Biochemical evidence for impaired nitric oxide synthesis in patients with peripheral arterial occlusive disease

BACKGROUND

We studied urinary nitrate and cGMP excretion rates, indices of systemic NO formation, and plasma concentrations of L-arginine and the endogenous NO synthase inhibitor asymmetrical dimethylarginine (ADMA) and its inactive stereoisomer, symmetrical dimethylarginine, in 77 patients with peripheral arterial occlusive disease (PAOD) in Fontaine stages IIb through IV and in 47 young and 37 elderly healthy control subjects.

METHODS AND RESULTS

Urinary nitrate excretion was 182.0+/-11.4 micromol/mmol creatinine and cGMP excretion was 186.2+/-13.0 nmol/mmol creatinine in young healthy control subjects. In elderly control subjects, both excretion rates were slightly lower (nitrate, 156.0+/-7.8 micromol/mmol creatinine; cGMP, 150.0+/-8.3 nmol/mmol creatinine; P=NS). In PAOD patients, there was a significant, progressive reduction of urinary nitrate (IIb, 138.4+/-11.9; III, 128.6+/-11.3; and IV, 91.9+/-8.0 micromol/mmol creatinine; P<.05) and cGMP (IIb, 139.9+/-25.2; III, 115.6+/-13.1; and IV, 76.9+/-7.9 nmol/mmol creatinine; P<.05) excretion rates related to the Fontaine stage of PAOD. These changes were independent of changes in renal excretory function. Plasma L-arginine concentrations were not significantly different between the groups, but ADMA concentrations were elevated in PAOD patients (young control subjects, 1.25+/-0.11; elderly control subjects, 1.01+/-0.05 micromol/L; IIb, 2.62+/-0.24; III, 3.06+/-0.48; and IV, 3.49+/-0.26 micromol/L; P<.05 for PAOD versus control subjects). There was a significant linear correlation between urinary nitrate and cGMP excretion rates and a significant negative linear correlation between plasma ADMA concentrations and urinary nitrate excretion.

CONCLUSIONS

In PAOD patients, there is a progressive reduction in urinary nitrate and cGMP excretion rates, which may be caused in part by accumulation of ADMA, an endogenous inhibitor of NO synthase.

Restoring vascular nitric oxide formation by L-arginine improves the symptoms of intermittent claudication in patients with peripheral arterial occlusive disease

BACKGROUND

Administration of L-arginine improves nitric oxide (NO) formation and endothelium-dependent vasodilation in atherosclerotic patients.

OBJECTIVES

We investigated in this double-blind, controlled study whether prolonged intermittent infusion therapy with L-arginine improves the clinical symptoms of patients with intermittent claudication, as compared with the endothelium-independent vasodilator prostaglandin E1, and control patients.

METHODS

Thirty-nine patients with intermittent claudication were randomly assigned to receive 2 x 8 g L-arginine/day, or 2 x 40 microg prostaglandin E1 (PGE1)/day or no hemodynamically active treatment, for 3 weeks. The pain-free and absolute walking distances were assessed on a walking treadmill at 3 km/h, 12% slope, and NO-mediated, flow-induced vasodilation of the femoral artery was assessed by ultrasonography at baseline, at 1, 2 and 3 weeks of therapy and 6 weeks after the end of treatment. Urinary nitrate and cyclic guanosine-3', 5'-monophosphate (GMP) were assessed as indices of endogenous NO production.

RESULTS

L-Arginine improved the pain-free walking distance by 230+/-63% and the absolute walking distance by 155+/-48% (each p < 0.05). Prostaglandin E1 improved both parameters by 209+/-63% and 144+/-28%, respectively (each p < 0.05), whereas control patients experienced no significant change. L-Arginine therapy also improved endothelium-dependent vasodilation in the femoral artery, whereas PGE1 had no such effect. There was a significant linear correlation between the L-arginine/asymmetric dimethylarginine (ADMA) ratio and the pain-free walking distance at baseline (r=0.359, p < 0.03). L-Arginine treatment elevated the plasma L-arginine/ADMA ratio and increased urinary nitrate and cyclic GMP excretion rates, indicating normalized endogenous NO formation. Prostaglandin E1 therapy had no significant effect on any of these parameters. Symptom scores assessed on a visual analog scale increased from 3.51+/-0.18 to 83+/-0.4 (L-arginine) and 7.0+/-0.5 (PGE1; each p < 0.05), but did not significantly change in the control group (4.3+/-0.4).

CONCLUSIONS

Restoring NO formation and endothelium-dependent vasodilation by L-arginine improves the clinical symptoms of intermittent claudication in patients with peripheral arterial occlusive disease.

Requirement for p27(KIP1) in retinoblastoma protein-mediated senescence

In vivo and in vitro evidence indicate that cells do not divide indefinitely but instead stop growing and undergo a process termed cellular proliferative senescence. Very little is known about how senescence occurs, but there are several indications that the retinoblastoma protein (pRb) is involved, the most striking being that reintroduction of RB into RB(-/-) tumor cell lines induces senescence. In investigating the mechanism by which pRb induces senescence, we have found that pRb causes a posttranscriptional accumulation of the cyclin-dependent kinase inhibitor p27(KIP1) that is accompanied by an increase in p27(KIP1) specifically bound to cyclin E and a concomitant decrease in cyclin E-associated kinase activity. In contrast, pRb-related proteins p107 and p130, which also decrease cyclin E-kinase activity, do not cause an accumulation of p27(KIP1) and induce senescence poorly. In addition, the use of pRb proteins mutated in the pocket domain demonstrates that pRb upregulation of p27(KIP1) and senescence induction do not require the interaction of pRb with E2F. Furthermore, ectopic expression of p21(CIP1) or p27(KIP1) induces senescence but not the morphology change associated with pRb-mediated senescence, uncoupling senescence from the morphological transformation. Finally, the ability of pRb to maintain cell cycle arrest and induce senescence is reversibly abrogated by ablation of p27(KIP1) expression. These findings suggest that prolonged cell cycle arrest through the persistent and specific inhibition of cdk2 activity by p27(KIP1) is critical for pRb-induced senescence.

L-arginine induces nitric oxide-dependent vasodilation in patients with critical limb ischemia. A randomized, controlled study

BACKGROUND

L-Arginine is the precursor of endogenous nitric oxide (NO), which is a potent vasodilator acting via the intracellular second-messenger cGMP. In healthy humans, L-arginine induces peripheral vasodilation and inhibits platelet aggregation due to an increased NO production. Prostaglandin E1 (PGE1) induces peripheral vasodilation via stimulating prostacyclin receptors.

METHODS AND RESULTS

We investigated the effects of one intravenous infusion of L-arginine (30 g, 60 minutes) or PGE1 (40 microgram, 60 minutes) versus those of placebo (150 mL 0.9% saline, 60 minutes) on blood pressure, peripheral hemodynamics, and urinary NO3- and cGMP excretion rates in patients with critical limb ischemia (peripheral arterial occlusive disease stages Fontaine III or IV). Blood flow in the femoral artery was significantly increased by L-arginine (+42.3 +/- 7.9%, P<.05) and by PGE1 (+31.0 +/- 10.2%, P<.05) but not by placebo (+4.3 +/- 13.0%, P=NS). Urinary NO3- excretion increased by 131.8 +/- 39.5% after L-arginine (P<.05) but only by 32.3 +/- 17.2% after PGE1 (P=NS). Urinary cGMP excretion increased by 198.7 +/- 84.9% after L-arginine (P<.05) and by 94.2 +/- 58.8% after PGE1 (P=NS). Both urinary index metabolites were unchanged by placebo.

CONCLUSIONS

We conclude that intravenous L-arginine induces NO-dependent peripheral vasodilation in patients with critical limb ischemia. These effects are paralleled by increased urinary NO3- and cGMP excretion, indicating an enhanced systemic NO production. Increased urinary NO3- excretion may be a sum effect of NO synthase substrate provision (L-arginine) and increased shear stress (PGE1 and L-arginine).

L-arginine infusion decreases peripheral arterial resistance and inhibits platelet aggregation in healthy subjects

1. L-Arginine is the physiological precursor of nitric oxide which induces vasodilatation and inhibits platelet aggregation by the formation of cyclic GMP. 2. In the present study we investigated the effects of an intravenous infusion of L-arginine (30 g, 30 min) compared with placebo on blood pressure, heart rate and peripheral haemodynamics in ten healthy male subjects. Cyclic GMP, NO2- and NO3- were determined in plasma and urine to assess NO production in vivo by a new, highly specific and sensitive gas chromatography-mass spectrometry method. 3. L-Arginine significantly decreased mean arterial blood pressure and increased heart rate. The effect was more pronounced on diastolic than on systolic blood pressure. This was due to a decreased peripheral arteriolar resistance, as in femoral artery Doppler sonography the arterial diameter was unchanged but blood flow was increased. These haemodynamic effects were not observed after placebo administration. 4. Urinary excretion of cyclic GMP increased by 65.4% after L-arginine and by 25.1 after placebo. Urinary NO2- excretion was near the threshold of detection. Urinary NO3- excretion increased by 79.7% after L-arginine. Plasma arginine levels increased nearly ten-fold after the L-arginine infusion, and plasma cyclic GMP increased by a similar rate as in urine. However, plasma NO2- and NO3- remained unchanged after both treatments, as did plasma alpha-atrial natriuretic peptide levels. 5. Platelet aggregation was inhibited by 32.7% after L-arginine (P < 0.05), but was unchanged after placebo. Platelet intracellular cyclic GMP was increased by 43.0% after L-arginine, but not after placebo (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Risk of hospitalized bacterial infections associated with biologic treatment among US veterans with rheumatoid arthritis

OBJECTIVE

The comparative risk of infection associated with non-anti-tumor necrosis factor (anti-TNF) biologic agents is not well established. Our objective was to compare risk for hospitalized infections between anti-TNF and non-anti-TNF biologic agents in US veterans with rheumatoid arthritis (RA).

METHODS

Using 1998-2011 data from the US Veterans Health Administration, we studied RA patients initiating rituximab, abatacept, or anti-TNF therapy. Exposure was based upon days supplied (injections) or usual dosing intervals (infusions). Treatment episodes were defined as new biologic agent use. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for hospitalization for a bacterial infection were estimated from Cox proportional hazards models, adjusting for potential confounders.

RESULTS

Among 3,152 unique RA patients contributing 4,158 biologic treatment episodes to rituximab (n = 596), abatacept (n = 451), and anti-TNF agents (n = 3,111), the patient mean age was 60 years and 87% were male. The most common infections were pneumonia (37%), skin/soft tissue (22%), urinary tract (9%), and bacteremia/sepsis (7%). Hospitalized infection rates per 100 person-years were 4.4 (95% CI 3.1-6.4) for rituximab, 2.8 (95% CI 1.7-4.7) for abatacept, and 3.0 (95% CI 2.5-3.5) for anti-TNF. Compared to etanercept, the adjusted rate of hospitalized infection was not different for adalimumab (HR 1.4, 95% CI 0.9-2.2), abatacept (HR 1.1, 95% CI 0.6-2.1), or rituximab (HR 1.4, 0.8-2.6), although it was increased for infliximab (HR 2.3, 95% CI 1.3-4.0). Infection risk was greater for those taking prednisone >7.5 mg/day (HR 1.8, 95% CI 1.3-2.7) and in the highest quartile of C-reactive protein (HR 2.3, 95% CI 1.4-3.8) and erythrocyte sedimentation rate (HR 4.1, 95% CI 2.3-7.2) compared to the lowest quartile.

CONCLUSION

In older, predominantly male US veterans with RA, the risk of hospitalized bacterial infections associated with rituximab or abatacept was similar to etanercept.

Effects of resistance exercise on glucose tolerance in normal and glucose-intolerant subjects

This study was conducted to determine whether improvements in glucose tolerance could be observed after a single bout of resistance exercise in young (27.1 +/- 1.24 yr) control subjects, older (53.3 +/- 1.7 yr) patients with non-insulin-dependent diabetes mellitus (NIDDM), and older (50.7 +/- 1.9 yr) age-matched control subjects. Each subject was screened for fitness level and any contraindications to exercise before inclusion in the study. A 75-g oral glucose tolerance test was administered 2 wk after the subjects were screened, and the subjects were familiarized with the exercise equipment. The maximum weight that could be lifted with one repetition was determined on seven Nautilus machines that utilized the upper and lower body. After a 48-h rest period, a 3-set x 10-repetition protocol based on the subject's one repetition maximum was completed by each participant on each machine. Eighteen hours after the lifting protocol, a second oral glucose tolerance test was administered. There was no change in the pre- to post-exercise glucose levels in any of the treatment groups, but the total insulin responses (area under the curve) of the young control and NIDDM groups were significantly lower after exercise: from 6.93 +/- 0.8 x 10(3) to 5.38 +/- 0.65 x 10(3) pM in the young control group and from 9.83 +/- 1.95 x 10(3) to 7.77 +/- 1.50 x 10(3) pM in the NIDDM group. The postexercise C-peptide levels were unchanged in all groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of polymeric dispersions of dimenhydrinate in ethyl cellulose for controlled release

Granulations of dimenhydrinate (DMH) were prepared using various concentrations of ethyl cellulose (EC) by the solid dispersion technique. Characterization was done using thermal analysis, powder X-ray diffraction, infrared spectroscopy, optical microscopy and dissolution studies. Humidity studies were performed to investigate the effect of moisture on the drug and solid dispersions. It was seen that the crystalline drug was converted into its amorphous form in all the granulations. There was no chemical interaction between the DMH and EC. The thermal decomposition of drug in the granules was not affected. Dissolution studies revealed that the drug release from the granulations was significantly reduced as compared to the pure drug. As the amount of ethyl cellulose increased, the drug release rate decreased and the drug release kinetics showed a better fit to zero-order kinetics. Humidity studies showed that the drug and granulations remained stable in conditions not exceeding 70%RH. At high humidity of 100%RH, there was formation of the hydrate crystal forms of the drug in the pure drug samples and granules with 1:1 DMH-EC content whereas the granules with higher polymer content did not show any significant changes indicating better drug stability in the granules.

Primary prevention of childhood lead exposure: A randomized trial of dust control

BACKGROUND

Dust control is recommended as one of the primary strategies to prevent or control children's exposure to residential lead hazards, but the effect of dust control on children's blood lead levels is poorly understood.

OBJECTIVE

To determine the effectiveness of dust control in preventing children's exposure to lead, as measured by blood lead levels, during their peak age of susceptibility.

DESIGN

A randomized, controlled trial.

SETTING

Rochester, NY.

PARTICIPANTS

A total of 275 urban children were randomized at 6 months of age, of whom 246 (90%) were available for the 24-month-old follow-up visit.

INTERVENTIONS

Children and their families were randomly assigned to an intervention group (n = 140), which received cleaning equipment and up to eight visits by a dust control advisor, or a control group (n = 135).

OUTCOME MEASURES

Geometric mean blood lead levels and prevalence of elevated blood lead levels (ie, >10 microg/dL, 15 microg/dL, and 20 microg/dL).

RESULTS

At baseline, children's geometric mean blood lead levels were 2.9 microg/dL (95% confidence interval [CI] = 2.7, 3.1); there were no significant differences in characteristics or lead exposure by group assignment, with the exception of water lead levels. For children in the intervention group, the mean number of visits by a dust control advisor during the 18-month study period was 6.2; 51 (36%) had 4 to 7 visits, and 69 (49%) had 8 visits. At 24 months of age, the geometric mean blood lead was 7.3 microg/dL (95% CI = 6.6, 8.2) for the intervention group and 7.8 microg/dL (95% CI = 6.9, 8. 7) for the control group. The percentage of children with a 24-month blood lead >/=10 microg/dL, >/=15 microg/dL, and >/=20 microg/dL was 31% versus 36%, 12% versus 14%, and 5% versus 7% in the intervention and control groups, respectively.

CONCLUSIONS

We conclude that dust control, as performed by families and in the absence of lead hazard controls to reduce ongoing contamination from lead-based paint, is not effective in the primary prevention of childhood lead exposure.

Effectiveness of maternal pertussis vaccination in preventing infection and disease in infants: The NSW Public Health Network case-control study

BACKGROUND

Infants are at the highest risk of severe complications - including death - as a result of pertussis infection. Controlling pertussis in this group has been challenging, particularly in those too young to be vaccinated. Following revised national recommendations in March 2015, the state of New South Wales, Australia, introduced a funded maternal vaccination campaign at 28 - 32 weeks of gestation using a 3-component tetanus-diphtheria-acellular pertussis vaccine (dTpa; Boostrix, GSK). This study aimed to assess the effectiveness of maternal vaccination and add to the growing body of evidence for this strategy.

METHODS

A 1:1 matched case-control study was conducted between 16 August 2015 and 17 August 2016. Cases were laboratory or doctor notified, laboratory confirmed (nucleic acid testing or culture) and aged <6 months at onset. Each control infant was randomly selected from public hospital births in the same geographical area in the period up to 3 days before and after the case's birthdate. Odds ratios (OR) were calculated using conditional logistic regression. Vaccine effectiveness (VE) was calculated as 1 - OR.

FINDINGS

In total, 117 cases and 117 controls were recruited. The overall VE estimate was non-significantly protective for infants <6 months old (VE 39%, 95% CI -12 to 66%). Higher VE was observed for infants <3 months old (VE 69%, 95% CI 13-89%) and against hospitalisation (VE 94%, 95% CI 59-99%).

INTERPRETATION

Maternal pertussis vaccination with a 3-component acellular vaccine was found to be highly effective at preventing severe disease in infants, but was less effective at preventing disease which did not require hospitalisation. The overall VE reported in this study was lower than in prior studies and suggests that maternal vaccination, while an effective strategy at preventing severe pertussis, is less effective at protecting against infection or mild disease.

Chemical and enzymic studies on the characterization of intermediates during the removal of the 14alpha-methyl group in cholesterol biosynthesis. The use of 32-functionalized lanostane derivatives

By using cell-free preparations of rat liver it was shown that the removal of the 14alpha-methyl group (C-32) of steroids containing either a delta7(8) or a delta8(9) double bond is attended exclusively by the formation of the corresponding 7,14- and 8,14-dienes respectively (structures of types III and VIII). Cumulative evidence from a variety of experimental approaches had led to the deduction that delta8(14)-steroids are not involved as intermediates on the major pathway of cholesterol biosynthesis. The metabolism of [32-3H]lanost-7-ene-3beta,32-diol (structure of type I) results in the formation of radioactive formic acid, no labelled formaldehyde being formed. By using appropriately labelled species of the compound (I) it was found that the release of formic acid and the formation of 4,4-dimethylcholesta-7,14-dien-3beta-ol (strurcture of type III) were closely linked processes, and that in the conversion of compound (I) into compound (III), 3-beta-hydroxylanost-7-en-32-al (II) is an obligatory intermediate. Both the conversion of lanost-7-ene-3beta,32-diol (I) into 3beta-hydroxylanost-7-en-32-al (II) and the further metabolism of the latter (II) to 4,4-dimethylcholesta-7,14-dien-3beta-ol (III) exhibited a requirement for NADPH and O2. This suggests that the oxidation of the 32-hydroxy group of compound (I) to the aldehyde group of compound (II) does not occur by the conventional alcohol dehydrogenase type of reaction, but may proceed by a novel mechanism involving the intermediacy of a gem-diol. A detailed overall pathway for the 14alpha-demethylation in cholesterol biosynthesis is considered, and proposals about the mechanism of individual steps in the pathway are made.

Evidence of linkage in a Hispanic cohort with a Class III dentofacial phenotype

Despite the prevalence of craniofacial disorders, the genetic contribution remains poorly understood. Class III malocclusion represents a specific craniofacial problem that can be handicapping, both functionally and socially. We hypothesized that the Class III phenotype is genetically linked to specific loci that regulate maxillary or mandibular growth. To determine the region linked to the Class III phenotype in four Hispanic families, we performed a genome-wide scan and linkage analysis using 500 microsatellite markers. Pedigree and linkage analyses revealed that the Class III phenotype (primarily maxillary deficiency) segregates in an autosomal-dominant manner, and that 5 loci (1p22.1, 3q26.2, 11q22, 12q13.13, and 12q23) are suggestive of linkage. Candidate genes within the 12q23 region (ZLR=2.93) include IGF1, HOXC, and COL2A1. Chromosome 1 results (ZLR=2.92) were similar to those reported previously in an Asian cohort with mandibular prognathism, suggesting that a common upstream genetic element may be responsible for both mandibular prognathism and maxillary deficiency.

Mechanism of termination of DNA replication of Escherichia coli involves helicase-contrahelicase interaction

Using yeast forward and reverse two-hybrid analyses, we have discovered that the replication terminator protein Tus of Escherichia coli physically interacts with DnaB helicase in vivo. We have confirmed this protein-protein interaction in vitro. We show further that replication termination involves protein-protein interaction between Tus and DnaB at a critical region of Tus protein, called the L1 loop. Several mutations located in the L1 loop region not only reduced the protein-protein interaction but also eliminated or reduced the ability of the mutant forms of Tus to arrest DnaB at a Ter site. At least one mutation, E49K, significantly reduced Tus-DnaB interaction and almost completely eliminated the contrahelicase activity of Tus protein in vitro without significantly reducing the affinity of the mutant form of Tus for Ter DNA, in comparison with the wild-type protein. The results, considered along with the crystal structure of Tus-Ter complex, not only elucidate further the mechanism of helicase arrest but also explain the molecular basis of polarity of replication fork arrest at Ter sites.

Local cerebral blood flow following transient cerebral ischemia. I. Onset of impaired reperfusion within the first hour following global ischemia

Using the hydrogen clearance technique, local cerebral blood flow (LCBF) in 22 dogs was estimated at 6 parietal sites prior to and following 5 min of total global ischemia. Ischemia was immediately followed by an initial reactive hyperemia during which the electrocorticogram (ECoG) usually began to recover, and within the first 30 min, most of the LCBF's decreased to subnormal values. This onset of hypoperfusion was accompanied by a concomitant decrease in ECoG activity. Two animals that maintained normal local perfusion after the initial hyperemia recovered ECoG activity quickly. These results suggest that the subsequent poor reperfusion was caused by an increased microvascular resistance rather than by blood aggregates, increased blood viscosity, or a variety of other mechanism which have been proposed. Increased vascular tonus was, at least, partly responsible for the increased vascular resistance. This report supports the hypothesis that impaired reperfusion (which occurs some time after an initial hyperemia) may be responsible for ultimate neuronal death, rather than the period of global ischemic hypoxia per se.

A new application for the Antoine equation in formulation development

Characterization of formulation components in pre-formulation and formulation studies will be made easier if a rapid method to evaluate the evaporation characteristics of an ingredient in the formulation is developed. This study aims at providing a simple and rapid thermogravimetric method for estimating the vapor pressure characteristics using the Antoine equation as the analytical tool. The heat treatment for the majority of benzoic acid derivatives follows zero-order rate processes that are in good correlation with their evaporation process. The optimum conditions for the rising temperature experiments were found when the heating rate was 10 degrees C/min in an atmosphere of dry nitrogen (100 ml/min). Methyl paraben was taken as the calibration compound since its Antoine constants are reported in the literature, and its selected thermodynamic parameters were evaluated using the Langmuir equation. The coefficient of vaporization (k macro) was determined to be 124,525+/-0.8, with units being reported in the S.I. system. The corresponding vapor-pressure plots were obtained for the remaining compounds and their Antoine constants calculated.

Comparison of magnetic resonance imaging, computed tomography, and radiography for assessment of noncartilaginous changes in equine metacarpophalangeal osteoarthritis

We compared the ability of 1.5 T magnetic resonance imaging (MRI), computed tomography (CT), and computed radiography (CR) to evaluate noncartilaginous structures of the equine metacarpophalangeal joint (MCP), and the association of imaging changes with gross cartilage damage in the context of osteoarthritis. Four CR projections, helical single-slice CT, and MRI (Ti-weighted gradient recalled echo [GRE], T2*-weighted GRE with fast imaging employing steady-state acquisition [FIESTA], T2-weighted fast spin echo with fat saturation, and spoiled gradient recalled echo with fat saturation ISPGR-FS]) were performed on 20 racehorse cadaver forelimbs. Osteophytosis, synovial effusion, subchondral bone lysis and sclerosis, supracondylar lysis, joint fragments, bone marrow lesions, and collateral desmopathy were assessed with each modality. Interexaminer agreement was inferior to intraexaminer agreement and was generally moderate (i.e., 0.4 < kappa < 0.6). Subchondral bone sclerosis scores using CT or MRI were correlated significantly with the reference quantitative CT technique used to assess bone mineral density (P < 0.0001). Scores for subchondral lysis and osteophytosis were higher with MRI or CT vs. CR (P < 0.0001). Although differences between modalities were noted, osteophytosis, subchondral sclerosis, and lysis as well as synovial effusion were all associated with the degree of cartilage damage and should be further evaluated as potential criteria to be included in a whole-organ scoring system. This study highlights the capacity of MRI to evaluate noncartilaginous changes in the osteoarthritic equine MCP joint.

The use of conjoint analysis to elicit community preferences in public health research: a case study of hospital services in South Australia

AIMS

To demonstrate the use of conjoint analysis (CA) in public health research through a survey of the South Australian community about aspects of their public hospital services.

METHODS

A series of focus groups determined the most important attributes in choice of hospital services. These were built into a CA survey, using the discrete choice approach. The survey was posted to a representative sample of 700 South Australians. Theoretical validity, internal consistency and non-response bias were all investigated.

RESULTS

Some 231 individuals returned the questionnaire. The attribute, 'improvement in complication rates' was positively associated with choice of hospital. Three attributes were found to be negatively associated with such choice: 'waiting times for casualty', 'waiting times for elective surgery' and, anomalously, 'parking and transport facilities'. 'Travel time' and the cost attribute, 'Medicare levy' were not statistically significant. Trade-offs between the significant attributes were estimated, as were satisfaction or utility scores for different ways of providing hospital services. Results concerning internal consistency and internal validity were encouraging, but some potential for non-response bias was detected.

CONCLUSION

A high premium is placed on the quality of hospital care and members of the community are prepared to choose between hospitals largely on the basis of outcomes and length of waiting times for elective surgery and in casualty.

IMPLICATIONS

CA can yield potentially policy-relevant information about community preferences for health services.

Phenotypic variation in FAM83H-associated amelogenesis imperfecta

FAM83H gene mutations are associated with autosomal-dominant hypocalcified amelogenesis imperfecta (ADHCAI), which is typically characterized by enamel having normal thickness and a markedly decreased mineral content. This study tested the hypothesis that there are phenotype and genotype associations in families with FAM83H-associated ADHCAI. Seven families segregating ADHCAI (147 individuals) were evaluated. Phenotyping included clinical, radiographic, histological, and biochemical studies, and genotyping was by mutational analysis. Multiple novel FAM83H mutations were identified, including two 2-bp-deletion mutations, the first non-nonsense mutations identified. Craniofacial deviation from normal was more prevalent in the affected individuals. Affected individuals having truncating FAMH3H mutations of 677 or fewer amino acids presented a generalized ADHCAI phenotype, while those having mutations capable of producing a protein of at least 694 amino acids had a unique and previously unreported phenotype affecting primarily the cervical enamel. This investigation shows that unique phenotypes are associated with specific FAM83H mutations.