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.

The impact of diabetes on arterial reconstructions for multilevel arterial occlusive disease11Presented at the 28th Annual Symposium on Vascular Surgery of the Society for Clinical Vascular Surgery, Rancho Mirage, California, March 15–19, 2000

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.

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.

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.

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.

2-Methoxyestradiol blocks estrogen-induced rat pituitary tumor growth and tumor angiogenesis: possible role of vascular endothelial growth factor

Natural and synthetic estrogens have been associated with several types of human and animal cancers including prolactin-secreting pituitary tumors in Fischer 344 rats. These prolactin-secreting tumors are highly angiogenic and their growth is angiogenic dependent. In the present study we have utilized this model to evaluate the effect of 2-methoxyestradiol (2-ME), an endogenous estrogen metabolite that is a potent inhibitor of endothelial cell proliferation in vitro, on estrogen-induced pituitary tumor growth and angiogenesis. Adult female rats were implanted (subcutaneously) with a silastic capsule containing estradiol-17beta (E2). After seven days of constant E2 exposure animals were injected (sc) daily with 25 mg/kg of 2-ME and killed either three or 8 days later. Changes in pituitary weight and proliferating cell nuclear antigen (PCNA) labeling index indicated growth while degree of angiogenesis was determined immunohistochemically using factor VIII related antigen. The results indicate that 2-ME inhibited estrogen-induced lactotroph growth by 32% and tumor angiogenesis by 89%. Furthermore, vascular endothelial growth factor (VEGF) expression, evaluated by immunohistochemical analysis, was down-regulated concomitant with tumor angiogenic suppression. These studies suggest that 2-ME may have therapeutic potential for hormone-induced cancer and that its angiostatic activity may be modulated through down-regulation of VEGF expression.

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.

Experimental tests of sex-allocation theory in plants

A general explanation for diversity in plant breeding systems is offered by sex-allocation theory. This theory assumes a trade-off between allocation of resources to the two sexual functions. It explains the high frequency of hermaphroditism in angiosperms by diminishing fitness returns on investment of more resources in a single function. Recent experimental studies provide tests of this theory by measuring male and female fitness gains, and examining the trade-off assumption. These studies show how fitness responds to shifts in allocation. Allocation traits often show heritable variation, but support for a trade-off remains weak.

Absence of conspecific pollen advantage in the dynamics of an Ipomopsis (Polemoniaceae) hybrid zone

The frequency of hybrid formation in angiosperms depends on how often heterospecific pollen is transferred to the stigma and on the success of that heterospecific pollen at fertilizing ovules. Even if heterospecific pollen is capable of effecting fertilization it may perform poorly when conspecific pollen is also available on the stigma. We applied pollen mixtures to stigmas to determine how pollen interactions affect siring success and the frequency of hybrid formation between two species of Ipomopsis (Polemoniaceae) in Colorado. Plants of both parental species and natural hybrids were pollinated with I. aggregata and I. tenuituba pollen in ratios of 100:0, 80:20, 50:50, 20:80, and 0:100 by mass. Plants were homozygous for different alleles at an isozyme marker, allowing us to distinguish the type of pollen parent for 2166 viable seeds from 273 fruits. In contrast to studies of many other hybridizing taxa, there was no evidence of an advantage to conspecific pollen, nor did composition of the stigmatic pollen load affect seed set. Instead, the frequency of seeds sired by a given species was proportional to its representation in the pollen load. In this hybrid zone, both the frequency of first-generation hybrid formation and the relative male fitness of the two parental species should be predictable from the rates of pollen transfer to stigmas.

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.

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.

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.

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.

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.

Overexpression of vascular endothelial growth factor164 and its co-receptor neuropilin-1 in estrogen-induced rat pituitary tumors and GH3 rat pituitary tumor cells

We have shown previously that the VEGF system plays a crucial role in regulation of tumor angiogenesis during the development of estrogen-induced prolactin-secreting pituitary tumors in Fisher 344 rats. Studies also suggested that both endothelial and non-endothelial cells expressed VEGF. However, several questions concerning the VEGF signals in regulation of estrogen-induced angiogenesis in rat pituitary remained unanswered. VEGF exists in a number of isoforms in human and rodent tissue (i.e., VEGF206h/205r, VEGF189h/188r, VEGF165h/164r, VEGF145h/144r and VEGF121) that differ in their molecular masses and biological activities. The VEGF isoforms bind with two tyrosine-kinase receptors, KDR/flk-1 and flt-1. In addition, VEGF165 binds with a newly identified co-receptor, neuropilin-1, which is expressed in human endothelial cells and several types of non-endothelial cells including tumor cells. The present study was undertaken to elucidate which isoforms of VEGF are predominantly expressed in normal Fisher 344 rat pituitaries, estrogen-induced prolactin secreting rat pituitary tumors and in prolactin secreting rat pituitary tumor cell line (GH3 cell line). To identify the isoform, RT-PCR with primer pairs derived from exon 1 and exon 8 of the VEGF gene, cloning, sequencing and Western blot analysis were performed. The status of neuropilin-1 in the rat pituitaries (normal and transformed) and GH3 pituitary tumor cell line has also been investigated using RT-PCR and Western blot analysis. These studies demonstrate that normal rat pituitaries, estrogen-induced rat pituitary tumors and GH3 pituitary tumor cells expressed VEGF164 and co-receptor, neuropilin-1. The VEGF164 was the predominant form in all of these cells. The VEGF164 and neuropilin-1 mRNA and protein levels were significantly higher in the estrogen-induced pituitary tumors and GH3 tumor cell line, as compared to normal pituitary. The data suggest that both VEGF164 and neuropilin-1 may actively participate in modulation of tumor angiogenesis and the development of pituitary tumors in Fisher 344 rats.

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.

Prospective long-term endoscopic and histologic follow-up of gastric lymphoproliferative disease of early stage IE low-grade B-cell mucosa-associated lymphoid tissue type following Helicobacter pylori eradication treatment

Long-term endoscopic and histologic follow-up of Stage IE gastric lymphoproliferative disease of the low-grade B-cell mucosa-associated lymphoid tissue (MALT) type following cure of H. pylori was undertaken. Clinical and endoscopic features (age, race, endoscopic appearance, cure of H. pylori and duration of follow-up) were also evaluated as potential prognostic indicators for complete or near-complete regression of low-grade MALT lymphoma. Sixty-eight MALT lymphoma patients prospectively underwent H. pylori eradication. follow-up at periodic intervals with endoscopy and extensive mucosal biopsy protocol on 65 patients ranging from 12 weeks up to 73 months (mean +/- SD of 22.5+/-15.8 months) has been completed. H. pylori was eradicated in 89.2% of MALT lymphoma patients with complete histologic regression noted in 58.5%, near-complete regression in 18.5%, partial in 4.6%, and no change in 18.5%. Univariate analysis revealed two factors predictive of complete and/or near complete MALT lymphoma regression, H. pylori cure (p=0. 001) and duration of follow-up (p=0.001). Stepwise logistic regression also demonstrated that both H. pylori cure (p<0.0001) and duration of follow-up (p<0.02) were independently associated with complete and near complete MALT lymphoma regression. Age, race, and endoscopic appearance were not predictive of regression. We conclude that this lymphoproliferative disease predictably undergoes complete to near-complete histologic regression at variable rates following cure of H. pylori in a majority of patients.

2-methoxyestradiol-induced growth suppression and lethality in estrogen-responsive MCF-7 cells may be mediated by down regulation of p34cdc2 and cyclin B1 expression

MCF-7 breast cancer cells increase their rate of proliferation, as indicated by incorporation of tritiated thymidine into DNA, when exposed to estrogen. In confirmation of other studies, 10 nM 17beta-estradiol (E2) increased proliferation by 2.8-fold after 6 days of exposure. As indicated by trypan blue exclusion and TUNEL assays, cell survival was increased and apoptosis decreased by the presence of E2. The estradiol metabolite 2-methoxyestradiol (2-ME) when present in the culture medium in concentrations greater than 1 microM for three days, dose-dependently reduced the effectiveness of E2 on cell proliferation by increasing the rate of apoptosis. To examine a mechanism for the increase in apoptosis, expression of p34cdc2 and cyclin B1 protein levels were monitored by examination of immunoblots of their proteins. E2 increased p34cdc2 and cyclin B1 protein levels significantly after 6 days of exposure. This effect was inhibited significantly by the presence of 2-ME. The results indicate that up-regulation of p34cdc2 and cyclin B1 is closely associated with increased survivability and lack of apoptosis in estrogen-induced proliferation of MCF-7 cells. Further, anti-estrogenic effects of 2-ME in these cells can be accounted for by its activation of apoptotic functions, which are correlated with reductions in expression of p34cdc2 and cyclin B1 genes.

Speech-intelligibility improvements using a binaural adaptive-scheme based conceptually on human auditory processing

A speech enhancement scheme is presented using diverse processing in sub-bands spaced according to a human-cochlear describing function. The binaural adaptive scheme decomposes the wide-band input signals into a number of band-limited signals, superficially similar to the treatment the human ears perform on incoming signals. The results of a series of intelligibility and formal listening tests are presented in which acoustic speech signals corrupted with recorded automobile noise were presented to 15 normal hearing volunteer subjects. For the experimental cases considered, the proposed binaural adaptive sub-band processing scheme delivers a statistically significant improvement in terms of both speech-intelligibility and perceived quality when compared with both the conventional wide-band processed and the noisy unprocessed case. The scheme is capable of extension to a potentially more flexible sub-band processing method based on a constrained artificial neural network (ANN).

Efficacy of dorsal pedal artery bypass in limb salvage for ischemic heel ulcers

PURPOSE

Although pedal artery bypass has been established as an effective and durable limb salvage procedure, the utility of these bypass grafts in limb salvage, specifically for the difficult problem of heel ulceration, remains undefined.

METHODS

We retrospectively reviewed 432 pedal bypass grafts placed for indications of ischemic gangrene or ulceration isolated to either the forefoot (n = 336) or heel (n = 96). Lesion-healing rates and life-table analysis of survival, patency, and limb salvage were compared for forefoot versus heel lesions. Preoperative angiograms were reviewed to evaluate the influence of an intact pedal arch on heel lesion healing.

RESULTS

Complete healing rates for forefoot and heel lesions were similar (90.5% vs 86.5%, P =.26), with comparable rates of major lower extremity amputation (9.8% vs 9.3%, P =.87). Time to complete healing in the heel lesion group ranged from 13 to 716 days, with a mean of 139 days. Preoperative angiography demonstrated an intact pedal arch in 48.8% of the patients with heel lesions. Healing and graft patency rates in these patients with heel lesions were independent of the presence of an intact arch, with healing rates of 90.2% and 83.7% (P =.38) and 2-year patency rates of 73.4% and 67.0% in complete and incomplete pedal arches, respectively. Comparison of 5-year primary and secondary patency rates between the forefoot and heel lesion groups were essentially identical, with primary rates of 56.9% versus 62.1% (P =.57) and secondary rates of 67.2% versus 60.3% (P =.50), respectively.

CONCLUSION

Bypass grafts to the dorsalis pedis artery provide substantial perfusion to the posterior foot such that the resulting limb salvage and healing rates for revascularized heel lesions is excellent and comparable with those observed for ischemic forefoot pathology.

Renal insufficiency and altered postoperative risk in carotid endarterectomy

PURPOSE

Higher complication rates have been reported in patients with renal insufficiency (RI) undergoing peripheral vascular surgery. Little attention has been paid specifically to carotid endarterectomy (CEA) in patients with RI where the risk/benefit considerations are very sensitive to small increases in postoperative complications.

METHODS

One thousand one consecutive CEAs performed since 1990 were reviewed from our vascular registry, and 73 CEAs on patients with RI were identified. For comparison, two groups were established: group I (n = 928), normal renal function (creatinine level, <1.5 mg/dL); and group II (n = 73), RI (creatinine level, >/=1.5 mg/dL).

RESULTS

Differences in the nonfatal stroke rates and combined stroke and death rates were statistically significant (P <.02) between the groups: group I (1. 08% and 1.18%) and group II (5.56% and 6.94%) respectively. Both groups were similar in regard to operative indications. In addition with the comparison of group I to group II, there was a statistically significant increase in hematoma rate, 1.61% versus 12. 5% ( P <.001), total cardiac morbidity, 1.72% versus 6.94% (P =.003), and total complications, 6.24% versus 36.1% (P =.001). Multivariate analysis demonstrated pre-existing RI to be the only significant predictor for perioperative stroke and hematoma.

CONCLUSION

Patients with preoperative RI are at a higher, but not prohibitive, risk for stroke and death after CEA than patients with normal renal function. They are also at risk for hematoma formation, cardiac morbidity, and overall complications. Care in selection of these patients for CEA must be emphasized.

Perioperative strokes after 1001 consecutive carotid endarterectomy procedures without an electroencephalogram: incidence, mechanism, and recovery

HYPOTHESIS

That alternative methods of cerebral protection, especially routine shunting of all patients undergoing general anesthesia or shunting on the basis of neurologic assessment with the patient awake under cervical plexus block, result in outcomes of carotid endarterectomy comparable with those reported using electroencephalographic monitoring.

DESIGN

Retrospective review of cases from a vascular registry established in 1990.

SETTING

Tertiary care center.

PATIENTS

Consecutive sample of 1001 patients who underwent carotid endarterectomy.

INTERVENTIONS

Carotid endarterectomy procedures were performed without electroencephalographic monitoring, using general anesthesia with routine shunting or using regional anesthesia.

MAIN OUTCOME MEASURES

Overall stroke and mortality rates and cause and consequence of the postoperative strokes.

RESULTS

There were 14 nonfatal strokes (1.4%) and 2 deaths (0.2%), for a combined stroke and death rate of 1.6%. Nine (64%) of the 14 strokes appeared to result from a technical error during the endarterectomy. Mild deficits were noted after 7 strokes (50%), with the remainder resulting in deficits that required inpatient rehabilitation. Twelve patients with strokes (86%) eventually returned home without need for assistance.

CONCLUSIONS

Most postoperative strokes in this series were due to technical errors. Overall, even in patients with strokes initially requiring inpatient rehabilitation, there was good recovery of function. Low stroke and mortality rates can be achieved in carotid endarterectomy without the use of electroencephalographic monitoring.

N-acetyltransferase 1 genetic polymorphism, cigarette smoking, well-done meat intake, and breast cancer risk

N-Acetyltransferase 1 (NAT1), encoded by the polymorphic NAT1 gene, has been shown to be one of the major enzymes in human breast tissue that activates aromatic and heterocyclic amines. Humans are mainly exposed to these carcinogens through cigarette smoking and consumption of well-done meat. To test the hypothesis that variations in the NAT1 gene are related to breast cancer risk, particularly among women who smoke or consume high levels of well-done meat, a nested case-control study was conducted in a prospective cohort study of 41,837 postmenopausal Iowa women. Information on cigarette smoking and other breast cancer risk factors was obtained at the baseline survey conducted in 1986. DNA samples and information on the consumption of well-done meat were obtained, in the case-control study, from breast cancer cases diagnosed from 1992 to 1994 and a random sample of cancer-free cohort members. Genomic DNA samples obtained from 154 cases and 330 controls were assayed for 11 NAT1 alleles (NAT1*3, *4, *5, *10, *11, *14, *15, *16, *17, *19, and *22). The NAT1*4 allele was the predominant allele observed in this study population, accounting for 73.2% (72.4% in cases versus 73.8% in controls) of the total alleles analyzed. Compared to controls, breast cancer cases had a slightly higher frequency of the NAT1*10 allele (18.8% in cases versus 17.3% in controls) and a substantially higher frequency of the NAT1*11 allele (3.6% versus 1.2%). In multivariate analyses, we found a 30% [95% confidence interval (CI) = 0.8-1.9] elevated risk of breast cancer associated with the NAT1*10 allele and a nearly 4-fold (95% CI = 1.5-10.5) elevated risk associated with the NAT1*11 allele. The positive association of breast cancer with the NAT1*11 allele was more evident among smokers [odds ratio (OR) = 13.2, 95% CI = 1.5-116.0] and those who consumed a high level of red meat (OR = 6.1, 95% CI = 1.1-33.2) or consistently consumed their red meat well done (OR = 5.6, 95% CI = 0.5-62.7). The association of the NAT1*10 allele with breast cancer was mainly confined to former smokers (OR = 3.3, 95% CI = 1.2-9.5). These findings are consistent with a role for the NAT1 gene in the etiology of human breast cancer.