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Biomedical subjects

C Irwin

Publications and source records attributed to C Irwin.

At least 19 recordsLinked to original sources
PubMed2001

The effect of telepharmacy counseling on metered-dose inhaler technique among adolescents with asthma in rural Arkansas.

The increased prevalence, morbidity, mortality, and health costs associated with asthma among children suggest the need for accessible asthma education. This study examined the effect of telepharmacy counseling, using interactive compressed video, on metered-dose inhaler (MDI) technique and patient satisfaction among adolescents with asthma in rural Arkansas. The telepharmacy counseling provided accessible education regarding MDI technique for adolescents in this study. Twenty percent of the adolescents who participated had never been shown the appropriate use of an MDI. The study used an experimental design with random assignment of participants to a telepharmacy counseling group (n = 15) or a control group (n = 21). Both groups participated in pre-test, post-test, and 2- to 4-week follow-up assessments for MDI technique and patients satisfaction (follow-up assessment only) via interactive compressed video. Results indicated that from pre-test to follow-up the telepharmacy counseling group showed more improvement in MDI technique than participants in the control group (p < 0.001). There was no significant difference between the telepharmacy counseling group and control group in satisfaction with the instructional sessions (p = 0.132). Both groups had high levels of satisfaction with the telepharmacy sessions. The study findings demonstrated that patient education provided by pharmacists via interactive compressed video was superior to education provided via written instructions on an inhaler package insert. Interactive compressed video is an effective medium for teaching and improving MDI technique in this rural, adolescent, predominantly African-American population.

Administration, Inhalation↗
PubMed2000

Results of radical radiotherapy for recurrent endometrial cancer.

OBJECTIVES: The aims of this study were to determine the overall survival (OS) and local control (LC) achieved in patients developing a locoregional recurrence of endometrial carcinoma and to define those prognostic factors that predict for improved LC and OS. METHODS: Between 1984 and 1988, 958 women were referred to Princess Margaret Hospital (PMH) with a diagnosis of endometrial carcinoma. Of these, 58 were treated for recurrent disease with radical radiotherapy (RT). Forty-two were referred with recurrence and 16 relapsed during follow-up at PMH for their primary tumor. None had received prior RT. The majority (n = 49) were treated with combined external beam RT followed by an intracavitary cesium insertion. RESULTS: The median time to relapse from original diagnosis was 1.3 years (range 0.2-13.4 years). The actuarial 5- and 10-year OS was 53 and 41%, respectively. The respective results for LC were 65 and 62%. All end-points were measured from the time of relapse. The median total dose received was 81.5 Gy. Univariate analysis showed that favorable histological features at original diagnosis (<50% myometrial involvement, grade 1-2, P = 0.007) and Perez modified staging (P = 0.02) were significant predictors for OS. The Perez staging (P = 0.02) and size of recurrence (<2 cm versus >/=2 cm, P = 0.04) were predictors for LC. CONCLUSION: Patients with localized relapse of endometrial carcinoma in whom radical radiotherapy can be administered should be treated aggressively and may be cured in over half the cases treated. Pathological findings in the original surgical specimen, size of recurrent disease, and a modified vaginal carcinoma staging system are significant predictors of local pelvic control and survival.

Adult↗
PubMed2000

Implementation of an electronic medical record system in a pediatric psychopharmacology program.

The design, implementation, and utilization of an electronic medical record system (EMRS) in a pediatric psychopharmacology clinic is described. The EMRS is a relational database with information entered directly by the clinician during a patient visit. It has been used during more than 2590 patient visits with 805 patients. Complete clinical documentation and simultaneous data entry as well as computer generated prescriptions for the patient were accomplished 75% of the time within a 20-min medication management session. One hundred consecutive parents of patients were asked to fill out a five-question survey to begin to assess the impact of the application. Of the 87 parents who responded, all (100%) noted that the doctor paid attention to their concerns. Between 88 and 90% of the parents reported that the use of the computer is a 'good' thing, made it easier to work with the doctor, and that they understood why the computer was being used. The findings support that the development and implementation of an EMRS with direct clinician information entry within pediatric psychopharmacology clinic, is feasible.

Attitude to Computers↗
PubMed1999

Differentiation of human CD8 T cells: implications for in vivo persistence of CD8+ CD28- cytotoxic effector clones.

CD8 T cells contain a distinct subset of CD8+ CD28- cells. These cells are not present at birth and their frequency increases with age. They frequently contain expanded clones using various TCRalphabeta receptors and these clones can represent >50% of all CD8 cells, specially in old subjects or patients with chronic viral infections such as HIV-1. Herein, it is shown that a large fraction of CD8+ CD28- cells expresses intracellular perforin by three-color flow cytometry, in particular when this subset is expanded. Together with their known ability to exert potent re-directed cytotoxicity, this indicates that CD8+ CD28- T cells comprise cytotoxic effector cells. With BrdU labeling, we show that CD8+ CD28- cells derive from CD8+ CD28+ precursors in vitro. In addition, sorted CD8+ CD28+ cells gave rise to a population of CD8+ CD28- cells after allo-stimulation. Moreover, ex vivo CD8+ CD28+ cells contain the majority of CD8 blasts, supporting the notion that they contain the proliferative precursors of CD8+ CD28- cells. CD95 (Fas) expression was lower in CD8+ CD28- cells, and this subset was less prone to spontaneous apoptosis in ex vivo samples and more resistant to activation-induced cell death induced by a superantigen in vitro. Thus, the persistence of expanded clones in vivo in the CD8+ CD28- subset may be explained by antigen-driven differentiation from CD8+ CD28+ memory precursors, with relative resistance to apoptosis as the clones become perforin(+) effector cells.

Adult↗
PubMed1998

The role of adjuvant radiotherapy in carcinoma of the endometrium-results in 550 patients with pathologic stage I disease.

OBJECTIVES: A retrospective analysis of 550 women with pathological stage I carcinoma of the endometrium who were seen between January 1984 and December 1988 was performed in order to assess the value of adjuvant radiation therapy. METHODS: Two-hundred twenty-eight patients were treated with surgery alone (S); 97 received adjuvant external beam radiotherapy (S + EXT); 217 received external beam radiotherapy and colpostats (S + EXT + IC); and 8 patients received only colpostats (S + IC). Pelvic radiation therapy, usually 40 Gy in 20 fractions, was administered to 94% of patients whose tumors showed greater than 50% myometrial invasion and to 89% of patients with FIGO grade 3 tumors. Colpostats were used in 40% of patients, the majority of whom had lower uterine segment involvement. RESULTS: The overall survival rate for the whole group using Kaplan-Meier estimates was 84% at 5 years. The 5-year overall survival rates for each treatment group, excluding the S + IC group, were 90% for S alone, 79% for S + EXT, and 82% for S + EXT + IC. The 5-year disease-free survival rates were 84, 77, and 77%, respectively. Local control rates at 5 years were 93, 94, and 95% in the three treatment groups, but the patterns of relapse were different. Distant metastases occurred more frequently among the patients who received adjuvant radiation therapy (36/49, 73%) than among those who did not (4/19, 21%). Late toxicity was documented in 66 patients. Twelve patients had EORTC/RTOG grade 3 and 4 complications; all had been treated with S + EXT + IC. FIGO grade (P = 0.009), lower uterine segment involvement (P = 0.009), and age (P = 0.03) were significant predictors of worse disease-free survival in a multiple regression analysis. CONCLUSIONS: The addition of vaginal vault brachytherapy to external beam radiotherapy did not appear to improve local cure rates nor survival, but increased the incidence of late radiation toxicity.

Adenocarcinoma↗
PubMed1998

Interactions between peripheral blood CD8 T lymphocytes and intestinal epithelial cells (iEC).

Intestinal intraepithelial lymphocytes (iIEL) are primarily CD8 cells and most of them have a CD28- phenotype, the phenotype of effector cytotoxic T cells. We asked whether the predominance of CD8+CD28- T cells in the gut may result from peripheral blood T cells preferentially migrating to the iIEL compartment and adhering to iEC. Compared with CD4 cells, adhesion of resting CD8+ T cells to iEC cell lines was significantly higher. Adhesion could be blocked with a MoAb to gp180, a molecule expressed on iEC which is known to interact with CD8/lck. No significant difference in the level of adhesion was observed between CD8+CD28+ and CD8+CD28- T cells. Thus CD8 cells may preferentially migrate to the iIEL compartment, but loss of CD28 expression could occur in situ after migration. Consistent with this hypothesis, the CD8+CD28- cells became enriched after co-culturing T cells with iEC cell lines and primary iEC. Induction of the CD8+CD28- phenotype in cord blood and adult T cells was observed in co-cultures with iEC and also with mitogens and superantigens. In the latter case, CD28 down-modulation was seen specifically in the Vbeta subset targeted by the superantigen, indicating that loss of CD28 expression is a direct result of T cell receptor (TCR)-mediated stimulation. The combined results suggest that CD8+CD28- T cells are antigen experienced T cells, and that they may have a survival advantage in the presence of gut epithelial cells in vitro. This may contribute to the predominance of CD8+CD28- T cells in the iIEL compartment.

Adult↗
PubMed1998

Ease your management workload and develop staff.

A community hospital created a program where staff nurses work as house supervisors. The plan improves house supervisor coverage and provides opportunity for nursing staff development.

Hospitals, Community↗
PubMed1996

Late renal function following whole abdominal irradiation.

Sixty patients treated with whole abdominal radiotherapy who had remained disease-free since completion of treatment participated in a study to assess the late clinical and biochemical effects of bilateral renal irradiation. Minimum follow-up was 5 years with a maximum of 20 years and a median of 9 years. Fifty-two patients in the study group were treated for primary ovarian cancer. Seven had non-Hodgkins lymphoma arising in the gastrointestinal tract and one patient had a carcinoid tumour arising in small bowel. None of the patients received chemotherapy. Abdominal radiation was given using an open beam technique to a mean dose of 22.92 Gy (range 6.68-27.54 Gy) in 1.02 to 1.25 Gy fractions treated once daily. Posterior kidney shields were used in order to limit the renal dose to < 20 Gy. Mean radiation dose to both kidneys (retrospectively calculated) was 19.28 Gy (range 6.68-22.99 Gy). Patients ranged in age from 32-81 years with a median of 61 years. No patient had clinical evidence of renal impairment. Nine patients were hypertensive prior to radiotherapy and a further five patients became hypertensive after treatment. Serum creatinine values ranged from 44-123 mumol/l, with a mean of 87 mumol/l. Creatinine clearance ranged from 0.61-2.38 ml/s (mean 1.28 ml/s). Tubular function tests revealed one borderline high 24-h protein excretion and normal 24-h phosphorous and uric acid. Using a multiple linear regression analysis with creatinine clearance as the endpoint, age was the only significant variable (P < 0.00001) and renal dose and interval from treatment were not independently significant. There was no evidence of late renal toxicity more than 5 years after whole abdominal radiotherapy delivered with this technique and dose/fractionation schedule, and using the clinical and biochemical endpoints assessed in this study.

Female↗
PubMed1996

Squamous cell carcinoma of the lip: the role of electron treatment.

After skin cancer, squamous cell carcinoma (SCC) of the lip is the most common cancer of the head and neck. It can be treated in a variety of ways, including both surgery and radiotherapy. Many centres have reported excellent cure and local control rates for their chosen treatment method. Electron beam treatment is recognized as a method of treatment and has theoretical advantages related to its depth-dose characteristics. We report a retrospective study of the treatment with electrons of 26 patients with Stage T1-2 SCCs of the lip. With a median follow-up period of 31 months (range 1.5-60) 100% local control was obtained, although two patients required surgical salvage, one for a geographical miss. One patient presented with metastatic neck nodes, and one relapsed in the neck, but both were treated with a combination of surgery and radiotherapy and were free of disease at follow-up. Patients tolerated the acute radiation reaction well and the long term cosmetic and functional results were good. Two patients experienced minor soft tissue necrosis, one of whom required surgical treatment. Electron treatment for T1-2 SCC of the lip is an effective, well tolerated treatment for these patients, many of whom are elderly and frail.

Aged↗
PubMed1996

Comorbidity of posttraumatic stress disorder and irritable bowel syndrome.

BACKGROUND: Irritable bowel syndrome (IBS) is a chronic disorder that has been found to be associated with psychiatric disorders and a history of physical and/or sexual abuse. To date, the relationship of posttraumatic stress disorder (PTSD) and IBS has not been investigated. The primary purpose of this study was to examine the relationship of IBS and PTSD. METHOD: Fifty consecutive IBS patients admitted to a clinical treatment study were assessed for IBS, trauma history, and psychiatric disorders. RESULTS: Twenty-seven IBS patients (54%) met criteria for a psychiatric diagnosis at some time in their lives. Twenty-two patients (44%) reported a trauma history. Eighteen (36%) were diagnosed with PTSD. Those IBS patients with a trauma history were more likely to have other comorbid psychiatric diagnoses. CONCLUSION: These results suggest that IBS is often associated with psychiatric disorders, indicating that assessment and treatment of these comorbid conditions may be important in the treatment of IBS. PTSD, which had not been previously investigated in relation to IBS, had a high prevalence, indicating the need for careful trauma and PTSD assessment in patients with IBS. Patients with IBS who have a trauma history may be more at risk for other comorbid psychiatric disorders than IBS patients without a trauma history.

Adolescent↗
PubMed1995

Polypeptide growth factors--a role in restorative dentistry?

Growth factors play an integral part in controlling many aspects of normal biological processes, including tissue repair. As the roles of individual factors have been determined, it has become increasingly apparent that some of these biological mediators show potential for clinical use in a number of areas, including restorative dentistry. This review highlights those areas where the passage from laboratory to dental clinic is most advanced.

Bone Morphogenetic Proteins↗
PubMed1994

Comparative efficacy of sunscreen reapplication regimens in children exposed to ambient sunlight.

Undercompliance with sunscreen reapplication recommendations is a probable factor in suboptimal childhood ultraviolet radiation (UVR) protection. However, improving on the ability of sunscreens to absorb UVR without requiring frequent reapplication is difficult because the models most frequently used to develop and evaluate photoprotectants have only a limited ability to incorporate behavioral and environmental variables that are primarily responsible for loss of sunscreen efficacy. Hence, the objective of the present work was to develop a method to evaluate the efficacy of various regimens of sunscreen reapplication in children, under conditions of unrestricted behavior and exposure to ambient sunlight. Ninety-eight children, ages 7-12, Fitzpatrick skin types I-III, were divided between two study groups. The majority were types I-II, and all types were approximately equally represented between the groups. The children received single or multiple applications of a sun protection factor 25 sunscreen to preassigned lateral halves of the body and engaged in unrestricted activities throughout a 6- (group I) or 8-h (group II) period of sun exposure at a seaside location. The end measurement for these studies was incidence and severity of erythema 18 to 22 h after peak UV exposure. The results obtained showed that 1 or 4 sunscreen applications yielded comparable erythema protection after a 6-hour sun exposure, totaling 13 minimal erythema doses (MED). However, after an 8-h, 21 MED exposure, incidence and severity of erythema was greater at body sites treated with 1 compared with 5 sunscreen applications.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrylates↗
PubMed1993

An ultraviolet radiation action spectrum for immediate pigment darkening.

The wavelength dependence for immediate pigment darkening (IPD) was investigated by exposing the midback skin of volunteers to a series of incremental fluences of narrow waveband radiation isolated by band-pass filters in the 310-400 nm region. The threshold IPD fluence for each waveband was determined by visual assessment of the skin responses immediately after each exposure. The action spectrum, constructed from the mean threshold fluences, was broad and extended from 320 nm to 400 nm with a peak at around 340 nm. No IPD could be evoked at 310 nm, even after erythemogenic fluences. The spectrum was similar in each of the three skin types investigated (III, IV, V). The broad nature of the action spectrum within the UVA region suggests that IPD may serve as an alternative endpoint for measuring photoprotection against these wavelengths.

Adult↗
PubMed1992

Different guanosine triphosphate-binding proteins couple vasopressin receptor to phospholipase C and phospholipase A2 in glomerular mesangial cells.

To evaluate the identity of the guanosine triphosphate--binding proteins coupling arginine vasopressin receptor occupancy with activation of phospholipase C, leading to Ca2+ mobilization, and activation of phospholipase A2, leading to arachidonate release and prostanoid formation, we used intact cells, saponin-permeabilized cells, and membranes of the rat mesangial cell. Arginine vasopressin 10(-7) mol/L produced a dose-dependent increase in cytosolic Ca2+ to maximal levels of 500 nmol/L with peak responses occurring within 10 seconds of addition of arginine vasopressin to cells in suspension. Arginine vasopressin 10(-7) mol/L elicited a maximal response. These increases were associated temporarily with a fourfold increase in tritiated D-myo-inositol 1,4,5-trisphosphate formation in prelabeled cells. Pertussis toxin (200 ng/ml) did not inhibit the Ca2+ increase nor did it inhibit the increase in tritiated D-myo-inositol 1,4,5-trisphosphate formation, suggesting a pertussis toxin--insensitive signaling pathway for phospholipase C hydrolysis in response to vasopressin. Membranes prepared from mesangial cells increased D-myo-inositol 1,4,5-trisphosphate formation in vitro in response to arginine vasopressin and guanosine-5'-0(3- thiotrisphosphate), and this stimulation was inhibited by guanosine-5'-0(2-thiodiphosphate), confirming the involvement of a guanosine triphosphate--binding protein. In contrast arginine vasopressin stimulated arachidonate release from intact mesangial cells, and this effect was blocked by pretreating cells with pertussis toxin. To demonstrate that this was through a pertussis toxin--sensitive guanosine triphosphate--binding protein, we permeabilized cells with saponin and determined that arginine vasopressin and guanosine-5'-0(3-thiotriphosphate) stimulated the release of arachidonic acid and the stimulation of guanosine-5'-0(3-thiotriphosphate) was inhibited by guanosine-5'-0(2-thiodiphosphate). Finally, pertussis toxin was able to stimulate adenosine diphosphate ribosylation in vivo of a substrate protein in mesangial cell membranes of 41 kd, and this ribosylation was inhibited by pretreating cells with pertussis toxin. These data suggest that the release of arachidonic acid by vasopressin in glomerular mesangial cells is linked to a pertussis toxin--sensitive guanosine triphosphate--binding protein and that this activation of phospholipase C in vasopressin is linked to a pertussis toxin--insensitive guanosine triphosphate--binding protein.

Adenosine Diphosphate Ribose↗
PubMed1991

The role of strontium-90 beta irradiation in the management of pterygium.

A pterygium is a benign, usually progressive fibrovascular overgrowth of the conjunctiva usually arising at the inner canthus of the eye which may cause local symptoms, particularly if large and impinging on the cornea. The treatment of choice for symptomatic pterygia is surgical excision, but early proliferation of fibroblasts and vascular buds leads to recurrence in a large proportion of cases. We review the published results of adjuvant postoperative beta irradiation using an ophthalmic applicator containing strontium-90 which is effective at reducing recurrence to an acceptable level. This treatment is well tolerated in the short term, and although a number of late sequelae are recognized, these are extremely uncommon in everyday clinical practice.

Combined Modality Therapy↗
PubMed1991

A randomized trial of carboplatin versus iproplatin in untreated advanced ovarian cancer.

Between August 1984 and October 1987, 120 patients with stage IC to IV epithelial ovarian cancer were randomly assigned to receive carboplatin (400 mg/m2) or iproplatin (300 mg/m2) every 4 weeks as initial treatment. Stratification was made according to International Federation of Gynecology and Obstetrics (FIGO) stage and according to size of residual disease after surgery. Response was evaluated after six courses when patients were restaged, with laparoscopy or laparotomy in clinical complete responders or those with no assessable disease. Treatment was then stopped in surgically proven complete responders. Patients with partial (PR) or minor response (MR) received a further six courses of their original drug at a reduced dose (carboplatin 300 mg/m2, iproplatin 225 mg/m2). Patients with stable (SD), progressive (PD), or recurrent disease were treated with cyclophosphamide (1 g/m2). The response rates were 63% (95% confidence interval [CI], 50% to 74%) for carboplatin and 38% (95% CI, 26% to 51%) for iproplatin. Fifteen patients were not assessable for response. The median survival was 114 weeks (95% CI, 82 to 233 weeks) for carboplatin patients and 68 weeks (95% CI, 48 to 82 weeks) for iproplatin patients (P = .008). The amount of residual disease after initial laparotomy was a prognostic factor for survival. Myelosuppression was the main toxicity and was greater with iproplatin. This study shows carboplatin to be more active than iproplatin in the treatment of ovarian cancer and less toxic. Few responses to cyclophosphamide occurred following either drug, implying resistance to the alkylating agent.

Adult↗