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J R Carter

Publications and source records attributed to J R Carter.

At least 37 records · Page 2Linked to original sources
PubMed1995

A novel strategy using G-CSF to support EMA/CO for high-risk gestational trophoblastic disease.

EMA/CO (etoposide-methotrexate-actinomycin D and Cytoxan-Oncovin) is an effective and well-tolerated chemotherapy regimen for the treatment of high-risk gestational trophoblastic disease. However, it is associated with significant neutropenia often requiring dose reductions and treatment delays. We describe the use of granulocyte colony-stimulating factor (G-CSF) in three patients in order to maintain the treatment schedule. A subcutaneous injection of 5 micrograms/kg/day was administered on Days 3-6 and 9-14 of each chemotherapy cycle. No patients had any adverse effects and all received full chemotherapy doses without any treatment delay. The addition of G-CSF to the EMA/CO regimen may benefit patients by achieving dose intensity in the treatment of high-risk gestational trophoblastic disease.

Adult↗
PubMed1995

The utility of preoperative screening colonoscopy in gynecologic oncology.

The American Cancer Society (ACS) recommends that asymptomatic women, age 50 and over, undergo sigmoidoscopy every 3 to 5 years, after two negative yearly exams. Epidemiologic evidence suggests that women with gynecologic or breast cancers have an increased risk of developing colon cancer. It is unclear whether the ACS guidelines are applicable for women with a new diagnosis of gynecologic malignancy. This retrospective study was undertaken to assess the usefulness of preoperative colonoscopy in our gynecologic oncology patient population. Patients undergoing evaluation for a major operative procedure for known or suspected gynecologic malignancies were referred for colonoscopy at the discretion of their attending surgeon. Five hundred patients' charts were reviewed to identify 212 patients in whom preoperative colonoscopy was performed (the study group). In this group, 17 cases of colonic polyps, 5 cases of synchronous colon cancer, and 2 cases of cancer metastatic to the colon were discovered, representing 11% of the study group. Whereas 23% of the patients screened were less than 50 years of age, only two cases of polyps occurred in this age group, and no cases of cancer. Patients aged 70 or greater made up 28% of the study group, but accounted for 41% of the cases of polyps and 40% of the colon cancers. Twenty-nine percent of the study group had adenocarcinoma of the endometrium, representing 7 of 17 cases of polyps, 1 of 5 colon cancers, and 1 of 2 metastatic cancers. Although this retrospective study involved colonoscopy, the locations of the observed lesions were within the theoretic reach of a flexible sigmoidoscope in 75% of cases. We conclude that in the preoperative workup of gynecologic oncology patients, no colon screening is needed in the asymptomatic patient less than 50 years of age. ACS guidelines are appropriate for patients aged 50-70, but for those 70 or greater we would consider full colonoscopy.

Age Factors↗
PubMed1995

Management of pelvic venous stenosis with intravascular stainless steel stents.

Patients with gynecologic malignancies may develop stenosis of the large pelvic veins as a result of their disease or its treatment. The percutaneous insertion of a stainless steel vascular stent is a novel approach to the management of an extrinsically compressed vein. The objective of this study was to review the results of treating lower extremity edema secondary to a pelvic venous stenosis through the percutaneous insertion of a stainless steel vascular stent. A retrospective review was performed on gynecologic oncology patients who presented with an edematous lower extremity and underwent an evaluation to diagnose proximal venous stenosis. The evaluation included sonography, venography, and balloon angioplasty prior to the percutaneous insertion of a stainless steel vascular stent. If a venous thrombosis was documented, thrombolysis with urokinase was performed prior to evaluation for venous stenosis. Records were reviewed for the etiology of the venous stenosis, the location and type of stent inserted, and the ability of the stent to maintain patency and provide symptomatic relief. Patency was evaluated at 1-week and then at 1-, 3-, and 6-month intervals. The probability of vascular stent patency was calculated using life table analysis. Ten patients with cervical (n = 4), corpus (n = 3), ovarian (n = 1), vulvar (n = 1), and vaginal (n = 1) cancer had one or more vascular stents inserted for the treatment of a stenosed pelvic vein. The etiologies of venous stenosis were radiation fibrosis and surgery (n = 5), postoperative fibrosis (n = 3), and metastatic tumor (n = 2). The stented vessels were the left common (n = 5) or left external (n = 4) iliac veins, the right common (n = 1) or right external (n = 3) iliac veins, and the right common femoral vein (n = 1). The median follow-up was 21 months. All patients had subjective resolution of their edematous extremity while the stents were patent. The interval probability of patency of stented veins was greater than 85% at each evaluation interval. Patency was 100% for patients beyond 6 months of follow-up. There were no major complications. The percutaneous intravascular insertion of a stainless steel stent was safe and subjectively effective in the management of venous stenosis associated with a gynecologic cancer. A prospective trial with objective endpoints may be warranted.

Adult↗
PubMed1995

Recurrent squamous cell carcinoma in a rectus abdominis neovagina.

The development of a carcinoma in a neovagina is rare. Most neovaginal neoplasias have been carcinomas in situ in the skin graft. To date, there has not been a report of a neovaginal carcinoma in a myocutaneous flap. This report is the first of a squamous cell carcinoma arising in a neovagina constructed from a rectus abdominis myocutaneous flap.

Carcinoma, Squamous Cell↗
PubMed1995

Nonsurgical management strategies for the functional complications of ileocolonic continent urinary reservoirs.

Urinary diversion with creation of a continent ileocolonic reservoir was performed in 25 patients with gynecological malignancies at our institution between September 1989 and September 1994. A retrospective review was conducted and cases were analyzed for functional complications associated with reservoir formation. Functional reservoir complications were defined as (1) difficulty with catheterization, (2) reservoir fistulae, (3) reservoir stones, and (4) ureteral stenosis. Management strategies and outcomes for these complications were determined. All patients had received prior pelvic radiation therapy. There was no surgical mortality. Median follow-up was 21 months, and 16 patients (64%) are currently alive. Fourteen of the patients (56%) had one or more complications attributable to a functional aspect of the continent reservoir. Two patients had difficulty with catheterization (8%), two patients had reservoir leak (8%), and one patient had reservoir stones (4%). Nonsurgical management strategies were used in these cases including balloon dilation of the ileocecal valve, stomal dilation, ureteral stenting, percutaneous nephrostomy, and endoscopic lithotripsy. All cases of catheterization problems, reservoir fistulae, and reservoir stones were resolved with nonoperative techniques. Thirteen of 50 ureters (26%) had some degree of stenosis. Percutaneous balloon dilation was utilized in nine cases of ureteral stenosis. Relief of stenosis was complete in five, partial in two, and not achieved in two of the cases. No patients required a reoperation for a reservoir complication. In conclusion, continent ileocolonic urinary diversion can be performed in patients previously treated with radiotherapy; however, functional reservoir problems may occur. Interventional radiology strategies are useful in managing many of these problems and reexploration can be successfully avoided.

Adult↗
PubMed1995

Evaluation of the medical diagnostic imaging support system based on 2 years of clinical experience.

The Medical Diagnostic Imaging Support (MDIS) system at Madigan Army Medical Center (MAMC) has been operational in a phased approach since March 1992. Since then, nearly all image acquisition has been digital with progressively increasing primary softcopy diagnosis used. More than 375,000 computed radiography (CR) images as well as other modality images have been archived. Considerable experience in installation and implementation phasing has been gained. The location and ergonomic aspects of equipment placement were refined with time. The original clinical scenario was insufficiently detailed and additions were made to facilitate smoother and more complete transition toward a filmless environment. The MDIS system effectiveness and performance have been good in terms of operational workload throughout, background operations, and reliability. The important areas regarding reliability are image acquisition, output, display, database operations, storage, and the local area network. Fail-safe strategies have been continually improved to maintain continuous clinical image availability during the times when the MDIS system or components malfunction. Many invaluable lessons have been learned for effective quality assurance in a hospital-wide picture archiving and communication system. These issues include training, operational quality control, practical aspects of CR image quality, and increased timeliness in the generation and distribution of radiographic reports. Clinical acceptability has been a continuous process as each phase has been implemented. Clinical physicians quickly used the workstations soon after the start of MDIS at MAMC. The major advantage for clinicians has been the amount of time saved when retrieving multimodality images for review. On the other hand, the radiologists have been slower in their acceptance of the workstation for routine use.(ABSTRACT TRUNCATED AT 250 WORDS)

Computers↗
PubMed1995

Blood flow characteristics of ovarian tumors: implications for ovarian cancer screening.

OBJECTIVES: Our purpose was to investigate the blood flow characteristics of benign and malignant ovarian tumors. Questions posed by our research were as follows: (1) Can malignant ovarian tumors be predicted by color flow Doppler imaging? (2) What are the sensitivity, specificity, and positive and negative predictive values of such prediction? (3) Which color flow Doppler parameter is superior in its accuracy of prediction? STUDY DESIGN: One hundred twenty-three consecutive patients seen for suspected pelvic masses were evaluated by transvaginal ultrasonography and color flow Doppler imaging. A morphologic assessment was initially performed, followed by color flow Doppler analysis. A comparison of findings between the benign and malignant tumors was made by analyzing different thresholds of the intratumoral pulsatility and resistance index values by means of receiver-operator characteristic curves. By calculation of the area index under each receiver-operator characteristic curve the efficiency of the pulsatility and resistance index values in predicting malignancy was determined. RESULTS: Fifty-six benign and 23 malignant tumors were pathologically confirmed. Patients with malignant tumors were more likely to be postmenopausal and were older than patients with benign tumors. Malignant tumors were more likely to be larger and to have either a complex or solid pattern. Absent color flow was more common in benign tumors, and increased color flow was found equally among benign and malignant tumors. There was no difference in systolic, diastolic, or mean velocities between benign and malignant tumors. The calculated pulsatility and resistance index values were lower in patients with malignant tumors compared with those with benign tumors. No significant difference exists in performance of either the pulsatility or resistance index in predicting malignancy. The best thresholds for predicting malignancy were obtained with a pulsatility index of 1.0 and resistance index of 0.6. CONCLUSIONS: Transvaginal ultrasonography is accurate in distinguishing benign from malignant ovarian tumors. Color flow Doppler findings are not specific enough to be used independent of gray-scale ultrasonography.

Female↗
PubMed1995

Tissue characterization of arteries with 4 MHz ultrasound.

Reflections of 4 MHz ultrasound pulses from 60 sites on 15 human aorta specimens were analysed using the plane-wave Born approximation (PWBA) inverse scattering method. The recovered high-resolution acoustic impedance profile for each site was correlated with an analysis (by microscope) of sections taken from that site. The shape of the impedance profile was found to be sensitive to the pathology of the tissue at each site. The severity of the various conditions could be gauged from the recovered impedance profiles. Some of the insonifications were done on aorta specimens that were shielded from the ultrasound transducer by a human tissue specimen about 1.25 cm thick in order to study the effects of intervening tissue. We found that it was possible to compensate for the distortion due to the frequency dependent attenuation of the intervening tissue. We conclude that ultrasound imaging, with the reflections analysed by means of PWBA inverse scattering provides a promising non-invasive tissue characterization modality.

Aorta↗
PubMed1995

Assessment of effect levels of chemicals from quantitative structure-activity relationship (QSAR) models. I. Chronic lowest-observed-adverse-effect level (LOAEL).

With the multitude of new chemicals being synthesized and the paucity of long-term test data on chemicals that could be introduced into the environment, innovative approaches must be developed to determine the health and environmental effects of chemicals. Research was conducted to employ quantitative structure-activity relationship (QSAR) techniques to study the feasibility of developing models to estimate the noncarcinogenic toxicity of chemicals that are not addressed in the literature by relevant studies. A database of lowest-observed-adverse effect level (LOAEL) was assembled by extracting toxicity information from 104 U.S. EPA documents, 124 National Cancer Institute/National Toxicology Program (NCI/NTP) reports, and 6 current reports from the literature. A regression model, based on 234 chemicals of diverse structures and chemical classes including both alicyclic and aromatic compounds, was developed to assess the chronic oral LOAELs in rats. The model was incorporated into an automated computer package. Initial testing of this model indicates it has application to a wide range of chemicals. For about 55% of the compounds in the data set, the estimated LOAELs are within a factor of 2 of the observed LOAELs. For over 93%, they are within a factor of 5. Because of the paucity or absence of long-term toxicity data, the public health and risk assessment community could utilize such QSAR models to determine initial estimates of toxicity for the ever-increasing numbers of chemicals that lack complete pertinent data. However, this and other such models should be used only by expert toxicologists who must objectively look at the estimates thus generated in light of the overall weight of evidence of the available toxicologic information of the subject chemical(s).

Algorithms↗
PubMed1994

Pelvic adhesion formation after pelvic lymphadenectomy: comparison between transperitoneal laparoscopy and extraperitoneal laparotomy in a porcine model.

Compared to extraperitoneal laparotomy, the transperitoneal approach is associated with increased enteric morbidity. Recently, transperitoneal laparoscopy has been employed as a method to surgically stage patients with gynecologic malignancies. The objective of this study was to investigate pelvic adhesion formation in a porcine model after pelvic lymphadenectomy performed via transperitoneal laparoscopy (LS) compared to extraperitoneal laparotomy (EP). Ten adult, female hogs underwent LS and 10 underwent EP. A complete pelvic lymphadenectomy was performed in each animal. Three weeks after the lymphadenectomy, the animals underwent exploratory laparotomy, and the adhesions were quantified. Nineteen animals were evaluable. The adhesion scores for the laparoscopy group (N = 10, mean = 0.075 +/- 0.17) were not statistically different from those of the laparotomy group (N = 9, mean = 0.28 +/- 0.52, P > 0.5). Eight of 10 (80%) and 5 of 9 (56%) animals in the LS and EP groups, respectively, had no adhesions after pelvic lymphadenectomy. Adhesion formation is one of many critical issues concerning the utility of pretreatment surgical staging, especially for cancer of the cervix. It is remarkable that only 20% of the animals undergoing laparoscopy in this study had de novo adhesions after pelvic lymph node dissection and that the mean total adhesion score was not statistically different from the extraperitoneal laparotomy. Therefore, transperitoneal laparoscopic pelvic lymphadenectomy may not induce the degree of adhesion formation associated with the transperitoneal laparotomy technique.

Animals↗
PubMed1994

Chemoprophylaxis with oral ciprofloxacin in ovarian cancer patients receiving taxol.

The purpose of this study was to review the clinical outcomes and cost of administration of a prophylactic antibiotic compared to G-CSF for the prevention of neutropenic morbidity associated with taxol. The study group was composed of 62 patients with ovarian cancer who received a 24-h infusion of a taxol-based regimen at doses less than or equal to 175 mg/m2 between June 1992 and April 1994. The records were retrospectively reviewed and the patients were grouped and analyzed according to the management of their myelosuppression. Group I patients (n = 29) were observed until their absolute neutrophil count (ANC) was less than 500/microliters and then were placed on ciprofloxacin 500 mg orally twice a day until their ANC was 1,000/microliters. Group II patients (n = 15) received G-CSF from Day 2 until the ANC was greater than 10,000/microliters beginning with their first cycle. Group III patients (n = 18) received their taxol regimen without either ciprofloxacin or G-CSF. Two hundred eighty-two taxol-based chemotherapy cycles were administered to these 62 patients. There was no statistically significant difference between the groups concerning disease status as measured by age, stage, performance status, dose intensity, or number of previous regimens. There were two episodes of febrile neutropenia in Group I and three episodes in Group II. Group III had 15 episodes of febrile neutropenia. The estimated cost of the different prophylactic regimens was $5,215.00 for Group I versus $104,000.00 for G-CSF in Group II. Within the three groups, there were 27 patients with an episode of febrile neutropenia (n = 20) or prolonged myelosuppression (n = 7) that were followed for an additional 104 taxol cycles. Twenty-four of these patients received G-CSF prophylaxis with intermittent ciprofloxacin and three received only ciprofloxacin. There were eight more episodes of febrile neutropenia in the patients receiving G-CSF. There were no additional febrile episodes on cycles prophylaxed with ciprofloxacin. There was no septic mortality. For patients receiving a 24 h infusion of taxol at doses less than 175 mg/m2, ciprofloxacin given through the ANC nadir may be effective in preventing febrile morbidity. A prospective randomized trial is underway to evaluate this approach.

Administration, Oral↗
PubMed1994

Gray scale and color flow Doppler characterization of uterine tumors.

The aim of this study was to investigate gray scale and color flow characteristics of a group of patients with a suspected uterine pathologic condition. One hundred and twenty-two consecutive patients at the Women's Cancer Center, University of Minnesota, undergoing transvaginal sonography and color flow Doppler imaging for suspected uterine corpus abnormality made up the study group. After gray scale morphologic assessment, color flow Doppler imaging of the tumor and uterus was performed, including the ipsilateral uterine artery. Malignant tumors were confirmed pathologically in all 35 patients who had them. In comparing patients with benign versus malignant tumors, gray scale morphologic assessment confirmed that malignant uterine tumors (31 endometrial cancers and four sarcomas) were more likely to have a thickened echoic endometrium (P = < 0.0001), be enlarged (P = 0.004), to be retroverted (P = 0.02), and to lack a subendometrial halo (P < 0.0001). Patients with four benign and 13 malignant tumors demonstrated increased flow when assessed by CFD. The calculated sensitivity of increased color flow in predicting malignancy was 39%, with a specificity of 92%, a positive predictive value of 77%, and a negative predictive value of 71%. No difference existed between the benign and malignant groups for the systolic, diastolic, and mean velocities and for the calculated pulsatility index and resistive index in both sampled uterine and intramyometrial or tumor vessels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Isolation, sequencing and overexpression of the gene encoding the theta subunit of DNA polymerase III holoenzyme.

The gene encoding the theta subunit of DNA polymerase III holoenzyme, designated holE, was isolated using a strategy in which peptide sequence was used to derive a DNA hybridization probe. Sequencing of the gene, which maps to 41.43 centisomes of the chromosome, revealed a 76-codon open reading frame predicted to produce a protein of 8,846 Da. When placed in a tac promoter expression vector, the open reading frame directed expression of a protein, that comigrated with authentic theta subunit from purified holoenzyme, to 6% of total soluble protein.

Amino Acid Sequence↗
PubMed1993

Experimental microsurgical vein grafts: quantitative temporal analysis of progressive media fibroplasia.

The sequential histopathologic changes in microvenous grafts placed in a microarterial system were studied. In 48 Sprague Dawley rats, a 1 cm segment of epigastric vein was interposed into a defect created in the femoral artery. Grafts were explored at 1, 2, 4, and 12 weeks. After an initial smooth muscle hyperplasia, a progressive fibroplasia of the media was observed. Only small focal areas of intimal hyperplasia were seen. The width of the media was measured with an eyepiece micrometer. A statistically significant (P < 0.01) increase in width from 17 microns at 1 week to 462 microns at 12 weeks was noted. Although this process has been described before, this is the first quantitative assessment.

Anastomosis, Surgical↗
PubMed1993

Lymph node yield from laparoscopic lymphadenectomy in cervical cancer: a comparative study.

Pretreatment surgical staging in cervical cancer has been studied extensively but remains controversial because a surgical procedure is required and the information gained may benefit only a small portion of the patients staged. Pelvic and paraaortic laparoscopic lymphadenectomies have been successfully performed in animal models and humans. Little information regarding the validity of the procedure in patients who have had subsequent laparotomy exists. In this series, we report our preliminary experience in 12 patients who underwent laparoscopic lymphadenectomy and then laparotomy. Overall, 377 pelvic nodes were removed, with 282 (75%) obtained at laparoscopy. The average number of pelvic nodes removed at laparoscopy was 23.5 (range 7-33). Two patients had positive pelvic nodes. No patient with negative nodes at laparoscopy had positive nodes at laparotomy. When studied in chronological order, the lymph node yield from our second 6 patients was much improved over our first 6 patients, 85% versus 63% (P < 0.005). Laparoscopy also proved to be a better predictor of lymph node spread than computed tomography. Two patients also had right-sided paraaortic lymphadenectomies, yielding 8 and 5 nodes. No additional right-sided paraaortic nodes were detected at laparotomy for either patient. In this preliminary series, laparoscopic lymphadenectomy appears to be a feasible procedure for surgical staging of cervical cancer. The yield of pelvic lymph nodes is adequate and improved with experience. Most importantly, no positive lymph nodes were missed by laparoscopy. The indications for operative laparoscopy have expanded rapidly. Gynecologic oncologists performing this procedure should be involved in prospective studies of this technique to set the standards and indications of this new technology.

Adult↗
PubMed1993

Rectus abdominis myocutaneous flap for primary vaginal reconstruction.

Reconstructive procedures are being performed with increasing frequency in conjunction with pelvic exenterations and other radical gynecologic surgeries. The most common reconstructive procedures include continent urinary diversion, rectosigmoid anastomosis, and vaginal reconstruction. Historically, the gracilis myocutaneous flap has been the procedure of choice for vaginal reconstruction. However, the gracilis myocutaneous flap has a history of partial to severe necrosis, a propensity to prolapse, and leaves ipsilateral donor scars on the thigh. In contrast, neovaginal reconstruction using a relatively new procedure, the distally based rectus abdominis myocutaneous flaps, has the advantage of using a large, single flap that can be incorporated into the primary incision. This flap is mobilized on a long vascular pedicle, the rectus muscle. In relation to the underlying rectus muscle, the orientation of the cutaneous portion of this flap may be customized to accommodate the pelvic defect or the surgeon's preference. Depending on their primary orientation, they are referred to as either a vertical or transverse rectus abdominis myocutaneous flap. The versatility and reliability of the rectus flap is demonstrated here through the presentation of a small pilot series of seven patients. The technique was used for vaginal reconstruction, primarily in conjunction with pelvic exenteration. The flaps were mobilized from the supraumbilical area and had a flap viability of 100% for the 2 years that they have been followed. There were no postoperative incisional or flap infections. There was one infraumbilical fascial dehiscence. The advantages of primary pelvic reconstruction along with the description of the operative techniques are presented.

Adult↗
PubMed1993

Identification, molecular cloning and characterization of the gene encoding the chi subunit of DNA polymerase III holoenzyme of Escherichia coli.

We have identified a previously reported open reading frame (ORF13) that maps between pepA and valS at 96.6 centisomes of the Escherichia coli genome as the structural gene for the chi subunit of DNA polymerase III holoenzyme. This conclusion is supported by a perfect match of the amino-terminal 24 residues of chi with the DNA sequence of ORF13 and a demonstration that ORF13 directs expression of a protein that co-migrates with authentic chi on SDS-polyacrylamide gels. ORF13, designated holC, was isolated from the E. coli chromosome and inserted into a tac promoter-based expression plasmid to direct production of the chi subunit to 5-7% of the total soluble protein. The 3' end of holC was sequenced to resolve discrepancies between two published versions.

Amino Acid Sequence↗