Ex-Ex Primer: An experimentally validated tool for designing oligonucleotides spanning spliced nucleic acid regions from multiple species.

A comparative study of existing junction-primer-designing software revealed many limitations among them. Hence, we developed a new computational program, Ex-Ex Primer, which offers many improved, user-friendly features, and reliably creates junction primers and probes. This online suite can also be used to design primers/probes from other sites of nucleic acid recombination, insertion, deletion, or splicing, and regular probes/primers. The threshold for Tm difference between the complete junctional primer vs its partial sequence, which maps to one of the junctional regions, was changed based on an important observation made during the initial experimental validations. The tool is now thoroughly checked with RT-PCR and RT-qPCR experiments with more than 250 primer pairs over a few years. The junction-primer-designing features of the software are also better than other equivalent tools. Visualizing the exons and introns across transcripts, and enabling primer designing based on information from Ensembl, are some of the unique features of this tool. The primers suggested by the tool can be used to detect the expression of known transcripts, to test the existence of predicted DNA or RNA joints via hybridization-based techniques, or for validation and in silico analysis of RNA-Seq. URL: http://resource2.ibab.ac.in/exprimer/.

Monocular blindness due to central retinal artery occlusion in bipolar hemireplacement arthroplasty of the hip.

Though rare, perioperative loss of vision after non-ocular surgeries is a disastrous complication. This has been reported after spine surgery or cardiopulmonary bypass surgery. We present an otherwise healthy 54-year-old man who underwent bipolar hemireplacement for a fractured neck of femur, and developed perioperative monocular visual loss due to central retinal artery occlusion, a complication hitherto unreported in hip replacement surgeries. The possible aetiological factors and the measures to prevent this complication are discussed.

Germ cell-specific localization of immunoreactive riboflavin carrier protein in the male golden hamster: appearance during spermatogenesis and role in sperm function.

Riboflavin carrier protein (RCP) is a phosphoglycoprotein (37 kDa) that is well studied in chicken. An immunologically cross-reacting protein was identified in mammals and active immunization of male rats and bonnet monkeys with chicken RCP lead to an approximately 80% reduction in fertility. However, the physiological mechanism responsible for inhibition of male fertility has not been investigated. Moreover, information on the cell type-specific localization and the origin of immunoreactive RCP during spermatogenesis is extremely limited. Hence, studies were carried out to determine the pattern of expression of immunoreactive RCP during spermatogenesis and its role in sperm function in the golden hamster. Immunoreactive RCP was germ cell-specific, found to be associated with the acrosome-organizing region of early spermatids and showed interesting patterns of immunolocalization during late stages of spermiogenesis. Mature spermatozoa exhibited acrosome-specific localization, mainly in the peri-acrosomal membrane. The immunoreactive protein was undetectable in (non)gonadal somatic cells tested. The protein had a molecular mass of 45-55 kDa and was biosynthesized by round spermatids. The acrosome-specific localization of immunoreactive RCP was unchanged during capacitation, but it was substantially lost during acrosome reaction. Functional studies indicated that treatment of spermatozoa with anti-RCP antibodies did not have any effect on either capacitation or acrosome reaction, but markedly reduced the rate of sperm penetration into zona-free hamster oocytes. These results show the existence of male germ cell-specific immunoreactive RCP, having a potential role in sperm-egg interaction in hamsters. Also the pattern of immunoreactive-RCP localization makes it an ideal marker to monitor development of acrosome in mammalian spermatozoa.

Duration of the luteotrophic memory of the stud male odors formed in the female mouse.

Presence of the stud male prevents the novel male-induced block to early pregnancy in mice, while reexposure to the stud male after the pregnancy block induces pseudopregnancy in the females. These two phenomena involve luteotrophy in the female, and a (luteotrophic) memory of the stud male characteristics formed in her is necessary for such a luteotrophic response. Two experiments were conducted to evaluate the effective duration of the "luteotrophic memory" of the stud male odors formed in the female mouse. The first experiment investigated whether exposure to excreta of the stud male at different intervals will induce pseudopregnancy in pregnancy-blocked females; some females mated with a second male and experienced a second consecutive pregnancy failure before the exposure to the excreta of the first stud male. The females, mated once or twice, failed to exhibit pseudopregnancy when exposure to the excreta of the first stud male was begun 8 or 9 days after the first mating. In the second experiment, each pregnancy-blocked female was mated with the (alien) male that induced failure of the first pregnancy and then housed with simultaneous access to the excreta of another alien male and that of the first stud male. Excreta of the first stud male did not prevent failure of the second pregnancy. The results indicate that the (luteotrophic) memory of the stud male-originating olfactory cues formed in the female or its effectiveness in reactivating the luteotrophic system (when the female is reexposed to the odors of the first stud male) lasts only up to about day 7 postcoitum. The present results also show that exposure to only the excreta of the stud male can prevent the pheromonal block to pregnancy or induce pseudopregnancy after pregnancy block in the female mouse.