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Biomedical subjects

Paul Johnson

Publications and source records attributed to Paul Johnson.

At least 19 recordsLinked to original sources
PubMed2006

Home telemonitoring of vital signs and cardiorespiratory signals in heart failure patients: system architecture and feasibility of the HHH model.

BACKGROUND: The Home or Hospital in Heart Failure Study (HHH) is a European Community funded trial (QLGA-CT-2001-02424) which compares usual care of heart failure (HF) with three home-based interventions in a multicenter, multicountry (Italy, Poland and UK), randomized controlled clinical trial. Home telemonitoring (HT) of clinical parameters represents a potential alternative (or addition) to traditional home care models. Nocturnal respiratory disorders (periodic breathing, sleep apnea) are very common in HF, and are associated with increased morbidity and mortality. We developed an integrated HT system for monitoring of both vital signs and respiration. All measurements were patient-managed. This paper describes the architecture of this system, and assesses its feasibility. METHODS AND RESULTS: 461 clinically stable patients were randomized first to usual vs home-monitored care; the latter were further randomized to 3 strategies. Over a 12-month follow-up 2 of these 3 groups (195 patients, age: 60+/-11 years, NYHA class II-III: 97%, LVEF 28+/-7%) underwent self-administered home monitoring of vital signs (weekly--12 parameters using an interactive voice response system) and respiration (monthly--24-hour recording). Data were transmitted over conventional telephone lines; 81% of actually practicable vital signs measurements were completed by the patients (range: 75% (PL)-93% (UK)), as well as 92% of practicable respiratory recordings (range: 85% (PL)-99% (UK)). 87% of nighttime recordings were eligible for the study (good quality signals for > or = 2.5 h). CONCLUSIONS: This study, the largest so far, demonstrates that self-managed home telemonitoring of both vital signs and respiration is feasible in HF patients, with surprisingly high compliance. We found an excellent rate of acceptable nocturnal respiratory recordings, which are those with the greatest clinical relevance.

Aged↗
PubMed2006

How good is the management of vascular risk after stroke, transient ischaemic attack or carotid endarterectomy?

BACKGROUND: Patients remain at high risk of vascular events after stroke, transient ischaemic attack or carotid endarterectomy. We studied how well this risk is addressed by the effective treatment of modifiable risk factors. METHODS: A total of 198 consecutive attenders at a rapid access stroke clinic and 98 consecutive patients undergoing carotid endarterectomy were studied. Treatment of hypertension and hyperlipidaemia, smoking status and the use of antithrombotic therapy were assessed at baseline and 6 months later. The findings were compared with targets from the UK National Clinical Guidelines for Stroke. RESULTS: Baseline and follow-up data were available on 284 patients. The rates of control of vascular risk factors improved only slightly during follow-up. Blood pressure was below target levels in only 69 (24%) at baseline and 79 (28%) at 6 months, and serum cholesterol was below target levels in only 55 (19%) at baseline and 63 (22%) at 6 months. At baseline, 55 (19%) were smokers, of whom 12 (22%) had quit at 6 months. Anticoagulant therapy was prescribed in 19 of 37 patients (51%) in atrial fibrillation at 6 months. Antiplatelet therapy was prescribed in 90% of patients in sinus rhythm. CONCLUSIONS: Despite the identification of vascular risk factors at the time of clinic or surgery, 6 months later these risk factors remain poorly addressed. More effective methods of managing vascular risk in these patients are needed.

Aged↗
PubMed2006

Baroreflex sensitivity measured by spectral and sequence analysis in cerebrovascular disease : methodological considerations.

Baroreflex sensitivity (BRS) is impaired and of prognostic value in cerebrovascular disease. However, no studies to date have been published on the reproducibility of current methods of measuring BRS in this group. The reproducibility of sequence and spectral analysis methods were therefore assessed in subjects with cerebrovascular disease. A total of 14 subjects were assessed on 2 separate occasions at least 2 weeks apart, and beat-to-beat blood pressure (BP) and ECG trace were recorded for three 5-minute periods. These traces were then analyzed by spectral analysis using Fast Fourier Transform and sequence analysis. Reproducibility was calculated as the coefficient of variation (CV) and reproducibility coefficient (RC). There were no significant differences in heart rate, BP or BRS derived by either method between visits. Reproducibility was CV 22.2%, RC 6.04 ms/mmHg with spectral analysis, and CV 26.3%, RC 7.48 ms/mmHg for sequence analysis. There was close agreement between sequence and spectral derived BRS (r = 0.90). We have demonstrated that the use of spectral and sequence analysis to measure BRS is reproducible in subjects with cerebrovascular disease. These techniques are suitable for follow-up and intervention studies of BRS in this patient group.

Aged↗
PubMed2006

The incidence of complications following primary inguinal herniotomy in babies weighing 5 kg or less.

The aim of this study was to quantify the incidence of complications following inguinal herniotomy in small babies weighing 5 kg or less. This was a retrospective review of inguinal herniotomies performed in our unit between December 1997 and March 2002 on babies weighing 5 kg or less. A total of 154 patients underwent hernia repair, of which 125 patients (221 hernias) were available for review (81%). The median weight at surgery was 3.6 kg (range 1.7-5 kg) and 84 patients (67%) were classified as premature (< 36 weeks gestation). Thirty-three patients presented with an irreducible hernia, in whom all but one were successfully reduced prior to surgery. Patients were reassessed at a clinic following surgery and follow-up data was obtained from the clinic notes after a median follow-up of 3 months (range 1-60 months). Five cases of hernia recurrence occurred in four patients (2.3%) and the incidence of testicular atrophy was 2.7% (six patients). In the testicular atrophy group, four of the six patients presented with an incarcerated hernia and of these, three were noted to have evidence of ischaemia at operation. There were six cases of high testes requiring subsequent orchidopexy (2.7%). Although neonatal inguinal herniotomy is a technically demanding procedure, this series has demonstrated a low complication rate. Testicular atrophy was associated with a history of preoperative incarceration in the majority of cases.

Digestive System Surgical Procedures↗
PubMed2006

Uptake of veterinary medicines from soils into plants.

Medicines play an important role in the treatment and prevention of disease. Whereas the side effects on human and animal health resulting directly from treatment have been widely documented, only recently have the occurrence and fate of medicines in the environment and the potential consequences for human health been recognized as an issue warranting consideration. Medicines have been shown to be released to soils and to persist in the environment. This study was performed to investigate the potential for a range of veterinary medicines to be taken up from soil by plants used for human consumption and to assess the potential significance of this exposure route in terms of human health. Soil analyses indicated that, for selected substances, measurable residues of these are likely to occur in soils for at least 5 months following application of manure containing these compounds. Experimental studies on the uptake of veterinary medicines into carrot roots (tubers) and lettuce leaves showed that only florfenicol, levamisole, and trimethoprim were taken up by lettuces, whereas diazinon, enrofloxacin, florfenicol, and trimethoprim were detected in carrot roots. Measured concentrations in plant material were used to model potential adult human exposure to these compounds. Although exposure concentrations were appreciable in a few instances, accounting for approximately 10% of the acceptable daily intake values (ADI), all were lower than the ADI values, indicating that, at least for compounds with properties similar to those considered here, there is little evidence of an appreciable risk. This exposure route may, however, be important when veterinary medicines have a very low ADI, at which they elicit subtle effects over prolonged periods, or when exposure is occurring via a number of routes at once. Although degradation products (produced in the soil or the plant) were not measured, it is possible for some substances that these could increase the risks to consumers.

Food Contamination↗
PubMed2005

Conformational preference in aromatic amides bearing chiral ortho substituents: its origin and application to relayed stereocontrol.

Tertiary aromatic amides bearing stereogenic centres ortho to the amide group may adopt two diastereoisomeric conformations which interconvert slowly on the NMR timescale at ambient temperature, and are therefore detectable by NMR. Certain classes of stereogenic centre--particularly sulfoxides, ephedrine-derived oxazolidines, and proline-derived imidazolidines--strongly bias the population of the two conformers. We propose a model, supported by molecular mechanics calculations, which rationalises the sense and magnitude of the conformational selectivity attained in terms of the steric and electronic properties of the controlling centre. The control over conformation may be exploited either by trapping the favoured conformer as an atropisomer, or by using it to relay information about the stereochemistry of the controlling centre.

Alkylation↗
PubMed2005

Conformational arm-wrestling: battles for stereochemical control in benzamides bearing matched and mismatched chiral 2- and 6-substituents.

The orientation of a tertiary amide group adjacent to an aromatic ring may be governed by the stereochemistry of an adjacent chiral substituent. With a chiral substituent in both ortho positions, matched/mismatched pairs of isomers result. Evidence for matched stereochemistry is provided by the clean NMR spectra of single conformers, while mismatching gives poor or unexpected selectivities in the formation of chiral substituents, or mixtures of amide conformers. Attempts to use the match-mismatch effect to select for racemic pairs of enantiomeric substituents, and hence develop a "racemate-sequestering" reagent, are described, along with the use of "matching" to scavenge a single enantiomer of a diamine from material of incomplete enantiomeric purity.

Aldehydes↗
PubMed2005

Seismology: dynamic triggering of earthquakes.

After an earthquake, numerous smaller shocks are triggered over distances comparable to the dimensions of the mainshock fault rupture, although they are rare at larger distances. Here we analyse the scaling of dynamic deformations (the stresses and strains associated with seismic waves) with distance from, and magnitude of, their triggering earthquake, and show that they can cause further earthquakes at any distance if their amplitude exceeds several microstrain, regardless of their frequency content. These triggering requirements are remarkably similar to those measured in the laboratory for inducing dynamic elastic nonlinear behaviour, which suggests that the underlying physics is similar.

Journal Article↗
PubMed2005

Acupuncture for subacute stroke rehabilitation: a Sham-controlled, subject- and assessor-blind, randomized trial.

BACKGROUND: Any adjunctive therapy that may reduce persistent disability after stroke should be considered. Acupuncture is used for this purpose, but there is conflicting evidence on its effectiveness. METHODS: Patients with a recent (<4 weeks) episode of stroke were randomized to receive 12 sessions of either real or sham acupuncture during 2 weeks. The primary outcome was the change in Barthel activities of daily living score at the end of treatment. Secondary outcome measures included National Institutes of Health Stroke Scale score, motoricity index, and quality of life (EQ-5D [ EuroQoL-5 Dimensional form] and EQ-VAS [EuroQoL-Visual Analog Scale]). Assessments were carried out by blinded physicians. RESULTS: A total of 116 patients (56 in the real acupuncture group and 60 in the sham group) were randomized, and 98 (real, 48; sham, 50) completed treatment and the 2-week assessment. Patient blinding by means of the sham acupuncture device was successful. Acupuncture was well tolerated except for 1 seizure during a real acupuncture session. The improvements in the Barthel scores were 4 points (interquartile range [IQR], 0-8) vs 3 points (IQR, 0-7) in the real and sham acupuncture groups, respectively (P = .38). The secondary outcome measures also essentially showed no significant effect of acupuncture. Post hoc analysis by baseline severity showed a greater improvement in leg function in the subgroup with baseline Barthel score less than the median (median score, 6): 22 points (IQR, 0-37) vs 0 [corrected] points (IQR, 0-4) in the acupuncture and sham control groups, respectively (P = .02). CONCLUSIONS: Acupuncture is not superior to sham treatment for recovery in activities of daily living and health-related quality of life after stroke, although there may be a limited effect on leg function in more severely affected patients.

Activities of Daily Living↗
PubMed2005

Reliability of preparation procedure for sphingosomal vincristine.

PURPOSE: The reliability of the preparation procedure for sphingosomal vincristine was studied. The effect of minor variations in the constitution conditions on the integrity of the drug product was also examined. METHODS: Two studies were conducted. The laboratory study, which had two parts, was conducted to determine the effects of deliberately varying the constitution conditions, including such key parameters as incubation time and incubation temperature. In the field study, 20 pharmacists unfamiliar with sphingosomal vincristine were asked to constitute the product using the written instructions provided in the package insert as their sole guidance. All samples in both studies were evaluated by measuring key product characteristics, including free (un-encapsulated) vincristine sulfate, total vincristine sulfate, vincristine degradation products, and in vitro release rate. Vincristine loading into sphingosomes was considered acceptable if the percentage of free vincristine sulfate did not exceed 10%. RESULTS: In the laboratory study, samples that were incubated at 60-75 degrees C for 5-60 minutes met all the acceptance criteria. However, acceptable loading was not achieved for samples that were incubated at 55 degrees C for 10 minutes or less. In the field study, all the pharmacist-prepared samples met the acceptance criteria, with the results for free vincristine sulfate demonstrating a high degree of statistical confidence in the reliability of the loading procedure. CONCLUSION: The recommended constitution procedure of sphingosomal vincristine from a three-vial kit can be reliably performed in pharmacies with a high degree of confidence. Small variations in temperature and incubation time had no effects on the quality of the product.

Antineoplastic Agents, Phytogenic↗
PubMed2005

Economic incentives and physicians' delivery of preventive care: a systematic review.

A systematic review of the randomized trial literature examining the impact of financial incentives on provider preventive care delivery was conducted. English-language studies published between 1966 and 2002 that addressed primary or secondary preventive care or health promotion behaviors were included in the review. Six studies that met the inclusion criteria were identified, which generated eight different findings. The literature is sparse. Of the eight financial interventions reviewed, only one led to a significantly greater provision of preventive services. The lack of a significant relationship does not necessarily imply that financial incentives cannot motivate physicians to provide more preventive care. The rewards offered in these studies tend to be small. Therefore, the results suggest that small rewards will not motivate doctors to change their preventive care routines.

Attitude of Health Personnel↗
PubMed2005

Slow dynamics and anomalous nonlinear fast dynamics in diverse solids.

Results are reported of the first systematic study of anomalous nonlinear fast dynamics and slow dynamics in a number of solids. Observations are presented from seven diverse materials showing that anomalous nonlinear fast dynamics (ANFD) and slow dynamics (SD) occur together, significantly expanding the nonlinear mesoscopic elasticity class. The materials include samples of gray iron, alumina ceramic, quartzite, cracked Pyrex, marble, sintered metal, and perovskite ceramic. In addition, it is shown that materials which exhibit ANFD have very similar ratios of amplitude-dependent internal-friction to the resonance-frequency shift with strain amplitude. The ratios range between 0.28 and 0.63, except for cracked Pyrex glass, which exhibits a ratio of 1.1, and the ratio appears to be a material characteristic. The ratio of internal friction to resonance frequency shift as a function of time during SD is time independent, ranging from 0.23 to 0.43 for the materials studied.

Elasticity↗
PubMed2004

Straight talk. New approaches in healthcare. Outsourcing in the business office increases cash.

Want more cash? Rather than simply sending old patient balances to collection agencies in knee-jerk fashion, sophisticated business offices are scrutinizing their days in accounts receivable, determining what types of accounts and dollar balances to outsource for collection and when to outsource them. In this installment of Straight Talk, we look at the outsourcing strategies in the business offices of three healthcare systems: 266-bed Tuomey Healthcare System, Sumter, S.C.' 3-hospital, 1,062-bed Montefiore Medical Center, New York; and 14,200-bed, 30-hospital New York Presbyterian Health System, New York. Modern Healthcare and PricewaterhouseCoopers present Straight Talk. The session on outsourcing of business office functions was held on September 23, 2004 at Modern Healthcare's Chicago headquarters. Charles S. Lauer, publisher of Modern Healthcare, was the moderator.

Accounts Payable and Receivable↗
PubMed2004

Female infertility after ileal pouch-anal anastomosis for ulcerative colitis.

PURPOSE: Although ulcerative colitis commonly affects young females, the impact of ulcerative colitis and its treatment on female fertility have not been well studied. The purpose of this survey was to examine the impact of ulcerative colitis and ileal pouch-anal anastomosis on female reproductive ability. METHODS: Demographic, reproductive history, and disease history information were obtained via a questionnaire mailed to females who had pelvic pouch surgery or nonoperative management for ulcerative colitis. Based on age at diagnosis, age at surgery, and marital status, 153 females who had pelvic pouch surgery and 60 females who had nonoperative management for ulcerative colitis were identified for inclusion. Patients were asked if they attempted to become pregnant, when relative to their diagnosis or surgery, and if they were successful. Married or cohabiting females aged 18 to 44 years who failed to become pregnant during 12 months of unprotected intercourse were defined as infertile. RESULTS: The infertility rate was significantly higher in females who had pelvic pouch surgery compared with females managed nonoperatively (59/153 (38.1 percent) vs. 8/60 (13.3 percent), respectively; P < 0.001). There was no difference in female fertility after diagnosis with ulcerative colitis compared with before diagnosis (odds ratio, 0.68; P = 0.23). In contrast, there was a 98 percent reduction in fertility after pelvic pouch surgery compared with before surgery (odds ratio, 0.021; P < 0.0001). By logistic regression, increasing age was the only factor associated with failure to become pregnant after surgery (odds ratio, 1.136 per additional year of age; P = 0.027). CONCLUSIONS: Females with ulcerative colitis who are managed nonoperatively have normal fertility, which suggests that ulcerative colitis and medical therapy do not decrease female reproductive ability. After pelvic pouch surgery for ulcerative colitis, female fertility is significantly decreased and this problem should be discussed routinely with patients considering this procedure.

Adolescent↗