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Cyclic α-quaternary carbon stereocenters were prepared from biselectrophillic substrates and an easily prepared chiral bicyclic sulfonyl lactam. This was achieved in two steps by spiroalkylation, employing biphasic reaction conditions with a phase-transfer catalyst, followed by reduction and alkylation with a series of alkyl halide electrophiles. The products of this method were isolated in good yields with with high levels of diastereoselectivity. This methodology was employed in the enantioselective total synthesis of (R)-puraquinonic acid (1) for a late-stage installation of the α-quaternary carbon stereocenter. This enabled the shortest synthesis of 1 to date, an eight-pot sequence providing an overall yield of 14%.

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A series of structurally modified Tm(3+) DOTAM-alkyl complexes as potential PARACEST MRI contrast agents has been synthesized with the aim to decrease the overall positive charge associated with these molecules and increase their biocompatibility. Two types of structural modification have been performed, an introduction of terminal carboxylate arms to the alkyl side chains and a conjugation of one of the alkyl side chains with aspartic acid. Detailed evaluation of the magnetic resonance imaging chemical exchange contrast associated with the structurally modified contrast agents has been performed. In contrast to the acutely toxic Tm(3+) DOTAM-alkyl complexes, the structurally modified compounds were found to be tolerated well during in vivo MRI studies in mice; however, only the aspartic acid modified chelates produced an amide proton-based PARACEST signal.

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Herein, we describe the synthesis and spectroscopic properties of five novel pyrrolodeoxycytidine analogs, and the related 5-(1-pyrenylethynyl)-2'-deoxycytidine analog; as well as fluorescence characterization of 5-(p-methoxyphenylethynyl)-2'-deoxyuridine. Within this series of compounds, rigidification of the structure from 6-phenylpyrrolodeoxycytidine to 5,6-benzopyrroldeoxycytidine made remarkable improvement of the fluorescence quantum yield (Φ ~1, EtOH) and substantially increased the Stokes shift. Exchange of the phenyl group of 6-phenylpyrrolodeoxycytidine for other heterocycles (benzofuryl or indolyl) produced an increase in the extinction coefficient at the excitation wavelength while preserving high quantum yields. The steady-state fluorescence response to the environment was determined by sensitivity of Stokes shift to solvent polarity. The effect of solvent polarity on fluorescence emission intensity was concurrently examined and showed that 5,6-benzopyrrolodeoxycytidine is highly sensitive to the presence of water. On the other hand, the previously synthesized 5-(p-methoxyphenylethynyl)-2'-deoxyuridine was found to be sensitive to solvent viscosity indicating molecular rotor behavior.

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The Tm(3+) chelate of DOTAM [1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane] possessing sterically demanding t-butyl amide substitution favors TSAP geometry. This chelate displayed a paraCEST signal associated with the highly shifted amide proton signal at approximately -100 ppm that was beyond the frequency of macromolecule magnetization transfer. This signal also displayed high temperature dependence (0.57 ppm °C(-1)) in the range of 35-42 °C and at neutral pH.

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A simple, convenient, and wide scope protocol for the N-formylation of amino acid esters and primary amines has been developed utilizing only imidazole in warm DMF.

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Cardiac electromechanical intervals were measured during labour in 103 unselected human fetuses. Mean values (+/- SD) for the three intervals measured were 76.01 +/- 9.93 ms for the pre-ejection period, 41.56 +/- 8.51 ms for the isovolumetric contraction time and 156.23 +/- 16.58 ms for the left ventricular ejection time. These are consistent with previously reported data from our own and other centres. the intervals studied did not alter significantly as labour proceeded or during uterine contractions. There was no consistent correlation between them and fetal scalp blood PO2, PCO2 or pH, although the pre-ejection period was shortened considerably in three very acidaemic or hypoxic fetuses, and it was prolonged in association with tight nuchal cord entanglement and variable decelerations in fetal heart rate. These findings raise the possibility of using recorded cardiac electromechanical intervals to determine the clinical significance of different fetal heart-rate patterns that suggest the possibility of fetal distress.

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Five infertile women, with normal menstrual rhythm who had been investigated previously by daily hormone analyses throughout at least one complete menstrual cycle and had shown poor luteal-phase steroid-hormone profiles were treated by a new approach. They were rendered hypogonadotrophic with large doses of a luteinizing hormone releasing-hormone analogue (Hoe 766) and were then treated with exogenous gonadotrophins to induce follicular growth and ovulation. Progesterone production after ovulation in all cases was superior to that observed in the individual patients' without treatment. One patients conceived in her first conception cycle and another in her fourth. This regimen offers a systematic approach to the treatment of unexplained infertility in women with deficient luteal-phase steroid-hormone profiles.

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One hundred uncomplicated pregnancies of primigravida and secundigravida gestation were scanned within 24 h of delivery. The ultrasonic appearances of the uterus were categorized into three groups: 1) empty uterus; 2) cavity separation indicating blood or clot; and 3) dense cavity echoes representing retained tissue. The presence of blood and clot in the puerperium is a common occurrence that resolves spontaneously. Retained tissues of conception were present in 10 cases and were passed spontaneously in four women within the first 3 days postpartum. The presence of retained tissue after the fourth day is support for surgical evacuation of the uterus. Gray-scale ultrasonic examination was accurate in diagnosing all of these cases.

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In a series of 366 patients identified as at risk for a fetal neural tube defect (NTD) before the 24th week of pregnancy, 64 had an abnormal fetus. The abnormalities included anencephaly (39), open spinal defect (17), closed spinal defect (2), encephalocele (1), and a miscellany of other abnormalities (5). An ultrasound examinaton prior to diagnostic anmiocentesis positively identified all anencephalic fetuses, the fetus with the encephalocele, and 15 of the 19 fetuses with spina bifida. The spinal defects in 3 of the remaining 4 fetuses were demonstrated at a second examination. Since both amniotic fluid alpha-fetoprotein (AFP) assays and ultrasound examination have been shown to give false results in the diagnosis of NTDs, the importance of using 2 independent diagnostic techniques is stressed. In patients with elevated levels of maternal serum AFP, a careful ultrasound examination, in addition to identifying the majority of cases associated with an abnormal fetus, provided a good explanation for the elevation in over half of the remainder. In this series more than half the patients (40/69) who underwent amniocentesis because of raised maternal serum AFP levels were shown to have an abnormal fetus.

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In 80 patients, multiple measurements of the fetal biparietal diameter were made during one examination using a real-time scanner equipped with a coded cephalometer. From the sets of data, the means and standard deviations for the group of 80 patients were calculated. In 80 per cent of cases, the individual standard deviations of the results were less than or equal to the estimated standard deviation of the group as a whole. The variability of measurement related to biparietal diameter was least in the range 59 to 83 mm. Comparison of the results obtained with the coded device and others obtained 'blind' does not reveal any significant advantage for the coded device.

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Antenatal ultrasound diagnoses of gross lymphatic system abnormalities were made in three fetuses. Although the diagnosis was made in only 1 fetus at a stage early enough in pregnancy to allow selective termination, knowledge of the abnormality in the remaining 2 fetuses proved to be valuable for subsequent management of those pregnancies. It is stressed that the extent of the abnormality must be carefully assessed because of the possibility of corrective surgery should the lesion be small and that the parents must be given detailed counseling before any definitive measures are taken.

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Human ovarian follicular development measured by peripheral plasma hormone levels and ovarian follicular growth assessed by ultrasonic visualization of the ovary were compared and contrasted in apparently normally menstruating women. The linear correlation coefficient between the mean values for plasma estradiol and follicular diameter on day -5 to day 0 of 15 normal cycles was r = 0.968. When the individual paired data were subjected to multiple linear regression analyses (on days -5 to 0), r = 0.771. These good correlations show that ultrasound measurements of follicular diameter are valuable in the assessment of follicular growth and development. Observations on apparently abnormal cycles are also discussed. Ultrasound measurement of follicular diameter offers an additional technique for the study of ovarian function.

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In a series of 168 patients in the first trimester of pregnancy, fetal crown-rump length (CRL) measurements were attempted in the Antenatal Clinic using a linear-array real-time ultrasound scanner. The measurements could not be made in 23 of the patients; most of them had a gestational age of less than 10 weeks and the difficulty in obtaining measurements was usually due to an underfilled maternal bladder. When compared with CRL measurements obtained with a conventional B-scanner, a good correlation was obtained (r = 0.92); 80 per cent of the 'real-time' values fell within a range of +/- 5 mm of the conventional values. In all patients the estimates of gestational age using the two methods were within one week of each other.

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Radiological estimates of gestational age in late pregnancy were compared with the gestational ages based on first trimester ultrasound crown-rump length measurements in a series of 125 patients. It was found that the 95 per cent confidence limits of a radiological estimate were +/- 3 1/2 weeks, that both distal femoral and upper tibial epiphyses were frequently present much earlier than 36 and 38 weeks respectively, and that in almost half of the growth-retarded babies in the series there was a bone-age discrepancy of three or more weeks. It is recommended that more liberal use is made of early ultrasound measurements for the assessment of gestational age.

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In 131 patients a comparison was made between measurements obtained using a real-time scanner and those obtained using a conventional "B" scanner with an attached "coded cephalometry system": 69 per cent of the readings agreed within +/- 2 mm and, when the "B" scan reading was considered "good", 90 percent fell within this range. Between 14 and 28 weeks, gestational age diagnoses using the two methods were within one week of each other in 88 of 89 patients.

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