Acute renal failure following Bull ant mass envenomation in two dogs.

Acute renal failure was diagnosed in a German Short Haired Pointer bitch and a Kelpie cross-bred dog following envenomation by Bull ants. Both dogs had been tethered over a Bull ant nest and had experienced mass envenomation. There was local reaction at the envenomation sites and each dog had experienced vomiting that was poorly controlled by symptomatic therapy. Intensive treatment of renal failure was successful in the German Short Haired Pointer and the bitch remains well 19 months after envenomation. The Kelpie cross-bred deteriorated despite intensive treatment and was euthanased 36 hours after presentation. Necropsy examination revealed haemorrhage and necrosis of the small intestine and myocardium, bilateral nephrosis with tubular necrosis, and patchy haemorrhage of the lung alveoli, pancreas and adrenal cortices. Electron microscopy revealed necrosis of the small intestine and hydropic swelling of proximal renal tubules with necrosis of medullary tubules.

The mouse telomerase RNA 5"-end lies just upstream of the telomerase template sequence.

Telomerase is a ribonucleoprotein enzyme with an essential RNA component. Embedded within the telomerase RNA is a template sequence for telomere synthesis. We have characterized the structure of the 5' regions of the human and mouse telomerase-RNA genes, and have found a striking difference in the location of the template sequence: Whereas the 5'-end of the human telomerase RNA lies 45 nt from the telomerase-RNA template sequence, the 5'-end of the mouse telomerase RNA lies just 2 nt from the telomerase-RNA template sequence. Analysis of genomic sequences flanking the 5'-end of the human and mouse telomerase RNA-coding sequences reveals similar promoter-element arrangements typical of mRNA-type promoters: a TATA box-like element and an upstream region containing a consensus CCAAT box. This putative promoter structure contrasts with that of the ciliate telomerase-RNA genes whose structure resembles RNA polymerase III U6 small nuclear RNA (snRNA) promoters. These and other comparisons suggest that, during evolution, both the RNA-polymerase specificity of telomerase RNA-gene promoters and, more recently, the position of the template sequence in the telomerase RNA changed.

Basal promoter elements as a selective determinant of transcriptional activator function.

In eukaryotes, activation of transcription involves an interplay between activators bound to cis-regulatory elements and factors bound to basal elements near the start site of transcription. The basal elements, for example the TATA box or proximal sequence element (PSE) of small nuclear RNA (snRNA) promoters, nucleate the assembly of basal transcription complexes, components of which interact with activators. Although one basal transcription complex can interact with many activators, it is unclear whether different basal transcription complexes can direct different responses to particular activators. We show here that changing the arrangement of basal elements can alter the response to transcriptional activation domains. Indeed, in the human U6 snRNA promoter, point mutation of either a TATA box or PSE results in diametrically opposed responses to VP16- and Sp1-derived activation domains. These basal elements can even discriminate small changes in an activation domain. Thus the arrangement of basal promoter elements provides a mechanism for differential regulation of transcription.

Homeodomain protein MHox and MADS protein myocyte enhancer-binding factor-2 converge on a common element in the muscle creatine kinase enhancer.

MHox is a mesoderm-specific homeodomain protein that binds an A/T-rich element that is essential for activity of the muscle creatine kinase (MCK) enhancer. The MHox binding site also binds the ubiquitous homeodomain protein Oct-1 as well as myocyte enhancer-binding factor-2 (MEF2), which belongs to the MADS superfamily of transactivators. To determine which of these proteins activates MCK transcription through the A/T element, we mutated this sequence such that it would selectively bind MHox, MEF2, or Oct-1 and tested the activities of the mutant enhancers in skeletal muscle cells. These mutant enhancers revealed that only MEF2 is able to activate the MCK enhancer through the A/T element. The convergence of homeodomain and MADS proteins on the A/T element in the MCK enhancer provides a mechanism through which a single DNA sequence can mediate positive and negative regulation of gene transcription and is reminiscent of the roles of these two classes of transcription factors in the control of other cell-specific genes.

Educational efforts in preventing preterm delivery among inner city adolescents.

The present study described the effectiveness of using an educational program for self-detection of premature labor in a group of forty-one indigent pregnant adolescents. Twenty-one of these teens self-detected premature labor and received appropriate medical intervention; only four had low birthweight infants and three delivered before 37 weeks. The overall results showed a significant use of the program and a high success to failure rate for those who received medical intervention. The cost-effectiveness and usefulness of this protocol in improving medical outcome for indigent teens are discussed.

Histone H2B gene transcription during Xenopus early development requires functional cooperation between proteins bound to the CCAAT and octamer motifs.

The ubiquitously expressed transcription factor Oct-1 and several other members of the POU domain protein family bind to a site, termed the octamer motif, that functions in the promoter and enhancer regions of a variety of genes expressed under diverse conditions. An octamer motif present in a conserved histone H2B-specific promoter element is required for S-phase-specific transcription of mammalian histone H2B genes in cultured cells. We have previously shown that the octamer motif in a Xenopus histone H2B gene promoter was inactive in nondividing frog oocytes. Here we show that the octamer motif, in addition to regulatory elements (TATAA, CCAAT, and ATF motifs) that are active in oocytes, is required for maximal H2B gene transcription in developing frog embryos. Factors binding to each of the H2B upstream promoter elements are present in oocytes and increase slightly in abundance during early development. The activity of the H2B octamer motif in embryos is not specifically associated with increased binding by Oct-1 or the appearance of novel octamer-binding proteins but requires the presence of an intact CCAAT motif. Our results indicate that synergistic interactions among promoter-bound factors are important for octamer-dependent H2B transcription. We suggest that the activity of the H2B promoter is regulated primarily by changes in the interactions between proteins already bound to the promoter rather than by alterations in their intrinsic abilities to bind DNA.

Maternal immunization with the capsular polysaccharide vaccine for Haemophilus influenzae type b.

Maternal immunization with the capsular polysaccharide (PRP) vaccine of Haemophilus influenzae type b has been shown to extend the time that protective levels of maternal antibody are detected in infants. In a randomized, blinded trial, PRP or placebo was administered uneventfully to 213 women in the third trimester of pregnancy. Infants born to PRP recipients had significantly higher levels of antibody to PRP than did infants born to placebo recipients: 2.73 micrograms/ml compared with 0.33 microgram/ml. It was estimated that infants of mothers who received the PRP vaccine would be protected for an average of 4 months compared to an average of only 2 months for those of mothers who received placebo. Infants were followed for invasive H. influenzae type b disease through the first year of life; none was detected.

Sequential expression of multiple POU proteins during amphibian early development.

The octamer motif is a common cis-acting regulatory element that functions in the transcriptional control regions of diverse genes and in viral origins of replication. The ability of a consensus octamer motif to stimulate transcription of a histone H2B promoter in frog oocytes suggests that oocytes contain a transcriptionally active octamer-binding protein(s). We show here that frog oocytes and developing embryos contain multiple octamer-binding proteins that are expressed in a sequential manner during early development. Sequences encoding three novel octamer binding-proteins were isolated from Xenopus cDNA libraries by virtue of their homology with the DNA binding (POU) domain of Oct-1. The predicted POU domains of these proteins were most highly related to mammalian Oct-3 (also termed Oct-4), a germ line-specific gene required for mouse early development. Transcripts from these amphibian POU-domain genes were most abundant during early embryogenesis and absent from most adult somatic tissues. One of the genes, termed Oct-60, was primarily expressed as a maternal transcript localized in the animal hemisphere in mature oocytes. The protein encoded by this gene was present in oocytes and early embryos until the gastrula stage of development. Transcripts from a second POU-domain gene, Oct-25, were present at low levels in oocytes and early embryos and were dramatically upregulated during early gastrulation. In contrast to the Oct-60 mRNA, translation of Oct-25 mRNA appeared to be developmentally regulated, since the corresponding protein was detected in embryos during gastrulation but not in oocytes or rapidly cleaving embryos. Transcripts from the third POU protein gene, Oct-91, were induced after the midblastula transition and reached their highest levels of accumulation during late gastrulation. The expression of all three genes decreased during late gastrulation and early neurulation. By analogy with other members of the POU-domain gene family, the products of these genes may play critical roles in the determination of cell fate and the regulation of cell proliferation.

Continuous emotional support during labor in a US hospital. A randomized controlled trial.

The continuous presence of a supportive companion (doula) during labor and delivery in two studies in Guatemala shortened labor and reduced the need for cesarean section and other interventions. In a US hospital with modern obstetric practices, 412 healthy nulliparous women in labor were randomly assigned to a supported group (n = 212) that received the continuous support of a doula or an observed group (n = 200) that was monitored by an inconspicuous observer. Two hundred four women were assigned to a control group after delivery. Continuous labor support significantly reduced the rate of cesarean section deliveries (supported group, 8%; observed group, 13%; and control group, 18%) and forceps deliveries. Epidural anesthesia for spontaneous vaginal deliveries varied across the three groups (supported group, 7.8%; observed group, 22.6%; and control group, 55.3%). Oxytocin use, duration of labor, prolonged infant hospitalization, and maternal fever followed a similar pattern. The beneficial effects of labor support underscore the need for a review of current obstetric practices.

A variant octamer motif in a Xenopus H2B histone gene promoter is not required for transcription in frog oocytes.

Xenopus oocytes, arrested in G2 before the first meiotic division, accumulate histone mRNA and protein in the absence of chromosomal DNA replication and therefore represent an attractive biological system in which to examine histone gene expression uncoupled from the cell cycle. Previous studies have shown that sequences necessary for maximal levels of transcription in oocytes are present within 200 bp at the 5' end of the transcription initiation site for genes encoding each of the five major Xenopus histone classes. We have defined by site-directed mutagenesis individual regulatory sequences and characterized DNA-binding proteins required for histone H2B gene transcription in injected oocytes. The Xenopus H2B gene has a relatively simple promoter containing several transcriptional regulatory elements, including TFIID, CBP, and ATF/CREB binding sites, required for maximal transcription. A sequence (CTTTACAT) in the H2B promoter resembling the conserved octamer motif (ATTTGCAT), the target for cell-cycle regulation of a human H2B gene, is not required for transcription in oocytes. Nonetheless, substitution of a consensus octamer motif for the variant octamer element activates H2B transcription. Oocyte factors, presumably including the ubiquitous Oct-1 factor, specifically bind to the consensus octamer motif but not to the variant sequence. Our results demonstrate that a transcriptional regulatory element involved in lymphoid-specific expression of immunoglobulin genes and in S-phase-specific activation of mammalian H2B histone genes can activate transcription in nondividing amphibian oocytes.

Maternal mortality in a maternal-fetal medicine intensive care unit.

Maternal mortality in a large, tertiary-care, intensive care, referral center was reviewed for a six-year period. The first three years of the review were prior to the institution of a maternal-fetal medicine intensive care unit, located in the labor-and-delivery suite. The subsequent three years encompassed a period during which an intensive care unit staffed by maternal-fetal medicine specialists and obstetric anesthesiologists was established in the labor-and-delivery suite. The maternal mortality rate was 21.7/100,000, or 10 maternal deaths in 45,984 deliveries, prior to establishment of the unit and 22.1/100,000, or 11 maternal deaths in 49,700 deliveries, after establishment of the unit. The major causes of maternal mortality were pregnancy-induced hypertension, hemorrhage and infection. It appears that a multi-disciplinary team composed of maternal-fetal medicine specialists and obstetric anesthesiologists can provide the same level of care for critically ill obstetric patients that traditionally would be provided by medical intensive care specialists.

Measurement of histone mRNA transcript abundance in Xenopus oocytes by a quantitative primer extension assay.

A quantitative primer extension method was used to measure the mass of histone gene transcripts in mature oocytes of the amphibian Xenopus laevis. The procedure, using a large excess of gene-specific oligonucleotide primer and continuous incorporation of a radiolabeled deoxynucleoside triphosphate precursor, is more sensitive and quantitative than primer extension assays employing end-labeled primers. It was determined that there are stoichiometric amounts, approximately 2 X 10(8) copies, of mRNA for each of the five major histone gene classes in mature Xenopus oocytes. These observations are consistent with a model whereby transcription of these genes is coordinately regulated in a cell cycle-independent manner during amphibian oogenesis.

Pregnancy associated with advanced adenocarcinoma of the lung.

A case of a poorly differentiated adenocarcinoma of the lung associated with pregnancy is presented with emphasis on the intense interdisciplinary team work required in order to achieve the optimal outcome of pregnancy.

Midtrimester genetic amniocentesis. Use of ultrasound direction vs. blind needle insertion.

A prospective comparison of ultrasound-directed second-trimester genetic amniocentesis to blind amniocentesis showed a significant reduction in the incidence of both bloody taps and failed amniocentesis. The incidence of other parameters, such as fetal outcome, failed culture of amniotic fluid fibroblasts and spontaneous abortion, was similar. These data support the use of amniocentesis under ultrasound control as a routine component of prenatal genetic diagnosis.

Fetal ascites not associated with Rh incompatibility: recognition and management with sonography.

Fetal ascites not associated with Rh incompatibility is an uncommon problem that can be detected in utero by sonography. The sonographer should make a systematic search for the cause of ascites in a given case on the basis of well known etiologic possibilities, since this may have a significant effect on the obstetrical management. The use of sonography in the detection, etiologic evaluation, and obstetrical management of nonimmunologic fetal ascites is discussed, and experience with 10 such cases is reported.