Prognosis in hypertrophic cardiomyopathy: role of age and clinical, electrocardiographic and hemodynamic features

Retrospective analysis of the clinical course of 254 patients with hypertrophic cardiomyopathy, followed up for 1 to 23 years (mean 6), disclosed that 58 had died, 32 of them suddenly. The 196 survivors were compared with the 32 patients who died suddenly and with the 38 who died suddenly or with heart failure. The combination of young age (14 years or less), syncope at diagnosis, severe dyspnea at last follow-up and a family history of hypertrophic cardiomyopathy and sudden death best predicted sudden death (false negative rate 30 percent, false positive rate 27 percent). A "malignant" family history was associated with poor prognosis, particularly in the younger patients; a family history of hypertrophic cardiomyopathy without sudden death was more frequent in the survivors (12 percent) than in the dead (5 percent). Patients who had a diagnosis in childhood were usually asymptomatic, had an unfavorable family history and a 5.9 percent annual mortality rate. In those aged 15 to 45 years at diagnosis, there was a 2.5 percent annual mortality rate and syncope was the only prognostic feature. Among those diagnosed between age 45 and 60 years, dyspnea and exertional chest pain were more common in the patients who died, and the annual mortality rate was 2.6 percent. Poor prognosis was better predicted by the history at the time of diagnosis and by changes in symptoms during follow-up than by an electrocardiographic or hemodynamic measurement.

Analysis of symptomatic course and prognosis and treatment of hypertrophic obstructive cardiomyopathy

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Cerebrospinal fluid diversion procedures in pseudotumor cerebri

We reviewed the efficacy of CSF diversion for pseudotumor cerebri (PTC) in patients from six different institutions. Thirty-seven patients underwent a total of 73 lumboperitoneal shunts and nine ventricular shunts. Only 14 patients remained "cured" after a single surgical procedure. The average time between shunt insertion and shunt replacement was 9 months, although 64% of shunts lasted less than 6 months. Shunt failure (55%) and low-pressure headaches (21%) were the most common causes for reoperation. The vision of most patients improved (13) or stabilized (13) postoperatively. However, three who had initially improved subsequently lost vision. Six had a postoperative decrease in vision. Two patients improved in one eye but worsened postoperatively in the other. Four lost vision despite apparently adequate shunt function. Shunt failure with relapse of PTC occurred as late as 7 years after insertion. CSF diversion procedures have a significant failure rate as well as a high frequency of side effects.

Anterior choroidal artery-territory infarction. Report of cases and review

Occlusion of the anterior choroidal artery (AChA) can cause infarction in the posterior limb of the internal capsule. Infarction is less frequent in the thalamus, midbrain, temporal lobe, and lateral geniculate body territories of the AChA. The most common clinical sign is hemiparesis. Hemisensory loss is usually transient but may be severe at onset. Homonymous upper-quadrant anopia, hemianopia, or upper- and lower-quadrant sector anopsia can be present. A homonymous defect in the upper and lower visual fields sparing the horizontal meridian is probably diagnostic of a lesion in the lateral geniculate body in the territory of the AChA. The most common stroke mechanism is small-vessel occlusive disease, predominantly found in hypertensive and diabetic patients, but cardiac-origin embolism also can affect the AChA territory. Two of our patients had infarction after temporal lobe resection for epilepsy. Occasionally patients have associated disabilities of higher cortical function that are usually transient. The lesion should be recognizable by computed tomography.

Raised calcium promotes α-synuclein aggregate formation

Parkinson's and Parkinson's-plus diseases are associated with abnormal, aggregated forms of the protein, α-synuclein. We have investigated the effects of calcium on α-synuclein aggregation in vitro and in vivo. We treated monomeric α-synuclein with calcium in vitro and used fluorescence imaging, fluorescence correlation and scanning electron microscopy to investigate protein aggregation. Incubation of fluorescent-labelled monomeric α-synuclein (24h) at low concentration (10 μM) with calcium resulted in surface aggregates (1.5±0.7 μm(2)) detected by fluorescence microscopy saturating at a half-maximum calcium concentration of 80 μM, whilst incubations without calcium showed few protein aggregates. Scanning electron microscopy revealed that α-synuclein surface plaques (0.5-1 μm) form in the presence of calcium and comprise 10-20 nm globular particles. Incubation of α-synuclein at high concentration (75 μM; 6h) resulted in soluble oligomeric aggregates detected by fluorescence correlation spectroscopy in a calcium dependent process, saturating at a half maximum calcium concentration of 180 μM. In cell culture experiments, we used thapsigargin or calcium ionophore A23187 to induce transient increases of intracellular free calcium in human 1321N1 cells expressing an α-synuclein-GFP construct and observed calcium flux and α-synuclein aggregation by fluorescence microscopy. The cell culture data shows that a transient increase in intracellular free calcium significantly increased the proportion of cells bearing cytoplasmic α-synuclein aggregates 6 and 12h post-treatment (P, 0.01). Our data indicates that calcium accelerates α-synuclein aggregation on surfaces, in free solution and in cultured cells and suggests that surface adsorption may play an important role in the calcium-dependent aggregation mechanism.

Pharmacodynamics of fosfomycin: insights into clinical use for antimicrobial resistance

The aim of this study was to improve the understanding of the pharmacokinetic-pharmacodynamic relationships of fosfomycin against extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli strains that have different fosfomycin MICs. Our methods included the use of a hollow fiber infection model with three clinical ESBL-producing E. coli strains. Human fosfomycin pharmacokinetic profiles were simulated over 4 days. Preliminary studies conducted to determine the dose ranges, including the dose ranges that suppressed the development of drug-resistant mutants, were conducted with regimens from 12 g/day to 36 g/day. The combination of fosfomycin at 4 g every 8 h (q8h) and meropenem at 1 g/q8h was selected for further assessment. The total bacterial population and the resistant subpopulations were determined. No efficacy was observed against the Ec42444 strain (fosfomycin MIC, 64 mg/liter) at doses of 12, 24, or 36 g/day. All dosages induced at least initial bacterial killing against Ec46 (fosfomycin MIC, 1 mg/liter). High-level drug-resistant mutants appeared in this strain in response to 12, 15, and 18 g/day. In the study arms that included 24 g/day, once or in a divided dose, a complete extinction of the bacterial inoculum was observed. The combination of meropenem with fosfomycin was synergistic for bacterial killing and also suppressed all fosfomycin-resistant clones of Ec2974 (fosfomycin MIC, 1 mg/liter). We conclude that fosfomycin susceptibility breakpoints (≤64 mg/liter according to CLSI [for E. coli urinary tract infections only]) should be revised for the treatment of serious systemic infections. Fosfomycin can be used to treat infections caused by organisms that demonstrate lower MICs and lower bacterial densities, although relatively high daily dosages (i.e., 24 g/day) are required to prevent the emergence of bacterial resistance. The ratio of the area under the concentration-time curve for the free, unbound fraction of fosfomycin versus the MIC (fAUC/MIC) appears to be the dynamically linked index of suppression of bacterial resistance. Fosfomycin with meropenem can act synergistically against E. coli strains in preventing the emergence of fosfomycin resistance.

Reduced gray matter volume in normal adults with a maternal family history of Alzheimer disease

OBJECTIVE

A consistently identified risk factor for Alzheimer disease (AD) is family history of dementia, with maternal transmission significantly more frequent than paternal transmission. A history of maternal AD may be related to AD-like glucose consumption in cognitively healthy subjects. In this cross-sectional study, we tested whether cognitively healthy people with a family history of AD have less gray matter volume (GMV), an endophenotype for late-onset AD, than individuals with no family history, and whether decreases in GMV are different in subjects with a maternal family history.

METHODS

As part of the Kansas University Brain Aging Project, 67 cognitively intact individuals with a maternal history of late-onset AD (FHm, n = 16), a paternal history of AD (FHp, n = 8), or no parental history of AD (FH-, n = 43), similar in age, gender, education, and Mini-Mental State Examination score, were scanned at 3 T. We used voxel-based morphometry to examine GMV differences between groups, controlling for age, gender, and apoE4.

RESULTS

Cognitively healthy individuals with a family history of late-onset AD had significantly decreased GMV in the precuneus, middle frontal, inferior frontal, and superior frontal gyri compared with FH- individuals. FHm subjects had significantly smaller inferior frontal, middle frontal, precuneus, and lingual gyri compared with FH- and FHp subjects.

CONCLUSIONS

Overall, maternal family history of Alzheimer disease (AD) in cognitively normal individuals is associated with lower gray matter volume in AD-vulnerable brain regions. These data complement and extend reports of cerebral metabolic differences in subjects with a maternal family history.

The role of citizen science in addressing grand challenges in food and agriculture research

The power of citizen science to contribute to both science and society is gaining increased recognition, particularly in physics and biology. Although there is a long history of public engagement in agriculture and food science, the term 'citizen science' has rarely been applied to these efforts. Similarly, in the emerging field of citizen science, most new citizen science projects do not focus on food or agriculture. Here, we convened thought leaders from a broad range of fields related to citizen science, agriculture, and food science to highlight key opportunities for bridging these overlapping yet disconnected communities/fields and identify ways to leverage their respective strengths. Specifically, we show that (i) citizen science projects are addressing many grand challenges facing our food systems, as outlined by the United States National Institute of Food and Agriculture, as well as broader Sustainable Development Goals set by the United Nations Development Programme, (ii) there exist emerging opportunities and unique challenges for citizen science in agriculture/food research, and (iii) the greatest opportunities for the development of citizen science projects in agriculture and food science will be gained by using the existing infrastructure and tools of Extension programmes and through the engagement of urban communities. Further, we argue there is no better time to foster greater collaboration between these fields given the trend of shrinking Extension programmes, the increasing need to apply innovative solutions to address rising demands on agricultural systems, and the exponential growth of the field of citizen science.

Genetic and biochemical dissection of transgenic RNA-mediated virus resistance

RNA-mediated virus resistance has been observed in transgenic plants at varying frequencies, suggesting that a nuclear requirement or other pre-condition must be met. This study was undertaken to characterize genetically transgenes that confer a highly resistant state to infection by tobacco etch virus (TEV). Transgenic tobacco line 2RC-6.13, expressing an untranslatable mRNA containing the TEV coat protein open reading frame, had three distinct transgene integration events that segregated as two linkage groups. A genetic series of plants that contained zero, one, two, or all three transgene inserts in both homozygous and heterozygous conditions was produced and examined. Genetic and biochemical data suggested that RNA-mediated virus resistance is a multigenic trait in line 2RC-6.13; three or more transgenes were necessary to establish the highly resistant state. One or two transgene copies resulted in an inducible form of resistance (i.e., recovery). Transcription rates and steady state RNA levels of the transgene-derived transcript present in different members of the genetic series supported a post-transcriptional RNA degradation process as the underlying mechanism for transgene transcript reduction and virus resistance. This degradation process appeared to initiate via cleavage of specific sites within the target RNA sequence, as determined by RNA get blot and primer extension analyses of transgene-derived mRNA from various transgenic plant lines.

The epidemiology of skin tears in the institutionalized elderly

While skin tears are a common occurrence in the institutionalized elderly population, nothing has been written about this problem. We retrospectively studied all incident reports during a 1-year period at a large, urban, long-term-care facility to identify residents with skin tears. The overall incidence of skin tears was 0.92 per patient per year. The incidence rate for females, but not for males, increased significantly with age (P = 0.012). The mean length of the skin tear was 1.9 cm +/- 1.4 (mean +/- SD). Eighty percent occurred in the upper extremities, with the most frequent location being the forearm. Almost half of the skin tears reported had an unknown cause. Wheelchairs and accidentally bumping into an object each accounted for a quarter of the skin tears where the cause was known. Transfers and falls contributed to a lesser extent. Impaired mental status was no more likely to be present in residents experiencing a skin tear than in all nursing home residents. Twenty-four of the 147 residents with skin tears had four or more tears, accounting for 40% of all skin tears reported. Ninety-seven percent of the episodes resulted in no attending physicians' orders other than the standing orders. Future studies should be designed to determine if there are adverse consequences of skin tears and to suggest programs to reduce their occurrence.

Clinical methods of goniometry: a comparative study

This investigation compared the reliability and interchangeable use of three currently available goniometers--a universal goniometer, a fluid goniometer, and an electrogoniometer. Three consecutive readings of the active range of movement of the right elbow joint were taken from each of 23 healthy female volunteers; three experienced observers each used each type of goniometer on two occasions. A balanced experimental design was used to eliminate order effects with respect to subject, tester, or goniometer, and a rigid protocol was employed to reduce error due to diurnal or methodological variations. The results show that there are significant differences between the goniometers used, the testers, and the replications. Significant interaction effects also exist between the goniometers and the occasion, the goniometers and the testers, and the testers and replications. The data suggest that the interchangeable use of different types of goniometer in a clinical setting is inadvisable.

Multiple electrodes for detecting spikes in partial complex seizures

The contribution of various electroencephalographic electrodes in detecting spikes from patients with seizures of suspected anterior temporal origin was prospectively studied with a standard protocol. The following electrodes were studied: International Standard 10-20 positions F7-8 and A1-2, sphenoidal (SP), nasopharyngeal (NP), anterior temporal (T1-2), mandibular notch surface (MNS), and mandibular notch subdermal (MNSD). Twenty patients were recorded of whom 16 demonstrated anterior temporal spikes. There was no difference in the number of spikes detected by SP, MNS, MNSD, or T1-2 electrodes (p less than 0.05); however these electrodes detected significantly more spikes than NP, F7-8, or A1-2. The SP electrode recorded spikes of highest amplitude (p less than 0.05). We conclude that for patients suspected of having seizures of anterior temporal origin, (1) a substantial number of spikes will be missed if only the International Standard electrode system is employed; (2) in comparison to SP electrodes the non-invasive and easily applied MNS or T1-2 electrodes will detect almost all spikes and should be used in outpatient EEG recordings; (3) NP electrodes provide no information that cannot be obtained by more reliable and better tolerated electrodes.

Neuro-ophthalmologic signs in the angiitic form of neurosarcoidosis

We studied eight patients with CNS sarcoidosis, including two patients with postmortem evidence of sarcoid granulomatous angiitis. Neuro-ophthalmologic findings included perivenular sheathing of retinal veins resembling the dripping of candle wax, vitreous cells, anterior uveitis, optic disk edema or granulomas, and conjunctival granulomas. Perivenous sheathing in the retina and the perivascular meningeal lesions in sarcoid angiitis were identical.

Resolution of pulmonary embolism

To assess restoration of pulmonary perfusion after pulmonary embolism serial lung scans were carried out on 74 patients. Of these, one-third showed almost complete recovery, one-third improved, and the remainder either failed to improve or became worse. Perfusion was most rapidly restored in the first few days after the embolus and more slowly during the next two to three weeks.Untreated patients improved less often and had more new defects in perfusion than patients treated with anticoagulant therapy, no difference occurring in either the amount of improvement or in the rate of recovery of perfusion between patients treated with different anticoagulant regimens. There was evidence of further pulmonary emboli in 35% of treated patients, 82% of these occurring within two weeks of the initial embolus. Patients with defects in perfusion greater than 30% showed considerable improvement but recovered less well than those with smaller defects.

Optic nerve sheath meningiomas. Role of MR imaging

Optic nerve meningiomas usually are seen in middle-aged and elderly women, and present as a slowly progressing axial proptosis and loss of vision. CT and MR imaging are the most valuable diagnostic tools to evaluate these tumors. This article reviews the MR imaging and CT characteristics of optic nerve sheath meningiomas and discusses features that may distinguish optic nerve sheath meningiomas from simulating lesions.

Correlates of menopausal hot flashes

The purpose of the present study was to examine the relationships of frequency, duration, and intensity of hot flashes with daily stress, ambient temperature, and caffeine, alcohol, and nicotine intake in menopausal women. Ten menopausal women suffering from hot flashes monitored these variables daily for 6 weeks. Intrasubject correlational analyses revealed significant relationships between hot-flash activity and stress for half of the sample; few women exhibited significant relationships between hot-flash activity and other variables. The results are discussed with respect to theoretical implications and treatment strategies.

Seasonal cold and circadian changes in blood pressure and physical activity in young and elderly people

AIM

To test the hypothesis that there is no association between seasonal cold and the circadian responses of blood pressure, deep-body temperature and physical activity in healthy young and elderly men.

METHODS

25 healthy elderly (aged 70-82 years) and 21 young volunteers (aged 20-30 years) participated in a 3-year prospective cross-seasonal study.

RESULTS

Ambulatory day-time blood pressures in the older men were higher in the winter than in the summer and higher in both seasons than in the young people. The seasonally related differences were associated with lower outdoor and indoor temperatures, lower body temperature and higher activity levels in the elderly group in the winter. The older but not the younger group had higher blood pressure and levels of physical activity at certain times of the day in the winter compared with the summer.

CONCLUSION

Time-of-day winter increases in blood pressure in older people may be related to increased activity as well as to levels of ambient temperature. Although it is generally advantageous for older people to be physically active in order to prevent circulatory disease, there may be a rationale for advising that that they should avoid intense activity at certain times of the day, especially in the winter.

Frequency of renal impairment, advanced age, obesity and cancer in venous thromboembolism patients in clinical practice

BACKGROUND

Low-molecular-weight heparin (LMWH) dosed by weight is recommended as first-line therapy for the initial treatment of venous thromboembolism (VTE) and as monotherapy for long-term treatment of cancer-related VTE. In 'special populations' such as those with renal impairment or the elderly, weight-based dosing may be excessive, and capping the dose in obese patients may lead to inadequate dosing.

OBJECTIVES

We determined the frequency of 'special population' characteristics (renal impairment, advanced age, obesity) and cancer among VTE patients in clinical practice, and assessed whether these characteristics appeared to influence the type and dose of anticoagulants prescribed.

METHODS

During 2004-2005, among consecutive patients with VTE at two large Canadian hospitals, the proportions with the above characteristics were calculated and treatments prescribed were determined.

RESULTS

Of 524 VTE patients, 31% were aged > 75 years. Moderate renal impairment [creatinine clearance (CrCl) 30-59 mL min(-1)] was present in 20% of patients, and severe renal impairment (CrCl < 30 mL min(-1)) in 5% of patients. LMWH was prescribed to 67% of patients with severe renal impairment and to 83% of patients with moderate renal impairment. Body weight was > 100 kg in 15% of patients. Underdosing of LMWH by > 10% was documented in 36% of such patients compared with 8% of patients < 100 kg (P < 0.001). Among 26% of patients with active cancer, only one-third were prescribed LMWH monotherapy.

CONCLUSIONS

In clinical practice, renal impairment, advanced age, obesity and cancer are frequently present in patients with VTE. A considerable proportion of these patients may not receive the optimal type or dose of medication to treat VTE.

Raised calcium and oxidative stress cooperatively promote alpha-synuclein aggregate formation

Cell loss in Parkinson's and Parkinson's-plus diseases is linked to abnormal, aggregated forms of the cytoplasmic protein, α-synuclein (α-syn). The factors causing α-syn aggregation may include oxidative stress, changes in protein turnover and dysregulation of calcium homeostasis, resulting in cytotoxic aggregated α-syn species. Recently, we showed that raised calcium can promote α-syn aggregation. We have now investigated the effects of raised calcium combined with oxidation/oxidative stress on α-syn aggregation both in vitro and in vivo. We treated monomeric α-syn with calcium, hydrogen peroxide or calcium plus hydrogen peroxide in vitro and used size exclusion chromatography, fluorescence correlation spectroscopy, atomic force microscopy and scanning electron microscopy to investigate protein aggregation. Our in vitro data is consistent with a cooperative interaction between calcium and oxidation resulting in α-syn oligomers. In cell culture experiments, we used thapsigargin or ionophore A23187 to induce transient increases of intracellular free calcium in human 1321N1 cells expressing an α-syn-GFP construct both with and without co-treatment with hydrogen peroxide and observed α-syn aggregation by fluorescence microscopy. Our in vivo cell culture data shows that either transient increase in intracellular free calcium or hydrogen peroxide treatment individually were able to induce significantly (P=0.01) increased 1-4μm cytoplasmic α-syn aggregates after 12h in cells transiently transfected with α-syn-GFP. There was a greater proportion of cells positive for aggregates when both raised calcium and oxidative stress were combined, with a significantly increased proportion (P=0.001) of cells with multiple (3 or more) discrete α-syn focal accumulations per cell in the combined treatment compared to raised calcium only. Our data indicates that calcium and oxidation/oxidative stress can cooperatively promote α-syn aggregation both in vitro and in vivo and suggests that oxidative stress may play an important role in the calcium-dependent aggregation mechanism.

Fat and carbohydrate metabolism during exercise in elderly and young subjects

We evaluated the effect of aging on fat and carbohydrate metabolism during moderate intensity exercise. Glycerol, free fatty acid (FFA), and glucose rate of appearance (Ra) in plasma and substrate oxidation were determined during 60 min of cycle ergometer exercise in six elderly (73 +/- 2 yr) and six young adults (26 +/- 2 yr) matched by gender and lean body mass. The elderly group was studied during exercise performed at 56 +/- 3% of maximum oxygen uptake, whereas the young adults were studied during exercise performed at the same absolute and at a similar relative intensity as the elderly subjects. Mean fat oxidation during exercise was 25-35% lower in the elderly subjects than in the young adults exercising at either the same absolute or similar relative intensities (P < 0.05). Mean carbohydrate oxidation in the elderly group was 35% higher than the young adults exercising at the same absolute intensity (P < 0.001) but 40% lower than the young adults exercising at the same relative intensity (P < 0.001). Average FFA Ra in the elderly subjects was 85% higher than in the young adults exercising at the same absolute intensity (P < 0.05) but 35% lower than the young adults exercising at a similar relative intensity (P < 0.05). We conclude that fat oxidation is decreased while carbohydrate oxidation is increased during moderate intensity exercise in elderly men and women. The shift in substrate oxidation was caused by age-related changes in skeletal muscle respiratory capacity because lipolytic rates and FFA availability were not rate limiting in the older subjects.

Structural and oxo-transfer reactivity differences of hexacoordinate and pentacoordinate (nitro)(tetraphenylporphinato)cobalt(III) derivatives

The oxo-transfer catalyst (nitro)(pyridyl)cobalt(III) tetraphenylporphyrin has been reinvestigated by substitution of the distal pyridine ligand with 4-N,N-dimethylaminopyridine and 3,5-dichloropyridine. Differences in their structures and in the reactivity of the compounds toward catalytic secondary oxo transfer were investigated by FT-IR and UV-visible spectroscopy, cyclic voltammetry, X-ray diffraction, semiempirical calculations, and reactions with alkenes in dichloromethane solution. Very modest differences in the hexacoordinate compounds' structures were predicted and observed, but the secondary oxo-transfer reactivity at the nitro ligand varies markedly with the basicity of the pyridine ligand and the position of the coordination equilibrium. Oxo transfer occurs rapidly through the pentacoordinate species (nitro)cobalt(III) tetraphenylporphyrin that is generated by dissociation of the pyridine ligand and therefore is strongly related to the Hammett parameters of these nitrogenous bases. The reactive pentacoordinate species CoTPP(NO(2)) can be generated in solution by addition of lithium perchlorate to (py)CoTPP(NO(2)) by Lewis acid-base interactions or more simply by using the weaker Lewis base Cl(2)py instead of py as the distal ligand. In contrast to pentacoordinate (nitro)iron porphyrins, disproportionation reactions of CoTPP(NO(2)) compound are not evident. This pentacoordinate derivative, CoTPP(NO(2)), is reactive enough to stoichiometrically oxidize allyl bromide in minutes. Preliminary catalytic oxidation reaction studies of alkenes also indicate the involvement of both radical and nonradical oxo-transfer steps in the mechanism, suggesting formation of a peroxynitro intermediate in the reaction of the reduced CoTPP(NO) with O(2).

Correlates of prescription and over-the-counter medication usage among older Mexican Americans: the Hispanic EPESE study. Established Population for the Epidemiologic Study of the Elderly

OBJECTIVES

To determine the prevalence rates of prescription and over-the-counter (OTC) medication usage among community-dwelling older Mexican Americans.

DESIGN

Cross-sectional survey of a regional probability sample of older Mexican Americans.

SETTING

The 1992-1997 Hispanic Established Population for the Epidemiologic Study of the Elderly (H-EPESE), a probability sample of noninstitutionalized Mexican Americans, age 65 and over, living in the five Southwestern states of Texas, New Mexico, Colorado, Arizona, and California.

PARTICIPANTS

2899 persons, age 65 and over, considered Mexican American, using appropriate weighting procedures to produce regional estimates.

OUTCOME MEASURES

Use of prescription and OTC medication within the last 2 weeks before the survey confirmed by in-home review of medication containers.

RESULTS

Medication users consumed a mean of 2.9 prescription and 1.3 OTC medications. Over half (58.9%, n = 1,798) of the participants used at least one prescribed medication, and 31.3% (n = 847) used at least one OTC medication within the 2 weeks before their participation in the study. Factors associated with both prescription and OTC medication usage were self-perceived health and number of co-morbid conditions. Factors associated only with prescription medication usage included female gender, alcohol usage, ADL dependency, and presence of additional insurance. Structural assimilation was associated only with OTC medication usage.

CONCLUSIONS

These data show lower prevalence rates of prescription medication usage among Mexican American older men and lower rates of OTC medication usage in older Mexican Americans of both genders than previously reported in other ethnic groups. This may reflect differences in time and geographic location of the Hispanic EPESE relative to other EPESE studies, ethnic differences in access to care as reflected by insurance in addition to Medicare, ethnic differences in survival, especially among males, or ethnic differences in medication preferences.

Pharmacodynamics of vancomycin for CoNS infection: experimental basis for optimal use of vancomycin in neonates

OBJECTIVES

CoNS are the most common cause of neonatal late-onset sepsis. Information on the vancomycin pharmacokinetics/pharmacodynamics against CoNS is limited. The aim of this study was to characterize vancomycin pharmacokinetic/pharmacodynamic relationships for CoNS and investigate neonatal optimal dosage regimens.

METHODS

A hollow fibre and a novel rabbit model of neonatal central line-associated bloodstream CoNS infections were developed. The results were then bridged to neonates by use of population pharmacokinetic techniques and Monte Carlo simulations.

RESULTS

There was a dose-dependent reduction in the total bacterial population and C-reactive protein levels. The AUC/MIC and Cmax/MIC ratios were strongly linked with total and mutant resistant cell kill. Maximal amplification of resistance was observed in vitro at an fAUC/MIC of 200 mg · h/L. Simulations predicted that neonates <29 weeks post-menstrual age are underdosed with standard regimens with respect to older age groups.

CONCLUSIONS

The AUC/MIC and Cmax/MIC ratios are the pharmacodynamic indices that best explain total and resistant cell kill in CoNS infection. This suggests that less-fractionated regimens are appropriate for clinical use and continuous infusions may be associated with increased risk of emergence of antimicrobial resistance. This study has provided the pharmacodynamic evidence to inform an optimized neonatal dosage regimen to take into a randomized controlled trial.