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Biomedical subjects

D R Miller

Publications and source records attributed to D R Miller.

At least 19 recordsLinked to original sources
PubMed2006

Treatment persistence: a comparison among patients with schizophrenia who were initiated on atypical antipsychotic agents.

BACKGROUND: Although clinical trials have demonstrated the efficacy of atypical antipsychotic agents in reducing symptoms of schizophrenia, the likelihood of sustaining control of schizophrenic symptoms may depend on treatment persistence. OBJECTIVE: In this study, we compared treatment persistence between patients who were initiated on risperidone or olanzapine, the two most widely prescribed atypical antipsychotic agents. METHOD: We identified patients with schizophrenia by ICD-9-CM codes (> or =1 inpatient or > or =2 outpatient ICD-9-CM codes > or =7 days apart) between 1 July 1998 and 30 June 1999. We further selected those who were prescribed the target drug during 1 April 1999 through 31 March 2000 provided that they were not on any antipsychotic agents during the prior 6 months. Using event history analysis, we compared the treatment persistence in terms of hazard ratio between olanzapine and risperidone initiators, adjusting for patient's sociodemographic and clinical characteristics. RESULTS: Following the initiation of the target drug, more patients switched from risperidone to olanzapine than vice versa. However, among patients with schizophrenia who had comorbid diabetes, there were more patients who made a switch from olanzapine to risperidone; whereas among those who used anxiolytics, there were more patients who switched from risperidone to olanzapine. Finally, olanzapine initiators had decreased hazards of discontinuation by 14% (unadjusted; P < 0.001) and 12% (adjusted; P = 0.002), respectively, than risperidone initiators. CONCLUSIONS: Compared with risperidone, olanzapine seems to be better tolerated by patients as indicated by better treatment persistence. As such, initiation of olanzapine may increase the likelihood of sustaining control of symptoms of schizophrenia. Future research needs to provide a more comprehensive assessment of treatment persistence by considering other antipsychotic agents in the study and developing models to assess treatment persistence and switching as two interdependent competing risks.

Adolescent↗
PubMed2005

Alternatives to antibiotics: chemical and physical antimicrobial interventions and foodborne pathogen response.

Successful control of foodborne pathogens requires placement of chemical and physical hurdles in the preharvest and postharvest food production sectors. Pathogens may also encounter indigenous antimicrobials in foods including certain botanical compounds that have historically been used for flavor enhancement as well as preservation. Chemical additives have traditionally included organic acids to control microbial contamination in foods and feeds. However, there is some concern that continuous application of certain chemical antimicrobials can lead to a buildup of microbial resistance. This creates problems if foodborne pathogens survive and develop resistance to a variety of environmental stressors encountered in pre- and postharvest animal production. To expand the diversity of potential antimicrobials that have practical application to food animal production requires exploring the interaction between the food matrix and foodborne pathogens. There is potential for isolating antimicrobial compounds that exhibit mechanisms unrelated to conventional antimicrobial compounds. However, understanding the potential for novel antimicrobial compounds in foods and feeds will require the physiological examination of foodborne pathogen response under experimental conditions comparable to the environment where the pathogen is most likely to occur. Research on foodborne Salmonella pathogenesis is extensive and should provide a model for detailed examination of the factors that influence antimicrobial effectiveness. Analysis of pathogen response to antimicrobials could yield clues for optimizing hurdle technologies to more effectively exploit vulnerabilities of Salmonella and other foodborne pathogens when administering antimicrobials during food and feed production.

Animal Feed↗
PubMed2005

Adjunctive use of atypical antipsychotics and anticholinergic drugs among patients with schizophrenia.

BACKGROUND: Treatment of schizophrenia with antipsychotics is often associated with extrapyramidal symptoms (EPS), a disorder involving involuntary muscle movement. Because EPS are often associated with the use of antipsychotics, anticholinergic agents are often indicated. OBJECTIVE: In this observational, retrospective study, we examined whether the initiation of olanzapine or risperidone, the two most widely prescribed atypical antipsychotics, is related to the adjunctive use of anticholinergic agents. METHOD: We identified patients with schizophrenia from outpatient clinics in the Veterans Health Administration (VA) and defined initiation of olanzapine or risperidone as patients who were not on any antipsychotics for 6 months and subsequently initiated on the target drug between 1/4/1999 and 31/3/2000. The data were analysed using tests of means or chi-square tests. RESULTS: The study yielded two major findings. First, compared with risperidone initiators, there were significantly fewer olanzapine initiators who used at least one anticholinergic agent adjunctively. Secondly, among olanzapine or risperidone initiators, patients who used at least one anticholinergic agent adjunctively tended to stay on the target drug significantly longer than those who did not use any anticholinergic agent adjunctively with the target drug. CONCLUSION: As the use of anticholinergics is a proxy for the presence of EPS, these findings suggest that risperidone may be more associated with EPS than olanzapine. However, to assess the benefits and side effects associated with olanzapine or risperidone, future research needs to examine various patient outcomes resulting from the initiation of each drug.

Antipsychotic Agents↗
PubMed2005

Ipsenol and ipsdienol attract Monochamus titillator (Coleoptera: Cerambycidae) and associated large pine woodborers in southeastern United States.

We determined the responses of the southern pine sawyer, Monochamus titillator (F.) (Coleoptera: Cerambycidae), to the pheromones (ipsenol, ipsdienol, and lanierone) used by pine engraver beetles (Coleoptera: Scolytidae) in the southeastern United States. (+/-)-Ipsenol, (+/-)-ipsdienol, or a combination increased catches of M. titillator in Florida, Louisiana, Georgia, and North Carolina. Catches of Acanthocinus obsoletus (Olivier) (Cerambycidae) were increased by (+/-)-ipsenol and (+/-)-ipsdienol in Florida and North Carolina, whereas only (+/-)-ipsenol was attractive in Georgia. (+/-)-Ipsenol and (+/-)-ipsdienol were attractive to Pachylobius picivorus (Germar) (Coleoptera: Curculionidae) in Florida, whereas only (+/-)-ipsdienol was active in Louisiana. In Florida, catches of M. titillator, A. obsoletus, and P. picivorus were greatest in traps baited with both (+/-)-ipsenol and (+/-)-ipsdienol. In Louisiana, catches of the woodborer Chalcophora virginiensis (Drury) (Buprestidae) were increased by (+/-)-ipsenol. Lanierone did not affect trap catches of the aforementioned species. The combination of (+/-)-ipsenol and (+/-)-ipsdienol may be a cost-effective lure for these four species because we found no evidence of interruption in attraction to baited traps, and the cost of the lure combination is relatively low.

Acyclic Monoterpenes↗
PubMed2005

Attraction of southern pine engravers and associated bark beetles (Coleoptera: Scolytidae) to ipsenol, ipsdienol, and lanierone in southeastern United States.

We determined the response of the small southern pine engraver, Ips avulsus (Eichhoff); eastern fivespined ips, Ips grandicollis (Eichhoff); sixspined ips, Ips calligraphus (Germar); and pine engraver, Ips pini (Say) to the pheromones (+/-)-ipsenol, (+/-)-ipsdienol, and lanierone in the southeastern United States. Catches of I. avulsus and I. grandicollis to baited multiple-funnel traps were increased by (+/-)-ipsenol and (+/-)-ipsdienol in Florida, Georgia, Louisiana, and North Carolina. In all four localities, the highest numbers of I. avulsus were caught in traps baited with the combination of (+/-)-ipsenol, (+/-)-ipsdienol, and lanierone. In Florida, the highest numbers of I. grandicollis were captured in traps baited with the combination of (+/-)-ipsenol and (+/-)-ipsdienol (with or without lanierone). In the remaining three localities, the largest catches of I. grandicollis occurred in traps baited with (+/-)-ipsenol alone or the combination of (+/-)-ipsenol and (+/-)-ipsdienol (with or without lanierone). (+/-)-Ipsdienol was the only consistent attractant for I. calligraphus and I. pini. Attraction of I. pini in North Carolina to (+/-)-ipsdienol-baited traps was synergized by lanierone but interrupted with (+/-)-ipsenol. The interruptive effect of (+/-)-ipsenol on attraction of I. pini to (+/-)-ipsdienol was negated by lanierone. (+/-)-Ipsdienol was attractive to black turpentine beetle, Dendroctonus terebrans (Olivier), in Florida but not North Carolina, whereas (+/-)-ipsdienol was attractive to I. calligraphus in Louisiana, Georgia, and Florida. Both (+/-)-ipsenol and (+/-)-ipsdienol affected catches of Gnathotrichus materiarus (Fitch) in North Carolina. Trap catches of Hylurgops rugipennis pinifex (Fitch), Hylastes salebrosus Eichhoff, and Hylastes tenuis Eichhoff were unaffected by the pheromone treatments. The combination of (+/-)-ipsenol, (+/-)-ipsdienol, and lanierone may be a cost-effective general lure for I. avulsus, I. grandicollis, and I. pini.

Acyclic Monoterpenes↗
PubMed2004

Wound dressings in diabetic foot disease.

Wound dressings represent a part of the management of diabetic foot ulceration. Ideally, dressings should alleviate symptoms, provide wound protection, and encourage healing. No single dressing fulfills all the requirements of a diabetic patient with an infected foot ulcer. Dressings research in this area is generally poor. However, each category of dressings has particular characteristics that aid selection. Nonadhesive dressings are simple, inexpensive, and well tolerated. Foam and alginate dressings are highly absorbent and effective for heavily exuding wounds. Hydrogels facilitate autolysis and may be beneficial in managing ulcers containing necrotic tissue. Dressings containing inidine and silver may aid in managing wound infection. Occlusive dressings should be avoided for infected wounds. All dressings require frequent change for wound inspection. Heavily exudating ulcers require frequent change to reduce maceration of surrounding skin. Dressing choice should be guided by the characteristics of the ulcer, the requirements of the patient, and costs.

Bandages↗
PubMed2004

Spinal subdural haematoma: how relevant is the INR?

STUDY DESIGN: Case report. OBJECTIVE: To report a rare cause of spinal cord compression. SETTING: University Hospital, Wales, UK. CASE REPORT: A 67-year-old gentleman on oral anticoagulation for atrial fibrillation presented with a 4-h history of progressive loss of sensation and weakness in both legs; there was no history of trauma. On examination, he had a flaccid paraplegia with altered sensation in the L1,2,3 dermatomes and complete anaesthesia in the L4,5 distribution. Knee and ankle jerk reflexes were absent, plantars were equivocal and anal sphincter tone was reduced. The patient's international normalized ratio (INR) was 4.1. An MR scan showed an extensive intradural haematoma compressing the cauda equina. The anticoagulation was reversed and an urgent T12-L2 laminectomy was performed; findings were a circumferential haematoma at L1 extending in the anterior canal between T10 and L3. The patient had an uneventful postoperative course generally, but at 1 week there was no neurological recovery. CONCLUSION: This case highlights that anticoagulation even when well controlled is not without risk. This is particularly of concern as the number of patients receiving long-term anticoagulation therapy has doubled between 1993 and 1998.

Aged↗
PubMed2004

Initiation of atypical antipsychotic agents and health outcomes in patients with schizophrenia.

BACKGROUND: Although pharmacological treatments are available for patients with schizophrenia, there is a lack of systematic and comprehensive evaluation of health outcomes following the initiation of atypical antipsychotic agents. OBJECTIVE: To assess the effects of the initiation of olanzapine or risperidone, the two most widely prescribed atypical antipsychotics, on patients' health outcomes, as measured by changes in patient clinical characteristics between 6 months prior to and post-initiation. METHOD: We identified patients with schizophrenia by >1 inpatient or > or = 2 outpatient ICD-9-CM codes (> or = 7 days apart) between 1 July 1998 and 30 June 1999, and those who were initiated on olanzepine or risperidone during the period 1 April 1999 to 31 March 2000 inclusive. We then subdivided these patients into three groups: (i) those who were not on olanzapine or risperidone, (ii) those who were not on any atypical agents, and (iii) those who were not on any antipsychotic agents, for 6 months prior to being issued with the new prescription. Using test of means or chi-square tests, we examined whether the initiation of olanzapine or risperidone is related to different changes in patient clinical indicators, such as number of drugs for psychiatric conditions, use of psychiatric services, and use of non-psychiatric services. RESULTS: Between pre- and post-initiation, olanzapine initiators had a greater decrease in the number of psychiatric hospitalizations and use of psychotropic agents, whereas risperidone initiators had a greater reduction in the number of non-psychiatric hospitalizations. The initiation of olanzapine and risperidone appear to be associated with different patient health outcomes. Compared with olanzapine initiators, risperidone initiators had a greater increase in the use of treatments related to mental health, but had greater decrease in the use of treatments related to physical health. CONCLUSION: Despite olanzapine and risperidone being often perceived as similar antipsychotic agents, our results suggest that the clinical outcomes associated with their use are different. Outcome data from routine clinical practice are required to provide a more comprehensive assessment of these drugs.

Adolescent↗
PubMed2003

Noradrenaline-induced lipolysis in adipose tissue is suppressed at hibernation temperatures in ground squirrels.

Responsiveness of white adipose tissue (WAT) and brown adipose tissue (BAT) from hibernating and nonhibernating golden-mantled ground squirrels (Spermophilus lateralis) to the lipolytic action of the sympathetic neurotransmitter, noradrenaline, was tested in vitro at temperatures characteristic of deep torpor (5 degrees C) and euthermia (37 degrees C). Noradrenaline-stimulated lipolysis, as indicated by WAT glycerol release, of tissue from hibernating ground squirrels was six- to ten-fold greater at 37 degrees C than at 5 degrees C. Noradrenaline was ineffective in increasing lipolysis at 5 degrees C. Noradrenaline-stimulated lipolysis in BAT was similarly suppressed at 5 degrees C. Noradrenaline-stimulated lipolysis was little affected by temperature change below approximately 15 degrees C but strongly correlated with temperature above approximately 15 degrees C. Noradrenaline-induced lipolysis of WAT from nonhibernating and hibernating ground squirrels did not differ at an incubation temperature of 5 degrees C. We conclude that noradrenaline-stimulated WAT lipolytic activity is markedly suppressed at the low temperatures characteristic of deep torpor and that there is no 'hibernation-specific' adaptation of WAT to enhance its responsiveness to noradrenaline at low tissue temperatures. Temperature dependence of noradrenaline-stimulated lipolysis may in part account for the shift from lipid to carbohydrate metabolism during the earliest stage of arousal from deep torpor.

Adipose Tissue↗
PubMed2002

Identifying patient and physician characteristics that affect compliance with antihypertensive medications.

BACKGROUND: Compliance with antihypertensive medications is essential to the clinical management of hypertension. Poor compliance with antihypertensive medications has often been associated with treatment failure and disease progression. OBJECTIVE: To identify patient and prescriber characteristics that may influence compliance with antihypertensive medications. METHOD: We used pharmacy records within the Veterans Health Administration, a database which included 1292 patients and 656 physicians over a 2-year time period from April 1, 1996, to April 1, 1998. The level of compliance with antihypertensive medications was assessed using a measure developed for this purpose within the Administration. Three separate ordinary least squares regression models were conducted to ascertain the effects of patient and physician characteristics on compliance. RESULTS: Despite the importance of compliance in the clinical management of hypertension, poor compliance with antihypertensive drug treatment was still widespread. Patients who were younger and less active in their treatment decisions tended to be less compliant (P < 0.05 and 0.05, respectively). Health care providers who were older, residents in speciality care, and physicians (as compared with non-physicians) had patients who were also less likely to be compliant (P < 0.01, 0.01, and 0.05, respectively). CONCLUSION: These findings suggest that in order to increase the effectiveness of medical care for hypertension, it is important to improve compliance with antihypertensive agents.

Adult↗
PubMed2002

Patient characteristics and prescription patterns of atypical antipsychotics among patients with schizophrenia.

BACKGROUND: Schizophrenia, one of the leading causes of disability, contributes substantially to the use of medical and mental health services. The treatment of schizophrenia is therefore particularly important to reduce deficits across a large number of neurocognitive domains. OBJECTIVE: To describe the prescription (e.g. initiation and switching) patterns of atypical antipsychotic agents and examine the extent to which patient sociodemographic and clinical characteristics are associated with the prescription patterns of atypical antipsychotics among patients with schizophrenia. METHODS: Using unique data sources from the Veterans Health Administration (VA), the study identified 89 107 patients with schizophrenia based on at least one inpatient or more than or equal to two outpatients' ICD-9-CM codes (> or =7 days apart). We defined a prior 6-month (1/1/99 to 6/30/99) and a post 6-month (7/1/99 to 12/31/99) period to describe patterns of initiation and switching of atypical antipsychotics. RESULTS: Only a small number of patients were on clozapine (1.8%) and quetiapine (1.4%). More patients were prescribed olanzapine (23%) than risperidone (20%) (P < 0.001). Compared with patients who were on risperidone, those who were on olanzapine were younger (P < 0.001), more likely Hispanic (P < 0.001), more likely married (P < 0.05), had more service-connected disability (P < 0.001), had fewer numbers of physical comorbidities (P < 0.001), and a lower body mass index (BMI) (P < 0.05). CONCLUSION: Olanzapine and risperidone appear to be prescribed to patients with different sociodemographic and clinical characteristics. Future research needs to explore the reasons for those differences.

Adolescent↗
PubMed2001

Clinical impact of interlaboratory variation in international normalized ratio determinations.

Variation among laboratories and point-of-care (POC) devices in International Normalized Ratio (INR) determinations for individual patients in the same community was studied. For each patient, blood samples obtained from a single venipuncture followed by a finger stick were tested at three laboratories and with two POC devices. A nonparametric analysis of variance and regression analysis were used to compare INRs across sources. The potential clinical impact of differences between pairs of INR readings (i.e., whether a difference was likely to result in a change in therapy) was evaluated. Complete data were obtained and analyzed for 41 patients. Of the five sources of INRs, results from two laboratories and one POC device were significantly similar. Results from one laboratory and one POC device were significantly different from the other results. Variation between INR readings from two different sources might have resulted in a change in therapy 10-30% of the time. Variations occurred in INR readings among three laboratories and two POC devices and could have led to a substantial number of inappropriate changes in therapy.

Anticoagulants↗
PubMed2001

Genetic analysis of testis weight and fertility in an interspecies hybrid congenic strain for Chromosome X.

A hybrid congenic strain, C57BL/6J.SPRET-Hprt(a), carrying 17 map units of Chromosome (Chr) X from Mus spretus on a background of C57BL/6J. has the novel phenotype of low fertility associated with small testis weight. In histological cross-section, many of the tubules in the testes of these congenic mice are empty except for Sertoli cells, while the other tubules appear to be normal. The gene, interspecific hybrid testis weight 1 (Ihtw1) causing this phenotype, has been fine mapped by using the strategy of generating subcongenic strains from recombinants within the congenic region. Genetic and phenotypic analysis of the subcongenic strains has defined a critical region of 1.8 map units for Ihtw1. This region of the genetic map is orthologous to the region on human Chr X containing the gene for the Borjeson-Forssman-Lehman syndrome, an inherited disease in which males show microorchidism.

Alleles↗
PubMed2001

Noninvasive transcutaneous determination of access blood flow rate.

BACKGROUND: Current indicator dilution techniques for determining the vascular access blood flow rate (Qa) require reversal of the dialysis blood lines and are time consuming. We have recently described an indicator dilution technique for determining Qa using a novel optical transcutaneous hematocrit (Hct) sensor that does not require reversal of the dialysis lines, and have validated the accuracy of this method (TQa) in vitro. METHODS: This study compared results using the TQa method with those obtained using a similar indicator dilution technique but which required reversal of the dialysis lines (HD01 Monitor, Transonic Systems, Ithaca, NY, USA) during routine hemodialysis in 59 patients (25 native fistulas and 34 synthetic grafts). The sensor for the TQa method was placed on the skin directly over the access to measure changes in Hct approximately 25 mm downstream of the venous needle. A single 30 mL bolus of saline was infused into the dialyzer venous line over approximately six seconds without reversal of the dialysis blood lines, and the vascular access flow rate was calculated using indicator dilution methods from the time-dependent decrease in the Hct downstream of the venous needle. Two additional small-scale studies were performed to assess the effect skin pigmentation and to evaluate further the reproducibility of the TQa method. RESULTS: Qa values determined by the TQa method were highly correlated with those determined by the HD01 method (N = 72, R2 = 0.948, P < 0.001) over the range of 153 to 2,042 mL/min. There was no significant difference between vascular access flow rates determined by the TQa method and those determined by the HD01 METHOD: Results from one small-scale study showed that the relationship between Qa values determined by the TQa and the HD01 methods was similar when tested only among black patients (N = 12), suggesting that skin pigmentation is not an important determinant of the accuracy of the TQa METHOD: The second small-scale study showed that the intratreatment coefficient of variation for the TQa method was 7.8 +/- 5.6% (N = 14). CONCLUSIONS: : These results show that transcutaneous measurement of Qa is an accurate, simple, and fast technique for determining Qa without requiring the reversal of the dialysis blood lines.

Aged↗