PubMed Health⌕ Search

Biomedical subjects

D R Campbell

Publications and source records attributed to D R Campbell.

At least 19 recordsLinked to original sources
PubMed2001

WISP-2: a serum-inducible gene differentially expressed in human normal breast epithelial cells and in MCF-7 breast tumor cells.

WISP-2 is a Wnt-1-induced signaling protein identified as a member of CCN growth factor family. A role for this molecule during tumorigenesis is suspected but remains unproven. Here we show that WISP-2 expression was undetectable, or minimally detectable, in nontransformed human mammary epithelial cells, but was overexpressed in MCF-7 cells. Expression of WISP-2 in MCF-7 cells was modulated by serum and correlated with the serum-induced MCF-7 tumor cell proliferation, suggesting that WISP-2 is serum responsive and may be a positive regulator of tumor cell proliferation.

Base Sequence↗
PubMed2001

Combined iliac angioplasty and infrainguinal revascularization surgery are effective in diabetic patients with multilevel arterial disease.

The success of percutaneous transluminal angioplasty (PTA) in the treatment of common and external iliac atherosclerotic lesions has been established for the general population. However, several studies have suggested that the presence of diabetes may reduce the effectiveness of iliac angioplasty, particularly in the setting of limb-threatening ischemia requiring concomitant lower extremity revascularization. This study compared the results of iliac artery PTA performed in conjunction with infrainguinal bypass for limb-threatening ischemia for diabetic (DM) and nondiabetic (non-DM) patients. Between 1991 and 2000, 159 PTA were performed in 126 patients (DM = 99/79%, non-DM = 27/21%) in conjunction with subsequent infrainguinal bypass for limb-threatening ischemia (gangrene = 42%, ulcer = 36%, rest pain = 22%). These patients were followed prospectively using a computerized vascular registry. Stents were placed in 34 (21.4%) cases for suboptimal angioplasty results. In this study the combined use of standard surgical and endoluminal modalities for the treatment of multilevel arterial occlusive disease resulted in excellent cumulative patency and limb salvage rates. The presence of diabetes did not alter these favorable results. Multimodal vascular therapy may be used effectively in diabetic patients with limb-threatening ischemia due to multiple levels of arterial occlusion.

Aged↗
PubMed2001

The impact of diabetes on arterial reconstructions for multilevel arterial occlusive disease.

PURPOSE: Critical limb ischemia due to multilevel arterial occlusive disease often may be treated with an inflow procedure alone; however, a subset patients require a subsequent infrainguinal revascularization for persistence of their symptoms. As diabetic patients typically exhibit a pattern of extensive distal arterial disease, we sought to determine if the presence of diabetes mellitus altered the need for an outflow procedure after inflow bypass. METHODS: A total of 504 patients undergoing inflow bypass for occlusive disease and lower extremity ischemia between 1990 and 1998 were entered prospectively into a computerized vascular registry. Inflow bypass procedures performed were as follows: aortofemoral (370; 73%), axillofemoral (56; 11%), femorofemoral (81; 16%). Of these patients, 79 required subsequent outflow bypass for unresolved ischemic symptoms. Multiple logistic regression analysis was used to analyze the effects of diabetes and multiple other risk factors on the need for an additional outflow procedure. RESULTS: The indications for surgery were limb salvage (78%) and disabling claudication (22%). Overall morbidity was 17.7% (hematoma, 3.8%; wound infection, 2.5%; graft occlusion, 1.3%; myocardial infarction, 2.5%; acute renal failure,1.3%; pulmonary failure, 2.5%; pneumonia, 3.8%). Overall mortality was 0%. Diabetic patients comprised a greater proportion of the total number of patients requiring inflow bypass (301 of 504) as well as a greater proportion of patients requiring inflow and outflow procedures (47 of 79). Diabetes was determined not to be an independent risk factor for the need for multiple revascularization procedures by multiple logistic regression analysis (P >0.10). CONCLUSION: Although patients with diabetes are predisposed to the development of distal arterial occlusive disease, in this study the subgroup of diabetic patients who present with aortoiliac occlusive disease were no more likely than patients without diabetes to require multiple levels of revascularization. These findings provide little rationale for simultaneous inflow and outflow procedures based on the presence of diabetes alone.

Arterial Occlusive Diseases↗
PubMed2001

Intelligibility, subjective ratings and completion time scores using the FAAF test with hearing-impaired subjects and noisy reverberant environments.

A series of experiments have been performed with the primary aim of assessing the performance of a signal-processing algorithm for a possible future hearing aid application. As part of this work the four alternative auditory feature (FAAF) test was used to obtain a quantitative assessment of speech intelligibility and a subjective assessment of speech quality. This paper reports results of experiments using normal hearing (NH) subjects that provide partial verification of the FAAF test originators' prior work. Also reported are intelligibility score, mean opinion score (MOS) and completion time data obtained by use of the

Adult↗
PubMed2001

Improvements in intelligibility of noisy reverberant speech using a binaural subband adaptive noise-cancellation processing scheme.

This article reports on the performance of an adaptive subband noise cancellation scheme, which performs binaural preprocessing of speech signals for a hearing-aid application. The multi-microphone subband adaptive (MMSBA) signal processing scheme uses the least mean squares (LMS) algorithm in frequency-limited subbands. The use of subbands enables a diverse processing mechanism to be employed, splitting the two-channel wide-band signal into smaller frequency-limited subbands, which can be processed according to their individual signal characteristics. The frequency delimiting used a linear- or cochlear-spaced subband distribution. The effect of the processing scheme on speech intelligibility was assessed in a trial involving 15 hearing-impaired volunteers with moderate sensorineural hearing loss. The acoustic material consisted of speech and speech-shaped noise signals, generated using simulated and real-room acoustic environments, at signal-to-noise ratios (SNRs) in the range -6 to +3 dB. The results show that the MMSBA scheme delivered average speech intelligibility improvements of 11.5%, with a maximum of 37.25%, in noisy reverberant conditions. There was no significant reduction in mean speech intelligibility due to processing, in any of the test conditions.

Acoustics↗
PubMed2001

Genotype-by-environment interaction and the fitness of plant hybrids in the wild.

Natural hybrid zones between related species illustrate processes that contribute to genetic differentiation and species formation. A common viewpoint is that hybrids are essentially unfit, but they exist in a stable tension zone where selection against them is balanced by gene flow between the parent species. An alternative idea is that selection depends on the environment, for example, by favoring opposite traits in the two parental habitats or favoring hybrids within a bounded region. To determine whether selection of hybrids is environment dependent, we crossed plants of naturally hybridizing Ipomopsis aggregata and I. tenuituba in the Colorado Rocky Mountains and reciprocally planted the seed offspring into a suite of natural environments across the hybrid zone. All types of crosses produced similar numbers and weights of seeds. However, survival of the offspring after 5 years differed markedly among cross types. On average, the F1 hybrids had survival and growth rates as high as the average for their parents. But hybrid survival depended strongly on the direction of a cross, that is, on which species served as the maternal parent. This fitness difference between reciprocal hybrids appeared only in the parental environments, suggesting cytonuclear gene interactions that are environment specific. These results indicate that complex genotype-by-environment interactions can contribute to the evolutionary outcome of hybridization.

Colorado↗
PubMed2001

Tests of pre- and postpollination barriers to hybridization between sympatric species of Ipomopsis (Polemoniaceae).

The Ipomopsis aggregata species complex (Polemoniaceae) includes species pairs that hybridize readily in nature as well as pairs that meet along contact zones with no apparent hybridization. Artificial hybrids can be made between I. aggregata and I. arizonica, yet morphological intermediates between these two species have not been observed in natural populations. This apparent lack of hybridization is perplexing given that plants of the two species often grow within a few metres of each other and both species have red flowers visited by the same species of hummingbirds. We used trained hummingbirds to examine pollen transfer within and between species. We also hand-pollinated flowers to examine paternal success of heterospecific and conspecific pollen, testing paternity with electrophoretic examination of seeds. Hummingbirds were not simply better at transferring pollen within than between species. Instead, I. arizonica was a better pollen donor so that considerable pollen transfer was observed from I. arizonica to I. aggregata, but very little in the opposite direction. Conversely, once pollen arrived at stigmas, I. arizonica pollen performed very poorly on I. aggregata pistils. However, pollen from I. aggregata could, in some cases, sire seeds on I. arizonica. We hypothesize that hybrids are scarce in nature, in part, because of asymmetric barriers to reproduction: little pollen transfer in one direction and poor pollen performance in the other.

Journal Article↗
PubMed2001

Fungal infections of the spine. Report of eleven patients with long-term follow-up.

BACKGROUND: Fungal infections of the spine are noncaseating, acid-fast-negative infections that occur primarily as opportunistic infections in immunocompromised patients. We analyzed eleven patients with spinal osteomyelitis caused by a fungus, and we developed suggestions for treatment. METHODS: All patients with a fungal infection of the spine treated by the authors over a sixteen-year period at three teaching institutions were evaluated. There was a total of eleven patients. Medical records and roentgenograms were available for every patient. Long-term follow-up of the nine surviving patients was performed by direct examination by the authors or by the patient's primary physician. RESULTS: For ten of the eleven patients, the average delay in the diagnosis was ninety-nine days. Nine patients were immunocompromised secondary to diabetes mellitus, corticosteroid use, chemotherapy for a tumor, or malnutrition. The sources of the spinal infections included direct implantation from trauma (one patient), hematogenous spread (four patients), and local extension (two patients). The infection followed elective spine surgery in three patients, and the cause was unknown in one. Paralysis secondary to the spine infection developed in eight patients. Ten patients were treated with surgical debridement. All eleven patients were treated with systemic antifungal medications for a minimum of six weeks. One patient died of generalized sepsis at thirty-three days, and another patient died of gastrointestinal hemorrhage at five months. After an average of 6.3 years of follow-up, the infection had resolved in all nine surviving patients. CONCLUSIONS: Treatment of fungal spondylitis is often delayed because of difficulty with the diagnosis. Delay in the diagnosis led to poorer results in terms of neurologic recovery in our study. Performing fungal cultures whenever a spinal infection is suspected might hasten the diagnosis. Patients should be given a guarded prognosis and informed of the many possible complications of the disease.

Female↗
PubMed2000

Lansoprazole compared with ranitidine for the treatment of nonerosive gastroesophageal reflux disease.

BACKGROUND: Traditionally, proton pump inhibitors are used primarily for patients with esophagitis. However, patients with nonerosive reflux disease may also benefit from these powerful medications. OBJECTIVE: To compare the safety and symptom relief efficacy of lansoprazole with ranitidine therapy and with placebo. METHODS: In 2 randomized, double-blind, multicenter trials of 901 patients with symptomatic reflux disease, which was confirmed by endoscopy to be nonerosive, received lansoprazole, 15 or 30 mg once daily; ranitidine, 150 mg twice daily; or placebo for 8 weeks. RESULTS: Analysis of daily diary data during the first 4 weeks and for the entire 8 weeks of treatment revealed that patients who were treated with either dosage of lansoprazole reported significantly (P<.05) lower percentages of days and nights with heartburn, less pain severity of both day and night heartburn, fewer days of antacid use, and smaller amounts of antacid use compared with patients who were treated with ranitidine or placebo. The incidence of possible or probable treatment-related adverse reactions was comparable among the treatment groups; abdominal pain and diarrhea were the most commonly reported adverse events. No statistically significant differences were noted between treatment groups in laboratory analyses. CONCLUSION: Lansoprazole therapy is more effective than standard dosages of ranitidine or placebo in relieving symptoms in patients with endoscopically confirmed non-erosive reflux esophagitis.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

Superiority of lansoprazole vs ranitidine in healing nonsteroidal anti-inflammatory drug-associated gastric ulcers: results of a double-blind, randomized, multicenter study. NSAID-Associated Gastric Ulcer Study Group.

BACKGROUND: The usefulness of nonsteroidal anti-inflammatory drugs (NSAIDs) is limited by adverse gastrointestinal tract events. OBJECTIVE: To identify the optimal antisecretory therapy for healing of gastric ulcer in patients using NSAIDs and the impact of concurrent Helicobacter pylori infection on ulcer healing. DESIGN: Prospective, double-blind, multicenter, parallel-group study. SETTING: Gastroenterology practices in ambulatory and referral center settings. PATIENTS: Three hundred fifty-three patients with an active, nonmalignant gastric ulcer at least 5 mm in diameter confirmed by endoscopy and biopsy and who continued to receive stable doses of NSAIDs. INTERVENTION: Patients were randomized to receive ranitidine hydrochloride, 150 mg twice daily, or lansoprazole, 15 mg or 30 mg once daily, for 8 weeks. MEASUREMENTS: Healing was assessed by endoscopy at 4 and 8 weeks in an intent-to-treat population. Helicobacter pylori status was assessed by histological examination. RESULTS: After 8 weeks of treatment, healing was observed in 61 (53%) of 115, 81 (69%) of 118, and 85 (73%) of 117 patients receiving ranitidine lansoprazole, 15 mg, and lansoprazole, 30 mg, respectively (P<.05 for ranitidine vs both lansoprazole doses; 95% confidence interval, 3.2-28.0 for ranitidine vs lansoprazole, 15 mg, and 7.4-31.8 for ranitidine vs lansoprazole, 30 mg). The gastric ulcer healing rates were similar between H pylori-infected and -noninfected patients, with a statistically significant increase with the use of lansoprazole vs ranitidine. CONCLUSIONS: In patients who require continuous treatment with NSAIDs, lansoprazole is superior to ranitidine for healing of NSAID-associated gastric ulcers. Healing is not delayed by the presence of H pylori infection.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

Lower extremity revascularization in diabetes: late observations.

HYPOTHESIS: Despite the success of infrainguinal arterial bypass in diabetic limb and foot salvage, optimism remains guarded because of purported high late mortality and limb loss in patients with diabetes. DESIGN: Inception cohort, with minimum 5-year follow-up. SETTING: Tertiary referral center. PATIENTS: Eight hundred forty-three consecutive patients undergoing lower extremity arterial reconstruction from July 1, 1990, through July 31, 1993. INTERVENTION: Infrainguinal arterial bypass with vein graft. MAIN OUTCOME MEASURES: Graft patency, limb salvage, and survival. RESULTS: A total of 962 vein grafts (843 patients) were performed; 795 grafts (82.6%) were performed in patients with diabetes (DM group) and 167 (17.4%) in nondiabetic patients (NDM group). Average age was 68.4 years, and was lower in the DM group (66.2 [range, 27-92 years] vs. 70.5 years [range, 37-96 years]) (P = .005). Inhospital 30-day perioperative mortality was 1.4%, lower in the DM group (0.9% vs. 4.2%) (P = .005). The target vessel was more frequently infrageniculate in the DM group (87% vs. 77%; P = .002). Five-year primary and secondary graft patencies were 74.7% (DM group, 75.6%; NDM group, 71.9%; P = .80) and 76.2% (DM group, 77.0%; NDM group, 73.6%; P = .90), respectively. The 5-year overall limb salvage rate was 87.1%, also unaffected by diabetes (DM group, 87.3%; NDM group, 85.4%; P = .80). Survival at 5 years was 58.1% overall and virtually identical in the DM (58.2%) and NDM groups (58.0%). CONCLUSIONS: Diabetes mellitus does not influence late mortality, graft patency, or limb salvage rates after lower extremity arterial reconstruction. Concern for longterm mortality and limb loss in diabetic patients is unwarranted and should not prevent aggressive attempts at limb salvage.

Adult↗
PubMed2000

Expression of cdc2 and cyclin B1 in Helicobacter pylori-associated gastric MALT and MALT lymphoma : relationship to cell death, proliferation, and transformation.

Mucosa-associated lymphoid tissue (MALT) may accumulate within gastric mucosa as a result of long standing Helicobacter pylori infection, and this acquired MALT may eventually develop into low-grade B-cell MALT lymphoma. To determine the possible association of cell cycle regulatory proteins and apoptotic cell death in the transformation of H. pylori gastritis to MALT lymphoma, the extent of cell proliferation, cell viability, expression of Cdc2/Cdk1 and cyclin B in gastric mucosal from patients with H. pylori-positive chronic gastritis (n = 7), MALT (n = 12), or MALT lymphoma (n = 12) were undertaken. Control tissue was obtained from H. pylori- negative patients (n = 5). Proliferating cell nuclear antigen (PCNA), Cdc2, and cyclin B1 were examined in paraffin embedded tissue by immunohistochemistry, while the apoptotic index (AI) was determined using the TUNEL assay. H&E staining for histology and modified Giemsa staining for the detection of H. pylori was conducted simultaneously. When compared to chronic gastritis tissue, those with MALT or MALT lymphoma had an increase in PCNA labeling index of 3.3- and 2.7-fold, while that for Cdc2/Cdk1 increased 2.3- and 3.1-fold, respectively. cyclin B1 labeling was 1.9 and 3.0 fold, while the AI was 3.4- and 1.4-fold higher in MALT and MALT lymphoma tissue, respectively, in the same comparison. On the other hand, the AI index of MALT lymphoma was 2. 5-fold lower than that for MALT tissues. The labeling scores for Cdc2/Cdk1 and cyclin B1 were significantly higher in the germinal center when compared to the mantle and marginal zones of MALT tissues. Using chi(2) and Pearson/Spearman's rho correlation coefficient with regression analyses, there was an inverse correlation between the AI and Cdc2/Cdk1 or cyclin B1 in MALT and MALT lymphoma tissues. There was no correlation between AI and PCNA labeling in any of the tissues. These results suggest that Cdc2/Cdk1 and cyclin B1 expression may be actively associated in the modulation of cellular death by apoptosis, as well as cellular proliferation and transformation during the evolution of H. pylori-associated gastritis to MALT lymphoma. Subclassification of high labeling score (>/=40) for Cdc2/Cdk1 and cyclin B1 and low labeling index (<0.6) for apoptotic cells in H. pylori-associated MALT may help in identifying a population of patients with an increased risk of developing MALT lymphoma.

Apoptosis↗
PubMed2000

The use of arm vein in lower-extremity revascularization: results of 520 procedures performed in eight years.

PURPOSE: The absence of an adequate ipsilateral saphenous vein in patients requiring lower-extremity revascularization poses a difficult clinical dilemma. This study examined the results of the use of autogenous arm vein bypass grafts in these patients. METHODS: Five hundred twenty lower-extremity revascularization procedures performed between 1990 and 1998 were followed prospectively with a computerized vascular registry. The arm vein conduit was prepared by using intraoperative angioscopy for valve lysis and identification of luminal abnormalities in 44.8% of cases. RESULTS: Seventy-two (13. 8%) femoropopliteal, 174 (33.5%) femorotibial, 29 (5.6%) femoropedal, 101 (19.4%) popliteo-tibial/pedal, and 144 (27.7%) extension "jump" graft bypass procedures were performed for limb salvage (98.2%) or disabling claudication (1.8%). The average age of patients was 68.5 years (range, 32 to 91 years); 63.1% of patients were men, and 36.9% of patients were women. Eighty-five percent of patients had diabetes mellitus, and 77% of patients had a recent history of smoking. The grafts were composed of a single arm vein segment in 363 cases (69. 8%) and of spliced composite vein with venovenostomy in 157 cases (30.2%). The mean follow-up period was 24.9 months (range, 1 month to 7.4 years). Overall patency and limb salvage rates for all graft types were: primary patency, 30-day = 97.0% +/- 0.7%, 1-year = 80.2% +/- 2.1%, 3-year = 68.9% +/- 3.6%, 5-year = 54.5% +/- 6.6%; secondary patency, 30-day = 97.0% +/- 0.7%, 1-year = 80.7% +/- 2.1%, 3-year = 70.3% +/- 3.4%, 5-year = 57.5% +/- 6.2%; limb salvage, 30-day = 97.6% +/- 0.7%, 1-year = 89.8% +/- 1.7%, 3-year = 82.1% +/- 3.3%, 5-year = 71.5% +/- 6.9%. Secondary patency and limb salvage rates were greatest at 5 years for femoropopliteal grafts (69.8% +/- 12.8%, 80.7% +/- 11.8%), as compared with femorotibial (59.6% +/- 10. 3%, 72.7% +/- 10.5%), femoropedal (54.9% +/- 25.7%, 56.8% +/- 26.9%, ) and popliteo-tibial/pedal grafts (39.0% +/- 7.3%, 47.6% +/- 15.4%). The patency rate of composite vein grafts was equal to that of single-vein conduits. The overall survival rate was 54% at 4 years. CONCLUSION: Autogenous arm vein has been used successfully in a wide variety of lower-extremity revascularization procedures and has achieved excellent long- and short-term patency and limb salvage rates, higher than those generally reported for prosthetic or cryopreserved grafts. Its durability and easy accessibility make it an alternative conduit of choice when an adequate saphenous vein is not available.

Adult↗
PubMed2000

Arm vein conduit is superior to composite prosthetic-autogenous grafts in lower extremity revascularization.

PURPOSE: Various alternative conduits have been used for lower extremity revascularization when an adequate ipsilateral greater saphenous vein is absent. This study compared the effectiveness of all-autogenous multisegment arm vein bypass grafts with that of composite grafts composed of combined prosthetic and autogenous conduits. METHODS: One hundred fifty-three lower extremity revascularization procedures performed between 1990 and 1998 were followed up prospectively using a computerized vascular registry. The grafts were composed of spliced arm vein segments with venovenostomy in 122 and of composite prosthetic-autogenous conduit in 31. Arm vein conduit was prepared by means of intraoperative angioscopy for valve lysis and identification of luminal abnormalities in 47.7% of cases. RESULTS: Bypass graft configurations were as follows: femoropopliteal (12 arm vein, 2 composite); femorotibial (75 arm vein, 23 composite); femoropedal (14 arm vein, 6 composite), and popliteo-tibial/pedal (21 arm vein, 0 composite). The indication for surgery was limb salvage in 98% and disabling claudication in 2% of cases. The mean follow-up was 25.1 months (range, 1 month to 7.9 years). Overall survival at 4 years was 51%. Overall patency and limb salvage rates were as follows: primary patency, at 1 year-arm vein, 76.9% +/- 4.8%; composite, 59. 5% +/- 9.6% (P =.02); at 3 years-arm vein, 70.0% +/- 8.0%; composite, 43.7% +/- 12.4% (P <.01); and at 5 years-arm vein, 53.8% +/- 8.7%; composite, 0%; secondary patency, at 1 year-arm vein, 77.5% +/- 4. 6%; composite, 59.8% +/- 9.5% (P =.02); at 3 years-arm vein, 70.7% +/- 7.5%, composite, 44.9% +/- 13.1% (P <.01); at 5 years-arm vein, 57.7% +/- 8.0%; composite, 0%; limb salvage, at 1 year-arm vein, 89. 3% +/- 3.7%; composite, 73.9% +/- 8.9% (P <.01); at 3 years-arm vein, 80.5% +/- 7.0%; composite, 49.6% +/- 14.3% (P <.01); at 5 years-arm vein, 76.3% +/- 9.9%; composite, 0%. CONCLUSION: In this study, multisegment autogenous arm vein was used successfully in a wide variety of lower extremity revascularization procedures and achieved good long-term patency and limb salvage rates, well in excess of those achieved with composite prosthetic-autogenous grafts. The use of autogenous conduit appears to offer superior results to composite conduit in lower extremity revascularization. The superior durability of arm vein makes it one of the alternative conduits of choice when an adequate greater saphenous vein is not available.

Aged↗
PubMed2000

Gender and carotid endarterectomy: does it matter?

OBJECTIVE: Multiple large series have retrospectively identified female gender as a risk factor for perioperative stroke and death after carotid endarterectomy (CEA). METHODS: Data for all patients who underwent CEA at a single institution from January 1990 to December 1998 were entered into a computerized vascular registry and form the basis of this report. RESULTS: A total of 1298 CEA procedures were performed, of which 520 (40%) were in women and 778 (60%) in men. The mean age was 69.8 +/- 8.7 years for men and 71.2 +/- 8.5 years for women (P <.001). Cardiac risk factors significantly varied among the two groups, with women more likely to have diabetes (42% vs 36%) and hypertension (77% vs 66%), whereas tobacco history was higher among men (85% vs 71%) (P <.05 for all). Female patients were more likely to be asymptomatic at presentation (men, 44% vs women, 51%; P =.022). Postoperative myocardial infarction occurred in eight patients (0.6%) with no differences between men (0.4%) and women (1.0%) (P = not significant). For all adverse postoperative cardiac events (myocardial infarction, congestive heart failure, or arrhythmia), the incidence was 1.9% (25 patients), again with no differences between men (1.5%) and women (2. 5%) (P = not significant). There were 25 postoperative neurologic events (19 strokes, six transient ischemic attacks) among the entire cohort (1.9%), of which 16 were in men (2.1%) and nine in women (1. 6%; P = not significant). The overall postoperative stroke rate was 1.5% (13 [1.7%] of 778 men; 6 [1.2%;] of 520 women; P = not significant). Total operative mortality was 0.3% (3 [0.4%] of 778 men; 1 [0.2%] of 778 women; P = not significant). Late recurrent stenosis requiring operation developed in 14 patients (1.1%) during follow-up (6 [0.8%] of 778 men; 8 [1.5%] of 520 women; P =.19). CONCLUSIONS: Although there is significant variability in cardiac risk factors and presentation, female gender is not a risk factor for stroke, death, or cardiac morbidity after CEA. Women are not at higher risk for reoperation for recurrent stenosis.

Age Factors↗
PubMed2000

A comparative study of alternative conduits for lower extremity revascularization: all-autogenous conduit versus prosthetic grafts.

PURPOSE: In the absence of an adequate ipsilateral greater saphenous vein, various alternative conduits have been used for the performance of lower extremity revascularization. In this study we compared the effectiveness of all-autogenous arm vein bypass grafts with that of prosthetic grafts. METHODS: Seven hundred forty lower extremity revascularization procedures (506 arm vein, 234 prosthetic) performed between 1990 and 1999 were followed prospectively by means of a computerized vascular registry. RESULTS: Bypass graft configurations were femoro-above-knee-popliteal (26 arm vein, 100 prosthetic); femoro-below-knee-popliteal (38 arm vein, 29 prosthetic); femorotibial (174 arm vein, 55 prosthetic); femoropedal (23 arm vein, 2 prosthetic); popliteotibial/pedal (101 arm vein, 1 prosthetic); and extension "jump" grafts (144 arm vein, 47 prosthetic). The indications for surgery were limb salvage (98.0% arm vein, 89.7% prosthetic) and disabling claudication (2.0% arm vein, 10.3% prosthetic). The mean follow-up was 23.4 months (range, 1 month-7.4 years). Overall patient survival at 4 years was 54% (arm vein) and 69% (prosthetic). Cumulative patency varied with graft configuration. The 1-year primary patency rates for femorotibial grafts were 81.6% +/- 3.6% (arm vein) and 58.0% +/- 8.4% (prosthetic); the 3-year rates were 68.3% +/- 6.1% (arm vein) and 41.1% +/- 9.8% (prosthetic) (P<.01). The 1-year limb salvage rates for femorotibial grafts were 91.1% +/- 2.8% (arm vein) and 69.1% +/- 8. 8% (prosthetic); the 3-year rates were 81.4% +/- 5.6% (arm vein) and 63.2% +/- 10.3% (prosthetic) (P =.02). The 1-year primary patency rates for femoro-below-knee-popliteal grafts were 92.9% +/- 5.1% (arm vein) and 83.4% +/- 8.0% (prosthetic); the 3-year rates were 72.8% +/- 10.1% (arm vein) and 55.5% +/- 12.1% (prosthetic) (P=.05). The 1-year limb salvage rates for femoro-below-knee-popliteal grafts were 100% (arm vein) and 91.3% +/- 7.0% (prosthetic); the 3-year rates were 94.7% +/- 7.3% (arm vein) and 75.3% +/- 14.6% (prosthetic) (P = NS). CONCLUSION: In this study autogenous arm vein grafts demonstrated increased patency and limb salvage, compared with prosthetic grafts. These increases achieved statistical significance in the femoro-below-knee-popliteal and femorotibial configurations. An effort to use an all-autogenous vein conduit is justified on the basis of these results; however, if no autogenous vein is available, prosthetic grafts provide a reasonable alternative to primary amputation.

Aged↗
PubMed2000

Tumor angiogenesis in chronic pancreatitis and pancreatic adenocarcinoma: impact of K-ras mutations.

Chronic pancreatitis (CP) is one condition in which epidemiologic studies have demonstrated a definite association with pancreatic adenocarcinoma (PAC). The pathophysiologic and molecular events that either predispose to the development of, or potentiate the growth of, PAC are unknown. Mutation of the codon 12 K-ras gene is one genetic aberration commonly associated with development of PAC. Tumor angiogenesis, or microvascular proliferation of new capillaries, is another pathophysiologic alteration associated with PAC. Although activated ras oncogenes modulate tumor angiogenesis/neovascularization in some tumors, the importance of tumor angiogenesis and the role of K-ras mutation in regulating angiogenesis in CP and PAC are unknown. The aim of this study was to elucidate the relationship between angiogenesis and K-ras mutations in CP and PAC. Tumor angiogenesis and K-ras mutations were evaluated in resected specimens from 25 CP (23 CP plus two CP with PAC) and 16 PAC patients. Tumor angiogenesis was determined using immunohistochemistry of factor VIII-related antigen (FVIIIRAg) and ras mutations were identified by enriched-nested polymerase chain reaction. The mean number of FVIIIRAg-positive blood vessels was significantly (p < 0.005) higher in PAC (23.0 +/- 7.5), CP with a mutant K-ras genome (17.7 +/- 2.8) and CP with a normal K-ras genome (6.5 +/- 3.8), compared to unaffected areas. Codon 12 K-ras mutations were detected in three of 25 CP specimens (12%) and in 15 of 16 PAC specimens (94%). In CP patients with mutant K-ras in their genome, microvessel density was significantly (p < 0.01) elevated, compared to patients with a normal K-ras genome. Statistical analyses (Spearman rank-difference correlation coefficient, Student t test, and chi2 analysis) indicated a significant association between codon 12 K-ras mutations and tumor angiogenesis in both CP and PAC. This study demonstrates a significant association between angiogenesis and K-ras mutation in both PAC and CP. At a minimum, K-ras mutation is associated with the events that increase angiogenesis and it may potentiate or promote tumor angiogenesis.

Adenocarcinoma↗