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Biomedical subjects

W Lawrence

Publications and source records attributed to W Lawrence.

At least 19 recordsLinked to original sources
PubMed2002

The effects of diet upon pupal development and cocoon formation by the cat flea (Siphonaptera: Pulicidae).

Cocoon formation by cat flea larvae was directly related to the quantity of eggs or yeast consumed. Larvae consuming either 1-3 eggs or 0.25-1.0 mg of yeast developed as naked pupae or formed incomplete cocoons. Third instar cat flea larvae fed upon naked pupae and pupae within partial cocoons, but complete cocoons protected pupae from cannibalism. First and second instars did not attack pupae. When larvae were provided with a carpet fiber for protection, a greater number of fleas successfully developed to the adult stage.

Animals↗
PubMed2000

In memoriam.

Explore the source record for details and available documents.

Journal Article↗
PubMed2000

A pilot trial assessing the efficacy of paroxetine hydrochloride (Paxil) in controlling hot flashes in breast cancer survivors.

BACKGROUND: Many breast cancer survivors suffer debilitating hot flashes. Estrogen, the drug of choice in perimenopausal women, is generally not recommenced to breast cancer survivors. Nonhormonal treatments are mostly disappointing. Anecdotal reports in our institution suggested that the selective serotonin-reuptake inhibitor, paroxetine hydrochloride, might be efficacious in alleviating hot flashes. PATIENTS AND METHODS: Thirty women with prior breast cancer who were suffering at least two hot flashes a day entered a single institution pilot trial to evaluate paroxetine's efficacy in reducing the frequency and severity of hot flashes. After completing daily diaries for one week on no therapy, the women received open-label paroxetine, 10 mg daily for one week, followed by four weeks of paroxetine, 20 mg daily. The women completed hot-flash daily diaries throughout the study period, and a health-related symptom-assessment questionnaire and a quality-of-life rating scale in the first and sixth week of the study. RESULTS: Twenty-seven women completed the six-week study period. The mean reduction of hot flash frequency was 67% (95% confidence interval (95% CI): 56%-79%). The mean reduction in hot flash severity score was 75% (95% CI: 66%-85%). There was a statistically significant improvement in depression, sleep, anxiety, and quality of life scores. Furthermore, 25 (83%) of the study participants chose to continue paroxetine therapy at the end of study. The most common adverse effect was somnolence, resulting in drug discontinuation in two women, and dose reduction in two women. One woman discontinued drug due to anxiety. CONCLUSIONS: Paroxetine hydrochloride is a promising new treatment for hot flashes in breast cancer survivors, and warrants further evaluation in a double-blind randomized placebo-controlled trial.

Adult↗
PubMed2000

The effects of flea egg consumption on larval cat flea (Siphonaptera: Pulicidae) development.

Cat flea larvae feeding on the feces of adult fleas that were maintained on cats and were provided with frozen flea eggs ad libitum each consumed an average of 21.7 +/- 3.9 eggs and developed rapidly with 100% adult emergence. In contrast, 93.4% of larvae held individually and provided with only flea feces did not survive to the adult stage. Developing larvae consumed eggs in the presence of yeast and rearing diet. In a second experiment, larvae provided with flea feces and eggs and maintained at 55% RH consumed 26.9 +/- 2.7 eggs per larva, compared to larvae maintained at 75% RH that consumed 20.4 +/- 1.9 eggs per larva.

Animals↗
PubMed1999

Accelerated superfractionated radiotherapy for inflammatory breast carcinoma: complete response predicts outcome and allows for breast conservation.

PURPOSE: Chemotherapy and accelerated superfractionated radiotherapy were prospectively applied for inflammatory breast carcinoma with the intent of breast conservation. The efficacy, failure patterns, and patient tolerance utilizing this approach were analyzed. METHODS AND MATERIALS: Between 1983 and 1996, 52 patients with inflammatory breast carcinoma presented to the Medical College of Virginia Hospitals of VCU and the New England Medical Center. Thirty-eight of these patients were jointly evaluated in multidisciplinary breast clinics and managed according to a defined prospectively applied treatment policy. Patients received induction chemotherapy, accelerated superfractionated radiotherapy, selected use of mastectomy, and concluded with additional chemotherapy. The majority were treated with 1.5 Gy twice daily to field arrangements covering the entire breast and regional lymphatics. An additional 18-21 Gy was then delivered to the breast and clinically involved nodal regions. Total dose to clinically involved areas was 63-66 Gy. Following chemoradiotherapy, patients were evaluated with physical examination, mammogram, and fine needle aspiration x 3. Mastectomy was reserved for those patients with evidence of persistent or progressive disease in the involved breast. All patients received additional chemotherapy. RESULTS: Median age was 51 years. Median follow-up was 23.9 months (6-86) months. The breast preservation rate at the time of last follow-up was 74%. The treated breast or chest wall as the first site of failure occurred in only 13%, and the ultimate local control rate with the selected use of mastectomy was 74%. Ten patients underwent mastectomy, 2 of which had pathologically negative specimens despite a clinically palpable residual mass. Response to chemotherapy was predictive of treatment outcome. Of the 15 patients achieving a complete response, 87% remain locoregionally controlled without the use of mastectomy. Five-year overall survival for complete responders was 68%. This is in contrast to the 14% 5-year overall survival observed with incomplete responders. The 5-year actuarial disease-free survival and overall survival for the entire patient cohort was 11% and 33%, respectively. All patients tolerated irradiation with limited acute effects, of which all were managed conservatively. CONCLUSION: Our experience demonstrates that induction chemotherapy, accelerated superfractionated radiotherapy, and the selected use of mastectomy results in excellent locoregional control rates, is well tolerated, and optimizes breast preservation. Based on our present results, we recommend that a patient's response to induction chemotherapy guide the treatment approach used for locoregional disease, such that mastectomy be reserved for incomplete responders and avoided in those achieving a complete response.

Adenocarcinoma↗
PubMed1999

Progress in the surgical management of vaginal rhabdomyosarcoma: a 25-year review from the Intergroup Rhabdomyosarcoma Study Group.

BACKGROUND/PURPOSE: During its 25 years of experience, the Intergroup Rhabdomyosarcoma Study Group (IRSG) has completed four sequential prospective clinical trials to improve survival and decrease morbidity rates in childhood rhabdomyosarcoma (RMS). Surgical management of vaginal RMS has changed dramatically. METHODS: The records of 72 patients with localized vaginal RMS were reviewed to assess surgical therapy, chemotherapy, and radiotherapy and their relation to outcome. RESULTS: Each successive IRSG trial resulted in decreased need for surgical resection (IRS-I, 100%; IRS-II, 70%; IRS-III, 30%; IRS-IV, 13%) and excellent disease-free survival using increasingly effective multiagent chemotherapy. CONCLUSIONS: Primary chemotherapy after initial biopsy provides excellent tumor control. Local resection may be appropriate, but removal of organs (ie, complete vaginectomy/hysterectomy) has no role except in persistent or recurrent disease. Mature, residual rhabdomyoblasts may be evidence of a chemotherapy response, and further surveillance and biopsy without surgical resection is adequate treatment.

Algorithms↗
PubMed1999

A unique role: the peer mentor on the spinal cord team at G.F. Strong Rehab Centre.

The peer mentor is a full time paid staff member of the G. F. Strong Rehab Centre Spinal Cord Program. To qualify for the position, an individual with a high lesion spinal cord injury must live a self-managed life in the community. The peer mentor's role bridges professional, lay, and client perspectives, and is a voice for both clients and staff unlike any other team member. This report focuses on the peer mentor's facilitation of communication between clients and staff and on two initiatives that promote clients' perspectives.

British Columbia↗
PubMed1998

Volunteers as adjunct researchers in a cancer prevention trial: the American Cancer Society Colon Polyp Prevention Study.

BACKGROUND: In April 1991, the Virginia Division of the American Cancer Society (ACS) initiated the feasibility phase of the Colon Polyp Prevention Study (CPPS) to determine whether a high fiber supplement would decrease new adenomatous colorectal polyp occurrence. The feasibility phase had two specific objectives: 1) to evaluate accrual and compliance to the designed protocol and 2) to evaluate and demonstrate the effectiveness of volunteers as research assistants. The CPPS is an innovative project in which trained volunteers play a significant role in the research process. METHODS: In the CPPS, volunteer adjunct researchers (VARs) were trained to perform individual dietary data collection and intervention and other general study monitoring functions. VARs were trained, certified, and monitored in the performance of their assigned tasks by ACS staff and expert consultants. RESULTS: A total of 119 volunteers were trained as VARs, 74 of whom were certified and matched to a study participant. Between 1991-1995, only six VARs left the study. After active accrual of participants to the study ceased in 1995, 38 VARs (50% of the certified VARs) continued to monitor the active study participants. All VARs were consistently able to conduct the functions for which they were trained. CONCLUSIONS: In spite of expected volunteer attrition rates, a core of 38 dedicated VARs were matched to 72 participants and demonstrated the ability to perform selected data collecting activities on a consistent and efficient basis. The use of trained volunteers has allowed the CPPS to function in its feasibility phase at personnel cost considerably less than that of other similar cancer prevention trials.

American Cancer Society↗
PubMed1998

Chronic vulvar ulceration in an immunocompetent woman due to acyclovir-resistant, thymidine kinase-deficient herpes simplex virus.

A 34-year-old healthy woman presented with a 15-month history of persistent, nonhealing vulvar ulcerations due to herpes simplex virus (HSV) type 2. Extensive dermatologic workup and serial skin biopsies failed to reveal an underlying vulvar dermatosis or autoimmune bullous disorder. Virologic studies revealed resistance to acyclovir in vitro due to deficiency in thymidine kinase activity. Serum antibody to human immunodeficiency virus was negative on two occasions, separated by 1 year. Immunologic evaluation showed normal HSV-specific proliferative and CD8 cytotoxic T lymphocyte responses as well as normal NK cell function. Vulvar lesions failed to heal in association with trials of topical trifluorothymidine and oral valacyclovir but resolved completely with the application of 1% foscarnet cream. No recurrence of HSV has been observed in 24 months of follow-up to date.

Acyclovir↗
PubMed1998

Thoracic sarcomas in children.

OBJECTIVE: This study reviews the experience of the Intergroup Rhabdomyosarcoma Studies (IRS) II and III with thoracic sarcomas. SUMMARY BACKGROUND DATA: Thoracic sarcomas in children present special problems with histologic diagnosis, total resection of tumor, and local control. Previous studies have shown high rates of local and distant relapse. METHODS: Data from evaluable patients enrolled in IRS II and IRS III were reviewed. Progression-free and overall survival were estimated by the Kaplan-Meier method and statistical differences were calculated by the log-rank test. The multivariate regression analysis of data was performed using the Cox proportional hazards model. RESULTS: A total of 84 patients presented with thoracic sarcomas during IRS II (51 patients) and IRS III (33 patients). Of these, 76 were chest wall tumors, 3 were lung tumors, 4 were pleural tumors, and 1 arose from the heart. The average age at diagnosis was 8.5 years (range, 1 month-20.5 years). Thirty-three patients had alveolar histology, 17 had embryonal histology, and 12 had extraosseous Ewing's sarcoma, with indeterminate, undifferentiated, and pleomorphic histologies in the remaining 22 patients. Thirteen patients presented as group I (localized disease completely resected), 18 as group II (microscopic residual or nodal disease), 31 as group III (gross residual disease or biopsy only), and 22 as group IV (distant metastatic disease). Sixty patients (71%) achieved a complete response. Thirty-nine patients had a local relapse, and 22 had a distant relapse. Thirty-five patients (42%) survived with a mean follow-up of 1.8 years (range 0.7-11.7 years); 49 (58%) have died with an average survival of 1.1 years (range 0.3-11.7 years). Four patients (5%) died of infection or treatment complications. Progression-free survival was not significantly associated with histology, site, clinical group, or IRS study. Overall survival was significantly associated with clinical group, size, and local or distant recurrence, but not with histology or IRS study by univariate analysis. In a multivariate analysis, only clinical group and local and distant recurrence showed statistical significance (p < 0.002, < 0.006, and < 0.001, respectively). CONCLUSIONS: As expected, outcome was better for patients with totally resected or microscopically residual tumor after resection. A higher rate of recurrence in group I versus group II,although not statistically significant, suggests that identification of margin status may be difficult, and these patients may require more intensive efforts for local control. These patients continued to have a high rate of local and distant relapse, and new strategies for preventing these are under development.

Adolescent↗
PubMed1998

Refsum's disease. A unique case.

Refsum's disease, or heredopathia atactica polyneuritiformis, is a peroxisomal disorder leading to the accumulation of phytanic acid throughout the body. It affects sensory and motor neurons and the skeletal system. Peripheral neuropathy, ataxia, blindness, deafness, and skeletal hyperostosis are significant findings used in the diagnosis of the disease.

Aged↗
PubMed1997

Pretreatment TNM staging of childhood rhabdomyosarcoma: a report of the Intergroup Rhabdomyosarcoma Study Group. Children's Cancer Study Group. Pediatric Oncology Group.

BACKGROUND: The Intergroup Rhabdomyosarcoma Study Group (IRSG) studies began in 1972 and initially used a clinicopathologic system to place patients into prognostic groups. Because of interest in the development of a pretreatment staging system for assessing the posttreatment outcomes of patients with this disease, potential staging elements were retrospectively evaluated in a subset of 505 patients who participated in IRS-II, an IRSG clinical trial. METHODS: Using the IRS-II data, a TNM pretreatment staging system was developed and used to stage prospectively the patients who were entering IRS-III, a subsequent treatment protocol of the IRSG. Failure free survival and overall survival were compared by pretreatment stage in IRS-III as a means of evaluating this TNM staging. RESULTS: The TNM staging system described the tumor (T) in terms of lesion size (< 5 cm or > or = 5 cm) instead of invasiveness, because these two features were not independent of each other. The clinical status of regional lymph nodes (N) was included in the staging system, as was the presence or absence of metastatic disease (M). The latter feature was extremely important, as expected. The anatomic site of the primary tumor also proved to be an important staging element. Classification of patients by tumor size, clinical status of regional lymph nodes, presence or absence of metastatic disease, and location of the primary tumor (at a favorable or unfavorable anatomic site) created four prognostically distinct staging categories that were relatively equal in size. In a prospective evaluation of this staging system with IRS-III patients, the pretreatment staging lost some prognostic impact. The survival of patients with smaller lesions at unfavorable anatomic sites without clinically involved lymph nodes (Stage II) was similar to that of patients with primary tumors at favorable anatomic sites (Stage I). CONCLUSIONS: A pretreatment TNM staging system for childhood rhabdomyosarcoma, developed with data from IRS-II, was not as predictive of patient outcome when applied prospectively to patients treated in the IRS-III trial. These findings could be due to differences in the management strategy used for IRS-III or the statistical variability in the model-fitting process used to develop the staging system. This demonstrates the need for continual reevaluation of staging systems as patient evaluation and treatment innovations are developed.

Child↗