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Biomedical subjects

A R Clark

Publications and source records attributed to A R Clark.

At least 19 recordsLinked to original sources
PubMed2000

Treatment of psoriasis: an algorithm-based approach for primary care physicians.

Psoriasis is characterized by red, thickened plaques with a silvery scale. The lesions vary in size and degree of inflammation. Psoriasis is categorized as localized or generalized, based on the severity of the disease and its overall impact on the patient's quality of life and well-being. Patient education about the disease and the treatment options is important. Medical treatment for localized psoriasis begins with a combination of topical corticosteroids and coal tar or calcipotriene. For lesions that are difficult to control with initial therapy, anthralin or tazarotene may be tried. The primary goal of therapy is to maintain control of the lesions. Cure is seldom achieved. If control becomes difficult or if psoriasis is generalized, the patient may benefit from phototherapy, systemic therapy and referral to a physician who specializes in the treatment of psoriasis.

Adrenal Cortex Hormones↗
PubMed2000

The emerging role of physician assistants in the delivery of dermatologic health care.

The NAMCS provides a wealth of information on use of PAs in all practices, including dermatology. Two important points regarding the NAMCS and SDPA data are addressed here: the number of visits to PAs for dermatologic symptoms and the expected growth of PA use in dermatologists' offices. Dermatologic symptoms were evaluated frequently by PAs, accounting for 14% of PA visits. These statistics do not address the number of referrals those PAs made to dermatologists. Perhaps PAs as a group should be targeted for increased dermatologic education, particularly stressing the need for appropriate referral to a dermatologist. PAs could increase the number of dermatology referrals from primary care offices with improved understanding of the importance of the dermatologist in the management of patients' overall skin health. At projected growth rates, the number of PAs employed by dermatologists should exceed 500 by the end of 2000. Most of this growth has been in private practices and rarely in HMOs or in large multispecialty clinics. There are a number of reasons for this growth, as follows: A PA may help reduce the patient load on the dermatologist, especially with sameday appointments and drop-ins. Some dermatologists are moving away from clinical dermatology into cosmetics, which not only leaves a vacuum in clinical dermatology, but also creates job opportunities for PAs in cosmetic dermatology. Regarding managed care growth, PAs can have a positive impact on the problem of having to see more patients for less money. PAs are cost-effective. In the 1998 SDPA survey, the ratio of billings generated (production) to gross income for the average dermatology PA ranged from 3:1 to 6:1. Even with inexperienced PAs new to dermatology, this ratio was usually at least 2:1 at the end of the first year. PAs can cover satellite offices, allowing for practice expansion. Effective with the new Medicare laws of January 1, 1998, PAs can now see new Medicare patients or Medicare patients with new conditions without the physician being on site, opening up the possibility for satellite offices in remote areas. Just as dermatologists may move toward specialization in surgery, cosmetics, or medical dermatology, PAs may do the same, filling a niche in a particular practice. As in other specialties, patient acceptance of seeing dermatology PAs has not been a significant problem. Continued access to the dermatologist remains unfettered, but, over time, many patients become willing to see either. Are PAs likely to become future competitors of dermatologists? Genuinely concerned dermatologists worry that a dermatology-trained PA will become part of a gatekeeper system that impedes patient access to dermatologists. This is not happening and is not at all likely to become a trend, for a number of reasons. First, primary care cannot compete with dermatology practices in remuneration for PAs. Just as financial benefits in high-production specialty practices entice physicians, the same benefits entice PAs as well. Second, according to member surveys of the SDPA, virtually 100% of fellow members work with dermatologists. Although PAs can work in any type of practice and evaluate dermatologic symptoms just as a general practitioner would, PAs who specialize in dermatology primarily practice with dermatologists, a collegial association most PAs seek out. PAs have steadfastly maintained their dependent, noncompetitive relationship with physicians and would not have it any other way. Although PAs see a good number of patients (2.8 million) with dermatologic symptoms, the NAMCS data indicate that most (72%) of these patients are also seen by a physician. Third, physicians are ultimately responsible for the actions of their PA employee. A general practitioner not trained to perform excisions or manage certain dermatologic conditions should not allow a PA to perform such duties. Similar to much of medicine, the PA profession continues to evolve, with many members moving awa

Delivery of Health Care↗
PubMed2000

Regulation of cyclooxygenase 2 mRNA stability by the mitogen-activated protein kinase p38 signaling cascade.

A tetracycline-regulated reporter system was used to investigate the regulation of cyclooxygenase 2 (Cox-2) mRNA stability by the mitogen-activated protein kinase (MAPK) p38 signaling cascade. The stable beta-globin mRNA was rendered unstable by insertion of the 2, 500-nucleotide Cox-2 3' untranslated region (3' UTR). The chimeric transcript was stabilized by a constitutively active form of MAPK kinase 6, an activator of p38. This stabilization was blocked by SB203580, an inhibitor of p38, and by two different dominant negative forms of MAPK-activated protein kinase 2 (MAPKAPK-2), a kinase lying downstream of p38. Constitutively active MAPKAPK-2 was also able to stabilize chimeric beta-globin-Cox-2 transcripts. The MAPKAPK-2 substrate hsp27 may be involved in stabilization, as beta-globin-Cox-2 transcripts were partially stabilized by phosphomimetic mutant forms of hsp27. A short (123-nucleotide) fragment of the Cox-2 3' UTR was necessary and sufficient for the regulation of mRNA stability by the p38 cascade and interacted with a HeLa protein immunologically related to AU-rich element/poly(U) binding factor 1.

Anti-Bacterial Agents↗
PubMed1999

p38 mitogen-activated protein kinase regulates cyclooxygenase-2 mRNA stability and transcription in lipopolysaccharide-treated human monocytes.

p38 mitogen-activated protein kinase (MAPK) is activated by inflammatory stimuli such as bacterial lipopolysaccharide (LPS), interleukin-1, and tumor necrosis factor. We have previously shown that the pyridinyl imidazole SB 203580, which inhibits it, blocks the interleukin-1 induction of cyclooxygenase-2 (COX-2) and matrix metalloproteinase 1 and 3 mRNAs in fibroblasts. Here we explore the role of p38 MAPK in the response of human monocytes to LPS. 0.1 microM SB 203580 significantly inhibited the LPS induction of COX-2 and tumor necrosis factor protein and mRNAs. The activity of MAPK-activated protein kinase-2 (a substrate of p38 MAPK) in the cells was commensurately reduced. Some isoforms of c-jun N-terminal kinase (which is also activated by LPS) are sensitive to SB 203580; the inhibitor had little effect on monocyte c-jun N-terminal kinases up to 2 microM. We investigated the mechanism of inhibition of COX-2 induction. Transcription (measured by a nuclear run-on assay) was 60% inhibited by SB 203580 (2 microM). Importantly, we found that p38 MAPK was essential for stabilizing COX-2 mRNA: when cells stimulated for 4 h with LPS were treated with actinomycin D, COX-2 mRNA decayed slowly. Treatment of stimulated cells with 2 microM SB 203580 caused a rapid disappearance of COX-2 mRNA, even with actinomycin D present. We conclude p38 MAPK plays a role in the transcription and stabilization of COX-2 mRNA.

Calcium-Calmodulin-Dependent Protein Kinases↗
PubMed1998

A p38 MAP kinase inhibitor regulates stability of interleukin-1-induced cyclooxygenase-2 mRNA.

The mechanism by which p38 mitogen-activated protein kinase (MAPK) regulates the induction of cyclooxygenase (COX)-2 by interleukin-1 (IL-1) has been investigated in HeLa cells. SB 203580, an inhibitor of p38 MAPK, in the range 0.1-1 microM inhibited IL-1-stimulated PGE2 (but not arachidonic acid) release and this was associated with inhibition of induction of COX-2 protein and mRNA. IL-1 stimulated COX-2 transcription in HeLa cells about 2-fold as judged by both reporter gene and nuclear run-on assays. The inhibitor had no significant effect on this. However, in cells previously stimulated with IL-1 it caused rapid destabilisation of COX-2 mRNA independently of on-going transcription. The results suggest a novel function for p38 MAPK in the regulation of mRNA stability.

Arachidonic Acids↗
PubMed1998

Psoriasis.

Psoriasis is a common skin condition that can be controlled in nearly every patient. The diagnosis of psoriasis is generally made on the basis of identification of skin lesions of characteristic morphology in characteristic locations. A variety of treatments and resources are available to patients with psoriasis and to the physicians who treat them. Development of an appropriate treatment regimen is facilitated by categorization of psoriasis into localized versus generalized forms.

Diagnosis, Differential↗
PubMed1998

Papular dermatitis (subacute prurigo, "itchy red bump" disease): pilot study of phototherapy.

BACKGROUND: Some patients with a subacute or chronic pruritic erythematous papular eruption are refractory to treatment. We previously described a number of these patients with papular dermatitis or subacute prurigo. OBJECTIVE: The purpose of this study was to examine the effectiveness of different types of phototherapy for treatment of papular dermatitis. METHODS: We reviewed the medical records of 11 patients who were diagnosed with papular dermatitis and who underwent phototherapy within the last 5 years. RESULTS: Eleven patients had a total of 17 phototherapy courses: psoralen-UVA (PUVA; 9), UVA/UVB light (3), and UVB alone (5). Within the PUVA treatment group, three of nine patients experienced total clearing, and six of nine patients experienced partial improvement. Although patients in all groups relapsed with time, overall the PUVA-treated patients had the best response rate and the best chance of the condition remaining clear after treatment was stopped. CONCLUSION: PUVA may be an effective treatment for papular dermatitis. The frequency of relapse indicates that maintenance treatments may be necessary for long-term control of the disease.

Aged↗
PubMed1998

Disappointing initial results with transurethral alprostadil for erectile dysfunction in a urology practice setting.

PURPOSE: We evaluate the response to intraurethral alprostadil administration using the Medicated Urethral System for Erection (MUSE) in unselect men with a history of erectile dysfunction. We determine the effects on blood pressure during in office monitoring and assess safety of this form of treatment. We compare the efficacy of MUSE in an office setting with the placebo controlled pivotal study. MATERIALS AND METHODS: A total of 115 men with erectile dysfunction underwent in office testing with MUSE following the algorithm recommended by the manufacturer and outlined in the original pivotal study. Patients were asked to rate the rigidity of erection from 1 to 5 with scores 4 and 5 for erections sufficient for intercourse, and level of discomfort from 1 (very uncomfortable) to 5 (very comfortable) at 15-minute intervals. Patients who did not achieve a sufficient erection were scheduled to return for in office testing using the next higher dose up to 1,000 microg. Patient supine and sitting blood pressures were recorded by a nurse before and every 15 minutes after administration. Telephone contact with patients 2 to 3 months after the last in office testing was made to determine whether they were using the system. RESULTS: Mean plus or minus standard deviation rigidity scores independent of dosage increased from 2.34+/-0.99 at 15 minutes to 2.49+/-0.96 at 30 minutes and decreased thereafter. Although the 1,000 microg. dosage resulted in highest mean score at all times, the differences between dosages were not significant. Rigidity score 4 or 5 was achieved in 13.2% (500 microg.) and 30% (1,000 microg.) of patients at 30 minutes. Mean level of discomfort was 3.6+/-1.2 at 15 minutes and improved thereafter. Comfort levels were not significantly different among dosages. Overall, at 15 minutes 16.8% of patients were uncomfortable (score 1 or 2) and 41.3% were somewhat uncomfortable (1, 2 or 3). For all dosages supine and sitting systolic and diastolic blood pressures decreased significantly from before treatment to 15 minutes and stayed lower during monitoring. Defined by strict criteria 41.2% of patients experienced orthostatic hypotension during in office testing. A total of 21 patients had adverse events, including pain, discomfort and burning in the penis (the most common), dizziness and chest pain. One patient had a syncopal episode and fell in the office. At last followup only 18.6% of the tested patients continued to use MUSE at home, while the remainder discontinued treatment due to pain, insufficient erections for intercourse and cost. CONCLUSIONS: We were unable to achieve similar results to the pivotal study following manufacturer instructions and the algorithm provided by that study. Independent of age and etiology no more than 30% of patients at any given time using any dose achieved erections sufficient for intercourse during in office testing. Because of this limited efficacy, discomfort, pain and burning associated with treatment, and cost, more than 80% of patients did not continue to use MUSE at home.

Adult↗
PubMed1998

Inspiratory flow rate and dynamic lung function in cystic fibrosis and chronic obstructive lung diseases.

STUDY OBJECTIVES: The peak inspiratory flow rates (PIFRs) generated by cystic fibrosis (CF) and COPD patients through a range of clinically relevant resistances have not yet been reported (to our knowledge). The objectives of this study were to (1) explore a relevant range of resistive loads and address whether patients with stable CF and COPD can generate the PIFR sufficient to disperse dry-powder inhalants (DPI) and (2) determine whether the optimal inspiratory flow rate effective for delivery of aerosolized pharmacologic therapeutic agents can be attained with a comfort rating acceptable to subjects. DESIGN: Prospective, controlled, subject-blinded study. SETTING: Pulmonary function laboratory at the VA Palo Alto Health Care System. PATIENTS OR PARTICIPANTS: Thirty-six subjects, including 12 healthy volunteers, 12 subjects with CF, and 12 subjects with COPD were studied. MEASUREMENTS: Studies of dynamic lung function and PIFR without and with varying resistances were obtained at a single laboratory visit. RESULTS: Dynamic lung function and PIFR varied inversely with the resistive load for all patient groups and did not correlate with the disease severity, as indicated by FEV1 of percent predicted. The average subjective comfort rating for any given resistive load was similar for subjects with CF and COPD. CONCLUSIONS: These results support the conclusion that subjects with stable CF and COPD of varying severity can comfortably generate the necessary flow rates to operate new and currently available DPIs over a wide range of inspiratory resistances.

Adolescent↗
PubMed1998

The incidence of allergic contact dermatitis in patients with psoriasis vulgaris.

BACKGROUND: Contact dermatitis is said to be rare in psoriasis patients, possibly because of accelerated epidermal turnover, the isomorphic (Koebner) response, and lymphocyte functional alterations. OBJECTIVE: To identify contact allergy in patients with psoriasis. METHODS: A written questionnaire was completed by 100 patients with psoriasis about contact history, flare factors for psoriasis, topical skin care, medications, and occupational/hobby exposures. Of these patients, 20 agreed to be patch tested with a standard screening series (Hermal) and a 20-item psoriasis patch-test series that included ingredients that might be found in topical psoriasis products. RESULTS: Of the 100 patients, eight suspected a topical medication caused a reaction that worsened their psoriasis, 29 gave a history of atopy, 11 reported reactions to metal jewelry, and 29 reported an allergy to poison ivy. Patch-test results identified four of the 20 patients with six positive patch tests to the materials tested: three of the six positive tests were interpreted as relevant to the patient's psoriasis (coal tar, ethylenediamine and dithranol), two patients tested positive to nickel and one to thimerosal. Five patients had irritant reactions to dithranol. CONCLUSIONS: In this small study, 20% of self-selected psoriasis patients had positive allergic reactions on patch testing. A screening contact and atopic history in psoriasis patients may help to identify a subset of patients who could benefit from a search for more relevant contact allergens with patch test evaluation. This could improve treatment strategies and possibly reduce disability.

Dermatitis, Allergic Contact↗
PubMed1997

The economic impact of psoriasis increases with psoriasis severity.

BACKGROUND: Psoriasis treatments are known to be costly, but little is known about the financial impact of psoriasis and the way in which it relates to the severity of the disease. OBJECTIVE: This study was performed to obtain an estimate of the treatment costs faced by patients with psoriasis. METHODS: A total of 578 anonymous mail surveys were distributed to patients with psoriasis; 318 surveys were returned (55%). Psoriasis severity was assessed with the previously validated Self-Administered Psoriasis Area Severity Index (SAPASI). RESULTS: The total and out-of-pocket expenses to care for psoriasis were correlated with psoriasis severity (r = 0.26, p = 0.0001). There were no sex (p = 0.9) or racial (p = 0.4) differences in total expenditures. Severity was correlated with how bothersome to the patient was the cost of treatment (r = 0.30, p = 0.0001), the time required for treatment (r = 0.38, p = 0.0001), and the time lost from work (r = 0.23, p = 0.0001). Lower quality of life at work and in money matters also correlated with severity of psoriasis. Higher family income was associated with less time spent caring for psoriasis and less interference with work around the home. CONCLUSION: As expected, the expenses caring for psoriasis are greater for patients with more severe disease. These costs and other financial implications are associated with lower quality of life for patients with more severe psoriasis.

Absenteeism↗
PubMed1997

Commercial tanning bed treatment is an effective psoriasis treatment: results from an uncontrolled clinical trial.

Phototherapy is highly effective in the therapy of psoriasis, but patient access to phototherapeutic facilities is not universal. Commercial tanning facilities are universal, but their efficacy in psoriasis treatment is unestablished. Our purpose was to conduct a study to assess the effect of a commercial tanning unit outfitted with nonprescription lamps on psoriasis. We conducted a 6-wk open study of 20 adult patients with stable psoriasis vulgaris. Clinical response was defined as a decrease in the Psoriasis Area Severity Index (PASI) or the Self-Administered PASI (SAPASI) by > or = 10%. There were 16 men and 4 women who participated with a mean (+/-SD) age of 43.0 +/- 14.8 y. Initial and final health-related quality of life information collected included the following instruments: the Brief Symptom Inventory (BSI), the Psoriasis-Related Stressor Scale (PRSS), and the Psoriasis Disability Scale (PDS). Side effects of tanning therapy were closely monitored. Fifteen subjects completed the entire 6-wk trial, and exit data on all subjects were used for analysis. The mean number of tanning sessions was 19 +/- 7.6 with a median of 19 and range of 3 to 29. Analysis of all 20 enrolled subjects found that 16 (80%) showed clinical response as measured by PASI, whereas 17 (85%) showed SAPASI response. Initial and final PASI scores decreased (p = 0.0001) from 7.96 +/- 1.77 to 5.04 +/- 2.5, and SAPASI scores also decreased (p = 0.02) from 11.8 +/- 4.4 to 7.9 +/- 7.7. When controlled for age and sex, a dose-response relationship was demonstrated with the PASI and SAPASI (p < 0.02). Decreases in the mean BSI and PRSS scales were demonstrated (p < 0.02), confirming the clinical significance of the reductions in disease severity scores. Episodes of mild burning occurred in 7 of 20 (35%) participants. Three subjects reported itching after one or two tanning sessions. This study showed that a tested commercial nonprescription tanning unit improved both psoriasis severity and health-related quality of life. Commercial tanning bed treatments may be a useful approach in patients unable to obtain office-based ultraviolet treatments.

Adult↗
PubMed1997

A new method for bronchial-provocation testing in asthmatic subjects using a dry powder of mannitol.

We developed a bronchial provocation test (BPT) with a dry powder preparation of mannitol. The mannitol was inhaled from gelatin capsules containing 5, 10, 20, or 40 mg to a cumulative dose of 635 mg, and was delivered via an inhalator, Halermatic, or Dinkihaler device. We studied the airway sensitivity to inhaled mannitol, the repeatability of the response, and the recovery after challenge in 43 asthmatic subjects 18 to 39 yr of age who had a 20% decrease in FEV1 in response to inhaling a 4.5% NaCl. We compared this with the airway response to methacholine in 25 subjects. The geometric mean (GM) for the dose of dry mannitol required to reduce the FEV1 by 15% of the baseline value (PD15) was 64 mg, with a 95% confidence interval (CI) of 45 to 91. Subjects responsive to mannitol had a PD20 to metacholine of < 7.8 mumol, with a GM of 0.7 mumol (CI: 0.4 to 1.2). For the first of two challenges to mannitol the PD15 was 59 mg (CI: 36 to 97) and for the second the PD15 was 58 mg (CI: 35 to 94) p = 0.91 (n = 23). Spontaneous recovery to within 5% of baseline occurred within 60 min and within 10 min after 0.5 mg terbutaline sulfate was inhaled. Arterial oxygen saturation (SaO2) remained at 93% or above during mannitol challenge. Subjects tolerated the inhalation of the mannitol well. A dry powder preparation of mannitol may be suitable to develop for bronchial provocation testing.

Administration, Inhalation↗
PubMed1997

The effect of inhaling a dry powder of sodium chloride on the airways of asthmatic subjects.

Wet aerosols of 4.5% sodium chloride (NaCl) are often used to assess the bronchial responsiveness associated with asthma. We questioned whether dry NaCl could be used as an alternative. Dry powder NaCl was inhaled from capsules containing either 5, 10, 20 or 40 mg to a cumulative dose of 635 mg. The powder was delivered via an Inhalator or Halermatic. The airway sensitivity to the dry and wet NaCl was compared in 24 patients with asthma aged 19-39 yrs. All subjects responded to both preparations and the geometric mean (95% confidence intervals) for the provocative dose of NaCl causing forced expiratory volume in one second (FEV1) to fall 20% from baseline (PD[20,NaCl]) for dry NaCl was 103 mg (68-157) versus 172 mg (102-292), p<0.03 for the wet NaCl. The response to dry NaCl was reproducible and on repeat challenge the PD20 was 108 mg (75-153). The mean maximum fall in FEV1 was approximately 25% on each of the two test days. Spontaneous recovery occurred within 60 min after challenge with dry NaCl and within 5 min after bronchodilator. There were no serious side-effects requiring medical attention, however some patients coughed on inhalation of the 40 mg dose and three gagged. Arterial oxygen saturation remained within normal limits. We conclude that a suitably prepared dry powder of sodium chloride could potentially replace wet sodium chloride to assess bronchial responsiveness in patients with asthma, but further studies are required to establish the long-term stability of the dry powder preparation.

Administration, Inhalation↗