Changes in fetoplacental vessel flow velocity waveforms following maternal administration of betamethasone

OBJECTIVE

To determine the timing of the onset of the umbilical artery flow velocity waveform changes following maternal administration of betamethasone in pregnancies complicated by umbilical artery absent end-diastolic flow, and to explore whether these changes are associated with flow velocity waveform changes in other fetoplacental vessels.

SUBJECTS AND METHODS

This was a prospective study of 12 women with pregnancies complicated by umbilical artery absent end-diastolic flow. Flow velocity waveforms were recorded from the umbilical artery, fetal middle cerebral artery, renal artery, aorta and ductus venosus, before and after maternal betamethasone administration, using real-time pulsed wave Doppler.

RESULTS

In all 12 pregnancies, the administration of maternal betamethasone was followed by the return of end-diastolic flow within 24 h. End-diastolic flow was first observed at 4 h and was present in all women studied at 8 h. In addition, there was a statistically significant decrease in the pulsatility index in the fetal aorta at 8 h and the middle cerebral artery at 24 h. No change was observed in the ductus venosus or the renal artery flow velocity waveforms.

CONCLUSION

The findings suggest that, in pregnancies complicated by absent end-diastolic flow in the umbilical artery, maternally administered betamethasone induces a return in umbilical artery end-diastolic flow as early as 4 h, along with widespread vasodilatation throughout the fetoplacental vasculature.

Discrete forms of amylose are synthesized by isoforms of GBSSI in pea

Amyloses with distinct molecular masses are found in the starch of pea embryos compared with the starch of pea leaves. In pea embryos, a granule-bound starch synthase protein (GBSSIa) is required for the synthesis of a significant portion of the amylose. However, this protein seems to be insignificant in the synthesis of amylose in pea leaves. cDNA clones encoding a second isoform of GBSSI, GBSSIb, have been isolated from pea leaves. Comparison of GBSSIa and GBSSIb activities shows them to have distinct properties. These differences have been confirmed by the expression of GBSSIa and GBSSIb in the amylose-free mutant of potato. GBSSIa and GBSSIb make distinct forms of amylose that differ in their molecular mass. These differences in product specificity, coupled with differences in the tissues in which GBSSIa and GBSSIb are most active, explain the distinct forms of amylose found in different tissues of pea. The shorter form of amylose formed by GBSSIa confers less susceptibility to the retrogradation of starch pastes than the amylose formed by GBSSIb. The product specificity of GBSSIa could provide beneficial attributes to starches for food and nonfood uses.

Carney's syndrome: complex myxomas. Report of four cases and review of the literature

Cardiac myxomas are rare tumors. They usually appear as a sporadic isolated condition in the left atrium of middle-aged women with no other coincidental pathology. Carney and others have described in young people a special complex group of cardiac myxomas associated to a distinctive complex pathology, giving identity to the "Syndrome Myxoma" or "Carney's Syndrome". Four additional cases of this syndrome, treated from 1977 to 1999 at the Hospital Clínico de la Universidad de Chile are presented here with a comprehensive review of the literature, accumulating 100 cases. The main features of our cases include the presence of malignant non cardiac tumors, a familial trend, follow-up of 23 years and an iterative recurrence in the elder case. To date all patients are tumor free. Reviewing the literature, patients with Carney's Syndrome were younger, with a mean age of 26 years and female predominance (62%). Cardiac myxomas affected the four chambers of the heart: 64% the left atrium; 44% the right atrium; 14% the left ventricle and 12% the right ventricle. They were multiple tumors in 41% and involved more than one chamber in 31%, being synchronous or metachronous. There was a marked familial trend (52%), a high incidence of recurrence (20%), with more than one occurring in half the cases. Extra-cardiac involvement consisted of: 68% pigmented skin lesions, 40% cutaneous myxomas, 37% adrenal cortical disease, 27% myxoid mammary fibroadenoma and 34% male patients with testes tumors. A low percentage had pituitary adenoma, melanotic schwannomas and thyroid disease. The diagnosis is made when two or more of these criteria are present. In agreement with these findings the four chambers of the heart should be examined at surgery for atypical myxoma locations, right atriotomy and combined superior-transseptal approach improve exposure of the cavities, careful screening of the first degree family members should be conducted, and closed short and long term follow up controls are important. Complex myxoma appears as a multi-systemic disorder, occasionally having an ominous prognosis and malignant potentiality, and is still undergoing investigation for better understanding and identification.

Aerobic biotransformation of 4-fluorocinnamic acid to 4-fluorobenzoic acid

The biotransformation of 4-fluorocinnamic acid (FCA) using non-acclimated industrial activated sludge was investigated. FCA is a common intermediate in organic synthesis, and it is often present in aqueous waste streams. Hence, the biotransformation reactions this compound undergoes when exposed to activated sludge micro-organisms should be understood before waste streams are sent to biological wastewater treatment plants (WWTPs). FCA biotransformation was monitored using a wide range of analytical techniques. These techniques were used to monitor not only FCA disappearance, but also the formation of degradation products, in order to propose the metabolic pathway. FCA was biotransformed to 4-fluorobenzoic acid via the formation of 4-fluoroacetophenone. The removal of FCA up to 200 mg L(-1) followed first order kinetics. The half-lives for removal of FCA from the test solutions supplied with 200 mg L(-1), 100 mg L(-1), and 50 mg L(-1) were 53, 18, and 5 hours respectively.

Choosing metaphases for biological dosimetry by fluorescence in situ hybridization (FISH)

Data are presented for a subset of lymphocytes characterized by FISH as missing painted chromosomal material. These lymphocytes occur in both control and irradiated subjects. These cells have a much greater frequency of one-way translocations than cells in which all of the painted chromosomal material is present. Their presence contributes to interindividual variability in control translocation yields. These cells do not appear to be more prevalent in persons exposed to high radiation doses. It is suggested that their exclusion when selecting cells for analysis may improve the sensitivity of FISH as a biological dosimeter at low doses. Mechanisms for the production of these one-way translocations in vivo are also discussed, with a proposal that their variable frequency in individuals may be consistent with exposure to chemical clastogens.

Role of granule-bound starch synthase in determination of amylopectin structure and starch granule morphology in potato

Reductions in activity of SSIII, the major isoform of starch synthase responsible for amylopectin synthesis in the potato tuber, result in fissuring of the starch granules. To discover the causes of the fissuring, and thus to shed light on factors that influence starch granule morphology in general, SSIII antisense lines were compared with lines with reductions in the major granule-bound isoform of starch synthase (GBSS) and lines with reductions in activity of both SSIII and GBSS (SSIII/GBSS antisense lines). This revealed that fissuring resulted from the activity of GBSS in the SSIII antisense background. Control (untransformed) lines and GBSS and SSIII/GBSS antisense lines had unfissured granules. Starch analyses showed that granules from SSIII antisense tubers had a greater number of long glucan chains than did granules from the other lines, in the form of larger amylose molecules and a unique fraction of very long amylopectin chains. These are likely to result from increased flux through GBSS in SSIII antisense tubers, in response to the elevated content of ADP-glucose in these tubers. It is proposed that the long glucan chains disrupt organization of the semi-crystalline parts of the matrix, setting up stresses in the matrix that lead to fissuring.

American Indians with HIV/AIDS: health and social service needs, barriers to care, and satisfaction with services among a Western tribe

This study investigated the health care and social service needs, barriers to care and satisfaction with services among American Indians with HIV/AIDS in a western tribe. Individual interviews were conducted with 28 respondents, which constituted nearly the entire population obtaining HIV/AIDS medical services from the IHS in the target area. The survey found that expressed need for services in this frontier rural area were lower than urban counterparts, but that access to needed services was lower. Common unmet medical needs include mental health services, eye and dental care, traditional Native medicine, and substance abuse treatment. Common unmet social service needs include housing assistance, help obtaining food and clothing, and transportation. Limited access to essential services impedes the ability of American Indians with HIV/AIDS to maintain effective medical regimens.

Structure of Thermotoga maritima stationary phase survival protein SurE: a novel acid phosphatase

BACKGROUND

The rpoS, nlpD, pcm, and surE genes are among many whose expression is induced during the stationary phase of bacterial growth. rpoS codes for the stationary-phase RNA polymerase sigma subunit, and nlpD codes for a lipoprotein. The pcm gene product repairs damaged proteins by converting the atypical isoaspartyl residues back to L-aspartyls. The physiological and biochemical functions of surE are unknown, but its importance in stress is supported by the duplication of the surE gene in E. coli subjected to high-temperature growth. The pcm and surE genes are highly conserved in bacteria, archaea, and plants.

RESULTS

The structure of SurE from Thermotoga maritima was determined at 2.0 A. The SurE monomer is composed of two domains; a conserved N-terminal domain, a Rossman fold, and a C-terminal oligomerization domain, a new fold. Monomers form a dimer that assembles into a tetramer. Biochemical analysis suggests that SurE is an acid phosphatase, with an optimum pH of 5.5-6.2. The active site was identified in the N-terminal domain through analysis of conserved residues. Structure-based site-directed point mutations abolished phosphatase activity. T. maritima SurE intra- and intersubunit salt bridges were identified that may explain the SurE thermostability.

CONCLUSIONS

The structure of SurE provided information about the protein's fold, oligomeric state, and active site. The protein possessed magnesium-dependent acid phosphatase activity, but the physiologically relevant substrate(s) remains to be identified. The importance of three of the assigned active site residues in catalysis was confirmed by site-directed mutagenesis.

A case of Brown-Sequard syndrome with associated Horner's syndrome after blunt injury to the cervical spine

A 26 year old motorcyclist was received by the trauma team in our accident and emergency department after a head on collision with a motor vehicle. He had been correctly immobilised and his primary survey was essentially normal. He was alert and orientated with a Glasgow Coma score of 15 and had no symptoms or signs of spinal injury. His cervical spine radiography was also normal. Neurological examination however, revealed anisocoria, his left pupil being smaller than his right, and a Brown-Sequard syndrome, with a sensory level at C6. Immobilisation was maintained and he was transferred to the regional neurosurgical centre where magnetic resonance imaging revealed a contusion of the left half of the spinal cord adjacent to the 6th cervical vertebrae. Computed tomography revealed no bony injury but spinal column instability was demonstrated after flexion-extension spinal views and he underwent surgery to fuse his spine at the C5-C6 level. This report highlights the necessity to observe strict ATLS guidelines. This must include a thorough examination of the central and peripheral nervous system where spinal injury is suspected, even in the absence of radiographic abnormality and neck pain. This article also presents the unusual phenomena of Brown-Sequard syndrome and unilateral Horner's syndrome after blunt traumatic injury to the cervical spine.

Understanding risk and lessons for clinical risk communication about treatment preferences

This paper defines risk and its component elements and describes where clinical practice may be starting from in terms of what is reported in the literature about understanding risks and the information requirements of consumers. It notes briefly how theoretical models in the literature contribute to our understanding by providing a basis from which to summarise current evidence about the effects of healthcare interventions which address risks and risk behaviour. The situations or types of interventions in which risk related interventions are most effective are described, but a significant caveat is noted about the types of outcomes which have been reported in the literature and which are most appropriate to evaluate. The effects of "framing" variations in the information given to consumers and the ethical dilemmas these raise for a debate about "informed choice" in healthcare programmes are discussed. In response to both the practical and ethical dilemmas that arise from the current evidence, some of the areas where attention should be focused in the future are outlined so that both health gain and informed choice might be achieved. These include the use of decision aids, although their implementation is not widespread at present. Lessons from the current literature on how further progress can be made towards improved communication, discussion between professionals and consumers, and enhancing informed choice are discussed.

Transport of plasma proteins across vasa recta in the renal medulla

In this study, we have extended a mathematical model of microvascular exchange in the renal medulla to elucidate the mechanisms by which plasma proteins are transported between vasa recta and the interstitium. In contrast with other work, a distinction was made between the paracellular pathway and the transcellular route (i.e., water channels) in descending vasa recta (DVR). Our model first indicates that concentration polarization on the interstitial side of vasa recta has a negligible effect on medullary function. Our results also suggest that, whereas proteins are cleared from the interstitium by convection, both diffusion and convection play a role in carrying proteins to the interstitium. In those regions where transcapillary oncotic pressure gradients favor volume influx through the paracellular pathway in DVR, diffusion is the only means by which proteins can penetrate the interstitium. Whether the source of interstitial protein is DVR or ascending vasa recta depends on medullary depth, vasa recta permeability to proteins, and vasa recta reflection coefficients to small solutes and proteins. Finally, our model predicts significant axial protein gradients in the renal medullary interstitium.

Antibiotics and shared decision-making in primary care

Antibiotics are often prescribed to patients with respiratory tract infections who are unlikely to benefit. Models of physician-patient interaction may help understanding of this problem and inform the design of communication skills interventions to enhance appropriate prescribing. The 'paternalistic model' of the consultation remains common in the setting of acute respiratory tract infections. However, the four assumptions that could support this model are not valid for most of these patients, because: best treatment is controversial; management is inconsistent; physicians are not in the best position to evaluate trade-offs between management options without understanding patients' perspectives; and many pressures (apart from patients' agendas) intrude into the consultation. One alternative is the 'informed model' of consulting, but this does not take society's interests into account. The 'shared decision-making model', however, provides a framework for addressing both clinicians' and patients' agendas, and could guide the development and evaluation of specific consultation strategies to promote more appropriate use of antibiotics in primary care.

Consumers' views of quality in the consultation and their relevance to 'shared decision-making' approaches

BACKGROUND

There is a recognized need to assess the effects of shared decision-making and other communication interventions. However, the outcomes usually assessed for evidence of 'effectiveness' are determined by researchers and have not been based on consumers' views.

AIM

This study aimed to identify the important outcomes of consultations for consumers, and to compare with those reported in the current literature.

SETTING AND PARTICIPANTS

Forty-seven participants attending six focus group interviews. Most interviews took place in and all were orientated towards the UK primary care setting.

METHODS

Focus group study.

RESULTS

Many affective outcomes were identified, consistent with the current literature trends. However, many cognitive and behavioural outcomes that are assessed in the current literature were not noted by participants as important. Furthermore, a broader range of outcomes than is evident in the current literature was viewed as important to these participants.

CONCLUSIONS

There is a need to revisit the outcomes which are assessed in decision-making and communication research. The outcomes of greatest importance to consumers must be identified and confirmed by new research which is based directly on the views of consumers themselves.

Understanding risk and lessons for clinical risk communication about treatment preferences

This paper defines risk and its component elements and describes where clinical practice may be starting from in terms of what is reported in the literature about understanding risks and the information requirements of consumers. It notes briefly how theoretical models in the literature contribute to our understanding by providing a basis from which to summarise current evidence about the effects of healthcare interventions which address risks and risk behaviour. The situations or types of interventions in which risk related interventions are most effective are described, but a significant caveat is noted about the types of outcomes which have been reported in the literature and which are most appropriate to evaluate. The effects of "framing" variations in the information given to consumers and the ethical dilemmas these raise for a debate about "informed choice" in healthcare programmes are discussed. In response to both the practical and ethical dilemmas that arise from the current evidence, some of the areas where attention should be focused in the future are outlined so that both health gain and informed choice might be achieved. These include the use of decision aids, although their implementation is not widespread at present. Lessons from the current literature on how further progress can be made towards improved communication, discussion between professionals and consumers, and enhancing informed choice are discussed.

Decision analysis in patient care

To help patients to fully participate in shared decision making is becoming an important goal in clinical practice and one which is receiving increasing attention in terms of the requisite skills and technological development. We discuss the potential application of decision analysis-a specific technology that has been introduced into clinical practice but to date only within research contexts-and examine the usefulness and feasibility of the technique for patients, particularly in settings where clinical presentations are diverse and characterised by uncertainty.

Analysis of loss of heterozygosity in lymphoma and leukaemia arising in F1 hybrid mice locates a common region of chromosome 4 loss

Previous studies have identified five lymphoma-related tumour suppressor gene regions on murine chromosome 4. Using detailed allelotype analysis on a range of lympho-haematopoietic tumour types arising in F1 hybrid mice, we now show a consistent pattern of loss of heterozygosity (LOH) which identifies a common region of loss delineated by microsatellites D4Mit21 and D4Mit53 on proximal chromosome 4. This critical segment corresponds to the thymic lymphoma tumour suppressor region 5 (TLSR5) identified in an earlier study. Tumours of this type have also been reported as showing allelic loss from the Trp53 and Ikaros regions on chromosome 11. In the present study, only a small fraction of tumours showed LOH in the Ikaros region, while a minority of lymphomas, but not acute myeloid leukaemias, showed allelic loss of the chromosome 11 segment encoding Trp53. These and other data indicate strongly that the genomic regions identified as showing recurrent LOH depend on the genetic background of the mice. Overall, the results indicate a key role for a tumour suppressor gene(s) encoded in an approximately 3 cM segment on proximal chromosome 4 and provide an experimental basis for the further investigation of the functional role of candidate genes which include Pax5 and Tgfbr1.

Benchmarking using simulated clinical scenarios: a feasibility project

'Benchmarking' clinical practice and integrating such data with national guidelines offers a way of establishing standards for use in clinical governance. We report on a feasibility project for benchmarking clinical practice in one topic area (otitis media) using simulated clinical scenarios. Consistency and variations in clinical management were identified for different scenarios. Participants perceived the process likely to reflect actual practice and effect change in clinical management.