Does gravidity influence the success of in vitro fertilization-embryo transfer cycles?

OBJECTIVE: To evaluate the influence of gravidity on the results of in vitro fertilization (IVF)-embryo transfer (ET) cycles. PATIENTS AND METHODS: All consecutive women aged <35 years admitted to our IVF unit from January 2002 to December 2004 were enrolled in the study. Only patients undergoing one of their first three IVF cycle attempts were included. Gravidity, ovarian stimulation characteristics, number of oocytes retrieved, number of embryo transferred and clinical pregnancy rate were assessed. RESULTS: Three hundred and forty-two consecutive IVF cycles were evaluated. One hundred and sixty-one cycles were from nulligravidas and 181 from women with a history of at least one previous clinical pregnancy. Forty-eight (29.8%) clinical pregnancies were observed in the nulligravida group and 56 (30.9%) in the gravida group. There were no differences between nulligravidas and gravidas in causes of infertility, length of ovarian stimulation, peak estradiol and progesterone levels, number of oocytes retrieved, fertilization rate and number of embryos transferred. Gravidas were significantly older (30.4 vs. 27.6 years, p < 0.001) and used more gonadotropin ampoules (36.1 vs. 31.8, p < 0.004) compared with the nulligravidas. CONCLUSIONS: Patient gravidity has no influence on the likelihood of achieving pregnancy in IVF-ET cycles.     

Rapid T1 estimation using tagged magnetization-prepared gradient-echo MR imaging.

A technique for estimation of the longitudinal relaxation time of a large homogeneous object with an acquisition time of 4 s or less was developed by combining spatially selective rf tagging pulses with a T1-weighted magnetization-prepared gradient-echo sequence. Multiple 5-mm-wide tagged areas are laid orthogonal to the imaging section of interest. The contrast between each tag and the untagged regions differs because each tag is produced at a different time. The T1 value is determined from the nulling time at which tagged and untagged areas have no contrast.     

The value of frequent positioning of treatment field in radiotherapy of esophageal cancer]

Since 1983 a clinical trial of proton beam radiotherapy has been conducted at the Proton Medical Research Center (PMRC) of the University of Tsukuba. We have made it a rule to do field localization by X-ray pictures before each treatment. For this purpose we have developed a localize-verify system consisting of a fluoroscopic unit and a real time digital image processing device. By using this system as well as X-ray films, field placement errors or corrected distance at field localization were measured in 11 patients with esophageal cancers. Measurements of corrected distances on a total of 177 localization attempts disclosed that correction by > 5 mm was necessary in 30.6% and by > 10 mm in 10.2% of all localization attempts. Corrected distances appeared to increase with age, possibly because the skin becomes looser and ambulatory status tends to be more limited in older patients. Field placement corrections of more than 5 mm were required in 66.7% of 60 localizations in patients > 80 years old. Two patients in whom the anatomical positions of the esophagus were easily movable are presented. The following common characteristics of these patients were considered high risk factors: they were more than 80 years old; lesions were located in the lower esophagus; and they had T1 tumors. These findings suggested that frequent positioning and verification of treatment fields are necessary in the accurate treatment of esophageal cancers, especially those in high-risk patients.     

Oral spore vaccine based on live attenuated nontoxinogenic Bacillus anthracis expressing recombinant mutant protective antigen

An attenuated nontoxinogenic nonencapsulated Bacillus anthracis spore vaccine expressing high levels of recombinant mutant protective antigen (PA), which upon subcutaneous immunization provided protection against a lethal B. anthracis challenge, was found to have the potential to serve also as an oral vaccine. Guinea pigs immunized per os with the recombinant spore vaccine were primed to B. anthracis vegetative antigens as well as to PA, yet only a fraction of the animals (30% to 50%) mounted a humoral response to all of these antigens. Protective immunity provided by per os immunization correlated with a threshold level of PA neutralizing antibody titers and was long-lasting. Protection conferred by per os immunization was attained when the vaccine was administered in the sporogenic form, which, unlike the vegetative cells, survived passage through the gastrointestinal tract. A comparison of immunization of unirradiated spores with immunization of gamma-irradiated spores demonstrated that germination and de novo synthesis of PA were prerequisites for mounting an immune protective response. Oral immunization of guinea pigs with attenuated B. anthracis spores resulted in a characteristic anti-PA immunoglobulin isotype profile (immunoglobulin [G1 IgG1] versus IgG2), as well as induction of specific anti-PA secretory IgA, indicating development of mucosal immunity.     

Muscle energetics in short-term training during hypoxia in elite combination skiers

Four well-trained combination skiers were studied through pre- and post-training for the effects of short-term intermittent training during hypoxia on muscle energetics during submaximal exercise as measured by Phosphorus-31 nuclear magnetic resonance and maximal aerobic power ( O_2max). The hypoxia and training in the cold was conducted in a hypobaric chamber and comprised 60-min aerobic exercise (at an intensity equivalent to the blood lactate threshold), using a cycle ergometer or a treadmill twice a day for 4, consecutive days at 5°C, in conditions equivalent to an altitude of 2000 m (593 mm Hg). No change in O_2max was observed over the training period, while in the muscle energetics during submaximal exercise, the values of phosphocreatine/(phosphocreatine + inorganic phosphate) and intracellular pH were found to be significantly increased by training during hypoxia. During recovery, the time constant of phosphocreatine was found to have been significantly reduced [pre, 27.9 (SD 6.7) s; post, 22.5 (SD 4.7) s, P < 0.01]. The observed inhibition of phosphocreatine as well as that of intracellular pH changes after training during hypoxia and quicker recovery of phosphocreatine in submaximal exercise tests, may indicate improved oxidative capacity (i.e. a high adenosine 5-triphosphate formation rate) despite the short-term hypoxia training. Present address: Department Life Sciences, Univ. of Tokyo, Komaba 3-8-1, Meguro-ku 153, Japan