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Biomedical subjects

J L Walker

Publications and source records attributed to J L Walker.

At least 37 records · Page 2Linked to original sources
PubMed1999

Cost analysis of laparoscopy versus laparotomy for early endometrial cancer.

OBJECTIVE: The purpose of this study was to determine whether the cost associated with treatment of early stage endometrial cancer differs on the basis of the surgical approach. METHODS: A retrospective analysis was performed on a series of women with presumed early stage endometrial cancer treated between 5/96 and 1/99 at a single institution. The patients were grouped according to the surgical approach utilized. The first group consisted of 19 patients who underwent laparoscopic assisted vaginal hysterectomy, bilateral salpingo-oophorectomy, and laparoscopic pelvic and paraaortic lymph node dissection. The second group consisted of 17 patients who underwent a total abdominal hysterectomy, bilateral salpingo-oophorectomy, and pelvic and paraaortic lymph node dissection. The two groups were compared with a two-tailed Student t test. Variables analyzed included age, Quetelet index (QI), surgical stage, number of lymph nodes, surgical time, estimated blood loss, postoperative complications, number of days in the hospital, and costs. The cost analysis was divided into room and board, pharmacy, ancillary services, operating room equipment, operating room services, and anesthesia. RESULTS: Both groups were similar in age, QI, and distribution of stage. The laparoscopic group required more OR time (237 vs 157 min, P < 0.001); however, the number of lymph nodes, estimated blood loss, and postoperative complications were not significantly different between the groups. The laparoscopic group required significantly shorter hospitalization than the laparotomy group (3.7 vs 5.2 days, P < 0.001) resulting in less room and board ($299 vs $454, P < 0.001) as well as pharmacy costs ($443 vs $625, P < 0.02). The cost of anesthesia was higher in the laparoscopic group ($696 vs $444, P < 0.001) but the costs of OR equipment, OR services, and total costs were not statistically different between the groups. CONCLUSION: Laparoscopic surgical management of early stage endometrial cancer is feasible with minimal morbidity. The cost savings of early hospital discharge is offset by longer surgical time and higher anesthetic costs. The total costs for each surgical approach are not statistically different. The presumed advantages of less pain, early resumption of normal activities, and overall improvement of quality of life await further investigation.

Aged↗
PubMed1999

The energy cost of horizontal walking and running in adolescents.

PURPOSE: This study developed and cross-validated generalized equations for predicting VO2 (mL x kg(-1) x min(-1)) and caloric expenditure (kcal x kg(-1) x min(-1)) during horizontal walking and running in adolescents. METHODS: Subjects were 47 male and 35 female adolescent volunteers, ages 12-18. Each subject underwent a submaximal treadmill exercise test to determine VO2 at randomly selected walking and jogging speeds (67-215 m x min(-1)). Caloric expenditure was estimated from VO2 and RER. Multiple regression was used to develop prediction equations for estimating VO2 and caloric expenditure from a derivation sample of 77 random observations, both walking and running. RESULTS: The group relationship between running speed and energy cost in the derivation sample was linear, whereas the relationship between walking speed and energy cost was quadratic. Gender, age, and height each failed to account for significant additional variation in energy cost after speed and mode were considered. Skinfolds accounted for a small yet significant amount of additional variation in energy cost. The derived equations were cross-validated on a sample of 76 separate random observations. The cross-validation statistics are: for VO2, R = 0.95, error = 3.58 mL x kg(-1) x min(-1), and for caloric expenditure, R = 0.94, error = 0.019 kcal x kg(-1) x min(-1). Most selected adult equations consistently underestimated both VO2 and caloric expenditure in the cross-validation sample. CONCLUSIONS: These results suggest that in adolescents, within the range of speeds tested, the relationship between speed of movement and energy cost for running is linear, but for walking is curvilinear. Also, adult models for estimating VO2 or caloric expenditure do not account for the higher relative energy cost of walking and running in adolescents.

Adolescent↗
PubMed1998

Low-grade endometrial stromal sarcoma preoperative treatment with Depo-Lupron and Megace.

A 46-year-old women presented with an inoperable low-grade endometrial stromal sarcoma. Two doses of Depo-Lupron, 7.5 mg, and Megace, 160 mg/day, were given to control uterine bleeding and shrink the tumor mass. In 9 weeks, significant reduction in the tumor occurred allowing for surgical resection. Total abdominal hysterectomy with bilateral salpingo-oophorectomy is the mainstay for primary treatment. The role of chemotherapy, radiation therapy, and hormonal therapy is poorly defined. This is a case report of neoadjuvant hormonal therapy which may improve outcomes in patients with endometrial stromal sarcomas. Additional research is needed to define the exact role of these agents.

Antineoplastic Agents, Hormonal↗
PubMed1998

Laparoscopic paraaortic lymphadenectomy using laparosonic coagulating shears.

With marked innovations in endosurgical instrumentation, operative laparoscopy to include lymphadenectomy has become feasible and has a valuable role in the management of gynecologic malignancy. We used laparosonic coagulating shears (LCS) for laparoscopic paraaortic lymphadenectomy in two women with cervical carcinoma. Operating times for the laparoscopic portion were 55 and 65 minutes and blood loss was 20 and 30 ml, respectively. No surgical complications were encountered. Lymphatic tissues were evaluated histologically and no thermal artifacts were identified. The major advantage of the ultrasonically activated scalpel of the LCS is the ability to cut and coagulate tissues simultaneously without electrical current. The LCS may afford the surgeon a greater margin of safety than unipolar electrocoagulation scissors by eliminating potential thermal and electrical injury to vital structures. Ultrasonic-activated technology deserves extended clinical investigation in laparoscopic lymphadenectomy to substantiate our preliminary findings, as well as to explore its potential in gynecologic oncology.

Adult↗
PubMed1998

A novel mutation affecting the interdomain link region of the growth hormone receptor in a Vietnamese girl, and response to long-term treatment with recombinant human insulin-like growth factor-I and luteinizing hormone-releasing hormone analogue.

A Vietnamese girl with Laron syndrome has been treated with recombinant human insulin-like growth factor-I for 4 yr from age 11.28 yr. Her height SD score increased from -6.3 to -4.7 without acceleration of bone age. Isolated breast development progressed despite pubertal suppression with luteinizing hormone-releasing hormone analogue, which was stopped after 3 yr because of growth deceleration. Facial coarsening was documented with serial photographs. Sequencing and in vitro analysis identified a homozygous base pair substitution in exon 6 of the proband's GH receptor (GHR), which changed amino acid 131 from proline to glutamine (P131Q) and disrupted GH binding. Both the P131Q-mutated human GHR and wildtype (wt) hGHR were transiently expressed in COS-1 cells, as demonstrated by Western blotting, but the P131Q-transfected cells did not bind 125I-hGH. Similarly, FDC-P1 cells transfected with wthGHR bound 125I-hGH with high affinity and proliferated in response to GH, whereas the P131Q hGHR cells did neither. In CHO-K1 cells cotransfected with wthGHR and the Egr-1 promotor linked to a luciferase reporter gene, GH evoked a 2.14 +/- 0.21-fold increase in luciferase activity, but there was no response in the cells carrying the P131Q hGHR mutation. From examination of the crystal structure of the GHR, we suggest that the P131Q mutation disrupts the interdomain link between the extracellular domains of the GHR, causing a conformational change that results in disruption of the GH binding site.

Animals↗
PubMed1997

Epidermal growth factor receptor in vulvar malignancies and its relationship to metastasis and patient survival.

OBJECTIVE: To evaluate the level of epidermal growth factor receptor (EGF-R) expression in vulvar malignancies and to determine if a correlation exists between EGF-R levels and metastasis or patient survival. METHODS: All patients with a diagnosis of invasive squamous cell carcinoma of the vulva who were treated at our institution with a primary radical vulvectomy and inguinal lymph node dissection from 1983 to 1993 were eligible for the study. Sixty-one patients with available tissue blocks of benign vulvar epithelium, the primary malignant vulvar lesion, and groin node metastasis (when positive) were included in the study. Semiquantitative EGF-R expression was determined in a blinded fashion utilizing immunohistochemical staining of appropriate tissue samples. Survival was calculated utilizing Kaplan-Meier life table analysis based upon disease-free survival. RESULTS: A significant increase (P < 0.001) in mean EGF-R levels was demonstrated in the primary tumor (67%) versus benign vulvar epithelium (31%). In the 14 patients with lymph node metastasis, the mean EGF-R level in the primary tumor was 65% versus 88% in the metastatic lesion (P < 0.001). The likelihood of lymph node metastasis was elevated in those patients with a benign tissue EGF-R level > or =40% (P < 0.03) and in those patients with a primary tumor EGF-R level > or =90% (P < 0.025). Life table analysis revealed a cumulative disease-free survival of 45% for all patients. Disease-free survival in those patients with EGF-R levels > or =90% in the primary tumor was 25%, contrasting with a disease-free survival of 54% in those patients with EGF-R levels <90% (P < 0.05). CONCLUSIONS: There is a progressive increase in EGF-R expression from benign vulvar epithelium to primary malignant tissue to metastatic lesions within the same patient. Increased expression of EGF-R in the primary vulvar malignancy is significantly associated with lymph node metastasis and decreased patient survival. Increased expression of EGF-R in histologically benign vulvar epithelium has a significant association with lymph node metastasis and may predict decreased patient survival.

Carcinoma, Squamous Cell↗
PubMed1997

Ovarian vein vs peripheral blood CA125 serum levels: a comparative study.

OBJECTIVE: Direct sampling from the ovarian vessels may be considered as a supplementary method of ovarian cancer diagnosis providing further clinical information for the staging and localization of ovarian carcinoma. This present multi-institutional study evaluates and compares the clinical values of CA125 serum levels sampled directly from the right and left ovarian veins to the peripheral blood supply in an effort to correlate CA125 values to tumor volume and location. METHODS: Serum samples from 43 patients with primary ovarian carcinoma were evaluated for the presence of CA125. All patients underwent surgery for the primary tumor, and stage was defined according to the classification of the International Federation of Gynecology and Obstetrics. The measurement of CA125 was accomplished by radioimmunoassay. RESULTS: Twenty of 20 patients with serous papillary adenocarcinoma, 8/12 patients with tumors of low malignant potential, 6/6 patients with endometrioid carcinoma, 2/4 patients with clear cell adenocarcinoma, and 1/1 patients with mucinous adenocarcinoma had elevated (>35 U/mL) peripheral CA125 levels. Peripheral blood CA125 values had Spearman correlation coefficients of 0.96 and 0.95 with left and right ovarian vein CA125 values, respectively. Similarly, left and right ovarian vein CA125 values had a correlation coefficient of 0.98. CA125 values were moderately correlated with tumor volume in this sample. Spearman correlation coefficients between left ovarian vein CA125 values and left and right tumor volume were 0.51 and 0.43, respectively. Spearman correlation coefficients between right ovarian vein CA125 levels and left and right tumor volume were 0.41 and 0.46, respectively. Those between peripheral CA125 values and left and right tumor volume were 0.56 and 0.36, respectively. Median CA125 values for stage I diseases were elevated (53.25, 101.5, and 74.50 for left, right, and peripheral, respectively). DISCUSSION: Direct sampling from the ovarian veins compared to that from the peripheral veins did not appear to offer additional information regarding ovarian tumor volume and location.

Adult↗
PubMed1997

P-glycoprotein as a prognostic indicator in pre- and postchemotherapy ovarian adenocarcinoma.

P-glycoprotein (P-gp) is a plasma membrane efflux transporter that maintains the intracellular concentration of chemotherapeutic agents at low levels. Since the clinical outcome of ovarian adenocarcinoma depends largely on its response to chemotherapy, an objective assessment of P-gp expression could serve as a prognostic indicator. Eighty-five patients were studied. Available tissue sections from the primary tumor (n = 75) and persistent or recurrent lesions (n = 19) were tested with anti-P-gp (JSB-1) monoclonal IgG. Multivariate survival analysis using Cox regression was performed controlling for fixed covariates (age, surgical stage, and presence of residual tumor) and included occurrence of postchemotherapy tumors and P-gp positivity in postchemotherapy neoplasms as time-dependent variables. P-gp was expressed in 49 prechemotherapy (65.3%) and 14 postchemotherapy (73.7%) tumors. After controlling for potentially confounding factors, patients with P-gp-positive postchemotherapy neoplasms were at three times greater risk of dying within 2 years than their counterparts with P-gp-negative tumors (hazard ratio = 3.1: 95% confidence interval = 1.2, 9.1; p < 0.05). Detection of P-gp-expressive subclones can serve as an independent poor prognostic indicator for patients with postchemotherapy tumors.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

The progression of untreated lumbar kyphosis and the compensatory thoracic lordosis in myelomeningocele.

Radiographs of 37 patients with untreated lumbar kyphosis without congenital vertebral anomalies associated with myelomeningocele were analyzed. With an average interval between radiographs of 6.2 years, the kyphosis was noted to increase at a mean rate of 4.3 degrees per year without correlation to its initial magnitude. The compensatory lordosis was more variable and progressed at a mean of 2.5 degrees per year. Children under the age of 2 years were more likely to increase the Cobb angle and the height of their kyphosis. There was an inverse relationship between the height of the kyphus and the lumbar spine height and the resultant growth of each. A modified kyphotic index less than 4 correlated with an increase in the curve and height of the kyphosis and the subsequent desire for surgery. Wide variability in radiographic parameters make predictions for an individual patient difficult.

Adaptation, Physiological↗
PubMed1997

Immunohistochemical assessment of proliferation markers and altered gene expression in archival specimens of ovarian epithelial tumors.

Recently reported morphologic and molecular genetic evidence suggests that some ovarian carcinomas arise from their benign and low malignant potential (LMP) counterparts. In order to help reach a better understanding of ovarian tumorigenesis, we studied a wide range of gene products involved in cellular growth regulation in archival material obtained from three groups of tumors with graduated malignant potential. Immunohistochemical staining was performed for Ki-67, proliferating cell nuclear antigen (PCNA), epidermal growth factor receptor (EGFR), HER-2/neu-encoded receptor protein, p53 gene product, and multidrug resistance gene product (P-glycoprotein). The expression of EGFR, HER-2/neu-encoded receptor protein, and mutant p53 product was significantly lower in LMP tumors than in carcinomas (p < 0.05). HER-2/neu immunopositivity was more prevalent in adenocarcinomas than in LMP tumors, and the proportion of HER-2/neu-positive adenocarcinomas increased with the progression of the disease. The staining differences between LMP tumors and adenocarcinomas with antibodies against Ki-67, PCNA, and P-glycoprotein were not statistically significant. Immunohistochemical detection of EGFR, HER-2/neu, and p53 in ovarian epithelial tumor is relevant to ovarian tumorigenesis. It could serve as a powerful tool for the pursuit of retrospective studies focused on these important biologic markers.

Adenocarcinoma↗
PubMed1996

Hepatic venoocclusive disease as a complication of whole abdominopelvic irradiation and treatment with the transjuglar intrahepatic portosystemic shunt: case report and literature review.

We report the novel use of the transjugular intrahepatic portosystemic shunt (TIPS) procedure for the treatment of intractable ascites due to hepatic venooclusive disease as a result of whole abdominopelvic radiotherapy. A patient with Stage III endometrioid carcinoma of the endometrium treated with postoperative whole abdominopelvic irradiation developed intractable ascites. Multiple paracenteses and computerized tomography were negative for recurrent carcinoma. Liver biopsy demonstrated hepatic venoocclusive disease, a rare complication of therapeutic radiation involving the liver. Successful relief of ascites and its adverse symptomology were achieved with the transjugular intrahepatic portosystemic shunt. Relevant literature regarding the pathogenesis, prognosis, and treatment of radiotherapy-related hepatic venoocclusive disease are reviewed.

Abdomen↗
PubMed1995

Acute treatment with pulsed electromagnetic fields and its effect on fast axonal transport in normal and regenerating nerve.

The mechanism whereby low-frequency electromagnetic fields accelerate axonal regrowth and regeneration of peripheral nerve after crush lesion is not known. One candidate is an alteration in axonal transport. In this study we exposed unoperated rats for 15 min/day, and rats that had undergone a crush lesion of the sciatic nerve, for 1 hr/day for 2 days, to 2-Hz pulsed electromagnetic fields. To label fast transported proteins, [3H]-proline was microinjected into the spinal cord, and the sciatic nerves were removed 2, 3.5, and 5 hr later. The rates of fast axonal transport were obtained for animals in all groups by counting sequential 2-mm segments of nerves. The following transport rates were found: in unoperated normal sciatic nerve not exposed to PEMF, 373 +/- 14 mm/day; in unoperated normal nerve exposed to PEMF, 383 +/- 14 mm/day; in sham crush nerves not exposed to PEMF, 379 +/- 19 mm/day; in sham crush nerve exposed to PEMF, 385 +/- 17 mm/day; in crushed nerves not exposed to PEMF, 393 +/- 16 mm/day. and in crushed nerves exposed to PEMF, 392 +/- 15 mm/day. The results of these experiments indicate that 1) a crush injury to the sciatic nerve does not alter the rate of fast axonal transport, and 2) low-frequency pulsed electromagnetic fields do not alter fast axonal transport rates in operated (crush) or unoperated sciatic nerves.

Animals↗
PubMed1995

Use of ileocecal continent urinary reservoir in patients with previous pelvic irradiation.

OBJECTIVE: To assess the results of the use of ileocecal continent urinary reservoirs in patients with previous pelvic irradiation. METHODS: A retrospective analysis for morbidity and clinical outcome was undertaken for 37 female patients with prior therapeutic pelvic irradiation who underwent continent urinary diversion with a detubularized right colonic segment as the urinary reservoir, a plicated ileocecal valve as the continence mechanism, and a tapered distal ileum for efferent catheterization. RESULTS: Thirty-one patients had persistent or recurrent pelvic malignancies, 17 of whom had total pelvic exenteration and 14 had anterior exenteration. The remaining 6 patients had radiation-induced vesicovaginal fistulas without evidence of recurrence and underwent urinary diversion alone. Follow-up ranged from 2 to 33 months (median 11 months). Postoperative radiographic evaluation revealed no evidence of urinary extravasation. Of the 74 implanted ureters, 4 had reflux (5%), 2 developed stricture (3%), and 5 had mild to moderate hydronephrosis (7%). All patients achieved daytime continence with catheterization intervals of 3-8 hr (median 4 hr) and capacities of 200-1000 cc (median 500 cc). Nighttime continence was reported by 33 of 37 patients (89%). Reoperation was required in 3 patients (8%), 2 with stoma stenosis and 1 with difficulty in catheterization. CONCLUSIONS: The use of the ileocecal continent urinary reservoir in patients with previous pelvic irradiation achieves results comparable to those reported for nonirradiated patients, thus supporting its use in this select group of patients.

Female↗
PubMed1995

Acute hepatitis C infection after sexual exposure.

A case is described of a woman with acute hepatitis C infection whose partner had chronic hepatitis C infection and where heterosexual contact was the only major risk factor. Infection of both partners was confirmed serologically and by the finding of virus RNA by reverse transcription and polymerase chain reaction amplification. Nucleotide sequence analysis of the NS5 region (RNA polymerase) was used to show that both partners were infected with virus of the same genotype (1a). The nucleotide sequence of virus RNA found in the female patient is closest to variants cocirculating in the male contact, consistent with transmission having occurred between the two.

Acute Disease↗
PubMed1995

Incidence and location of para-aortic lymph node metastases in gynecologic malignancies.

BACKGROUND: We sought to determine the location of metastases to para-aortic lymph nodes in patients with gynecologic malignancies. STUDY DESIGN: A retrospective chart review was performed for all cases of endometrial, ovarian, and cervical carcinoma in which right and left para-aortic lymph node dissection was done at our institution from 1985 to 1993. Records were assessed for tumor type as well as for presence and location of metastases to para-aortic lymph nodes. RESULTS: A total of 315 patients had bilateral para-aortic lymphadenectomy performed at the time of laparotomy as part of staging or therapy for their gynecologic malignancies. A total of 47 patients (15 percent) had metastasis to the para-aortic lymph nodes. Para-aortic metastasis were identified in 22 (30 percent) of 73 patients with ovarian carcinoma, 11 (8 percent) of 141 patients with cervical carcinoma, and 14 (14 percent) of 101 patients sampled. Unilateral left-sided para-aortic node involvement was observed in 13 patients, unilateral right-sided involvement was present in 14 patients, and bilateral involvement occurred in 20 patients. Regarding tumor type or origin, no significant difference was noted in right-sided compared with left-sided para-aortic metastases. CONCLUSIONS: Our data suggest no difference in the incidence of metastases to right-sided compared with left para-aortic lymph nodes in patients with gynecologic malignancies, emphasizing the need for bilateral evaluation of the para-aortic lymph nodes. This information is important in the clinical staging of gynecologic malignancies and in establishing protocols requiring para-aortic lymph node dissection.

Abdomen↗
PubMed1994

Spinal deformity in Charcot-Marie-Tooth disease.

STUDY DESIGN: This retrospective study reviewed 100 children with clinically and electrodiagnostically proven Charcot-Marie-Tooth disease (CMTD). OBJECTIVE: To determine the incidence of spinal deformity in children with CMTD. SUMMARY OF BACKGROUND DATA: A 10% incidence of kyphoscoliosis has been reported. METHODS: All charts and electrodiagnostic studies were reviewed to confirm that CMTD diagnostic criteria were met. Existing radiographs on 89 children were available. Cobb angles were measured and deformity was defined as scoliosis > or = 10 degrees and kyphosis > 40 degrees. RESULTS: Thirty-seven of 89 CMTD children had spinal deformity. There was scoliosis in 20, kyphoscoliosis in 14, and kyphosis in 3. In children with radiographs taken at maturity, 50% had deformity. The most common scoliotic pattern was a thoracic curve with convexity in either direction. Spinal deformity is more likely in female and Type I patients. CONCLUSIONS: This study found an incidence of 37%-50% spinal deformity in children with CMTD, with female and Type I patients at greatest risk. However, the deformity rarely required treatment.

Adolescent↗
PubMed1994

Spinal deformity after multiple-level cervical laminectomy in children.

Considerable controversy exists in the orthopedic and neurosurgical literature over the true incidence and nature of spinal deformity after multiple-level cervical laminectomy in children. Eighty-nine patients with a mean radiographic follow up of 5.1 years (range 2-9 years) were reviewed. Mean age at surgery was 5.7 years (range 1 month-18 years). Most common diagnoses were Arnold-Chiari malformation, syringomyelia, or both (81%). Significant deformity developed in 46 patients (53%), with 33 developing a mean kyphosis of 30 degrees (range 5-105 degrees) and 13 developing a mean hyperlordosis of 62 degrees (range 40-95 degrees). Peak age at surgery of 10.5 years correlated weakly (P = 0.08) with the development of kyphosis. The development of hyperlordosis was strongly correlated (P = 0.01) with a peak age at surgery of 4.2 years. There was no correlation between diagnosis, sex, location, or number of levels decompressed and the subsequent development of deformity.

Adolescent↗