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Biomedical subjects

F E Johnson

Publications and source records attributed to F E Johnson.

At least 19 recordsLinked to original sources
PubMed1998

How tumor stage affects surgeons' surveillance strategies after surgery for carcinoma of the upper aerodigestive tract.

BACKGROUND: The factors that influence decision-making among surgeons are not well understood. The authors evaluated how tumor stage in otherwise healthy patients subjected to potentially curative surgery for upper aerodigestive tract (UADT) epidermoid carcinoma affects the self-reported follow-up strategies employed by practicing surgeons. METHODS: Hypothetical patient profiles and a detailed questionnaire based on these profiles were mailed to the 824 members of the Society of Head and Neck Surgeons (SHNS) and the 522 members of the American Society for Head and Neck Surgery who were not members of SHNS. The effect of TNM stage on the surveillance strategies chosen by the respondents was analyzed. RESULTS: Ten of the 14 most commonly employed surveillance modalities were ordered significantly more frequently with increasing TNM stage. This effect persisted through 5 years of follow-up, but the differences across stages were small. Only 30% of respondents modified their strategies according to the patient's TNM stage. CONCLUSIONS: Most surgeons performing surveillance after potentially curative surgery in otherwise healthy patients with UADT carcinoma use the same follow-up strategy irrespective of TNM stage. These data permit rational design of a randomized clinical trial of two alternate follow-up plans.

Adult↗
PubMed1998

Costs of posttreatment surveillance for patients with upper aerodigestive tract cancer.

OBJECTIVES: To determine the range of recommended follow-up strategies for patients with upper aerodigestive tract cancer treated with curative intent and to estimate the cost of follow-up. DESIGN: Economic analyses of the costs associated with 31 follow-up strategies (12 generic and 19 site specific) identified from a MEDLINE search of the literature for 1978 to 1997 and a search of major textbooks. Generic strategies are not specific for site or histology and are exclusive of strategies designed for the rare patient, ie, patients who would not be considered average in terms of clinical characteristics. Charge data obtained from the Part B Medicare Annual Data File and the Hospital Outpatient Bill File were used as a proxy for cost. SETTING: Ambulatory care. MAIN OUTCOME MEASURES: Nationwide Medicare-allowed charges and an actual-charge proxy for 5 years of surveillance after treatment for upper aerodigestive tract cancer. RESULTS: Medicare-allowed charges for 5-year follow-up ranged from a low of $739 to a high of $14,079 for the generic and site-specific strategies combined and from $739 to $4646 for the 12 generic strategies alone. When Medicare-allowed charges were converted to a proxy for actual charges using a conversion ratio of 1.62, the range was $1198 to $22,807 for all strategies combined (a 19-fold difference in charges) and $1198 to $7597 for the generic strategies alone (a 5-fold difference in charges). CONCLUSIONS: Charges vary extensively across surveillance strategies, particularly if site-specific strategies are considered, although the potential benefit of more intensive, higher-cost strategies on survival or quality of life has yet to be demonstrated.

Continuity of Patient Care↗
PubMed1998

A comparison of adrenalectomy with other resections for metastatic cancers.

BACKGROUND: Although adrenal metastases were once considered incurable, recent anecdotal reports recommend adrenalectomy for isolated metastases. METHODS: Computerized files of all US Department of Veterans Affairs (DVA) hospital admissions and deaths from 1988 to 1994 identified patients undergoing isolated adrenal resections, and hospitalization records were obtained. Patients without a death record were assumed to be alive. RESULTS: In 47 patients with adrenalectomy for metastases, only 5 patients did not die within 3 years: 2 each had metachronous renal or colorectal metastases, and 1 had a pulmonary primary. Thirteen patients with other primary sites all expired within 3 years. Operative mortality was 4% in these 47 patients and also in 706 other adrenalectomies without metastases. CONCLUSIONS: Adrenalectomy for metastatic carcinoma in the DVA was safe, with a projected 5-year survival rate (13%) that is significantly inferior (P < or = 0.05) to resections for colorectal metastases to lung (36%) or liver (26%), but superior to brain (none).

Adrenal Gland Neoplasms↗
PubMed1998

Outcome after proctectomy for rectal cancer in Department of Veterans Affairs Hospitals: a report from the National Surgical Quality Improvement Program.

OBJECTIVE: To define risk factors that predict adverse outcomes after proctectomy for cancer in Department of Veterans Affairs Medical Centers. SUMMARY BACKGROUND DATA: Accurate presurgical assessment of the risk of perioperative complications and death is important in planning surgical therapy. METHODS: The National VA Surgical Quality Improvement Program contains prospectively collected and extensively validated data on >287,000 patients. All patients undergoing proctectomy for rectal cancer from 1991 to 1995 who were registered in this data base were selected for study. Independent variables examined included 68 presurgical and 12 intraoperative clinical risk factors; dependent variables were 21 specific adverse outcomes. Stepwise logistic regression analysis was used to construct models predicting 30-day morbidity rates for each of the 10 most common complications and the 30-day mortality rate. RESULTS: Five hundred ninety-one patients were identified; 467 (79%) underwent abdominoperineal resection and 124 (21%) were treated with sphincter-saving procedures. Thirty percent of patients had one or more complications after proctectomy. Prolonged ileus, urinary tract infection, pneumonia, and deep wound infection were the most frequently reported complications. The 30-day mortality rate was 3.2% (19 deaths). For most complications, 30-day mortality rates were significantly higher for patients with complications than for those without. Thirty-day mortality rates for several complications exceeded 50%: cardiac arrest requiring cardiopulmonary resuscitation, deep venous thrombosis or thrombophlebitis, coma lasting >24 hours, acute renal failure, cerebrovascular accident, and pulmonary embolism. Four presurgical factors predicted a high risk of 30-day mortality in the logistic regression analysis: elevated blood urea nitrogen level, impaired sensorium, low serum albumin concentration, and partial thromboplastin time < or =25 seconds. CONCLUSIONS: Mortality rates after proctectomy in VA hospitals are comparable to those reported in other large series. Most postsurgical complications are associated with an increased 30-day mortality rate. Elevated presurgical blood urea nitrogen level, impaired sensorium, low serum albumin concentration, and partial thromboplastin time < or =25 seconds predict a high risk of 30-day mortality.

Adult↗
PubMed1998

A phase II evaluation of pentoxifylline combined with radiation in the treatment of brain metastases.

Pentoxifylline (PTX) has pharmacological properties that suggest potential utility as a radiation sensitizer, and preclinical animal studies have been promising. In a non-randomized phase II trial, we used PTX plus standard-dose external-beam whole-brain radiation treatment (WBRT) in patients with brain metastases. Seventeen patients were entered; 14 received both WBRT and PTX and were considered evaluable. Nine of the 14 completed treatment. Analyzing data on all 14 evaluable patients according to intent to treat, median survival time was 33 days, comparable to published data from historical controls. PTX toxicity was not a common cause of patient dropout, supporting higher PTX doses in future trials.

Adult↗
PubMed1997

Transforming growth factor beta peptide antagonists and their conversion to partial agonists.

Transforming growth factor beta (TGF-beta) has been implicated in the pathogenesis of various human diseases. Synthetic TGF-beta antagonists therefore could have therapeutic utility. Here we show the development of such compounds. Three synthetic pentacosapeptides designated beta125-(41-65), beta225-(41-65), and beta325-(41-65), whose amino acid sequences correspond to the 41st to 65th amino acid residues of TGF-beta1, TGF-beta2, and TGF-beta3, respectively, inhibit the binding of 125I-labeled TGF-beta isoforms to TGF-beta receptors in mink lung epithelial cells with IC50 of approximately 0.06-2 microM. beta125-(41-65) blocks TGF-beta1-induced growth inhibition and TGF-beta1-induced plasminogen activator inhibitor-1 expression in these cells. The variants designated beta125-(41-65)W52A/D55A and beta325-(41-65)R52A/D55A, in which both Trp52/Arg52 and Asp55 are replaced by alanine residues, do not have TGF-beta antagonist activity. Multiple conjugation of beta125-(41-65) to carrier proteins enhances its antagonist activity but also confers partial agonist activity as measured by DNA synthesis inhibition. These results suggest that the (W/R)XXD motif is important for the activities of these TGF-beta peptide antagonists and that this motif may be the active site sequence of TGF-beta.

Animals↗
PubMed1997

Major hepatic resection. Indications and results in a national hospital system from 1988 to 1992.

OBJECTIVE: To determine the indications for and outcomes of hepatic resection in a US hospital system. DESIGN: A retrospective study of 444 consecutive hepatic resections (i.e., 286 wedge or segmental resections and 158 lobectomies) using computerized medical records. SETTING: All US Department of Veterans Affairs hospitals. PATIENTS: US veterans (99% men). INTERVENTION: Major hepatic resection. MAIN OUTCOME MEASURE: Survival, as determined by the absence of a death record. RESULTS: One hundred fifty-eight lobectomies or larger resections were recorded (36% of the total); the 30-day operative mortality was 12% for lobectomies and 5% for wedge resections. However, the diagnosis had a greater influence on the operative mortality: 11 (4%) of 275 patients with colorectal metastases, 15 (21%) of 71 patients with hepatomas, 2 (9%) of 23 patients without cancer (but 0 [0%] of 7 patients with hemangiomas), 3 (12%) of 25 patients with cholangiocarcinomas, and 4 (8%) of 50 patients with metastases from other primary cancers. Approximately one third (i.e., 92) of the patients who underwent a resection of their colorectal metastases underwent a resection of their colorectal metastases underwent a concurrent colectomy, while the rest of the patients underwent these surgical procedures metachronously. The operative mortality was equal (i.e., 4%) for the resection of synchronous vs metachronous colorectal metastases. The mean survival time after the resection of metachronous vs synchronous colorectal metastases was 34 months vs 30 months, respectively, and the projected 5-year survival after either procedure was 26%. The projected 5-year survival was 20% for patients with hepatoma and 8% for patients with cholangiocarcinoma. With uncommon pathologic types, the mean survival time after metastatic resection was longest for those with renal primary tumors (3 patients, 55 months). CONCLUSIONS: Hepatic resection is a safe and effective therapy for colorectal metastases (5-year survival, 26%) and hemangioma; hepatoma resection is dangerous (operative mortality, 21%) but effective (5-year survival, 20%).

Female↗
PubMed1997

Experience with distal bile duct cancers in U.S. Veterans Affairs hospitals: 1987-1991.

BACKGROUND: Treatment selection and results were reviewed in a population with distal bile duct cancers. METHOD: Cases of bile duct cancer were retrieved from computerized U.S. Department of Veterans Affairs records from 1987-1991. RESULT: A total of 156 patients with distal bile duct cancers were recovered (34 resections, 37 operative bypasses, and 85 nonoperative biliary intubations). Mean survival after resection was 22 months, which was significantly higher than after biliary bypass (14 months) or intubation (11 months). Death rate within 30 days of resection, bypass, or intubation was 11%. Distal bile duct cancer had a much higher resectability rate (48%) than did pancreatic cancer (22%) and significantly longer mean survival by stage. Projected 5-year survival rate after resection was 21% for localized cancers, but no 3-year survivors were seen with nodal metastases regardless of treatment. CONCLUSIONS: Resection increases survival in patients with distal bile duct cancer. Five-year survival was achieved only when patients when nodal or other metastases were absent; most resections do not result in cure and prolonged survival also can occur without resection.

Adenocarcinoma↗
PubMed1997

Lower gastrointestinal bleeding.

BACKGROUND: Lower gastrointestinal bleeding can be a confusing clinical conundrum, the satisfactory evaluation and management of which requires a disciplined and orderly approach. Diagnosis and management has evolved with the development of new technology such as selective mesenteric angiography and colonoscopy. PURPOSE: This study was undertaken to review the available data in the literature and to determine the current optimum method of evaluation and management of lower gastrointestinal hemorrhage most likely to result in a successful outcome. METHODS: Data available on the topic of lower gastrointestinal bleeding in the English literature were obtained via MEDLINE search and were reviewed and analyzed. RESULTS: The colonic origin of lower gastrointestinal hemorrhage in order of decreasing incidence is diverticulosis, inflammatory bowel disease, including ischemic and infectious colitis, colonic neoplasia, benign anorectal disease, and arteriovenous malformations. Approximately 10 to 15 percent of all cases of rectal bleeding are attributable to a cause that is proximal to the ligament of Treitz. Small intestinal sources such as arteriovenous malformations, diverticula, and neoplasia account for between 3 and 5 percent of all cases. Colonoscopy successfully identified an origin in severe hematochezia in 74 to 82 percent of cases. Mesenteric angiography has a sensitivity of 42 to 86 percent. The best method of management depends on whether hemorrhage persists, the severity of continued hemorrhage, the cumulative transfusion requirement, and the specific origin of bleeding. CONCLUSION: Lower gastrointestinal hemorrhage is a complex clinical problem that requires disciplined and sophisticated evaluation for successful management. Diverticulosis is the most common cause. Colonoscopy is the diagnostic procedure of choice both for its accuracy in localization and its therapeutic capability. Selective mesenteric angiography should be reserved for those patients in whom colonoscopy is not practical. Precise identification of the bleeding source is crucial for a successful outcome. Specific directed therapy, such as segmental colonic resection for bleeding diverticulosis, is associated with the highest success rate and the lowest morbidity. A complete review of lower gastrointestinal bleeding is contained herein.

Angiography↗
PubMed1997

Outcome of abdominal aortic aneurysm repair in patients with previous spinal cord injury in the Department of Veterans' Affairs hospitals.

A retrospective review was carried out to determine the morbidity and mortality of abdominal aortic aneurysm repair in patients with previous spinal cord injury. A population-based study utilizing computer records on all patients in Department of Veterans' Affairs medical centers from 1987-1991 identified 31 patients with spinal cord injury who underwent subsequent infrarenal abdominal aortic aneurysm repair. Additional information was obtained from individual medical records. Some twenty patients (65%) were paraplegics and 11 (35%) were quadriplegics. Aneurysms were most commonly discovered incidentally during work-up of other conditions. All patients had no symptoms referable to their abdominal aortic aneurysm. In total, 29 patients (94%) underwent elective operations. The complication rate (57%) involved mostly pulmonary, cutaneous or urinary tract morbidity. The 30-day mortality rate was 3% for elective abdominal aortic aneurysm repair. Two patients were operated upon as emergencies for rupture, with one operative death. Long-term follow-up revealed a median survival duration of 5.4 years after aneurysm repair. In conclusion, abdominal aortic aneurysm repair in patients with previous spinal cord injury has a low mortality rate. Postoperative complications are often related to spinal cord injury and are potentially preventable; thus, such injury should not preclude surgical intervention for abdominal aortic aneurysm.

Aged↗
PubMed1997

How tumor stage affects surgeons' surveillance strategies after lung cancer surgery.

The factors that influence decision making among surgeons are not well understood. We evaluated how tumor stage in patients subjected to potentially curative surgery for lung cancer affects the self-reported follow-up strategies employed by practicing surgeons. Hypothetical patient profiles and a detailed questionnaire based on these profiles were mailed to the 3,700 members of the Society of Thoracic Surgeons. The effect of TNM stage on the surveillance strategies chosen by the respondents was analyzed. All of the ten most commonly employed surveillance modalities were ordered significantly more frequently with increasing TNM stage, although the differences are small. Only 23% of respondents modified their strategies according to the patient's TNM stage. This effect persisted through 5 years of follow-up. We conclude that most surgeons performing surveillance after potentially curative surgery for otherwise healthy patients with lung cancer use the same follow-up strategy irrespective of TNM stage. These data should help in the design of prospective trials of this topic.

Adult↗
PubMed1997

Sociosexual behaviour and paternity in procarbazine-exposed rats with or without regional testicular circulatory isolation.

Male Sprague-Dawley rats were used in two experiments in which a procarbazine bolus (400 mg kg-1 body mass) was administered with or without testicular circulatory isolation in the form of brief clamping of the spermatic cord and gubernaculum during drug administration. Separate tests of aggressiveness, sexual motivation, copulatory performance and paternity over the subsequent 6 weeks were used to assess functional changes resulting from testicular circulatory isolation. Experiment 1 compared intermale aggression and sexual motivation of animals in groups receiving procarbazine plus testicular circulatory isolation lasting 0, 15 or 45 min with that of animals in control groups with no clamp and no drug. Experiment 2 used a 2 x 2 factorial design to evaluate sexual performance and resulting paternity in animals 2 months after testicular circulatory isolation and drug exposure compared with that in control animals. Procarbazine treatment induced minimal disruption of normal interest in a receptive female, copulatory measures (intromissions or ejaculations) and structural integrity of seminal vesicles, bulbospongiosus muscles and ventral prostate glands. Animals exposed to the drug without testicular circulatory isolation were significantly less aggressive than animals in other groups. The most profound influence of procarbazine was on paternity. Males exposed to procarbazine with or without testicular circulatory isolation impregnated notably fewer females than did control males that were not exposed to the drug. There was no evidence of recovery of normal fertility up to 10 weeks after exposure to the drug. In conclusion, the deleterious influence of procarbazine on androgen-sensitive processes appears to be specific to intermale aggression and to fertility. The testicular circulatory isolation technique, for 45 min in particular, softened the impact of the drug on social behaviour, although procarbazine suppressed fecundity even with testicular circulatory isolation.

Animals↗
PubMed1996

Effect of chronic oral pentoxifylline administration on murine erythrocyte deformability.

BACKGROUND: Pentoxifylline has been reported to increase radiation sensitivity in vivo. We sought to evaluate whether this effect is mediated by changes in murine erythrocyte flexibility. METHODS: Pentoxifylline was administered via liquid or solid diet to young adult male CF-1 mice for 1-6 weeks. After 1, 3, and 6 weeks of drug administration, plasma levels of pentoxifylline and major derivatives were measured and erythrocyte deformability was assessed by rheoscopy, a technique which permits direct measurement of individual cellular dimensions. RESULTS: Contrary to prior reports, we found no discernible effect of the drug on erythrocyte deformability. CONCLUSIONS: The beneficial effect of pentoxifylline administration on radiation sensitivity in tumor-bearing mice is mediated by other mechanisms.

Administration, Oral↗
PubMed1996

Ischemic colitis complicating abdominal aortic aneurysm surgery in the U.S. veteran.

Ischemic colitis (IC) is an infrequent but serious complication of abdominal aortic surgery. Prior reports have generally described small, selected populations. The aim of this paper is to evaluate characteristics of clinically diagnosed IC in a large non-referral-based population. Using national Veterans Affairs (VA) computer data sets, we identified all patients with the diagnostic codes for both prosthetic replacement of aorta for abdominal aortic aneurysm and subsequent vascular insufficiency of the intestine in the entire VA population from 1987 to 1991. Clinical information on these patients was then requested from the VA Medical Centers where they received care. Patients demographics, clinical data regarding both the aortic surgery and IC, and survival data were extracted from patient charts and computer records. Of 4957 patients who underwent surgery of the abdominal aorta for infrarenal abdominal aortic aneurysm, 58 (1.2%) also had the code for subsequent IC. In 49/58 (74%), sufficient chart-derived and computer-derived data were available for analysis. The mean age was 69 (range 57-95); all were males. Bloody diarrhea was the most frequent symptom and colonoscopy the most common means of diagnosis. Mean time to diagnosis of IC was 5.5 days after aortic surgery (range 1-21 days). Aneurysmal rupture or perioperative hypotension were present in 35/49 patients. Bowel resection with fecal diversion was required in 32/49 (65%). The overall mortality was 54% but it was 89% if bowel resection for bowel infarction was required. Only 2/12 (16%) of those who required fecal diversion and survived underwent eventual stoma closure. Among 7 patients who received second-look laparotomy for IC, additional bowel resection was required in 6. No patient had aortic graft infection diagnosed during the index hospitalization. The overall mean hospitalization duration after the diagnosis of IC was 38 days (range 1-164). IC following aortic aneurysm surgery in this national patient population is infrequently diagnosed. Emergency aneurysm operation and perioperative hypotension are common in patients who develop IC. The majority of patients diagnosed receive surgical intervention. Most patients who undergo fecal diversion retain their stomas.

Aged↗
PubMed1996

Incidence and treatment of periampullary duodenal cancer in the U.S. veteran patient population.

BACKGROUND: Because fewer than 1000 cases of primary adenocarcinoma of the duodenum have been reported, earlier series are limited by local referral patterns and the long periods of time needed for retrospective reviews. METHODS: This study reports the outcomes of preiampullary duodenal adenocarcinoma treatments in all hospitals of the Department of Veterans Affairs from 1987 through 1991, using computer and tumor registry records. Patients were grouped by their most aggressive treatment (resection > operative bypass > percutaneous biliary intubation) and survival calculated from the date of this procedure. RESULTS: Of 2185 patients with periampullary cancers (1753 pancreatic, 432 other periampullary), 85 were duodenal and thus comprised only 4% of periampullary tumors. Thirty-four duodenal cancers were resected, 44 bypassed, and 7 had biliary intubation, with 30-day mortality rates of 6%, 18%, and 0%, respectively. Mean survival exceeded 1 year in all groups, and resection resulted in a significant increase in mean survival (784 vs. 438 days for nonresection, P = 0.01). The projected 5-year survival rate after resection was 23%. Mean survival after resection of 9 Stage I-II cancers was 668 days, but was similar after 5 resections with nodal or other metastases. Similarly, survival did not correlate with cancer stage in 13 palliated patients. CONCLUSIONS: This large study of patients with duodenal cancer provides a unique perspective of disease prevalence and response to surgical treatment. Prolonged survival is common with any treatment, but the longest survivals were after resection.

Adenocarcinoma↗
PubMed1996

Colorectal cancer in patients with previous spinal cord injury.

BACKGROUND: The optimum management of large-bowel cancer in patients with previous spinal cord injury (SCI) is uncertain. PURPOSE: The aim is to determine the outcome of patients with SCI who are undergoing colectomy or proctectomy for cancer. METHODS: A population-based study of patients receiving care at hospitals in the Department of Veterans Affairs system from 1987 to 1991 was performed. Patients with ICD-9 codes for SCI and colon and rectal cancer were identified. Patients with previous SCI who underwent colectomy or proctectomy for their cancer comprised the study population. Data were compiled from national computerized Veterans Affairs datasets, supplemented by individual operative reports and discharge summaries. RESULTS: Forty-four patients were evaluable. Mean age was 65 (range, 40-80) years, and mean time since SCI was 24 (range, 1-50) years. Mean follow-up was 4.6 years after resection. Distribution of tumors was 39 percent rightsided, 43 percent left-sided, and 18 percent rectal. All 32 patients with colonic tumors underwent resection; 26 of 32 patients (81 percent) had an anastomosis. Seven of eight (88 percent) rectal lesions were treated by abdominoperineal resection. Twenty-six of 44 patients (59 percent) presented with Stage III or IV disease. Twelve of 44 (27 percent) died, 8 of 12 from cancer. Overall 30-day mortality rate was 4.5 percent (2/44). In-hospital morbidity rate (pulmonary, cutaneous, and urinary tract only) was 34 percent. Among those who received postoperative chemotherapy, 80 percent completed treatment. CONCLUSIONS: Patients with previous SCI tolerate resection well. Tumor distribution and stage are similar to those of neurally intact patients. Morbidity is commonly related to pre-existing complications of SCI. Adjuvant therapy is well tolerated.

Adult↗
PubMed1996

Testicular circulatory isolation: not a cause of immune-mediated testis injury in the rat.

BACKGROUND: Testicular circulatory isolation (TCI), a regional drug exclusion approach designed to prevent chemotherapy-induced male infertility, can reduce testicular drug exposure and preserve fertility. The immunological sequelae of this surgical procedure were investigated. METHODS: Forty Sprague-Dawley rats received unilateral TCI for 45 min and were killed at intervals of up to 43 days later. Testicular histology was evaluated qualitatively using hematoxylin and eosin stain, a direct immunofluorescent technique for detection of antigen-antibody complexes, and an indirect immunofluorescent technique to detect circulating antitestis antibodies. RESULTS: No immune-mediated injury was evident up to 43 days after TCI. CONCLUSION: The current work, taken together with previously published data, indicate that TCI produces no immunological damage in the rat testis. Because TCI is well tolerated in humans, this work also supports the institution of human clinical trials of this technique in men about to receive fertility-threatening chemotherapy.

Animals↗