Pressure Waves as a Noninvasive Tool for Artery Stiffness Estimation

In hypertension and aging, central elastic arteries become stiffer and hence the central pulse pressure is augmented due to the increase in the pulse wave velocity and the early return of reflected waves to the heart from the periphery. Valuable information on arterial properties, such as stiffness, can be obtained from both central (aortic) and peripheral (radial) pressure wave forms. A feasibility study for the noninvasive estimation of arterial stiffness using pressure waves detected by a pneumatic cuff wrapped around the upper arm is presented. The propagation and reflection of arterial pressure waves (generated by the heart) in the central elastic arteries are simulated using a simplified water hammer acoustic model. Furthermore, a lumped parameter model is used to describe the transmission of the pressure waves from the brachial artery to the cuff external wall. By combining the two models, we were able to simulate the pressure contours in the brachial artery and illustrate how these pressures transmit to the cuff’s external wall. The effects of aortic stiffness are investigated by simulating the model at different values of aortic elastic moduli and observing the pressure augmentation and the timing of feature points. This work was done as part of the development of a noninvasive diagnostic device by Pulsecor Ltd. The model results obtained in this work are in agreement with published experimental results and the device output; hence, the model can be used to develop the device’s stiffness estimation algorithm.

Outcomes of isolated tibial shaft fractures treated at level 1 trauma centres

BACKGROUND

Although most tibial shaft fractures are expected to heal within 24 weeks, the long-term effects of these injuries on patients in terms of self-reported health status, disability, and pain are largely unknown.

OBJECTIVES

To investigate the clinical and patient-reported outcomes of patients with isolated tibial shaft fractures treated at the two level 1 adult trauma centres in Victoria, Australia.

METHODS

Sixty patients with isolated tibial shaft fractures treated at the Royal Melbourne Hospital and the Alfred Hospital between August 2003 and August 2004 were identified via the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR). Patient-reported outcomes were prospectively measured 1 year post-injury using the 12-Item Short-Form Health Survey (SF-12) (also administered at baseline); the Work subscale of the Sickness Impact Profile; and a Numerical Rating Scale for pain. A priori defined clinical outcomes were also determined by retrospectively reviewing hospital medical records and X-rays.

RESULTS

Full weight-bearing status was achieved after a median inter quartile range (IQR) time of 14.0 (12.5-20.0) weeks, and the median (IQR) time to radiological union was 35.8 (23.3-51.6) weeks. Sixty percent of patients completed the SF-12 at both baseline and 12 months post-injury. Although there were no clear changes in mental health scores (median change=+1.0; IQR=-3.5 to 4.0; p=0.52), physical health scores were significantly reduced (median change=-3.0; IQR=-19.5 to 0.3; p=0.003). Additionally, 47% of patients reported work-related disability and 40% experienced persistent pain 1 year post-injury.

CONCLUSIONS

These results indicate that long-term physical disability remains a problem for many patients following tibial shaft fracture, and they should be considered when providing prognostic information to patients. Further research is required to identify the specific health problems experienced as well as the factors contributing to disability in order to inform post-fracture rehabilitation planning.

Outcome of noninvasive ventilation in children with neuromuscular disease

OBJECTIVE

To assess the effect of institution of noninvasive ventilation (NIV) on clinical outcome and quality of life (QOL) in a cohort of children with severe neuromuscular disorders.

METHODS

We reviewed records and obtained clinical data from the year prior to commencing NIV and annually thereafter. Data obtained included diagnosis, patient symptoms, mortality, NIV adverse effects, pulmonary function tests, polysomnographic data, length of hospitalizations, and health care costs. Patients and parents completed questionnaires assessing QOL with NIV and recalling QOL before NIV.

RESULTS

Fourteen of 17 (82%) suitable patients were enrolled. Follow-up ranged from 6 to 84 months (median 30). Symptoms of daytime sleepiness (p = 0.003) and headache (p = 0.046) improved after initiation of NIV. Sleep quality assessed by polysomnography also improved. Hospitalization rates (p = 0.002) and health care costs (p = 0.003) decreased. QOL remained stable after NIV, despite disease progression.

CONCLUSION

Treatment of respiratory failure, in children with neuromuscular disease, with noninvasive ventilation results in a reduction in symptoms, hospitalizations, and health care costs without adverse effects on quality of life.

An investigation into effects of long-distance seed dispersal on organelle population genetic structure and colonization rate: a model analysis

A simulation-based modelling approach is used to examine the effects of stratified seed dispersal (representing the distribution of the majority of dispersal around the maternal parent and also rare long-distance dispersal) on the genetic structure of maternally inherited genomes and the colonization rate of expanding plant populations. The model is parameterized to approximate postglacial oak colonization in the UK, but is relevant to plant populations that exhibit stratified seed dispersal. The modelling approach considers the colonization of individual plants over a large area (three 500 km x 10 km rolled transects are used to approximate a 500 km x 300 km area). Our approach shows how the interaction of plant population dynamics with stratified dispersal can result in a spatially patchy haplotype structure. We show that while both colonization speeds and the resulting genetic structure are influenced by the characteristics of the dispersal kernel, they are robust to changes in the periodicity of long-distance events, provided the average number of long-distance dispersal events remains constant. We also consider the effects of additional physical and environmental mechanisms on plant colonization. Results show significant changes in genetic structure when the initial colonization of different haplotypes is staggered over time and when a barrier to colonization is introduced. Environmental influences on survivorship and fecundity affect both the genetic structure and the speed of colonization. The importance of these mechanisms in relation to the postglacial spread and genetic structure of oak in the UK is discussed.

Assessment of the anthelmintic effect of natural plant cysteine proteinases against the gastrointestinal nematode,Heligmosomoides polygyrus,in vitro

We examined the mechanism of action and compared the anthelmintic efficacy of cysteine proteinases from papaya, pineapple, fig, kiwi fruit and Egyptian milkweedin vitrousing the rodent gastrointestinal nematodeHeligmosomoides polygyrus. Within a 2 h incubation period, all the cysteine proteinases, with the exception of the kiwi fruit extract, caused marked damage to the cuticle ofH. polygyrusadult male and female worms, reflected in the loss of surface cuticular layers. Efficacy was comparable for both sexes of worms, was dependent on the presence of cysteine and was completely inhibited by the cysteine proteinase inhibitor, E-64. LD50values indicated that the purified proteinases were more efficacious than the proteinases in the crude latex, with purified ficin, papain, chymopapain, Egyptian milkweed latex extract and pineapple fruit extract, containing fruit bromelain, having the most potent effect. The mechanism of action of these plant enzymes (i.e. an attack on the protective cuticle of the worm) suggests that resistance would be slow to develop in the field. The efficacy and mode of action make plant cysteine proteinases potential candidates for a novel class of anthelmintics urgently required for the treatment of humans and domestic livestock.

Cellular and serological responses in resistant and susceptible mice exposed to repeated infection with Heligmosomoides polygyrus bakeri

An experiment was carried out to compare the parasitological and immunological responses of SWR and CBA mice to trickle (repeated) infection with Heligmosomoides polygyrus. Male mice were given 125 L3 once per week and were killed in groups, together with naïve control mice, weekly until week 8. Worm burdens accumulated in CBA, stabilizing in week 5 in excess of 400 worms and remaining high until week 8. In contrast in SWR worm burdens peaked in week 3 at a mean worm burden of 129 and then fell sharply so that by week 6, despite continuing re-infection, no more worms were recovered from these mice. SWR mice showed a marked mast cell and mMCP-1 response, peaking in weeks 2-3, whereas in CBA mice these responses were slower, and even at their height in week 8 still less intense than those in SWR mice. Both strains responded initially with a very similar goblet cell response, which declined in SWR mice as worms were eliminated, but was sustained in CBA mice until week 8. Serum TNFalpha concentrations were higher in SWR mice throughout the experiment. Infection elicited strong serological responses against adult and L4 antigens in both SWR and CBA mice, involving all the isotypes tested (IgG1, IgA and IgE). Anti-L3 responses were examined only for IgG1. However, only two responses differed significantly between the strains: the IgE response to L4 antigens was more intense in SWR mice, and interestingly and unexpectedly, the IgG1 response to adult worm antigens was more intense in CBA mice. These results reflect the activation of predominantly Th2-driven effector mechanisms, that may be associated with host-protective immunity developing under the trickle infection protocol exploited in these experiments.

Mapping of chromosomal regions influencing immunological responses to gastrointestinal nematode infections in mice

This paper reports the results of a genome-wide search for quantitative trait loci (QTL) influencing immunological responses to infection with the gastro-intestinal nematode parasite Heligmosomoides polygyrus in an F2 population created by crossing the resistant SWR and the susceptible CBA inbred mouse strains. Following infections, intestinal granuloma score at post mortem, mucosal mast cell protease 1, and IgE and IgG1 titres were recorded. The susceptible CBA mice had significantly higher IgG1, but significantly lower IgE, mucosal mast cell protease 1 and granuloma scores than SWR mice. Significant QTL were mapped to chromosomes 4, 11, 13 and 17 for granuloma score; chromosomes 12 and 17 for IgE; chromosome 10, 17 and 18 for IgG1 and chromosomes 1, 9, 10, 11, 17 and 18 for mucosal mast cell protease 1. Chromosomes 10, 11, 17 and 18 had QTL affecting more than one trait, and these are most likely to represent single QTL with multiple effects rather than multiple QTL. Some of these QTL map to regions known to harbour genes responsible for the induction of immunological responses to intestinal worms.

Senescence, sleep, and circadian rhythms

The goal of this review article is to summarize our knowledge and understanding of the overlapping (interdisciplinary) areas of senescence, sleep, and circadian rhythms. Our overview comprehensively (and visually wherever possible), emphasizes the organizational, dynamic, and plastic nature of both sleep and circadian timing system (CTS) during senescent processes in animals and in humans. In this review, we focus on the studies that deal with sleep and circadian rhythms in aged animals and how these studies have closely correlated to and advanced our understanding of similar processes in ageing humans. Our comprehensive summary of various aspects of the existing research on animal and human ageing, both normal and pathological, presented in this review underscores the invaluable advantage of close collaboration between clinicians and basic research scientists and the future challenges inherent in this collaboration. First, our review addresses the common age-related changes that occur in sleep and temporal organization of both animals and humans. Second, we examine the specific modifications that often accompany sleep and CTS during aging. Third, we discuss the clinical epidemiology of sleep dysfunctions during ageing and their current clinical management, both pharmacological and non-pharmacological. Finally, we predict the possible future promises for complementary and alternative medicine (CAM) that pave the way to the emergence of a "Holistic Sleep Medicine" approach to the treatment of sleep disorders in the ageing population. Further studies will provide additional valuable insights into the understanding of both sleep and circadian rhythms during senescence.

The graphical presentation of decision support information in an intelligent anaesthesia monitor

This contribution examines the graphical presentation of decision support information generated by an intelligent monitor, named SENTINEL, developed for use during anaesthesia. Clinicians make diagnoses in real-time during operations by examining clinically significant trends in multiple signals. SENTINEL attempts to mimic this decision process by using a system of fuzzy trend templates. SENTINEL's implementation of fuzzy trend templates is capable of providing the dual fuzzy measures of belief and plausibility, which are derived from the theory of evidence. It is thus capable of generating fairly rich diagnostic decision support information. However, for SENTINEL to be effective, the visual presentation of this information must be intuitive to the anaesthetist, who may not be familiar with the theory of evidence. This paper discusses techniques that are being evaluated to meet the requirements of the SENTINEL anaesthesia monitor. Specifically, the paper presents methods for highlighting clinically significant trends in physiological (or derived) signals by superimposing a coloured band on the signal that reflects fuzzy output from the intelligent monitor. This paper also discusses the intuitive graphical presentation of binary diagnostic fuzzy measures, including their further interpretation and presentation as crisp "alarm" and "warning" conditions.

The construction of a network at Health Waikato. The "towards clinical budgeting" project

The purpose of this paper is to provide an explanation and understanding of developments in casemix and related information systems at a large regional hospital, Health Waikato (HW), in the centre of the North Island of New Zealand. The themes will be explicated and theorised, drawing on the sociology of translation (Latour). A central idea will be the use of accounting techniques to influence decision makers both within and outside the health institutions. The power of accounting in the translation and inscription of data (the fabrication of accounting systems per Preston et al.), will be a central theme in understanding the role of accounting systems as technology. Drawing from Latour has helped to provide a frame of reference to allow an assimilation of disparate changes and influences as they have come to affect the health sector at a national level, within New Zealand, and also at an organisational level, within a large regional health provider. This paper provides a detailed description of events at the research site, a large regional hospital (HW). The paper consists primarily of a descriptive case study of aspects of the change process as it has impacted on the research site.

Phase II study of rituximab in combination with chop chemotherapy in patients with previously untreated, aggressive non-Hodgkin's lymphoma

PURPOSE

To determine the safety and efficacy of the combination of the chimeric anti-CD20 antibody Rituxan (rituximab, IDEC-C2B8; Genentech Inc, South San Francisco, CA) and cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy in patients with aggressive non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

Thirty-three patients with previously untreated advanced aggressive B-cell NHL received six infusions of Rituxan (375 mg/m2 per dose) on day 1 of each cycle in combination with six doses of CHOP chemotherapy given on day 3 of each cycle.

RESULTS

The ORR by investigator assessment confirmed by the sponsor was 94% (31 of 33 patients). Twenty patients experienced a complete response (CR) (61%), 11 patients had a partial response (PR) (33%), and two patients were classified as having progressive disease. In the 18 patients with an International Prognostic Index (IPI) score > or = 2, the combination of Rituxan plus CHOP achieved an ORR of 89% and CR of 56%. The median duration of response and time to progression had not been reached after a median observation time of 26 months. Twenty-nine of 31 responding patients remained in remission during this follow-up period, including 15 of 16 patients with an IPI score > or = 2. The most frequent adverse events attributed to Rituxan were fever and chills, primarily during the first infusion. Rituxan did not seem to compromise the ability of patients to tolerate CHOP; all patients completed the entire six courses of the combination. The bcl-2 translocation of blood or bone marrow was positive at baseline in 13 patients; 11 patients had follow-up specimens obtained (eight CR, three PR), and all had a negative bcl-2 status after therapy. Only one patient has reconverted to bcl-2 positivity, and all patients remain in clinical remission.

CONCLUSION

This is the first report to demonstrate the safety and efficacy of the Rituxan chimeric anti-CD20 antibody in combination with standard-dose CHOP in the treatment of aggressive B-cell lymphoma. The clinical responses are at least comparable to those achieved with CHOP alone with no significant added toxicity. The presence or absence of the bcl-2 translocation did not affect the ability of patients to achieve a CR with this regimen. The ability to achieve sustained remissions in patients with an IPI score > or = 2 warrants further investigation with a randomized study.

Computerised anaesthesia monitoring using fuzzy trend templates

The task of administering anaesthesia requires the clinician to be vigilant for long periods of time to detect the onset of adverse conditions. Large amounts of data must be analysed in real-time and, if a problem is detected, it must be diagnosed as a matter of urgency, this being done while other management protocols are being carried out. For these reasons it would be of benefit if automated decision support could be provided for anaesthesia monitoring, to lighten the cognitive load on the anaesthetist. The Sentinel anaesthesia monitor has been developed with this objective in mind. It uses a fuzzy time-domain pattern matching technique, termed fuzzy trend templates, to detect vaguely specified patterns in multiple physiological data streams. These patterns are representative of symptoms associated with undesirable patient states. The system is capable of detecting trends and states such as 'significant rise' and 'high', and associating vague duration and temporal intervals with individual trends. Fuzzy trend templates have proven to be quite intuitive to specify, given linguistic (anaesthetists') knowledge about the problem domain. Sentinel's implementation of fuzzy trend templates also uses an extension to fuzzy logic based on the theory of evidence, to handle situations where desired information is not available, for example, when sensors are not being used. In off-line testing, Sentinel has achieved sensitivity and specificity of above 90% in the diagnosis of seven common or serious conditions that can arise during anaesthesia.

Trend recognition in clinical signals using template-based methods

The recognition of clinically significant trends in monitored signals plays an important role in many medical diagnostic applications. A template-based system technique to identify characteristic patterns in time-series data is described, based on fuzzy logic. Fuzzy set theory allows the creation of fuzzy templates from linguistic rules. The resulting fuzzy template system can accommodate multiple time signals, relative or absolute trends, and automatically generates a normalised "goodness of fit" score. The template approach was originally developed for monitoring during anaesthesia but has the potential to be useful in other domains that require temporal pattern recognition.

Genetic variability determinants of Helicobacter pylori: influence of clinical background and geographic origin of isolates

Helicobacter pylori has an unusual pattern of genetic variation, which complicates research on this organism. To gain a better understanding of the forces behind this phenomenon, the extent to which recombination and single point mutations affect genetic variability in H. pylori was quantified and the influence of both geographical distance and clinical background were assessed. Site-directed restriction-endonuclease digestion of 2 gene fragments was performed on 168 isolates from Montreal and Berlin. Allelic diversity was found to be much higher for H. pylori than for other bacterial species. This finding is consistent with those of previous studies on H. pylori that were conducted using other techniques. However, nucleotide diversity was within the range reported for other bacterial species. Phylogenetic analysis found no grouping of strains with clinical background or geographical origin. Recombination at a rate that resulted in linkage equilibrium within genes can explain these observations.

Association of Helicobacter pylori genotype with gastroesophageal reflux disease and other upper gastrointestinal diseases

OBJECTIVE

Helicobacter pylori (H. pylori) is a recognized pathogen, but it may also have a protective effect for gastroesophageal reflux disease (GERD). We compared the prevalence of potential virulence factors (cagA, cagE, vacA genotypes) in GERD to other upper gastrointestinal diseases and controls.

METHODS

A total of 405 patients underwent gastroscopy with H. pylori isolation and serum testing. Patient diagnostic subgroups were prospectively defined. Genotypes were determined by amplification using polymerase chain reaction. CagA antibodies were determined by western blot, enzyme-linked immunosorbent, and flow microsphere immunofluorescent assays.

RESULTS

Patients were grouped as follows: nonulcer dyspepsia (26%), GERD (20%), gastric ulcer (17%), duodenal ulcer (12%), gastric cancer (6%), or controls (19%). The cagA gene was present in 94-97% of subjects in all categories, but the cagA antibody was less prevalent in nonulcer dyspepsia (69%, 95% CI: 48-86%, p = 0.02) and GERD (69%, CI: 39-91%, p < 0.05) than in those with gastroduodenal pathology including gastric ulcer, duodenal ulcer, and gastric cancer (92%, CI: 81-98%). The cagE gene and vacA S1 genotype were more frequent in patients with gastroduodenal pathology (p < 0.01). GERD was associated with a significantly lower rate of vacA S1 genotype than controls (29% (CI: 10-56%) versus 80% (CI: 59-93%), p < 0.01). The vacA S1 genotype was associated with the presence of cagA antibodies.

CONCLUSIONS

The cagE and vacA S1 genotypes are more prevalent in patients with peptic ulcer or gastric cancer, suggesting a potential function in virulence for these genes. However, the vacA S1 genotype was also more prevalent in controls than GERD, suggesting a potential protective effect against GERD.

Physical and chemical evidence remaining after the explosion of large improvised bombs. Part 1: firings of ammonium nitrate/sugar and urea nitrate

Recent criminal acts in the United Kingdom, United States and other countries have demonstrated the dangers to public safety from the criminal use of improvised explosives on a large scale. Four sets of trials were carried out over four years, partly in collaboration with the United States Federal Bureau of Investigation, involving the firing of large bombs, mostly fertilizer based. The principal objectives of the firings were to measure the physical effects of the explosions upon objects representative of those that would be found at a real bomb scene and to recover any chemical traces deposited on these objects. The results are intended for use as an aid in determining the approximate size and type of an explosive employed in a terrorist attack. This paper describes the background behind the trials, the procedures for preparation of witness materials and charges, and the collection and analysis of physical and chemical evidence.

Physical and chemical evidence remaining after the explosion of large improvised bombs. Part 2: Firings of calcium ammonium nitrate/sugar mixtures

Six test firings of large improvised explosive devices were carried out. The principal objectives of the firings were to measure the physical effects of the explosions upon representative objects placed nearby and to recover any chemical traces deposited on these objects. The results are intended for use as an aid in determining the approximate size and type of an explosive employed in terrorist attacks. Three 454 kg charges of a mixture of calcium ammonium nitrate (CAN) fertilizer and sugar, and three 2268 kg charges of a similar mixture, all confined in cylindrical steel containers were fired. Each charge was surrounded by 19 road signs mounted on posts and four vehicles, to act as witness materials. The analysis of aqueous swab extracts taken from the witness materials after firing showed the recovery of nitrate, ammonium and low levels of glucose. No sucrose was detected. Nitrate was usually recovered in greater quantities than ammonium and recovery generally decreased with increasing distance from the charges in any given direction. Quantities recovered from objects placed at the same distance in different directions varied considerably. Patterns of physical damage to the witness materials could be discerned according to their distance from the charge and the size of the charge. The velocities of detonation and air blast effects were measured.

Diagnostic monitoring in anaesthesia using fuzzy trend templates for matching temporal patterns

A technique based on the concept of a 'fuzzy trend template' has been developed to identify characteristic patterns in multiple time-series. The method has its foundation in fuzzy logic and allows for the intuitive and transparent description of 'templates', which preserve nuances of vagueness, temporal relationships and quantitative descriptors. Evaluation of fuzzy trend templates can provide both belief and plausibility information for use in diagnostic applications. The technique has been applied to the diagnosis of specific problems in anaesthesia and has demonstrated sensitivity and specificity of 95 and 65%, respectively. Evaluation of fuzzy trend templates is, computationally, relatively efficient and has allowed a real-time implementation. The technique has the potential to be useful in any domain that requires temporal pattern recognition based on linguistic rules.

Computer-enhanced diagnosis of malignant hyperpyrexia

A computer program using fuzzy logic templates has been developed to enhance the diagnosis of malignant hyperpyrexia. When tested, retrospectively, against the physiological changes that occurred during the onset of a bona fide malignant hyperpyrexia episode it made the diagnosis about 10 minutes before the anaesthetist. When tested against the changes associated with laparoscopic surgery, which has certain similarities, the diagnosis of malignant hyperpyrexia was very transient. The use of this program may assist the anaesthetist in the diagnosis of this rare event.

Diagnostic image quality of mobile neonatal chest X-rays and the radiation exposure incurred

A study was undertaken to identify the variation of entrance skin doses (ESDs) in mobile neonatal chest radiography with regard to the European Commission (EC) reference dose and to examine potential relationships with image quality and radiographic techniques. Five sites from the former North West Thames region participated. All mobile neonatal radiographic techniques were surveyed. Dose-area product per examination was directly measured and the ESD calculated. Image quality criteria were developed from those published by the EC. Image quality was graded by two independent observers. Over the five sites, 144 examinations were recorded. Calculated ESDs ranged up to 160 microGy, with an appreciable variation not only between sites but also within sites. A clear relationship between actual rather than nominal speed and dose over all sites was demonstrated (r = -0.95, p = 0.013). No correlation between image quality and dose was noted (r = -0.044, p = 0.665). Neonatal imaging systems at participating sites, within the North Thames region, comply with EC guidelines on patient dose and image quality for mobile chest X-rays. Significant variation in ESDs was encountered between sites with no discernible relationship with image quality or the employed radiographic techniques as described by the EC. The strong inverse relationship between ESDs and actual rather than nominal speed suggests a neglected aspect of radiation protection.

A preliminary exploration of the interactional skills of trainee surgeons

BACKGROUND

The interactional skills of 21 surgical trainees were studied in the areas of breaking bad news to patients and preparing patients for potentially threatening medical procedures. When compared to the established guidelines for dealing with these issues, the trainees performed poorly.

METHODS

Trainees were videotaped using clinical histories delivered by simulated patients in simulated consulting rooms. All videos were scored on standard rating scales where the criteria for rating the specific interactional skills were adopted from existing guidelines.

RESULTS

The proportion of trainees who could meet the guidelines when breaking bad news was low. The proportion of trainees who met the guidelines were: closing the the consultation (0%), provided patient information about prognosis (43%) and treatment (38%) and when they gave support (10%). There were also low numbers of trainees who could meet the guidelines when they prepared patients for potentially threatening procedures. Ten per cent of trainees followed the guidelines when providing information, 25% could establish treatment goals, 35% could give a prognosis and 0% could deal appropriately with psychosocial issues or close the consultation appropriately.

CONCLUSIONS

It is concluded that there is a need for further formal training in interactional skills as part of surgical training.

Four-year follow-up of Palmaz-Schatz stent revascularization as treatment for atherosclerotic renal artery stenosis

BACKGROUND

Stent revascularization is perceived as superior to balloon angioplasty and surgical revascularization, but the paucity of stent publications precludes even historical comparison with surgical data.

METHODS AND RESULTS

Palmaz-Schatz stent revascularization of renal artery stenosis was successfully performed on 163 consecutive patients for poorly controlled hypertension or preservation of renal function. Of these, 145 were eligible for > or =6-month clinical follow-up of the effect of the procedure on renal function, blood pressure control, number of antihypertensive medications, and survival. At 4 years, systolic and diastolic blood pressures significantly decreased (from 166+/-26 to 148+/-22 mm Hg and from 86+/-14 to 80+/-11 mm Hg, respectively; P<0.05), and blood pressure control was more facile in approximately half of the patients. Creatinine decreased or remained stable in approximately two thirds of the patients. The cumulative probability of survival was 74+/-4% at 3 years, with few deaths related to end-stage renal disease. Survival was good in patients with normal (92+/-4%) baseline renal function, fair (74+/-7%) in those with mildly impaired renal function, and poor (52+/-7%) in patients with elevated baseline creatinine levels (> or =2.0 mg/dL). The combination of impaired renal function and bilateral disease adversely affected survival.

CONCLUSIONS

Renal artery stent revascularization in the presence of normal or mildly impaired renal function had a beneficial effect on blood pressure control and a nondeleterious effect on renal function. Survival was adversely affected by renal dysfunction despite adequate revascularization. Early diagnosis and adequate revascularization before the onset of renal dysfunction could beneficially affect blood pressure control, preserve or prevent deterioration of renal function, and improve patient survival.

Stent revascularization for atherosclerotic renal artery stenosis. 1-year clinical follow-up

Patients who had undergone stent revascularization of renal artery stenosis for poorly controlled hypertension, preservation of renal function, or both were monitored to assess the procedure's effect upon subsequent renal function and blood pressure control. At 1-year follow-up, systolic and diastolic blood pressures had significantly decreased (166 +/- 26 to 156 +/- 25 mmHg and 86 +/- 14 to 80 +/- 13 mmHg, respectively; P < 0.05), and creatinine levels decreased or remained stable in approximately two thirds of the patients. Renal artery stent revascularization appears to have a beneficial effect upon blood pressure control and a nondeleterious effect upon renal function in the majority of patients.

Measuring outcomes: a nursing report card

Balancing quality health care with the pressures of managed care and restructuring requires monitoring and measuring outcomes. The "nursing report card" organizes data in an informative manner, allowing nursing's contributions to patient outcomes to be assessed and reported to all customers in an ongoing fashion.

Clinical research on bonded amalgam restorations. Part 1: SEM study of in vivo bonded amalgam restorations

Exfoliated deciduous teeth, in which bonded or nonbonded amalgams had been placed two to three years previously, were examined directly and indirectly with the use of a scanning electron microscope (SEM). Bonding resin was found in the interface between the amalgam and the tooth structure, frequently obliterating the microspace. Several materials now are available that bond amalgam to tooth surfaces with bonding strength exceeding 10 MPa. Amalgam can be retained in preparations without undercuts, or in pits and fissures without any tooth preparation. The article consists of two parts: in part 1, results of a pilot study on bonded amalgam-tooth interfaces is presented. In part 2, the authors discuss further studies and clinical technique. Commercial products are compared; and other clinical trials now in progress, concerning amalgam bond strength adhesion and ability to eliminate microspace, are discussed.

Clinical research on bonded amalgam restorations. Part 2: Further studies and clinical technique

In vitro studies show that the adhesive amalgam technique is superior to the nonadhesive technique. Also, early clinical results indicate that the adhesive technique can eliminate the microspace between amalgam and tooth. And, it can retain amalgam on unprepared occlusal surfaces of molars and premolars, sealing the fissures. Moreover, amalgam can be retained in preparations without undercuts. Early results indicate in traditional preparations, the adhesive technique appears to be at least equivalent to nonadhesive technique.

The beta3-adrenergic receptor in the obesity and diabetes prone rhesus monkey is very similar to human and contains arginine at codon 64

The beta3-adrenergic receptor (ADRbeta3) is a seven-membrane spanning, G-protein linked receptor expressed in brown adipose tissue in rodents, and visceral adipose tissue in humans. Stimulation of the receptor by norepinephrine leads to lipolysis and thermogenesis. In rodent models of obesity and diabetes, administration of beta3-agonists results in weight loss and improved glucose tolerance. Studies indicate that the pharmacological properties of the ADRbeta3 differ markedly between rodents and humans, making generalizations of rodent studies to humans difficult. We hypothesized that the obesity and diabetes prone rhesus monkey (Macaca mulatta) would provide an excellent animal model to study the role of the ADRbeta3 in the development of obesity and diabetes as well as for assessment of the therapeutic efficacy of beta3-agonists. We sequenced the entire coding region of the rhesus ADRbeta3 gene. Like humans, the rhesus ADRbeta3 has two exons. There is 89% amino acid (aa) identity between human and rhesus compared to 82% aa identity between human and mouse. A single base deletion results in divergence of the intracellular carboxy terminus accounting for 26 of the 45 aa changes and 10 additional aa. Of the 15 rhesus monkeys studied, all were homozygous for Arg64. In humans, Arg64 (rather than Trp) is associated with increased body mass index, insulin resistance, and an earlier onset of type II diabetes mellitus. We conclude that the rhesus ADRbeta3 is more similar to the human ADRbeta3 than to the rodent ADRbeta3 suggesting that this primate model may be more appropriate for physiologic and therapeutic studies of the ADRbeta3 axis, and that Arg64 may influence susceptibility in this species to obesity, insulin resistance, and type II diabetes.

[Clinical monitoring. A method for quality control]

Clinical monitoring approximates the quality control standards that have been developed by the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) and utilizes clinical indicators to measure the relative quality of the health care given. This method can be used to compare the quality of desired care against actual day by day care. To demonstrate how it can be applied, an example of clinical monitoring performed in a U.S. hospital is presented.

The vesicle-associated membrane protein family of proteins in rat pancreatic and parotid acinar cells

BACKGROUND & AIMS

The vesicle-associated membrane protein (VAMP) family of proteins may play an important role in regulating enzyme secretion from pancreatic and parotid acini. The purpose of this study was to characterize the isoforms produced in pancreatic and parotid acini and determine their subcellular locations.

METHODS

Using a battery of specific antisera and recombinant tetanus toxin light chain (which cleaves VAMP-2 and cellubrevin), the presence of each VAMP molecule in the acini was determined by immunoblotting of subcellular membrane fractions; their localization was determined by confocal immunofluorescence microscopy and immunogold electron microscopy.

RESULTS

Both VAMP-2 and cellubrevin were present on both the zymogen granule membrane and plasma membrane. VAMP-1 was not present in the acinar cell but was found in the nerve endings innervating the acini. As expected, pancreatic acinar VAMP-2 and cellubrevin were sensitive to cleavage by recombinant tetanus toxin.

CONCLUSIONS

VAMP-2 and cellubrevin may play integral roles in exocytosis of the pancreatic and parotid acinar cells, whereas VAMP-1 is restricted to nerves that innervate the acini and may function to modulate exocrine activity.