Mutations in the gene encoding starch synthase II profoundly alter amylopectin structure in pea embryos

Mutations at the rug5 (rugosus5) locus have been used to elucidate the role of the major soluble isoform of starch synthase II (SSII) in amylopectin synthesis in the developing pea embryo. The SSII gene maps to the rug5 locus, and the gene in one of three rug5 mutant lines has been shown to carry a base pair substitution that introduces a stop codon into the open reading frame. All three mutant alleles cause a dramatic reduction or loss of the SSII protein. The mutations have pleiotropic effects on the activities of other isoforms of starch synthase but apparently not on those of other enzymes of starch synthesis. These mutations result in abnormal starch granule morphology and amylopectin structure. Amylopectin contains fewer chains of intermediate length (B2 and B3 chains) and more very short and very long chains than does amylopectin from wild-type embryos. The results suggest that SSII may play a specific role in the synthesis of B2 and B3 chains of amylopectin. The extent to which these findings can be extrapolated to other species is discussed.

Mutations in the gene encoding starch synthase II profoundly alter amylopectin structure in pea embryos

Mutations at the rug5 (rugosus5) locus have been used to elucidate the role of the major soluble isoform of starch synthase II (SSII) in amylopectin synthesis in the developing pea embryo. The SSII gene maps to the rug5 locus, and the gene in one of three rug5 mutant lines has been shown to carry a base pair substitution that introduces a stop codon into the open reading frame. All three mutant alleles cause a dramatic reduction or loss of the SSII protein. The mutations have pleiotropic effects on the activities of other isoforms of starch synthase but apparently not on those of other enzymes of starch synthesis. These mutations result in abnormal starch granule morphology and amylopectin structure. Amylopectin contains fewer chains of intermediate length (B2 and B3 chains) and more very short and very long chains than does amylopectin from wild-type embryos. The results suggest that SSII may play a specific role in the synthesis of B2 and B3 chains of amylopectin. The extent to which these findings can be extrapolated to other species is discussed.

The development of regional nuclear medicine audit in south Thames

A programme of audit, including clinical audit, organizational audit and patient/clinician satisfaction surveys, has been implemented in nuclear medicine departments throughout the South Thames Regional Health Authority (RHA). The clinical topics which have been audited include. ventilation-perfusion lung imaging, bone imaging, liver imaging, thyroid imaging and renal static DMSA imaging. Guidelines have been set for nuclear medicine practice in each of these areas against which further audit can be performed. Organizational audits have been performed in 10 nuclear medicine departments in the South Thames RHA and a confidential report supplied to the head of each department, consisting of findings and recommendations. A programme of re-audit has also commenced. The main findings have been a lack of facilities and space. Patient satisfaction surveys have been implemented in nine departments and a high level of patient satisfaction has been demonstrated. A clinical satisfaction survey has been implemented in 13 departments. It is hoped to continue this successful programme of audit to improve nuclear medicine practice by closing audit loops.

Population review: (9). Summary of issues

Previous population reviews--published as the 1977 and 1984 Demographic Reviews--were published as free-standing reports. This Review has appeared, initially, as a series of eight articles in this journal. The aim (to quote from the introduction in Population Trends 81) has been to: 'describe the changing make-up of the population of the United Kingdom in a form that will be useful to both general readers and to demography specialists'. The articles have shown that since the 1984 review was issued the demographic picture has become clearer-and now looks a little different. This concluding article brings together the key changes since the last Review and summarises the current situation.

High-dose chemotherapy supported by peripheral blood progenitor cells in poor prognosis metastatic breast cancer--phase I/II study. Edinburgh Breast Group

Current treatments for metastatic breast cancer are not associated with significant survival benefits despite response rates of over 50%. High-dose therapy with autologous bone marrow transplantation (ABMT) has been investigated, particularly in North America, and prolonged survival in up to 25% of women has been reported, but with a significant treatment-related mortality. However, in patients with haematological malignancies undergoing autologous transplantation, haematopoietic reconstruction is significantly quicker and mortality lower than with ABMT, when peripheral blood progenitor cells (PBPCs) are used. In 32 women with metastatic breast cancer, we investigated the feasibility of PBPC mobilisation with high-dose cyclophosphamide and granulocyte colony-stimulating factor (G-CSF) after 12 weeks' infusional induction chemotherapy and the subsequent efficacy of the haematopoietic reconstitution after conditioning with melphalan and either etoposide or thiotepa. PBPC mobilisation was successful in 28/32 (88%) patients, and there was a rapid post-transplantation haematopoietic recovery: median time to neutrophils > 0.5 x 10(9) l-1 was 14 days and to platelets > 20 x 10(9) l-1 was 10 days. There was no procedure-related mortality, and the major morbidity was mucositis (WHO grade 3-4) in 18/32 patients (56%). In a patient group of which the majority had very poor prognostic features, the median survival from start of induction chemotherapy was 15 months. Thus, PBPC mobilisation and support of high-dose chemotherapy is feasible after infusional induction chemotherapy for patients with metastatic breast cancer, although the optimum drug combination has not yet been determined.

Advances in conventional and innovative therapies for respiratory distress syndrome in children

Adult respiratory distress syndrome is a phenomenon encountered by many pediatric critical care nurses. Care of these complex patients is multifaceted and requires an in-depth understanding of pathophysiology and therapeutic intervention. Several innovative treatments are now available as biomedical and technical advances have evolved. Outcomes will improve as clinicians improve patient selection, identify therapeutic endpoints, and risk/benefits. This article addresses the current understanding of pathophysiology, innovative treatments, and nursing care issues.

Use of astemizole in a large group practice

Astemizole was released in 1988. In late 1992, a new warning label was added in response to reports of syncope and death from arrhythmia. Records of patients given new prescriptions for astemizole were reviewed to assess compliance with the warnings in a large multispecialty practice. The indication was appropriate in 89% of cases. Excessive doses were used in 4% of cases. Two percent of prescriptions were given to patients with contraindications. Only two complications were documented. Despite carrying a drug warning, astemizole continues to be used inappropriately and is a medicolegal concern. Education and drug evaluations can be used to enhance compliance and decrease the risk associated with the use of astemizole.

A comparison of referral patterns and characteristics of patients with first episode symptomatic genital HSV-1 and HSV-2 infections in Sheffield

OBJECTIVE

To ascertain factors associated with HSV-1 and HSV-2 isolates in patients attending a genitourinary medicine clinic with symptomatic first episode genital herpes (FEGH).

DESIGN

Retrospective study.

SUBJECTS

A total of 606 females and 333 males presenting with culture positive FEGH between 1990-94.

SETTING

Department of Genitourinary Medicine, Royal Hallamshire Hospital, Sheffield, UK.

METHODS

Group comparison of referral patterns, demographic data, prior and concurrent episodes of STD, recent partner change.

RESULTS

HSV-1 infected patients of either sex were more likely to be general practitioner (GP) referred, to be white, and less likely to have had preceding STD episodes. Recent sexual partner change had occurred significantly more often in HSV-2 infected females but there was no similar difference between HSV-1 and HSV-2 infected males.

CONCLUSION

The relative HSV-1:HSV-2 isolate ratio in FEGH is influenced by the referral patterns. HSV-1 isolates predominate in patients presenting to GPs who refer the patients to GUM clinics for accurate diagnosis, counselling, follow up and screening for other STDs.

Retinoic acid treated P19 embryonal carcinoma cells differentiate into oligodendrocytes capable of myelination

Retinoic acid treatment of P19 embryonal carcinoma cells induces their differentiation into cultures containing neurons and astrocytes. We present two lines of experimentation indicating that oligodendrocytes also develop from retinoic acid-treated P19 cells. We isolated an immortal cell line from retinoic acid-treated P19 cell cultures whose proliferation is dependent upon epidermal growth factor. Upon removal of the growth factor these cells differentiate into both astrocytes and oligodendrocytes as determined by immunostaining with antibodies to the astrocyte marker glial fibrillar acidic protein and the oligodendrocyte markers, myelin associated glycoprotein and 2', 3'-cyclic nucleotide 3'-phosphodiesterase. This cell line appears to be a bi-potential glial precursor. We also found that oligodendrocytes developed directly from P19 cells when retinoic acid-treated cells were transplanted into the brains of neonatal rat pups. Cells that developed into oligodendrocytes migrated into fiber bundles up to several millimeters from the site of the graft. These P19-derived oligodendrocytes appeared to myelinate axons from host neurons. Thus, retinoic acid-treated P19 cells differentiate into neurons, astrocytes and oligodendrocytes, the three cell types that normally develop from embryonic neuroectoderm, indicating that these cell cultures differentiate in a fashion closely resembling that of embryonic neuroectoderm.

Nitric oxide inhalation in infants and children: physiologic and clinical implications

Nitric oxide is a significant biologic mediator in a number of physiologic processes. Clinical and laboratory studies in both human and animal models have uncovered a number of conditions responsive to nitric oxide therapy. The use of inhaled nitric oxide is rapidly expanding into neonatal and pediatric critical care. Presently, the primary clinical indication for nitric oxide is pulmonary hypertension of either a primary or secondary etiology. Some patient populations that are refractory to conventional management demonstrate significant improvement when receiving nitric oxide therapy. This article discusses the physiologic properties of nitric oxide, as well as its diagnostic and therapeutic indications. Specific issues regarding nitric oxide delivery, monitoring, safety standards, and nursing care are also addressed.

Nitric oxide inhalation in infants and children: physiologic and clinical implications

Nitric oxide is a significant biologic mediator in a number of physiologic processes. Clinical and laboratory studies in both human and animal models have uncovered a number of conditions responsive to nitric oxide therapy. The use of inhaled nitric oxide is rapidly expanding into neonatal and pediatric critical care. Presently, the primary clinical indication for nitric oxide is pulmonary hypertension of either a primary or secondary etiology. Some patient populations that are refractory to conventional management demonstrate significant improvement when receiving nitric oxide therapy. This article discusses the physiologic properties of nitric oxide, as well as its diagnostic and therapeutic indications. Specific issues regarding nitric oxide delivery, monitoring, safety standards, and nursing care are also addressed.

Cells differentiating into neuroectoderm undergo apoptosis in the absence of functional retinoblastoma family proteins

The retinoblastoma (RB) protein is present at low levels in early mouse embryos and in pluripotent P19 embryonal carcinoma cells; however, the levels of RB rise dramatically in neuroectoderm formed both in embryos and in differentiating cultures of P19 cells. To investigate the effect of inactivating RB and related proteins p107 and p130, we transfected P19 cells with genes encoding mutated versions of the adenovirus E1A protein that bind RB and related proteins. When these E1A-expressing P19 cells were induced to differentiate into neuroectoderm, there was a striking rise in the expression of c-fos and extensive cell death. The ultrastructural and biochemical characteristics of the dying cells were indicative of apoptosis. The dying cells were those committed to the neural lineages because neurons and astrocytes were lost from differentiating cultures. Cell death was dependent on the ability of the E1A protein to bind RB and related proteins. Our results suggest that proteins of the RB family are essential for the development of the neural lineages and that the absence of functional RB activity triggers apoptosis of differentiating neuroectodermal cells.

Placental passage of the oxytocin antagonist atosiban

OBJECTIVE

We wanted to determine the degree of placental transfer of atosiban (Antocin), an oxytocin antagonist, in pregnant women at term. We also assessed the effects of the infusion on umbilical cord blood gases at birth and the maternal hematocrit drop after cesarean section.

STUDY DESIGN

Eight women undergoing elective cesarean section at term were studied. Each received an infusion of 300 micrograms/min of atosiban over 208 to 443 minutes; the infusion was continued up to the time of cord clamping. Uterine vein and umbilical blood samples were obtained simultaneously. They were assayed by specific radioimmunoassay. Cord blood gases were obtained and compared with those from a control group of women undergoing elective cesarean section.

RESULTS

The mean (+/- SD) maternal uterine vein concentration was 331.9 +/- 42.9 ng/ml, compared with 42 +/- 13 ng/ml in the umbilical vein (p < 0.05). The mean maternal/fetal was 12 +/- 0.03, which was not affected by the length of infusion. There was no significant difference in the hematocrit drop between the cesarean delivery groups: 5.9 +/- 0.4 for the control group versus 5.8 +/- 1.1 for the atosiban group (p > 0.1). The mean cord pH was 7.27 for the atosiban group versus 7.27 for the control group (n = 141) (p > 0.1). One year follow-up of the infants (n = 7) was normal.

CONCLUSIONS

Our results show minimal placental transfer of atosiban. Drug levels did not increase with longer infusions, and no effect was seen on umbilical cord gases. Administration of atosiban even at high doses up to the time of delivery did not increase maternal blood loss at cesarean section.

Through a dark glass more clearly? Health information managers and strategic planning in the 1990s

This article considers the application of a formal strategic planning approach to the health information management profession. After a brief discussion of the two main strategic planning models, the process adopted by the Health Information Management Association of Australia at its recent strategic planning workshop is described and the planning outcomes are outlined. The merits of explicitly expressing strategic intent through the creation of a vision of the future and the establishment of strategies and an action plan to realise the vision are discussed.

Adenovirus 5 E1A induced differentiation of P19 embryonal carcinoma cells requires binding to p300

We transfected P19 embryonal carcinoma (EC) cells with genes encoding the adenovirus 5 E1A products. Expression of either the 12S or 13S transcripts yielded P19 cells either incapable of proliferating or able to proliferate but having lost the characteristics of the EC cell parent. The proliferating clones of E1A expressing P19 cells were incapable of differentiating in response to retinoic acid or dimethyl sulfoxide, no longer expressed the SSEA-1 surface antigen characteristic of EC cells, and did express cytokeratin 55, a marker of epithelial tissues. We used a number of 12S E1A constructs carrying deletions in the first exon and found that the effects on P19 cell growth and differentiated properties were lost with alterations affecting either the N terminal 25 amino acids or the CR1 region of the E1A protein. Both regions are required to bind the cellular p300 protein that we showed is present in P19 cells. We conclude that binding of E1A to the p300 protein in P19 cells results in the loss of EC cell characteristics.

Unstable integration of transfected DNAs into embryonal carcinoma cells

Plasmid DNA can be efficiently transfected into embryonal carcinoma cells but it is difficult to isolate clones of cells stably expressing genes present on the transfected plasmids. Even in clonal populations derived from transfected cells, the introduced genes are expressed in some but not all cells. Cotransfection with a region of the Pgk-1 gene results in more efficient, stable cotransformation due to increased numbers of copies of the transfected plasmids integrated into the genomic DNA. The PgK-1 genomic sequences did not allow the plasmid DNA to replicate autonomously but seemed to enhance the ligation of transfected plasmids before their integration into the host genome. Our results suggest a model in which the plasmid DNAs are able to integrate and subsequently excise from the host genome by recombination events enhanced by transcription through the tandemly repeated sequences of the transfected plasmids.