is most important to those women likely to experience future fertility, including unwanted births.

Adult↗

The sterilization of bacteriological media and other fluids with ethylene oxide.

Ethylene oxide is an effective sterilizing agent for bacteriological broths, milk, and serum. A short time after it has exerted its sterilizing effect, the treated fluids again become capable of supporting bacterial growth. Ethylene oxide has been shown to destroy a number of aerobic Gram-positive and Gram-negative organisms, aerobic and anaerobic spore-forming bacilli, fungi, and vaccinia virus. No organisms have been encountered which withstand its action. The quantity of ethylene oxide necessary for sterilization depends to some degree on the character of the medium sterilized. None of the materials tested required more than 1 volume per cent of liquid ethylene oxide. Ethylene oxide is highly reactive chemically, and its reactions with many of the components of complex biological fluids cannot be fully anticipated. Regardless of the chemical changes produced, ethylene oxide did not permanently alter the essential qualities of the growth factors in broth and milk which are required by fastidious organisms such as group A streptococci and others. However, its effect on the biological activity of any particular organic compound should be assayed before it can be assumed not to have a deleterious effect. The sterilization of media by ethylene oxide is accompanied by a rise in pH. Fluids which have a relatively high initial pH may require adjustment with sterile acid to return them to the optimal pH for bacterial growth. A mixture of ethylene oxide and broth was toxic to mice for 6 hours after admixture. Toxicity disappeared on incubating the mixture longer, and no residual toxicity could be demonstrated after 6 hours, even on repeated intraperitoneal inoculations. As a means of sterilizing bacteriological media and other biological fluids, ethylene oxide deserves consideration when heat and filtration cannot be used.

Animals↗

Fertility outcome after reversal of sterilization.

OBJECTIVE: The study was designed to evaluate the fertility outcome in sterilization reversals and a variety of factors that have been suggested to influence the successful outcome of sterilization reversal procedures. METHOD: It is a retrospective study involving all sterilization reversals performed between January 1991 and December 1995 in our hospital. A total of 58 cases were treated. Tubal anastomosis was performed according to rules of microsurgery. The loupe microsurgical technique with 4 x magnification comprising two main phases, preparation of healthy tubal segments and anastomosis carried out in two layers. RESULTS: It was possible to study subsequent fertility of 50 patients in all, as 8 patients were lost to follow-up (13.76%). The overall conception rate was 68% (34 cases), out of which intrauterine pregnancy rate was 62% (31 cases), ectopic pregnancy rate was 6% and the abortion rate was 6%. Fifty percent of patients conceived within first 12 months of reversal of sterilization. The isthmic-isthmic type of anastomosis has maximum incidence of pregnancies (88.88%). CONCLUSION: Laparoscopic (Falope ring) sterilization should be preferred in women who are willing for interval sterilization and it should be done at isthmic segment of the tube, whereas the Pomeroy's method is to be reserved for occasional postpartum procedure. Reversal of sterilization should be done with strict adherence to principles of microsurgery.

Adult↗