Diagnosis of multiple pregnancy.

A study was made of 94 sets of twins born during 1975-8. Nine of these sets had not been diagnosed before labour started. Of the others, 75 were diagnosed as a result of clinical suspicion and 10 were diagnosed unexpectedly during the antenatal period, nine by ultrasonic examination. Thus, while ultrasonic examination has substantially reduced the incidence of undiagnosed twins, a fifth of all patients who had ultrasonography performed in the presence of a twin pregnancy were reported on at least one occasion to have a singleton pregnancy. Ultrasonography must be performed at least twice, therefore, before a multiple pregnancy can be confidently excluded.     

Anaemia of pregnancy: the changing postwar pattern.

A popluation survey covering over a quarter of a century has shown clearly the improvement in haemoglobin levels in women attending antenatal clinics at the Glasgow Royal Maternity Hospital. Various influences have helped to bring this about, foremost among these being routine early prophylaxis with combined iron and folate supplements. Indeed, a time-space relationship between changes in prophylactic therapy, rates of improvement, and the incidence of megaloblastic anaemia can be shown. The women at risk are still essentially the same except for a new group of young, unmarried girls, who must be watched. In our view the withdrawal of routine prophylactic therapy in pregnancy would be retrograde step.     

Loss in higher multiple pregnancy and multifetal pregnancy reduction.

From early pregnancy into childhood, higher multiples have much higher rates of mortality, whether from spontaneous abortion, the 'vanishing twin' syndrome, fetal or infant death. Many parents must cope with the death of one baby whilst the siblings remain critically ill or later become disabled and yet there grief is often underestimated. Little is known about the long term feelings of parents who choose to have a multifetal pregnancy reduction (MFPR). Most say they made the right decision but also that there was insufficient respect for their loss. They are often anxious about what, if anything, to tell the survivors and how they might react. Long term follow-up studies of the children as well as the parents are needed. Meanwhile parents who chose to have a MFPR must be given more information and ongoing support.     

A specific sequence with a bulged guanosine residue(s) in a stem-bulge-stem structure of Rev-responsive element RNA is required for trans activation by human immunodeficiency virus type 1 Rev.

We demonstrate that both the in vitro RNA binding and in vivo trans activation functions of human immunodeficiency virus type 1 Rev regulatory protein Rev require the presence of a 9-nucleotide 5'-CACUAUGGG-3' RNA motif on its cognate target, the Rev-responsive element RNA. For optimal Rev recognition, this sequence must be presented as a stem-bulge-stem structure and must contain at least two G's, one of which must be unpaired, and include some or all of the CACUAU sequence upstream of the three G's. Distal mutations which result in the base pairing of the G's eliminate the Rev response. The first G is crucial, but changes at the other G's are tolerated if at least one G is unpaired. The secondary structure or the three-dimensional orientation of the B1 and B2 stem-loops of the Rev-responsive element are not relevant as long as the 5'-CACUAUGGG-3' sequence is preserved, with at least one bulged G residue.     

Essential hypertension and pregnancy.

Approximately 1% of pregnancies are complicated by essential hypertension. During pregnancy the blood pressure often stabilizes or improves. In patients with sustained hypertension, prospective controlled studies have demonstrated enhanced fetal survival when the blood pressure was controlled with antihypertensive medication. Such medication must be chosen carefully to avoid fetal and mateerial toxicity, and diuretics and salt restriction during pregnancy should be avoided. Among patients with essential hypertension the problem accelerates late in pregnancy in 2% to 11%; the acceleration may be predicted by determination of maternal mean arterial pressures and intravascular volumes early in pregnancy. The treatment of accelerated hypertension is identical to that of severe pre-eclampsia. Fetal loss is considerable but can be lessened by careful fetal and maternal monitoring and early controlled delivery. The risks of pregnancy in most patients with essential hypertension are small, and essential hypertension is not a uniform contraindication to pregnancy.     

Unique modification of adenine in genomic DNA of the marine cyanobacterium Trichodesmium sp. strain NIBB 1067.

The genomic DNA of the marine nonheterocystous nitrogen-fixing cyanobacterium Trichodesmium sp. strain NIBB 1067 was found to be highly resistant to DNA restriction endonucleases. The DNA was digested extensively by the restriction enzyme DpnI, which requires adenine methylation for activity. The DNA composition, determined by high-performance liquid chromatography (HPLC), was found to be 69% AT. Surprisingly, it was found that a modified adenine which was not methylated at the usual N6 position was present and made up 4.7 mol% of the nucleosides in Trichodesmium DNA (15 mol% of deoxyadenosine). In order for adenine residues to be modified at this many positions, there must be many modifying enzymes or at least one of the modifying enzymes must have a degenerate recognition site. The reason(s) for this extensive methylation has not yet been determined but may have implications for the ecological success of this microorganism in nature.     

Nutritional services during pregnancy and birthweight: a retrospective matched pair analysis.

Since 1963, unselected prenatal patients at the Royal Victoria Hospital, Montreal, have been given nutritional counselling and, if it was judged necessary, dietary supplementation by the Montreal Diet Dispensary. From uniform data collected for all obstetric patients in 1963--74, 1213 recipients of the dispensary services (89.7% of those available and eligible for matching) were paired with controls matched for date of delivery (within 12 months), religious affiliation, parity, trimester of pregnancy during which prenatal care was begun and weight at the time of conception. The proportion of infants of low birthweight (less than 2500 g) was 5.7% for the recipients and 6.8% for the controls; the difference was not significant, but the recipients'' infants were heavier at birth than the controls'' infants, by an average of 40 g (P less than 0.05). The difference in birthweight was greatest for the infants of women in their first pregnancy (average 61 g) and least for the infants of women with three or more past deliveries (average 9 g). Increased birthweight (by an average of 53 g, P less than 0.02) among the recipients'' infants was limited to those born to women weighing less than 140 lb (63 kg) at the time of conception; among the heavier women the controls had infants who were heavier, but not significantly so. Differences between the groups in duration of gestation and maternal weight gain accounted for only a small part of these differences in birthweight. This study provides evidence that the Montreal Diet Dispensary program significantly increased birthweight. Further efforts must now be directed towards judging the long-term benefit of these changes.     

Turnover rate of anti-D IgG injected during pregnancy.

Anti-D IgG was injected into 15 Rh-negative women in the 28th week of gestation and into three non-pregnant women. The uptake of anti-D after the intramuscular injections was calculated by measuring the concentration of antibody in the plasma with an autoanalyser. The biological half life and the catabolic rate of anti-D IgG were calculated according to a compartmental model. The recovery in vivo of anti-D was an average 24% in the non-pregnant women and 21% in the pregnant women. The half life of anti-D were 24 and 21 days, respectively. With a dose of 125 micrograms the plasma anti-D concentration was less than 1 ng/ml at about 10 weeks after the injection. With double the dose the concentration at delivery was at least 1 ng/ml. Although 250 micrograms of anti-D IgG seems to be effective when given in the 28th weeks of gestation, the great individual variations in uptake and recovery rates will lead to occasional cases of Rh-immunisation during pregnancy despite all routine regimens.     

Proteinases and proteinase inhibitors as modulators of animal cell growth.

1. Three distinct lines of evidence indicate that proteinases are involved in the growth of cultured animal cells. 2. Endogenous growth-related proteinases have been identified, and exogenous proteinases can also stimulate cell proliferation, probably by different mechanisms. In some cases, higher concentrations of proteinases are cytotoxic. 3. Proteinase inhibitors, not surprisingly, inhibit cell growth, but can also be mitogenic at sub-inhibitory concentrations. 4. There must, therefore, be at least three major cellular processes in which proteinases or proteinase inhibitors can operate to exert a direct effect on cell proliferation. 5. Details of one action of an exogenous proteinase, typified by thrombin and the thrombin receptor, are becoming clear at the molecular level, but thrombin probably activates at least two intracellular signalling systems, as well as acting as a growth inhibitor in some situations. 6. Much remains to be investigated in other examples.     

Clinical factors affecting pregnancy rates among infertile couples.

In a follow-up study of 1297 couples registered at a Nova Scotia infertility clinic with a complaint of infertility of at least 12 months'' duration, the cumulative pregnancy rate at 36 months, with 95% confidence limits, was found to be 49 +/- 4%. The predictors of pregnancy by univariate analysis were a favourable primary clinical diagnosis (p less than 0.001), a duration of infertility of less than 3 years (p less than 0.001), a single diagnosis for the infertility (p less than 0.001), a previous pregnancy in the partnership (p = 0.001) and a length of marriage of less than 4 years (p = 0.002). Proportional hazards analysis confirmed these variables as predictors of pregnancy. The highest cumulative pregnancy rates after 12 and 36 months of follow-up were observed in cases of ovulation deficiency, and the lowest were seen in cases of tubal defects. However, before the process of diagnosing infertility begins, useful prognostic information can be determined from the length of marriage, the duration of infertility and the partnership''s history of previous pregnancy.     

An ecological study of Laminaria ochroleuca Pyl. growing below 50 metres in the Straits of Messina

A dense population of large plants of Laminaria ochroleuca Pyl. occurs at depths in excess of 50 m on the Sicilian side of the Straits of Messina in the central Mediterranean. It is found that the plants have a relatively high growth rate and are larger than individuals of either the same species on the Atlantic coasts of Spain and southern England, or of L. hyperborea growing in more northern waters. It is suggested that the large size and also great variability in dimensions of L. ochroleuca plants is at least in part due to the less damaging effect of the strong but unidirectional currents at Messina as compared with the turbulent water movements at open-sea sites. Inclination of the substratum, herbivorous grazing, and thermal stratification of the water may be responsible for the restriction of these plants to depths below 40 m. Calculations of productivity and photosynthetic efficiency show that such plants at 55 m depth must be utilizing available light energy at an efficiency of about 37% which approaches the theoretical maximum, so that growth of those plants found deeper in the Straits, to at least 100 m, must be severely limited by light; they are, indeed, both smaller and sparser in occurrence.     

Electric shock-mediated transfection of cells. Characterization and optimization of electrical parameters.

The effect of various parameters on the electric shock-mediated permeabilization and transfection of CHO cells has been investigated. Up to 70% of the cells can be maintained transiently permeable to erythrosin B for periods of at least 1 h at 20 degrees C. Electrical conditions optimal for transient permeabilization were also optimal for efficient DNA transfection by pSV2neo. However, the DNA must be present during exposure to the electric field for efficient transformation. The same requirement existed for voltage-induced DNA toxicity. The results suggest that DNA moves into the cells by electrophoresis, not by simple diffusion. Based on these observations a simple, rapid procedure for optimizing the conditions for electric shock-mediated DNA transfer into cells has been developed.     

The breakdown of 2,3-bis(phospho)-D-glycerate by Fe(III)-haemoglobin.

Fe(III)-haemoglobin is shown to catalyse the hydrolysis of 2,3-bis(phospho)-D-glycerate to Pi and 3-phosphoglycerate, although the rate is slow, even when the protein is present at concentrations in the millimolar range. The rate of hydrolysis is proportional to the subtrate concentration up to at least 10 mM, so if the process is enzymic, the Km must be high.     

The critical period for the maternal recognition of pregnancy in pony mares.

Two experiments were performed to deterine the critical time at which the equine blastocyst must be present within the uterus of the mare to prevent regression of the corpus luteum, and thus establish the critical time for the maternal recognition of pregnancy. A non-surgical blastocyst collection technique was developed to study this relationship between the blastocyst and the maternal ovary. Results from these experiments demonstrated that the cyclic life-span of the corpus luteum is not affected by the presence of the blastocyst within the mare's uterus until after Day 14 after ovulation. Luteal function was prolonged when blastocysts were removed on Day 15 or later. The critical period for the maternal recognition of pregnancy in the Pony mare appears to be confined to the period between Days 14 and 16 after ovulation.     

Virus-directed post-translational cleavage in Sindbus virus-infected cells.

The viral polypeptides synthesized in cells coinfected with group C and group D or E Sindbis virus mutants were studied. Cleavage of the ts2 protein occurs in cells coinfected with ts2 and ts20. Since the ts2 protein fails to chase in cells infected with ts2 alone, the activity effecting this cleavage must be, at least in part, virus specified.     

Economical factors in the assessment of various cellulosic substances as chemical and energy resources.

Economic factors in the assessment of various cellulosic substances as chemical and energy resources are many and complex. No substrate nor conversion process can be singled out as significantly advantageous. Agricultural wastes appear to have the best volume and availability characteristics. If glucose is to be the end product, then it will probably have to compete with corn syrup. If SCP is to be the end product, then productivities of 2-4 g/liter-hr must be achieved and the protein demand be such that the product can sell for at least $225/ton. If alcohol is to be the end product, then an intermediate product stream of glucose and other sugars must be obtained for 1-3cent/lb of fermentable sugars.     

Diagnosis and management of thrombosis in pregnancy

Pregnancy‐related thrombosis is a major cause of maternal mortality. Pregnancy and the puerperium are associated with a fourfold to fivefold increased risk of thrombosis when compared with the nonpregnant state. The greatest time of risk is in the postpartum period. Diagnosis of venous thromboembolism (VTE) during pregnancy can be challenging as many of the symptoms can be associated with normal pregnancy. Almost all deep venous thrombosis occurs in the left leg or iliac veins. Diagnostic procedures for pulmonary embolism carry some exposure to radiation, although risks are low when compared with risks associated with an undiagnosed maternal PE. The anticoagulant of choice during pregnancy is low‐molecular‐weight heparin. Certain medical conditions require alternative approaches as management around the time of delivery. In women with VTE during pregnancy, anticoagulation should continue for at least 3 months and until at least 6 weeks postpartum. Birth Defects Research (Part C) 105:185–189, 2015. © 2015 Wiley Periodicals, Inc.     

Functional differentiation of T cell precursors. I. Parameters of carrier-specific tolerance in murine helper T cell precursors.

Irradiated mice reconstituted with bone marrow from sheep gamma-globulin- (SGG) tolerant syngeneic donors display reduced IgG responsiveness to challenge with trinitrophenylated (TNP)-SGG compared with recipients of normal marrow. This effect is SGG-specific and is due neither to suppressor T cells nor to antigen carryover. "Helper T cell precursor tolerance" can be induced with as little as 40 micrograms tolerogen (SGG). Unlike mature helper T cells, these precursors show both a rapid induction and rapid waning patterns, suggesting a high rate of turnover. Our results imply that marrow helper T cell precursors bear antigen-specific receptors and that the T cell repertoire must be at least partially generated before residence in the thymus.     

A simple method for visualization of phenolics exudation by roots of intact lupin plants; the effect of nitrate and pH.

Phenolics exudation by imbibed seeds and roots of intact lupin plants (Lupinus albus L.) was studied during the first 4 days of growth by a new agar test with specific reagents for phenolics (Gibbs reagent, Naturstoffreagenz A). Comparative studies of the phenolics exudation reveal that legumes exude different phenolics (even if not qualitatively, then at least quantitatively) than oat. The exudation of phenolics starts very quickly after the imbibition of seeds and can be visualized as early as 24 h after sowing. In older seedlings, the exudation of phenolics can be detected along root zones and is influenced by nitrate and pH. At acidic pH, nitrate reduces phenolics exudation, but at pH 7.5 the exudation of phenolics becomes restricted to only some root zones. Nitrate must be present in the rooting media for at least 24 h to cause visible changes in the pattern of exudation at different pH values.