Natural history of visceral branch artery dissections and the influence of concurrent aortic dissection on overall and intervention-free survival

OBJECTIVE

Visceral branch artery dissection (VBAD) is uncommon and may occur with or without an associated aortic dissection (AD). We hypothesized that isolated VBAD would have a more benign clinical course than those with concurrent AD and compared survival outcomes stratified based on aortic involvement.

METHODS

VBAD over a 5-year period were identified using International Classification of Diseases codes. Data related to patient demographics, comorbid conditions, clinical presentation, management (including procedural interventions), and survival were obtained from medical records. Anatomic imaging studies were reviewed to characterize anatomy, including the presence or absence of concurrent AD. Overall survival and intervention-free survival were evaluated using Kaplan-Meier and Cox proportional hazards models.

RESULTS

A total of 299 VBAD were identified, 174 of which were isolated VBAD and 125 were associated with concurrent AD. Seventy-one percent of patients were men, 77% were White, and 85% were non-Hispanic. The mean age was 61.1 ± 14.4 years. The mean follow-up was 53.2 ± 50.0 months. The estimated overall survival was 88.2% and the estimated overall intervention-free survival was 55.6% at 12 months. Isolated VBAD had better overall survival than those with concurrent AD (69.2% vs 32.4%; P < .001). Concurrent AD was also associated with inferior intervention-free survival (57.5% vs 7.3%; P < .001). Acute presentation was associated with decreased intervention-free survival (86.1% vs 13.4%; P < .001). Acute presentation was also associated with decreased overall survival in patients with isolated VBAD (60.8% vs 80.0% at 180 months; P < .001) and inferior intervention-free survival (48.4% vs 69.5% at 180 months; P < .001) in the subgroup of patients with isolated VBAD. Multivariable Cox models identified that age (hazard ratio [HR]: 1.05, standard deviation [SD]: 0.02; P = .001) was associated with inferior survival and renal dissections (HR: 3.08, SD: 0.99; P = .001) or mesenteric and renal dissections (HR: 3.39, SD: 1.44; P = .004) were associated with inferior intervention-free survival.

CONCLUSIONS

Isolated VBAD has superior overall and intervention-free survival to those associated with concurrent AD. The absence vs presence of aortic involvement is useful for risk stratification and may support tailored approaches to the frequency of imaging surveillance.

The Inequitable Experiences of Left-Handed Medical Students in Surgical Education

PURPOSE

Left-handed medical students contend with unique educational barriers within surgery, such as lack of educational resources, lack of left-handed-specific training, and widespread stigmatization of surgical left-handedness. This study aimed to highlight the surgical experiences of left-handed medical students so educators may be empowered to act with greater care and appreciation of these students' circumstances.

METHOD

In this qualitative study, the authors conducted semistructured interviews on surgical experiences during medical school between January 31, 2021, and June 20, 2021, on 31 current surgical residents and fellows from 15 U.S. institutions and 6 surgical specialties. Left-handed trainees were included regardless of their surgical hand dominance.

RESULTS

The authors identified 3 themes related to left-handed medical students' surgical experience: (1) disorienting advice from faculty or residents, (2) discouraging right-handed pressures and left-handed stigmatization, and (3) educational wishes of left-handed medical students. Trainees describe dialogues during medical school in which their handedness was directly addressed by residents and faculty with disorienting and nonbeneficial advice. Often trainees were explicitly told which hand to use, neglecting any preferences of the left-handed student. Participants also described possible changes in future surgical clerkships, including normalization of left-handedness, tangible mentorship, or granular and meaningful instruction.

CONCLUSIONS

Left-handed medical students encounter unique challenges during their surgical education. These students report being disoriented by the variability of advice provided by mentors, discouraged by how pressured they feel to operate right-handed, and burdened by the need to figure things out by themselves in the absence of adequate left-handed educational resources. Surgical education leadership should detail the unique problems left-handed learners face, impartially elicit the learner's current operative hand preference, take responsibility for their left-handed students, promote acceptance and accommodation strategies of left-handed surgical trainees, and endeavor to improve the breadth of left-handed surgical resources.

Factors associated with successful median arcuate ligament release in an international, multi-institutional cohort

OBJECTIVE

Prior research on median arcuate ligament syndrome has been limited to institutional case series, making the optimal approach to median arcuate ligament release (MALR) and resulting outcomes unclear. In the present study, we compared the outcomes of different approaches to MALR and determined the predictors of long-term treatment failure.

METHODS

The Vascular Low Frequency Disease Consortium is an international, multi-institutional research consortium. Data on open, laparoscopic, and robotic MALR performed from 2000 to 2020 were gathered. The primary outcome was treatment failure, defined as no improvement in median arcuate ligament syndrome symptoms after MALR or symptom recurrence between MALR and the last clinical follow-up.

RESULTS

For 516 patients treated at 24 institutions, open, laparoscopic, and robotic MALR had been performed in 227 (44.0%), 235 (45.5%), and 54 (10.5%) patients, respectively. Perioperative complications (ileus, cardiac, and wound complications; readmissions; unplanned procedures) occurred in 19.2% (open, 30.0%; laparoscopic, 8.9%; robotic, 18.5%; P < .001). The median follow-up was 1.59 years (interquartile range, 0.38-4.35 years). For the 488 patients with follow-up data available, 287 (58.8%) had had full relief, 119 (24.4%) had had partial relief, and 82 (16.8%) had derived no benefit from MALR. The 1- and 3-year freedom from treatment failure for the overall cohort was 63.8% (95% confidence interval [CI], 59.0%-68.3%) and 51.9% (95% CI, 46.1%-57.3%), respectively. The factors associated with an increased hazard of treatment failure on multivariable analysis included robotic MALR (hazard ratio [HR], 1.73; 95% CI, 1.16-2.59; P = .007), a history of gastroparesis (HR, 1.83; 95% CI, 1.09-3.09; P = .023), abdominal cancer (HR, 10.3; 95% CI, 3.06-34.6; P < .001), dysphagia and/or odynophagia (HR, 2.44; 95% CI, 1.27-4.69; P = .008), no relief from a celiac plexus block (HR, 2.18; 95% CI, 1.00-4.72; P = .049), and an increasing number of preoperative pain locations (HR, 1.12 per location; 95% CI, 1.00-1.25; P = .042). The factors associated with a lower hazard included increasing age (HR, 0.99 per increasing year; 95% CI, 0.98-1.0; P = .012) and an increasing number of preoperative diagnostic gastrointestinal studies (HR, 0.84 per study; 95% CI, 0.74-0.96; P = .012) Open and laparoscopic MALR resulted in similar long-term freedom from treatment failure. No radiographic parameters were associated with differences in treatment failure.

CONCLUSIONS

No difference was found in long-term failure after open vs laparoscopic MALR; however, open release was associated with higher perioperative morbidity. These results support the use of a preoperative celiac plexus block to aid in patient selection. Operative candidates for MALR should be counseled regarding the factors associated with treatment failure and the relatively high overall rate of treatment failure.

Characterizing patient-reported claudication treatment goals to support patient-centered treatment selection and measurement strategies

OBJECTIVE

Patient-reported outcomes (PRO) have been increasingly emphasized for peripheral artery disease (PAD). Patient-defined treatment goals and expectations, however, are poorly understood and might not be achievable or aligned with guidelines or clinical outcomes. We evaluated the patient-reported treatment goals among patients with claudication and the associations between patient characteristics, goals, and PAD-specific PRO scores.

METHODS

Patients with a diagnosis of claudication were prospectively recruited. Patient-defined treatment goals and outcomes related to walking distance, duration, and speed were quantified using multiple-choice survey items. Free-text items were used to identify activities other than walking distance, duration, or speed associated with symptoms and treatment goals. The peripheral artery disease quality of life and walking impairment questionnaire instruments were included as PRO. The treatment goal categories were compared with the PRO percentile scores using 95% confidence intervals (CIs), categorical tests, and logistic regression models. Associations between the patient characteristics and PRO were evaluated using linear and ordinal logistic regression models.

RESULTS

A total of 150 patients meeting the inclusion criteria were included in the present study. Of these 150 patients, 144 (96%) viewed the entire survey. Their mean age was 70.0 ± 11.3 years, and 32.9% were women. Most of the respondents had self-reported their race as White (n = 135), followed by Black (n = 3), Asian (n = 2), Native American (n = 2), and other/unknown (n = 2). Two participants self-reported Hispanic ethnicity. The primary treatment goals were an increased walking distance or duration without stopping (62.0%), the ability to perform a specific activity or task (23.0%), an increased walking speed (8.0%), or other/none of the above (7.0%). The specific activities associated with symptoms or goals included outdoor recreation (38.5%), labor-related tasks (30.7%), sports (26.9%), climbing stairs (23.1%), uphill walking (19.2%), and shopping (6%). Among the patients choosing an increased walking distance and duration as the primary goals, 64% had indicated that a distance of ≥0.5 mile (2640 ft) and 59% had indicated a duration of ≥30 minutes would be a minimum increase consistent with meaningful improvement. Increasing age was associated with lower odds of a distance improvement goal of ≥0.5 mile (odds ratio [OR], 0.68 per 5 years; 95% CI, 0.51-0.92; P = .012) or duration improvement goal of ≥30 minutes (OR, 0.76 per 5 years; 95% CI, 0.58-0.99; P = .047). Patient characteristics associated with PAD Quality of Life percentile scores included age, ankle brachial index, and gender. Ankle brachial index was the only patient characteristic associated with the walking impairment questionnaire percentile scores.

CONCLUSIONS

Patients define treatment goals according to their desired activities and expectations, which may influence their goals and perceived outcomes. Patients' expectations of minimum increases in walking distance and duration consistent with meaningful improvement exceeded reported minimum important difference criteria for many patients and would not be captured using common clinic-based walking tests. Patient age was associated with both treatment goals and PRO scores, and the related floor and ceiling effects could influence sensitivity to PRO changes for younger and older patients, respectively. Heterogeneity in treatment goals supports consideration of tailored decision-making and outcomes informed by patient characteristics and perspectives.

Focus group study of factors relevant to treatment decisions and experiences among patients with symptomatic peripheral artery disease

BACKGROUND

Clinical guidelines recommend shared decision-making for treatment of peripheral artery disease (PAD), which requires understanding of patient perspectives and preferences. We conducted a focus group study of patients with symptomatic PAD to identify factors important and relevant to treatment choices, and to characterize aspects of the healthcare process that contribute to positive versus negative experiences apart from the specific treatment(s) received.

METHODS

Participants were recruited from an academic medical center over two years using a purposeful sampling approach based on a clinical diagnosis of symptomatic PAD (either claudication or chronic limb threatening ischemia [CLTI]) confirmed by abnormal ankle or toe brachial index. Focus groups were led by a non-physician moderator, consisted of 5-12 participants, and were conducted separately for patients with CLTI and claudication. Audio recordings converted to verbatim transcripts were used for qualitative analysis.

RESULTS

51 patients (26 with CLTI and 25 with claudication) were enrolled and participated in focus groups. Major themes related to the process of care included: decision-making input, provider communication and trust, the timeline from diagnosis to definitive treatment, and compartmentalized care (including different venues of care). Major themes related to the process of care included: decision-making input, provider communication and trust, the timeline from diagnosis to definitive treatment, and compartmentalized care (including different venues of care).

CONCLUSIONS

The results provide insights into patient preferences, perspectives, and experiences related to PAD treatment. These observations can be used to inform patient-centered approaches to shared decision making, communication, and assessment of PAD treatment outcomes.

Reliability of hospital-level mortality in abdominal aortic aneurysm repair

OBJECTIVE

The relationship between volume and surgical outcomes has been shown for a variety of surgical procedures. The effects in abdominal aortic aneurysm repair have continued to be debated. Reliability adjustment has been used as a method to remove statistical noise from hospital-level outcomes. However, its impact on aortic aneurysm repair is not well understood.

METHODS

We used prospectively collected data from the Vascular Quality Initiative to identify all patients who had undergone abdominal aortic aneurysm repair from 2003 to 2019. We first calculated the hospital-level risk-adjusted 30-day mortality rates. We subsequently used hierarchical logistic regression modeling to adjust for measurement reliability using empirical Bayes techniques. The effect of volume on risk- and reliability-adjusted mortality rates was then assessed using linear regression.

RESULTS

Between 2003 and 2019, 67,073 abdominal aortic aneurysms were repaired, of which 11,601 (17.3%) were repaired with an open approach. The median annual volume was 7.4 (interquartile range, 3.0-13.3) for open repairs and 35.4 (interquartile range, 18.8-59.8) for endovascular repairs. Of the 223 hospitals that had performed open repairs during the study period, only 11 (4.9%) had performed ≥15 open repairs annually, and the risk-adjusted mortality rates varied from 0% to 75% across all centers. After reliability adjustment, the variability of the risk-adjusted mortality rates had decreased significantly to 1.3% to 8.2%. The endovascular repair risk-adjusted mortality rate variability had decreased from 0% to 14.3% to 0.3% to 2.8% after reliability adjustment. A decreasing trend in mortality was found with increasing an annual case volume for open repair with each additional annual case associated with a 0.012% decrease in mortality (P = .05); however, the relationship was not significant for endovascular repair (P = .793).

CONCLUSIONS

We found that most hospitals do not perform a sufficient number of annual cases to generate a reliable center-specific mortality rate for open aneurysm repair. Center-specific mortality rates for low-volume centers should be viewed with caution, because a substantial proportion of the variation for these outcomes will be statistical noise rather than true center-level differences in the quality of care.

How We Do It: A Multicenter National Experience of Virtual Vascular Surgery Rotations

OBJECTIVE

To describe the development and implementation of virtual vascular surgery rotations among 6 integrated vascular surgery programs.

DESIGN

A collaborative teleconference retrospectively discussing 6 independently developed virtual vascular surgery rotations to make a framework for future use.

SETTING

University of California Davis initiated a joint teleconference among the various integrated vascular surgery programs.

PARTICIPANTS

Vascular surgery faculty and residents from 6 programs participated in the teleconferences and drafting of a framework for building a virtual vascular surgery rotation.

RESULTS

Four specific domains were identified in discussing the framework to build a virtual vascular surgery rotation: planning, development, curriculum, and feedback. Each domain has specific aspects in making a virtual rotation that has applicability to other surgical rotations that seek to do the same.

CONCLUSION

Virtual vascular surgery rotations are feasible and important; these electives can be established and implemented successfully with appropriate planning and consideration. This work hopes to help programs navigate this new space in education by making it more transparent and highlighting potential pitfalls.

Exploring the rapid expansion of office-based laboratories and peripheral vascular interventions across the United States

OBJECTIVE

To characterize the relationship between office-based laboratory (OBL) use and Medicare payments for peripheral vascular interventions (PVI).

METHODS

Using the Centers for Medicare and Medicaid Services Provider Utilization and Payment Data Public Use Files from 2014 to 2017, we identified providers who performed percutaneous transluminal angioplasty, stent placement, and atherectomy. Procedures were aggregated at the provider and hospital referral region (HRR) level.

RESULTS

Between 2014 and 2017, 2641 providers performed 308,247 procedures. The mean payment for OBL stent placement in 2017 was $4383.39, and mean payment for OBL atherectomy was $13,079.63. The change in the mean payment amount varied significantly, from a decrease of $16.97 in HRR 146 to an increase of $43.77 per beneficiary over the study period in HRR 11. The change in the rate of PVI also varied substantially, and moderately correlated with change in payment across HRRs (R2 = 0.40; P < .001). The majority of HRRs experienced an increase in rate of PVI within OBLs, which strongly correlated with changes in payments (R2 = 0.85; P < .001). Furthermore, 85% of the variance in change in payment was explained by increases in OBL atherectomy (P < .001).

CONCLUSIONS

A rapid shift into the office setting for PVIs occurred within some HRRs, which was highly geographically variable and was strongly correlated with payments. Policymakers should revisit the current payment structure for OBL use and, in particular atherectomy, to better align the policy with its intended goals.

Industry Compensation to Physician Vascular Specialist Authors of Highly-referenced Aortic Aneurysm Studies

BACKGROUND

Industry payments to physicians may influence their attitudes toward medical devices and products. Disclosure of industry compensation by authors of scientific manuscripts usually occurs at the authors' discretion and is seldom audited as part of the peer review process. The purpose of this analysis was to characterize industry compensation among highly cited research articles related to aortic aneurysm.

METHODS

A Web of Science search for English language articles published from 2013-2017 using the search term "aortic aneurysm" identified publications for this study. The top 99 most-cited publications were abstracted by author. Physician authors with reported industry compensation from 2013-2016 were identified using the ProPublica Dollars for Docs search tool (linked to Centers for Medicare and Medicaid Services Open Payments data), based on provider name, medical specialty, and geographic location. Statistical analysis included descriptive statistics and categorical tests.

RESULTS

The 99 articles had 1,264 unique authors, of whom 105 physicians (8.3%) received industry compensation during the study period. Fourteen of the 105 authors self-reported having received industry compensation. The remaining 91 authors (86.7%) did not disclose their industry-reported compensation. Industry payments during the study period totaled $6,082,574 paid through 13,489 transactions from 169 different manufacturers. In-kind items and services were the most common form of payment (65.3%). The median transaction amount was $58.32. [$138.34]. Food and beverage accounted for the largest number of transactions (N=9653), followed by travel and lodging (N=2365), consulting (N=513), and promotional speaking (N=436). Consulting accounted for the most total dollars over the study period ($1,970,606), followed by travel and lodging ($1,122,276), promotional speaking ($972,894), food and beverage ($568,251), royalty or license ($504,631), honoraria ($452,167), and education ($428,489). Royalty and license payments had the highest median transaction amount ($15,418. [$29,049]), and was the only category with a median transaction amount greater than $5,000. In contrast, several categories had median transaction amounts under $50, including food and beverage ($32. [$77]), gifts ($34. [$86]), and entertainment ($30. [$69]). No significant difference in payment amounts by medical specialty was identified (P=0.071).

CONCLUSIONS

Only 8.3% of physician authors of highly cited aortic aneurysm studies received industry compensation, but 86.7% of those physician authors receiving payments did not disclose industry compensation within the manuscripts. Potential bias associated with industry compensation may be underestimated and conservatively biased based on author self-reporting.

Effect of concomitant deep venous reflux on truncal endovenous ablation outcomes in the Vascular Quality Initiative

OBJECTIVE

Few studies have investigated outcomes after truncal endovenous ablation in patients with combined deep and superficial reflux and no studies have evaluated patient-reported outcomes.

METHODS

We investigated the short- and long-term clinical and patient-reported outcomes among patients with and without deep venous reflux undergoing truncal endovenous ablation from 2015 to 2019 in the Vascular Quality Initiative. Preprocedural and postprocedural comparisons were performed using the t-test, χ², or their nonparametric counterpart when appropriate. Multivariable logistic regression models were used to assess for confounding.

RESULTS

A total of 4881 patients were included, of which 2254 (46.2%) had combined deep and superficial reflux. The median follow-up was 336.5 days. Patients with deep reflux were less likely to be female (65.9% vs 69.9%; P = .003), more likely to be Caucasian (90.2% vs 86.5%; P = .003) and had no difference in BMI (30.6 ± 7.5 vs 30.6 ± 7.2; P = .904). Additionally, no difference was seen in rates of prior varicose vein treatments, number of pregnancies, or history of deep venous thrombosis; however, patients without deep reflux were more likely to be on anticoagulation at the time of the procedure (10.9% vs 8.1%; P < .001). Patients without deep reflux had slightly higher median preprocedural Venous Clinical Severity Score (VCSS) scores (8 [interquartile range (IQR), 6-10]) vs 7 [IQR, 6-10]; P = .005) as well as postprocedural VCSS scores (5 [IQR, 3-7] vs 4 [IQR, 2-6]; P < .001). The median change in VCSS from before to after the procedure was lower for patients without deep reflux (3 [IQR, 1.0-5.5] vs 3.5 [IQR, 1-6]; P = .006). Total symptom score was higher for patients without deep reflux both before (median, 14 [IQR, 10-19] vs median, 13.5 [IQR, 9.5-18]; P = .005) and postprocedurally (median, 4 [IQR, 1-9] vs median, 3.25 [IQR, 1-7]; P < .001), but no difference was seen in change in symptom score (median, 8 [IQR, 4-13] vs median, 9 [IQR, 4-13]; P = .172). Patients with deep reflux had substantially higher rates of complications (10.4% vs 3.0%; P < .001), with a particular increase in proximal thrombus extension (3.1% vs 1.1%; P < .001). After controlling for confounding, this estimate of effect size for any complication increased (odds ratio, 5.72; 95% confidence interval, 2.21-14.81; P < .001).

CONCLUSIONS

No significant difference is seen in total symptom improvement when patients undergo truncal endovenous ablation with concomitant deep venous reflux, although a greater improvement was seen in VCSS score in these patients. Patients with deep venous reflux had a significantly increased rate of complications, independent of confounding variables, and should be counseled appropriately before the decision for treatment.

Comparison of unilateral vs bilateral and staged bilateral vs concurrent bilateral truncal endovenous ablation in the Vascular Quality Initiative

OBJECTIVE

Venous insufficiency is commonly bilateral, and patients often prefer single-episode care compared with staged procedures. Few studies have investigated clinical outcomes after unilateral vs bilateral venous ablation procedures or between staged and concurrent bilateral procedures. Here, we report data from the Vascular Quality Initiative regarding truncal venous ablation for chronic venous insufficiency.

METHODS

Using data from the Vascular Quality Initiative, we investigated immediate postoperative as well as long-term clinical and patient-reported outcomes of patients undergoing unilateral vs bilateral truncal endovenous ablation from 2015 to 2019. We further investigated outcomes between staged bilateral and concurrent bilateral ablations. Preprocedural and postprocedural comparisons were performed using t-test, χ² test, or their nonparametric counterpart when appropriate. Multivariable ordinal logistic regression was performed on ordinal outcome variables.

RESULTS

A total of 5029 patients were included, of whom 3782 (75.2%) underwent unilateral procedures. Median follow-up was 227 days (interquartile range [IQR], 55-788 days). Unilateral patients were less likely to be female (67.0% vs 70.3%; P = .031) and white (86.3% vs 91.2%; P < .001) and had lower body mass index (30.3 ± 7.3 kg/m² vs 31.8 ± 7.6 kg/m²; P < .001) compared with patients undergoing bilateral procedures. In addition, unilateral patients had fewer prior varicose vein treatments (23.0% vs 15.7%; P < .001) and had higher median preprocedural Venous Clinical Severity Score (VCSS; 8 [IQR, 6-10] vs 7 [IQR, 5.5-9]; P < .001). No difference was seen in complications (6.9% vs 8.2%; P = .292), and systemic complications were rare in both groups. No difference was seen in VCSS improvement after treatment (median, 3 [IQR, 1-6] for unilateral; median, 3 [IQR 1-5] for bilateral; P = .055). In comparing staged with concurrent bilateral procedures, there was no difference in overall complications (7.5% vs 12.2%; P = .144). Staged bilateral patients were older (56.9 ± 13.3 years vs 54.2 ± 12.9 years; P = .002), less likely to have had prior varicose vein treatment (14.3% vs 19.8%; P = .020), and more likely to be therapeutically anticoagulated (10.8% vs 6.5%; P = .028) compared with concurrent bilateral patients. Staged patients also have higher preprocedural VCSS compared with concurrent patients (median, 8 [IQR, 6-10] vs 7 [IQR, 5.5-9]; P < .001). In multivariable analysis, there was no difference in the likelihood of VCSS improvement for concurrent compared with staged procedures (odds ratio, 0.70; 95% confidence interval, 0.40-1.24; P = .226).

CONCLUSIONS

Concurrent bilateral truncal endovenous ablation can be performed safely without increased morbidity compared with staged bilateral or unilateral ablations.

Need for additional anesthesia after single injection spinal analgesia for labor: a retrospective cohort study

BACKGROUND

There is little information about the use and efficacy of single injection spinal blocks for labor analgesia; specifically, how frequently subsequent analgesia or anesthesia is needed. This study determined how frequently an additional anesthetic intervention was needed in women who received single injection spinal analgesia.

METHODS

This retrospective study examined electronic medical records to find all single injection spinal analgesic blocks for labor analgesia over a 14-year (2003-2016) period. Patient and block characteristics and patient outcomes were recorded. The primary outcome was need for an additional anesthetic intervention following single injection spinal for labor analgesia.

RESULTS

Four-hundred-and-twenty-eight patients received single injection spinal blocks for labor and 60 (14.0%) needed an additional anesthetic either for labor analgesia (n=49) or an unexpected procedure (n=11). Two of these (0.5%) required general anesthesia. Parity of zero (nulliparous), a low cervical dilation at the time of the spinal injection, and induction of labor status, were associated with an increased risk of needing an additional anesthetic intervention.

CONCLUSIONS

This retrospective review provides evidence that single injection spinal anesthesia may be used for multiparous women with spontaneous labor and more advanced cervical dilation.

Aggressive Phenotype of Intravascular Lymphoma Relative to Other Malignant Intraabdominal Tumors Requiring Vascular Reconstruction

BACKGROUND

Safe resection of intraabdominal and retroperitoneal malignancies with a goal of negative margins may require vascular surgical assistance with grafting of the aorta and/or vena cava. The current report reviews malignancies associated with major vascular reconstructions at a single tertiary referral center.

METHODS

Adults with abdominal or retroperitoneal tumors involving the aorta, vena cava, or iliac arteries that underwent reconstruction with vascular grafts at the University of Michigan from 2010 to 2016 were reviewed retrospectively. The initial presentation, surgical management, and outcomes were analyzed.

RESULTS

Twelve patients with tumors involving the abdominal aorta, vena cava, or iliac arteries underwent major vascular reconstruction in this seven-year study period. Tumor pathology included solid tumors (leiomyosarcoma [n = 7], germ cell tumor [n = 3], and intravascular lymphoma [n = 2]). Surgical treatment included grafting of the vena cava (n = 6), aorta (n = 3), iliac artery (n = 4), or both the aorta and vena cava (n = 1). Patients with intravascular lymphoma were identified incidentally during treatment of abdominal aortic aneurysm or on pathological analysis of thromboembolism from an aortic source. Other patients had planned resection. Follow-up ranged from 9 to 86 months (median: 28.9). There were no graft occlusions. Tumor metastasized or recurred in patients with sarcoma (n = 2; 28.6%), germ cell tumor (n = 1; 33.3%), and intravascular lymphoma (n = 2; 100%). Both patients with lymphoma had multiple anastomotic or tumor-embolic pseudoaneurysms for <14 months after vascular reconstruction. Both lymphoma patients died during follow-up.

CONCLUSIONS

This single-center review suggests that sarcoma and germ cell tumors may be safely resected in conjunction with major vascular reconstruction in carefully selected patients. In comparison, intravascular lymphoma identified incidentally at the time of aortic reconstruction resulted in a more malignant course with pseudoaneurysm formation of anastomoses or native vessels, cancer recurrence, and 100% mortality. Aneurysm contents and emboli should be carefully reviewed perioperatively by pathologists.

New predictors of complications in carotid body tumor resection

OBJECTIVE

This study examined the relationship between two new variables, tumor distance to base of skull (DTBOS) and tumor volume, with complications of carotid body tumor (CBT) resection, including bleeding and cranial nerve injury.

METHODS

Patients who underwent CBT resection between 2004 and 2014 were studied using a standardized, multi-institutional database. Demographic, perioperative, and outcomes data were collected. CBT measurements were determined from computed tomography, magnetic resonance imaging, and ultrasound examination.

RESULTS

There were 356 CBTs resected in 332 patients (mean age, 51 years; 72% female); 32% were classified as Shamblin I, 43% as Shamblin II, and 23% as Shamblin III. The mean DTBOS was 3.3 cm (standard deviation [SD], 2.1; range, 0-10), and the mean tumor volume was 209.7 cm³ (SD, 266.7; range, 1.1-1642.0 cm³). The mean estimated blood loss (EBL) was 257 mL (SD, 426; range, 0-3500 mL). Twenty-four percent of patients had cranial nerve injuries. The most common cranial nerves injured were the hypoglossal (10%), vagus (11%), and superior laryngeal (5%) nerves. Both Shamblin grade and DTBOS were statistically significantly correlated with EBL of surgery and cranial nerve injuries, whereas tumor volume was statistically significantly correlated with EBL. The logistic model for predicting blood loss and cranial nerve injury with all three variables-Shamblin, DTBOS, and volume (R² = 0.171, 0.221, respectively)-was superior to a model with Shamblin alone (R² = 0.043, 0.091, respectively). After adjusting for Shamblin grade and volume, every 1-cm decrease in DTBOS was associated with 1.8 times increase in risk of >250 mL of blood loss (95% confidence interval, 1.25-2.55) and 1.5 times increased risk of cranial nerve injury (95% confidence interval, 1.19-1.92).

CONCLUSIONS

This large study of CBTs demonstrates the value of preoperatively determining tumor dimensions and how far the tumor is located from the base of the skull. DTBOS and tumor volume, when used in combination with the Shamblin grade, better predict bleeding and cranial nerve injury risk. Furthermore, surgical resection before expansion toward the base of the skull reduces complications as every 1-cm decrease in the distance to the skull base results in 1.8 times increase in >250 mL of blood loss and 1.5 times increased risk of cranial nerve injury.

Ethanol and/or radiofrequency ablation to treat venolymphatic malformations that manifest as a bulging mass in the head and neck

AIM

To evaluate the efficacy of ultrasound (US)-guided ethanol ablation (EA) and radiofrequency ablation (RFA) for treating venolymphatic malformations (VLM) of the head and neck.

MATERIALS AND METHODS

US-guided EA and/or RFA were performed on 17 patients with VLM of the head and neck. Computed tomography (CT) or magnetic resonance imaging (MRI) was used to locate the cranial nerves and salivary gland ducts that were close to targets, and these were avoided during the procedures. Treatment response was assessed using volume reduction and cosmetic grading scoring.

RESULTS

Nine VLMs were located close to the functional structures: Stensen's duct (n=3), cranial nerve branch (n=3), or both (n=3). All patients demonstrated >50% volume reduction, except one patient with a microcystic lymphatic malformation that was abutting the facial nerve. Median cosmetic grading scores improved from 4 to 1 (p<0.001).

CONCLUSION

US-guided EA and/or RFA are effective and safe treatment methods in patients with VLMs of the head and neck. Treatment selection of EA and/or RFA could be performed based on the composition of VLMs as assessed at CT and MRI.

General Anesthesia Is Not Necessary for Hemodialysis Access Surgery

Chronic kidney disease has been identified as a risk factor for mortality after procedures under general anesthesia (GA). However, a recent study showed that 85 per cent of arteriovenous fistulas in the United States are performed under GA. Our aim was to demonstrate that GA can be avoided in patients with chronic kidney disease and end-stage renal disease by using local anesthesia (LA) with monitored anesthesia care or brachial plexus block (BPB) during hemodialysis access surgery. A retrospective review was performed at a single institution. Outcome measures included need for conversion to GA, major perioperative complications, and 30-day mortality. Four hundred and fourteen access procedures were performed by seven vascular surgeons between 2011 and 2014. Arteriovenous fistulas were placed in 379 (92%), arteriovenous grafts were placed in 31 (7%), and four (1%) received unsuccessful extremity exploration. Anesthetic approach was LA in 344 (83%) and BPB in 64 (15%). GA was initially induced in three (0.7%) and three (0.7%) additional patients required conversion to GA from LA. There were no cardiopulmonary events or perioperative deaths. Of the 32 patients who received an arteriovenous graft, only three (10%) required GA. In conclusion, LA and BPB are safe and conversion to GA is rare. GA should be avoided in hemodialysis access surgery.

General Anesthesia is Not Necessary for Hemodialysis Access Surgery

Chronic kidney disease has been identified as a risk factor for mortality after procedures under general anesthesia (GA). However, a recent study showed that 85 per cent of arteriovenous fistulas in the United States are performed under GA. Our aim was to demonstrate that GA can be avoided in patients with chronic kidney disease and end-stage renal disease by using local anesthesia (LA) with monitored anesthesia care or brachial plexus block (BPB) during hemodialysis access surgery. A retrospective review was performed at a single institution. Outcome measures included need for conversion to GA, major perioperative complications, and 30-day mortality. Four hundred and fourteen access procedures were performed by seven vascular surgeons between 2011 and 2014. Arteriovenous fistulas were placed in 379 (92%), arteriovenous grafts were placed in 31 (7%), and four (1%) received unsuccessful extremity exploration. Anesthetic approach was LA in 344 (83%) and BPB in 64 (15%). GA was initially induced in three (0.7%) and three (0.7%) additional patients required conversion to GA from LA. There were no cardiopulmonary events or perioperative deaths. Of the 32 patients who received an arteriovenous graft, only three (10%) required GA. In conclusion, LA and BPB are safe and conversion to GA is rare. GA should be avoided in hemodialysis access surgery.

Adjuvant chemotherapy for gastric cancer: a randomised phase 3 trial of mitomycin-C plus either short-term doxifluridine or long-term doxifluridine plus cisplatin after curative D2 gastrectomy (AMC0201)

BACKGROUND

This phase 3 study evaluated the efficacy of new adjuvant chemotherapy (MFP), which intensified the mitomycin-C (MMC) plus short-term doxifluridine (Mf) for gastric cancer.

PATIENTS AND METHODS

A total of 855 patients (424 in Mf, 431 in MFP) with pathological stage II-IV (M0) gastric cancer after D2 gastrectomy were randomly assigned to receive either Mf (MMC 20 mg m(-2), followed by oral doxifluridine 460-600 mg m(-2) per day for 3 months) or MFP (MMC 20 mg m(-2), followed by oral doxifluridine 460-600 mg m(-2) per day for 12 months with 6 monthly infusions of 60 mg m(-2) of cisplatin) chemotherapy.

RESULTS

With a median follow-up of 6.6 years, there was no difference between the two groups in recurrence-free survival (RFS) (5-year RFS 61.1% in Mf and 57.9% in MFP; hazard ratio 1.10 (95% CI 0.89-1.35); P=0.39) and overall survival (OS) (5-year OS 66.5% in Mf and 65.0% in MFP; hazard ratio 1.11 (95% CI 0.89-1.39); P=0.33).

CONCLUSION

Intensification of Mf adjuvant chemotherapy by prolonging the duration of oral fluoropyrimidine and adding cisplatin was safe but not effective to improve the survivals in curatively resected gastric cancer patients.

Effects of international health electives on medical student learning and career choice: results of a systematic literature review

BACKGROUND AND OBJECTIVES

The present study reviewed the published literature to examine the effects of international health electives (IHEs) on medical student learning and career choice.

METHODS

A systematic literature review was conducted to identify key English-language articles on IHEs, using PubMed journal databases for the period 1990--2009. Article inclusion for this review was vetted by a rigorous evaluation of each article's study methods, content, and data quality. Pooled or aggregate information from 11 key articles, including information on type and duration of IHE, study and comparison group characteristics, and measured outcomes such as self-reported changes in cultural competency, clinical skills, and specialty choice, were extracted and summarized.

RESULTS

Findings suggest that having IHE experiences contributed to a more well-rounded training for medical students; students reported being more culturally competent and were more likely to choose a primary care specialty and/or a public service career.

CONCLUSIONS

Although IHE experiences appear to have educational benefits, the quality and availability of these electives vary by institution. Barriers to ensuring that students attain a safe and rich experience include the lack of consistent categorical funding, safety concerns when traveling, and limited faculty experience and resources to support and guide students during their rotations abroad.

A non-doped organic light emitting diode with pure red emission using a new host emitter

A red fluorescent material (2E,2'E)-3,3'-[4,4"-bis(dimethylamino)-1,1': 4',1 "-terphenyl-2',5'-diyl]bis[2-(2-thienyl)acrylonitrile] (ABCV-Th) was synthesized for use in organic light emitting diodes (OLEDs) as the host emissive material. It has been reported some green and blue host emissive materials used in OLEDs revealed high device performance but, owing to concentration quenching, comparable red light emitting materials are still rare in OLEDs application. Non-doped organic light emitting diodes, with the structure of ITO/NPB/ABCV-Th (30 nm and 50 nm)/BCP/Alq3/Liq/Al were fabricated using ABCV-Th as the host emitter. The peak wavelength and full width at half maximum (FWHM) of electroluminescence (EL) were 629.5 nm and 68.5 nm, respectively. The maximum brightness and turn on voltage of the device were measured to be 1330 cd/m2 at 14.6 V and 3.4 V, respectively. The device exhibited authentic red emission (Commission Internationale De L'Eclairage (CIE(xy)) = 0.65, 0.34) which is almost close to the standard red (CIE(xy) = 0.67, 0.33) demanded by the national television system committee (NTSC).

Isolated acute cellular rejection of the liver after simultaneous liver and kidney transplantation: a case report

Simultaneous liver and kidney transplantation (SLKT) is now considered the treatment of choice for patients with concurrent end-stage liver and kidney diseases. Even though the early postoperative mortality rate following SLKT is reported to be high compared to that of liver transplantation alone, the liver graft from the same donor has been argued to induce better kidney graft acceptance as evidenced by a low rate of acute renal rejection episodes. There have been many reports of a low incidence of acute renal rejection following SLKT; however, only a few cases were proven by simultaneous biopsies. The authors experienced a case of biopsy-proven isolated acute cellular rejection of the liver graft following SLKT.

Dual enteric and respiratory tropisms of winter dysentery bovine coronavirus in calves

Although winter dysentery (WD), which is caused by the bovine coronavirus (BCoV) is characterized by the sudden onset of diarrhea in many adult cattle in a herd, the pathogenesis of the WD-BCoV is not completely understood. In this study, colostrum-deprived calves were experimentally infected with a Korean WD-BCoV strain and examined for viremia, enteric and nasal virus shedding as well as for viral antigen expression and virus-associated lesions in the small and large intestines and the upper and lower respiratory tract from 1 to 8 days after an oral infection. The WD-BCoV-inoculated calves showed gradual villous atrophy in the small intestine and a gradual increase in the crypt depth of the large intestine. The WD-BCoV-infected animals showed epithelial damage in nasal turbinates, trachea and lungs, and interstitial pneumonia. The WD-BCoV antigen was detected in the epithelium of the small and large intestines, nasal turbinates, trachea and lungs. WD-BCoV RNA was detected in the serum from post-inoculation day 3. These results show that the WD-BCoV has dual tropism and induces pathological changes in both the digestive and respiratory tracts of calves. To our knowledge, this is the first detailed report of dual enteric and respiratory tropisms of WD-BCoV in calves. Comprehensive studies of the dual tissue pathogenesis of the BCoV might contribute to an increased understanding of similar pneumoenteric CoV infections in humans.

Differential induction of glioblastoma migration and growth by two forms of pleiotrophin

Glioblastoma is the most common malignant brain tumor of adults and one of the most lethal cancers. The secreted growth factor pleiotrophin (PTN) promotes glioblastoma migration and proliferation, initiating its oncogenic activities through two cell surface receptors, the protein tyrosine phosphatase receptor zeta (PTPRZ1) and the anaplastic lymphoma kinase (ALK), respectively. Here, we report on the presence and purification of two naturally occurring forms of PTN (18 and 15 kDa) that differentially promote glioblastoma migration and proliferation. Using a panel of glioblastoma cell lines, including low passage patient-derived cultures, we demonstrate that PTN15 promotes glioblastoma proliferation in an ALK-dependent fashion, whereas immobilized PTN18 promotes haptotactic migration of glioblastoma cells in a PTPRZ1-dependent fashion. Mass spectrometric analysis indicated that PTN15 differs from PTN18 by processing of 12 C-terminal amino acids. To demonstrate clinical relevance, we show that PTN15, PTN18, and PTPRZ1 are significantly overexpressed in glioblastoma relative to normal brain at both mRNA and protein levels using microarray, Western blot, and tissue microarray analyses on human tumors. These results indicate that the PTN18-PTPRZ1 and the PTN15-ALK signaling pathways represent potentially important therapeutic targets for glioblastoma invasion and growth.

Chromogenic in situ hybridization analysis of HER-2/neu status in cytological samples of breast carcinoma

The current use of humanized monoclonal antibody trastuzumab for the treatment of patients with metastatic breast cancer has made evaluation of HER-2/neu status an important clinical issue. Chromogenic in situ hybridization (CISH), in which the DNA probe is detected with an immunohistochemistry (IHC)-like peroxidase reaction, has been recently developed for the assessment of HER-2/neu status in formalin-fixed breast cancer specimens. We have applied the technique of dual-colour CISH using HER-2/neu and chromosome 17 centromere probes in 27 cytological smears, and these cytological samples were obtained from scrapings of fresh breast tumours. We also investigated HER-2/neu amplification and protein overexpression in the corresponding surgical tissues by CISH and IHC using the monoclonal antibody CB11. Of the 27 cytological cases, HER-2/neu gene amplification was observed in nine cases that were positive cases (2+ and 3+) for IHC. Among the 13 IHC positive cases (2+ and 3+), four of them showed no gene amplification. Identical results for the CISH technique were obtained in the matched surgical samples. The scrape samples from fresh breast tumour offer a monolayer cell population that is especially suitable for CISH. This study has shown that the cytological smear might be a good alternative for the CISH test.

Rewarding and locomotor-activating effects of direct dopamine receptor agonists are augmented by chronic food restriction in rats

RATIONALE

Previous studies indicate that chronic food restriction augments the rewarding and motor-activating effects of diverse drugs of abuse. The drugs that have so far proved susceptible to the augmenting effect of food restriction all increase synaptic concentrations of dopamine (DA). It is not known whether behavioral effects of selective, direct DA receptor agonists are also subject to the augmenting effect of food restriction.

OBJECTIVES

The first objective of this study was to investigate whether the rewarding and locomotor-activating effects of the D1 agonist, A77636, and the D2 agonist, quinpirole are augmented by chronic food restriction. The second purpose was to investigate whether the augmented rewarding and locomotor-activating effects of d-amphetamine in food-restricted rats are reversed by the D1 antagonist, SCH23390.

METHODS

Rewarding effects of drugs were measured in terms of their ability to lower the threshold for lateral hypothalamic self-stimulation (LHSS) using a rate-frequency method. Locomotor-activating effects were measured in terms of the number of midline crossings exhibited by rats in a shuttle apparatus.

RESULTS

A77636 (1.0 and 2.5 mg/kg, i.p.) produced a greater threshold-lowering effect in food-restricted than ad libitum fed rats but produced variable effects on locomotor activity with no difference between groups. Quinpirole (0.2 and 0.5 mg/kg, i.p.) produced a marginally greater threshold-lowering effect in food-restricted rats and a dramatic locomotor response that was exclusive to food-restricted rats. The D1 antagonist, SCH23390, at a dose of 0.01 mg/kg (i.p.), had no effect on the lowering of LHSS threshold by amphetamine (0.5 mg/kg, i.p.) in ad libitum fed rats but blocked the augmentation otherwise observed in food-restricted rats. SCH23390, at a dose of 0.025 mg/kg, had no effect on locomotor activity induced by amphetamine (0.5 mg/kg) in ad libitum fed rats but blocked the augmentation otherwise observed in food-restricted rats.

CONCLUSIONS

These results indicate that the augmentation of reward by food restriction extends to drugs that bypass the DA terminal and act postsynaptically. When taken together with prior immunohistochemical and behavioral findings, these results suggest that food restriction may increase the "enabling" effect of the D1 receptor on DA-mediated behaviors.

Chronic food restriction in rats augments the central rewarding effect of cocaine and the delta1 opioid agonist, DPDPE, but not the delta2 agonist, deltorphin-II

RATIONALE

Chronic food restriction augments the self-administration and locomotor stimulating effects of opiates, psychostimulants and NMDA antagonists. The extent to which these effects can be attributed to changes in drug pharmacokinetics and bioavailability versus sensitivity of the neuronal circuits that mediate the affected behavioral functions, has not been established. Recent studies point to central adaptive changes insofar as rewarding, locomotor and c-fos-inducing effects of amphetamine and MK-801, injected directly into the lateral ventricle, are greater in food-restricted than ad libitum fed rats. The increased expression of c-fos in nucleus accumbens (NAC) shell, in particular, suggests that food restriction may augment drug reward by modulating dopamine (DA) synaptic function in this area.

OBJECTIVES

The first purpose of this study was to investigate whether the rewarding effects of cocaine and the delta1 opioid agonist DPDPE, both of which increase DA synaptic transmission, are augmented by food restriction. The second purpose was to determine whether the delta2 opioid agonist, deltorphin-II, which has been reported to exert DA-independent rewarding effects, is subject to the potentiating effect of food restriction.

METHODS

Rewarding effects of drugs were measured in terms of their ability to lower the threshold for lateral hypothalamic self-stimulation (LHSS) using a rate-frequency method.

RESULTS

In separate experiments, cocaine (50, 100 and 150 microg, ICV) and DPDPE (10 and 25 microg, ICV) produced greater threshold-lowering effects in food-restricted than ad libitum fed rats. Deltorphin-II (5.0, 10 and 25 microg, ICV) had no effect on reward thresholds, regardless of feeding regimen.

CONCLUSIONS

While the reported DA-independence of deltorphin-II rewarding effects seemed to offer a means of testing the hypothesis that DA transmission is the critical modulated variable in food-restricted subjects, rewarding effects of this compound could not be demonstrated in the LHSS paradigm. The present results do, however, confirm and extend prior findings indicating that the enhanced self-administration of abused drugs by food-restricted subjects is due to enhanced sensitivity of a final common pathway for drug reward.

Annexin I is a stress protein induced by heat, oxidative stress and a sulfhydryl-reactive agent

Annexin I (also called lipocortin 1) is a 37-kDa member of the annexin family of proteins. It has been proposed to be involved in the regulation of cell growth and differentiation, apoptosis, and inflammation. Previously, we have reported that annexin I displays a chaperone-like function (Kim, G.Y., Lee, H.B., Lee, S.O., Rhee, H.J. & Na, D.S. (1997) Biochem. Mol. Biol. Int. 43, 521-528). To determine the possibility that annexin I is a stress protein, we examined whether expression of annexin I and annexin I mRNA increases in response to stresses in A549 and HeLa cells. Treatments of cells with heat, hydrogen peroxide or sodium arsenite resulted in (a) an increase in annexin I and annexin I mRNA and (b) translocation of annexin I from the cytoplasm to the nucleus and perinuclear region. The annexin I gene promoter region, cloned upstream of a reporter gene, was inducible in response to heat, hydrogen peroxide, and sodium arsenite. These results indicate that annexin I serves as a stress protein and annexins may constitute a new class of stress proteins.

Altered cell cycle control at the G(2)/M phases in aryl hydrocarbon receptor-null embryo fibroblast

The aryl hydrocarbon receptor (AHR) is known to mediate the toxic and carcinogenic effects of polycyclic aromatic hydrocarbons and dioxins. High-affinity AHR ligands, such as 2,3,7, 8-tetrachlorodibenzeno-p-dioxin, have been shown to modify cell proliferation and differentiation. However, the mechanisms by which AHR affects cell proliferation and differentiation are not fully understood. To investigate the role of AHR in cell proliferation, mouse embryonic fibroblasts (MEFs) derived from AHR-null mice were obtained and characterized. Compared with wild-type MEFs, AHR-null cells exhibited a lower proliferation rate with an accumulation of 4N DNA content and increased apoptosis. The expression levels of Cdc2 and Plk, two kinases important for G(2)/M phase of cell cycle, were down-regulated in AHR-null MEFs. In contrast, transforming growth factor-beta (TGF-beta), a proliferation inhibitor in several cell lines, was present at high levels in conditioned medium from AHR-null MEFs. Concomitant with G(2)/M cell accumulation, treatment of wild-type MEFs with TGF-beta3 also resulted in down-regulation of both Cdc2 and Plk. Thus, overproduction of TGF-beta in AHR-deficient cells appears to be the primary factor that causes low proliferation rates and increased apoptosis. Taken together, these results suggest that AHR influences TGF-beta production, leading to an alteration in cell cycle control.

Solubilization of biphenyl dimethyl dicarboxylate by cosolvency

Biphenyl dimethyl dicarboxylate (BDD) is a synthetic analogue of schizandrin C, one of the components isolated from Fructus schizandrae, and has been widely prescribed for improvement of liver functions and symptoms of patients with liver disease. However, its oral preparations have been known to have limited bioavailability due to its extremely low solubility in water, and its solubility problem also limits preparation of its parenteral dosage forms. In this research, we searched for solvent systems to solubilize BDD to overcome these problems. The ternary solvent systems of N,N'-dimethylacetamide (DMA)/alcohol/water and Cremophor EL/DMA/alcohol were studied intensively for this purpose. BDD was solubilized effectively in these cosolvents, and the results showed that the cosolvent systems were effective for solubilizing BDD up to the concentration that might be employed for preparation of parenteral dosage forms. Formulation of a BDD concentrate for intravenous infusion was proposed employing the cosolvent system of Cremophor EL/DMA/alcohol.

Reduced expression of tissue inhibitor of metalloproteinase in nodal metastasis of stomach cancer

The matrix metalloproteinases (MMPs) have been associated with tumor cell invasion and metastasis of human cancers by mediating the degradation of extracellular matrix components. Therefore, these enzymes and their inhibitor (TIMP-2) constitute promising targets in the development of anticancer therapies. In order to investigate the correlation between expressions of TIMP-2, MMPs and clinical outcome, immunohistochemical staining of MMP-2, MMP-9, and TIMP-2 were performed on paraffin-embedded tissue sections of 15 early gastric cancers (EGC) and 15 advanced gastric carcinomas (AGC) without nodal metastasis and 15 AGC with nodal metastasis (AGCn+). MMP-2 and MMP-9 were expressed in neoplastic cell plasma membrane in 83.3% and 88% of cases of AGC, respectively with inter-tumoral variability of staining intensity. MMP-2 and MMP-9 staining were not correlated with presence of nodal metastasis or degree of invasion depth at the time of diagnosis (p>0.05). The immunoreactivity of TIMP-2 was detected in the peri-tumoral stroma. Residual benign stomach tissue showed no or weak immunoreactivity for TIMP-2 staining. Among AGC, neoplasms with diffuse and strong TIMP-2 staining have less frequent metastasis (28.6%) than cases with focal and weak (68.8%) (p<0.05). Early gastric cancer revealed diffuse and strong TIMP-2 expressions. We conclude that clinical outcome such as depth of invasion or metastasis is more closely related to the expression of TIMP-2 than the corresponding MMPs.

Chaperone-like function of lipocortin 1

Lipocortin 1 (LC1) is a 37 kDa member of the annexin family of proteins. It has been proposed to act as a mediator of some of the actions of glucocorticoids in anti-inflammatory and immune suppressive functions. LC1 has been shown to play a role in cell proliferation, apoptosis, and differentiation. However, the exact biological functions of LC1 still remain obscure. Here it is shown that LC1 displays a chaperone-like function. Stoichiometric amounts of LC1 suppressed thermally induced inactivation and aggregation of the test enzymes citrate synthase and glutamate dehydrogenase. LC1 was also effective in refolding guanine hydrochloride-denatured glutamate dehydrogenase, as judged by circular dichroism spectroscopy.

Purification and characterization of novel heparin-binding growth factors in uterine secretory fluids. Identification as heparin-regulated Mr 10,000 forms of connective tissue growth factor

Uterine growth factors are potential effector molecules in embryo growth signaling pathways. Pig uterine luminal flushings contained a heparin-binding growth factor (HBGF) that required 0.8 M NaCl for elution from heparin columns and was termed HBGF-0.8. This factor, which was heat- and acid-labile and of Mr 10,000 as assessed by gel filtration, stimulated DNA synthesis in fibroblasts and smooth muscle cells but not endothelial cells. Two forms of HBGF-0.8, termed HBGF-0.8-P1 and HBGF-0.8-P2, exhibited differential heparin-binding properties. SDS-polyacrylamide gel electrophoresis showed that each form of HBGF-0.8 migrated with an apparent Mr of 10, 000 under reducing conditions. Amino acid sequencing revealed the N-terminal sequence EENIKKGKKXIRTPKI for HBGF-0.8-P1 and ENIKKGKKXIRT for HBGF-0.8-P2. These sequences corresponded, respectively, to residues 247-262 and 248-259 of the 349-residue predicted primary translation product of porcine connective tissue growth factor (pCTGF). 10-kDa CTGF-mediated fibroblast DNA synthesis was modulated by exogenous heparin, and CTGF-immunoreactive proteins of 10, 16, and 20 kDa were present in unfractionated uterine luminal flushings. These data reveal the identity of a novel growth factor in uterine fluids as a highly truncated form of CTGF and show that the N-terminal two-thirds of the CTGF primary translation product is not required for mitogenic activity or heparin binding.

Inhibition of neointimal proliferation of rat carotid artery by sulodexide

Sulodexide, a glycosaminoglycan-containing compound, is known to have an antiproliferative effect on vascular smooth-muscle cells, in vitro, as well as antithrombotic and fibrinolytic effects. But there are few reports about the effect of neointimal proliferation in vivo. In this study, we examined whether Sulodexide was effective in the inhibition of neointimal proliferation after vascular injury. Ten-week-old Sprague-Dawley rats were subjected to vascular injury by endothelial denudation of the common carotid artery by using a balloon catheter. They were then allocated randomly into a control group (saline 2 ml for 3 days, and then 1 ml for 18 days, IM) and a treated group (Sulodexide 10 mg/kg/day for 3 days, and then 4 mg/kg/day for 18 days, IM). Three weeks after vascular injury, we analyzed the neointimal proliferation using morphometry. The neointimal proliferation was significantly reduced in the treated group compared to the control group (Ratio of neointimal area to medial area; 118.39 +/- 6.80% in the treated group, 177.25 +/- 17.25% in the control group). This result showed that Sulodexide might be effective in reducing the rate of restenosis after balloon angioplasty.

High molecular mass forms of epidermal growth factor in pig uterine secretions

Accumulating evidence suggests that uterine luminal fluids contain a variety of polypeptide growth factors and cytokines that, it is speculated, have roles in the development, growth and differentiation of the uterus and, during pregnancy, in the growth and survival of the embryo. Although epidermal growth factor (EGF) has previously been identified by radioimmunoassay and immunohistochemistry in the pig uterus, there have been no detailed studies of the secreted EGF protein. EGF was therefore purified from uterine flushings and uterine fluids of nonpregnant pigs of mixed breed using a variety of ion-exchange chromatography steps. Uterine flushings and fluids contained an anionic factor(s) that at 4 degrees C competed with 125I-labelled mouse EGF for binding to EGF receptors on an endometrial carcinoma cell line and stimulated DNA synthesis in Balb/c mouse 3T3 fibroblasts. As analysed by gel filtration, uterine fluids contained a 3-6 kDa factor that stimulated 3T3 cell DNA synthesis and was a competitor of cellular 125I-labelled EGF binding. Gel filtration further revealed that uterine flushings and fluids contained, respectively, 45 kDa and 40-70 kDa moieties that were mitogenic and that bound to the EGF receptor. SDS-PAGE and western blotting using an antiserum specific for pig EGF revealed immunoreactive forms of EGF of approximately 25 kDa in partially purified uterine flushings. It is concluded that uterine secretory EGF occurs, at least in part, as high molecular mass proteins. The ability of these high molecular mass EGFs to bind to and activate the EGF receptor suggests that they may be authentic ligands for the EGF receptor in utero.

Pig uterine luminal fluid contains the developmentally regulated neurotrophic factor, pleiotrophin

The pig conceptus produces a non-invasive placenta which is probably dependent on uterine secretory products during both the pre- and post-attachment periods. Since some of these factors are also produced during the oestrous cycle, uterine luminal flushings (ULF) from adult nonpregnant pigs were analysed to identify potentially important maternally-secreted growth factors or cytokines. ULF contained several proteins that were detected on Western blots by an antibody raised against the N-terminal 14 amino acids of rat pleiotrophin (PTN). One of the proteins co-migrated on SDS-PAGE gels and co-eluted from heparin-affinity columns with 18 kDa recombinant human PTN, suggesting its identity as the intact native porcine PTN (pPTN) molecule. Additional immunoreactive forms of pPTN were identified that were of lower molecular mass (14-16 kDa), had lower heparin-affinities, were more hydrophobic, and were apparently C-terminally truncated. Native pPTN was isolated from ULF using cation-exchange chromatography, heparin-affinity fast protein liquid chromatography and C4 reverse-phase high performance liquid chromatography. Structural analysis of the purified protein resulted in definitive identification of 15 out of 17 N-terminal amino acids; these were 100% conserved with the corresponding residues of human, bovine and rat PTN. These results demonstrate various biochemical properties of pPTN and suggest that, in addition to the apparent involvement of PTN in differentiation during early neonatal life, it may be delivered in uterine secretory fluids to, as yet, undefined target cells in the reproductive tract of the adult female.

Purification of heparin-binding epidermal growth factor-like growth factor from pig uterine luminal flushings, and its production by endometrial tissues

Pig uterine luminal flushings contain at least four heparin-binding growth factors (HBGF) that stimulate fibroblast [3H]thymidine incorporation. One of these factors, which appeared to be a relatively minor HBGF, was eluted from heparin affinity columns by 1.0 M NaCl and was found to compete with 125I-epidermal growth factor (EGF) for binding to an endometrial carcinoma cell line. This EGF receptor (EGF-R)-binding property was abolished by an antiserum to heparin-binding EGF-like growth factor (HB-EGF) that specifically blocks binding of HB-EGF to the EGF-R. Reverse-phase HPLC resulted in the purification of two EGF-R-binding activities correlated with 13,500 and 17,000 M(r) proteins that reacted with an antiserum raised against residues 9-26 of human HB-EGF. Uterine extracts also contained an EGF-R-binding factor that was eluted from heparin by 1.0 M NaCl and was antagonized by HB-EGF antiserum. Endometrial mRNA subjected to reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR through the use of HB-EGF-specific primers yielded fragments of the predicted size. Cloning of the nested PCR product revealed a 380-bp porcine HB-EGF cDNA sequence that was 78-85% homologous to primate or rodent HB-EGF. HB-EGF was immunohistochemically localized primarily to the luminal epithelium in both pregnant and nonpregnant animals.

Differential effects of transforming growth factor-beta 1 and bone morphogenetic proteins in cultured rat osteogenic sarcoma and mink lung epithelial cells

The effects of porcine bone morphogenetic protein (BMP) on DNA and collagen synthesis in cultured rat osteogenic sarcoma cells and mink lung epithelial cells were studied and compared with the effects induced by transforming growth factor-beta 1 (TGF-beta 1). In both cells, DNA synthesis was slightly but significantly increased by BMP whereas it was notably decreased by TGF-beta 1. The inhibitory action of TGF-beta 1 overrode the activation of DNA synthesis by BMP when the cells were incubated together with TGF-beta 1 and BMP. In osteogenic sarcoma cells, collagen synthesis was enhanced by both BMP and TGF-beta 1, but the stimulatory action of BMP was weaker than that of TGF-beta 1. In epithelial cells, TGF-beta 1 increased collagen synthesis but BMP induced no significant changes. No synergistic effects of TGF-beta 1 and BMP on collagen synthesis were observed in both cells. The present study demonstrates the possibility of direct actions of BMP and TGF-beta 1 on cultured rat osteogenic sarcoma cells and mink lung epithelial cells in vitro.

Kinetics and mechanism of an NADPH-dependent succinic semialdehyde reductase from bovine brain

An NADPH-dependent succinic semialdehyde reductase has been purified from bovine brain by several chromatographic procedures. The preparation appeared homogeneous on SDS/PAGE. The enzyme is a monomeric protein with a molecular mass of 28 kDa. A number of properties of the bovine brain enzyme, such as substrate specificity, specific activity, molecular mass, optimum pH, amino acid composition, and kinetic parameters, have been determined and compared with those reported for preparations from other sources. The results indicate that the enzyme isolated from bovine brain in the present study is different from those reported for preparations from other sources. The inhibition kinetic patterns obtained when the products of the reaction or substrate analogs are used as inhibitor of the reaction catalyzed by the enzyme are consistent with an ordered sequential mechanism involving the formation of an intermediate ternary complex and in which NADPH is the first substrate to bind the enzyme.

Interaction of heparin-binding EGF-like growth factor (HB-EGF) with the epidermal growth factor receptor: modulation by heparin, heparinase, or synthetic heparin-binding HB-EGF fragments

The binding of heparin-binding EGF-like growth factor (HB-EGF) to the epidermal growth factor (EGF) receptor of human endometrial carcinoma cells was compared to that of EGF using an 125I-EGF radioreceptor assay. The inhibitory effect of HB-EGF on 125I-EGF binding was reversed either in the presence of heparin (but not by chondroitin sulfate) or by pre-treating the cells with heparinase. These treatments did not affect the binding of EGF to its receptor. To map potential regions in the HB-EGF molecule that mediate its heparin-dependent interaction with the EGF receptor, HB-EGF peptides were synthesized that were non-homologous to EGF. Accordingly residues 20-25 and 36-41, but not residues 8-19, of HB-EGF were found to be (i) heparin-binding and (ii) modulators of HB-EGF (but not of EGF) binding to the EGF receptor.

Aluminum interrupts the formation of alkaline-ribonuclease-inhibitor complex from bovine brain

The effect of aluminum on alkaline ribonuclease (RNase) and RNase inhibitor, purified from bovine brain, was investigated. Incubation of alkaline RNase with aluminum interrupted binding of RNase inhibitor to alkaline RNase. A stoichiometry of 1:1 for the binding of aluminum to brain alkaline RNase was estimated, whereas no aluminum was found to be bound to the RNase inhibitor. Aluminum-bound alkaline RNase, however, retained a full alkaline RNase activity. None of the enzyme-bound aluminum was dissociated by dialysis against 50 mM Hepes, pH 7.0, at 4 degrees C for 24 h. Citrate, EDTA, NaF and apotransferrin protected the alkaline RNase against aluminum binding. Aluminum did not bind to the incubated alkaline RNase-inhibitor complex, suggesting that aluminum might compete with RNase inhibitor for the binding site. However, the data from chemical modification and spectroscopic studies indicate that it is also highly possible that aluminum binding to the enzyme induces conformational changes at or near the inhibitor-binding site, which subsequently interrupt binding of RNase inhibitor to alkaline RNase. These results suggest that accumulation of aluminum in brain might affect the regulation of RNA metabolism.

Activation of acid ribonuclease from bovine brain by aluminum

An acid ribonuclease (optimum pH 6.0) has been purified from bovine brain in a five-step procedure. The preparation appeared homogeneous on SDS-polyacrylamide gel electrophoresis. The molecular size of the acid ribonuclease is 70 kDa and it is a dimeric protein with a subunit molecular size of 35 kDa. The acid RNase was activated by aluminum at low concentration. Preincubation of the acid RNase with 10 microM increased the specific activity of the enzyme 2.3-fold at acid pH, while the effect of aluminum was much weaker at alkaline pH under otherwise the same conditions. A stoichiometry of 1: 1 for the binding aluminum to brain acid RNase was estimated. None of the enzyme-bound aluminum was dissociated by dialysis against 50 mM HEPES, pH 7.0 at 4 degrees C for 24 h. Citrate, EDTA, NaF, and apotransferrin abolished the effects of aluminum on the enzyme. Ribonucleic acid also protected the enzyme against the activation caused by aluminum. These results suggest that accumulation of aluminum in brain may change the regulation of ribonucleic acid metabolism.