Colorectal Cancer Screening and Postpolypectomy Surveillance

CASE SUMMARY

A healthy 52-year-old woman without any family history presents for a health maintenance appointment and opts for a fecal immunochemical test for colorectal cancer screening after reviewing her options. After a positive result, she is referred for colonoscopy. She is found to have 3 small (<10 mm) polyps that are completely resected via snare polypectomy and return as tubular adenomas on histologic examination. It is recommended that she return for repeat colonoscopy in 3 years, at which point she has a normal examination with excellent preparation by an experienced endoscopist and is given the option to return to her average-risk screening interval.

Benign Anal Disease: Implementation of an Educational Program Across Specialties

BACKGROUND

Benign anal diseases, including hemorrhoids, fissures, abscesses, fistulas, and anal condylomata, affect 10%-15% of our population. Most patients seen by nonsurgical providers experience delayed treatment. We examined at our institution whether an educational session on anorectal diseases would benefit trainees from medical and surgical specialties.

MATERIALS AND METHODS

The study took place at Oregon Health & Science University, a primary institutional practice with 130 resident participants. An exploratory study using a 10-point pretest and posttest regarding these diseases was designed and administered to medical subspecialties, including general surgery (GS), emergency medicine, internal medicine, and family medicine, obstetrics/gynecology, and pediatric residents. Intervention was a 50-min presentation highlighting anatomy, history and physical findings, and disease treatment. The posttest was repeated after 6 mo to evaluate retention and overall satisfaction, and differences were evaluated.

RESULTS

With the exception of GS, posttest scores improved. Internal medicine improved most significantly. GS residents scored better on the pretest than other specialties; their posttest scores, however, declined. The survey demonstrated residents with prior education scored better on the pretest. PGY-1 and PGY-2 residents improved most on their posttest. On 6-mo retest, 17.6% of residents responded and posttest performance was 72%.

CONCLUSIONS

Nonsurgical residents have limited knowledge about benign anal diseases but demonstrate improvement after educational intervention. Surgery residents performed well, but demonstrate regression to the mean, common in test taking, but may also require a more advanced lecture. Formal institutional, regional, and national educational interventions are needed to improve the understanding of these diseases.

Who Undergoes Cytoreductive Surgery and Perioperative Intraperitoneal Chemotherapy for Appendiceal Cancer? An Analysis of the National Cancer Database

BACKGROUND

We sought to identify patterns of care for patients with appendiceal cancer and identify clinical factors associated with patient selection for multimodality treatment, including cytoreductive surgery and perioperative intraperitoneal chemotherapy (CRS/PIC).

MATERIALS AND METHODS

National Cancer Database (NCDB) data from 2004 to 2014 of all diagnoses of appendiceal cancers were examined. We examined treatment modalities, as well as demographic, tumor-specific, and survival data. A multivariate logistic regression analysis was performed to determine the patient cohort most likely to receive CRS/PIC. Kaplan-Meier was used to estimate survival for all treatment groups. Significance was evaluated at P ≤ 0.05.

RESULTS

We analyzed data on 18,055 patients. Nine thousand nine hundred ninety-two (55.3%) were treated with surgery only, 5848 (32.4%) received surgery and systemic chemotherapy, 1393 (7.71%) received CRS/PIC, 520 (2.88%) received chemotherapy alone, and 302 (1.67%) received neither surgery nor chemotherapy. Significant predictors of receiving CRS/PIC included male sex (OR 1.33, 95% CI: 1.11-1.59), white race (OR 2.00, 95% CI 1.40-2.86), non-Hispanic ethnicity (OR 1.92, 95% CI 1.21-3.05), private insurance (OR 1.52, 95% CI 1.26-1.84), and well-differentiated tumors (OR 4.25, CI: 3.39-5.32) (P < 0.05). Treatment with CRS/PIC was associated with a higher 5-year survival for mucinous malignancies, when compared to surgery alone (65.6% versus 62.4%, P < 0.01). Treatment with CRS/PIC was also associated with higher 5-year survival for well-differentiated malignancies, when compared to all other treatment modalities (74.9% versus 65.4%, P < 0.01).

CONCLUSIONS

Patients were more likely to undergo CRS/PIC if they were male, white, privately insured, and with well-differentiated tumors. CRS/PIC was associated with improved survival in patients with mucinous and low-grade tumors.

Gastrointestinal Stromal Tumors of the Distal Gastrointestinal Tract

Gastrointestinal stromal tumors (GISTs) are rare in occurrence, but comprise the most common mesenchymal tumors of the gastrointestinal tract and affect between 15 and 20 individuals per million per year. Due to recent advancements in molecular classification of these tumors, medical therapy has provided improved outcomes to a historically surgically managed disease. This review article briefly discusses the molecular characteristics, medical and surgical therapies, and future of GIST management.

Travel distance influences readmissions in colorectal cancer patients-what the primary operative team needs to know

BACKGROUND

Many colorectal cancer patients receive complex surgical care remotely. We hypothesized that their readmission rates would be adversely affected after accounting for differences in travel distance from primary/index hospital and correlate with mortality.

MATERIALS AND METHODS

We identified 48,481 colorectal cancer patients in the Surveillance, Epidemiology and End Results (SEER)-Medicare database. Travel distance was calculated, using Google Maps, and SAS. Multivariate negative binomial regression was used to identify factors associated with readmission rates. Overall survival was analyzed, using Kaplan-Meier and Cox proportional hazard.

RESULTS AND CONCLUSIONS

Thirty-day readmissions occurred in 14.9% of the cohort, 27.5% of which were to a nonindex hospital. In the colon and rectal cancer cohorts, readmissions were 14.5% and 16.5%, respectively. Rectal cancer patients had an increase in readmission by 13% (incidence rate ratios [IRR] 1.13; 95% confidence interval [CI] 1.05-1.21). Factors associated with readmission were male gender, advanced disease, length of stay (LOS), discharge disposition, hospital volume, Charlson score, and poverty level (P < 0.05). Greater distance traveled increased the likelihood of readmission but did not affect mortality. Travel distance influences readmission rates but not mortality. Discharge readiness to decrease readmissions is essential for colorectal cancer patients discharged from index hospitals.

Variation in the Use of Chemoradiotherapy for Stage II and III Anal Cancer: Analysis of the National Cancer Data Base

BACKGROUND

Treatment for anal canal cancer has evolved from radical operations to definitive chemoradiotherapy (CRT), which allows for sphincter preservation in most patients.

OBJECTIVE

The aim of this study was to examine the use of CRT for patients with stage II and III anal cancer, among different patient demographics, geographic regions, and facility types.

METHODS

Utilizing the National Cancer Data Base, we examined patients with stage II and III anal canal squamous cell carcinoma from 2003 to 2010. Via univariate analysis, we examined patterns of treatment by patient demographics, tumor characteristics, geographic region, and facility type (academic vs. community). A multivariable logistic regression model was built to evaluate differences in treatment patterns when adjusting by age, sex, race, comorbidities, and stage.

RESULTS

A total of 12,801 patients were analyzed, of which 11,312 (88 %) received CRT. After adjusting for confounders, CRT was less likely to be administered to males [odds ratio (OR) 0.61, 95 % confidence interval (CI) 0.54-0.69], Black patients (OR 0.70, 95 % CI 0.59-0.83), and those with multiple comorbidities (OR 0.60, 95 % CI 0.51-0.72). CRT was not as widely utilized in the West (OR 0.74, 95 % CI 0.59-0.93), and patients treated in academic-based centers were less likely to receive CRT (OR 0.81, 95 % CI 0.72-0.92). Improved median overall survival was observed when CRT was utilized (p = 0.008).

CONCLUSION

When controlling for age, sex, race, comorbidities, and stage, discrepancies in the use of CRT for anal cancer treatment exist between demographic subtypes, geographical regions, and facility types.

Psychiatric Illness is a Disparity in the Surgical Management of Rectal Cancer

BACKGROUND

Psychiatric disorders are common in the US and represent a major health disparity but little is known about their impact on surgical management and outcomes in cancer.

OBJECTIVE

The aim of this study was to determine whether rectal cancer patients with psychiatric diagnoses have fewer sphincter-preserving procedures and higher postoperative complications.

METHODS

Overall, 23,914 patients from the Nationwide Inpatient Sample (NIS) who underwent surgery for rectal cancer from 2004 to 2011 were identified. Patients with comorbid common psychiatric diagnoses were identified by International Classification of Diseases, Ninth Revision (ICD-9) codes. Main outcomes were measured by operation performed, length of stay (LOS), postoperative complications, and discharge disposition.

RESULTS

Twenty percent of patients had a psychiatric diagnosis, with substance use being the most common psychiatric disorder (63 %). Patients with psychiatric diagnoses were more likely to be younger, White, have lower income, and have Medicaid insurance (p < 0.001) than those without. In a logistic regression model, patients with any psychiatric diagnosis were less likely to have sphincter-sparing surgery, controlling for patient sociodemographics, Charlson score, hospital procedure volume, and year (odds ratio 0.77; 95 % CI 0.72-0.83). LOS and postoperative complications were similar among the cohorts. Patients with psychiatric disorders were more likely to have home health care at discharge (p < 0.001).

CONCLUSIONS

Fewer sphincter-sparing procedures were performed on rectal cancer patients with psychiatric diagnoses. However, no significant differences in postoperative complications were observed.

Strictureplasty for Treatment of Crohn's Disease: an ACS-NSQIP Database Analysis

INTRODUCTION

Strictureplasty is an alternative to resection for treatment of Crohn's disease (CD) strictures. It preserves bowel length, and specialized centers report favorable outcomes. Strictureplasty rates, however, are thought to be low, and it was recently removed from required cases for colon and rectal surgery residents. We examined operative characteristics, and trends in its use using a large national database.

MATERIALS AND METHODS

We examined the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2005 to 2012, identifying patients with CD who underwent strictureplasty. We identified patient characteristics, outcome variables, and trends in utilization of strictureplasty.

RESULTS

A total of 9172 patients underwent surgery for CD. Two hundred fifty-six (2.8 %) underwent strictureplasty. Median preoperative albumin was 3.6. Preoperative steroid use and weight loss rates were 39 and 8 %. Rates of wound infection and organ space infection were 11 and 4 %. Rate of reoperation was 6 %. Outcomes did not change significantly over time (all p = NS). The proportion of CD operations that included a strictureplasty decreased from 5.1 to 1.7 % (OR 0.902 with each additional year, 95 % CI (0.852, 0.960), p < 0.001).

CONCLUSION

Strictureplasty as treatment for CD is decreasing in the ACS-NSQIP database. Infectious complications and reoperation rates following strictureplasty are low and have not changed over time.

Serrated polyposis syndrome

SUMMARY 

Serrated polyposis syndrome, also called hyperplastic polyposis, is a condition characterized by numerous neoplastic polyps throughout the colon and rectum. The polyps possess a distinct serrated morphology. The term serrated refers to the ‘saw-tooth’ pattern formed by epithelial cells in the colonic crypts on standard histologic preparations. Historically, serrated lesions have been lumped together under the term ‘hyperplastic polyps’, and were assumed to carry no malignant potential. Over the past decade, however, an increasing body of evidence suggests that serrated lesions exist along a spectrum and represent an alternative molecular pathway to the development of colorectal cancer in contrast to the traditional adenocarcinoma sequence. Although a hallmark genetic signature for serrated polyposis syndrome remains unidentified, this is an area of active investigation.

A virtual reality endoscopic simulator augments general surgery resident cancer education as measured by performance improvement

Colorectal cancer is the second most common cause of death in the USA. The need for screening colonoscopies, and thus adequately trained endoscopists, particularly in rural areas, is on the rise. Recent increases in required endoscopic cases for surgical resident graduation by the Surgery Residency Review Committee (RRC) further emphasize the need for more effective endoscopic training during residency to determine if a virtual reality colonoscopy simulator enhances surgical resident endoscopic education by detecting improvement in colonoscopy skills before and after 6 weeks of formal clinical endoscopic training. We conducted a retrospective review of prospectively collected surgery resident data on an endoscopy simulator. Residents performed four different clinical scenarios on the endoscopic simulator before and after a 6-week endoscopic training course. Data were collected over a 5-year period from 94 different residents performing a total of 795 colonoscopic simulation scenarios. Main outcome measures included time to cecal intubation, "red out" time, and severity of simulated patient discomfort (mild, moderate, severe, extreme) during colonoscopy scenarios. Average time to intubation of the cecum was 6.8 min for those residents who had not undergone endoscopic training versus 4.4 min for those who had undergone endoscopic training (p < 0.001). Residents who could be compared against themselves (pre vs. post-training), cecal intubation times decreased from 7.1 to 4.3 min (p < 0.001). Post-endoscopy rotation residents caused less severe discomfort during simulated colonoscopy than pre-endoscopy rotation residents (4 vs. 10%; p = 0.004). Virtual reality endoscopic simulation is an effective tool for both augmenting surgical resident endoscopy cancer education and measuring improvement in resident performance after formal clinical endoscopic training.

Increasing the number of lymph nodes examined after colectomy does not improve colon cancer staging

BACKGROUND

Current quality initiatives call for examination of at least 12 lymph nodes in curative colon cancer resections. The aim of this study was to determine if the number of nodes harvested has increased, and if the increased number nodes correlates with improved staging or overall survival.

STUDY DESIGN

A review of the Surveillance, Epidemiology, and End Results program database from 2004-2010 was performed. All patients who underwent colon cancer resection during this date range were analyzed. Number of nodes retrieved, patient stage, overall survival, and overall survival by stage were examined. Multivariable analysis controlled for stage, cancer site, age, year of diagnosis, and number of nodes retrieved. Improved staging was defined as increased detection of stage III patients.

RESULTS

A total of 147,076 patients met inclusion criteria. Median number of nodes analyzed increased sequentially with each year examined, from 12 in 2004 to 17 in 2010. Despite greater number of total nodes obtained and analyzed, there was no increase in the percentage of patients with positive nodes (stage III disease). On multivariable analysis, after controlling for stage, site of disease, age, and year of diagnosis, there was a slight overall survival benefit with increasing nodal retrieval (hazard ratio = 0.987 for each additional node removed; 95% CI, 0.986-0.988; p < 0.001).

CONCLUSIONS

Since quality initiatives have been put in place, there has been an increase in the number of nodes examined in colon cancer resections, but no improvement in staging. The improved survival seen with higher node counts was independent of stage, site of disease, patient age, and year of diagnosis.

Surgeon leadership enables development of a colorectal cancer biorepository

BACKGROUND

We hypothesized that surgeons can improve the collection of all necessary elements (tissue and clinical data) needed to build a complete, robust research biorepository.

METHODS

All colorectal cancer patients treated at a university medical center and its affiliates were eligible for inclusion. Data were collected from an 18-page personal and family health questionnaire, a prospectively maintained clinical database, and molecular testing. Tissues included serum, plasma and peripheral blood mononuclear cells, and tumor and normal tissue. We compared 2 groups: the surgeon-referred group and the other clinician-referred group. The primary outcome was the complete collection of data (ie, preoperative/staging clinical data, blood samples, and tissue collection). Statistical analysis was performed using the Student t test.

RESULTS

Since 2006, 452 patients were approached, and 430 (95%) have been enrolled. Of these, 124 were referred by their surgeon, and 306 were consented in a clinic or over the telephone. Of patients referred by their surgeon, tumor tissue, blood samples, and preoperative/staging clinical data were obtained in 119 patients; conversely, in patients referred by oncologists or other clinicians, only 133 patients had complete data (96% vs 43.5%, P < .05). A total of 257 tissue samples were obtained from all patients. Additional testing has been performed on 228 specimens including immunohistochemistry, microsatellite testing, and genotype mutational analysis.

CONCLUSIONS

Surgeon-directed enrollment in a biorepository improves the ability to collect blood and tissue samples. Surgeons should take a leadership role in the development of tumor biorepositories.

Laparoscopic colectomy reduces morbidity and mortality in obese patients

BACKGROUND

Obesity is a growing epidemic in the US and increases the difficulty of laparoscopic surgery. Randomized, controlled trials of laparoscopic vs. open colectomy have shown equivalence but often exclude obese patients thus not answering whether obese patients may specifically benefit from laparoscopy. We hypothesized that obese patients would benefit from use of laparoscopy for colectomy.

METHODS

We used the National Surgical Quality Improvement Program database from 2005 to 2009 and chose elective laparoscopic and open segmental colectomy and ileocecal resections. We compared patients' demographics, comorbidities, and outcomes. We used multivariate models to assess for predictors of complications in obese patients. These models included demographics, comorbidities, and outcomes.

RESULTS

35,998 patients were identified who underwent elective colectomy with primary anastomosis. Forty-four percent of the included cases were laparoscopic and 31 % of patients had a BMI greater than 30 (obese). Obese patients were more likely to have diabetes, hypertension, prior percutaneous coronary intervention, and dyspnea on exertion. We constructed a new variable called any complication that included all complications except 30-day mortality. In our multivariate analysis, laparoscopic approach in obese patients independently decreased the relative risk of superficial (odds ratio (OR) 0.72, 95 % confidence interval (CI) 0.63-0.82) and deep (OR 0.44, CI 0.31-0.61) surgical site infections, intra-abdominal infection (OR 0.61, CI 0.49-0.78), dehiscence (OR 0.50, CI 0.35-0.69), pneumonia (OR 0.60, CI 0.44-0.81), failure to wean from the ventilator (OR 0.64, CI 0.47-0.87), renal failure (OR 0.58, CI 0.35-0.96), urinary tract infection (OR 0.62, CI 0.49-0.79), sepsis (OR 0.53, CI 0.43-0.66), septic shock (OR 0.65, CI 0.47-0.90), any complication (OR 0.61, CI 0.55-0.67) and 30-day mortality (OR 0.56, CI 0.31-0.98).

CONCLUSIONS

Due to the significant decrease in the risk of morbidity and mortality, laparoscopic colectomy should be offered to obese patients whenever feasible.

Anal canal squamous cell carcinoma: overview, surveillance after treatment and management of local recurrence

SUMMARY Anal canal cancer is an uncommon gastrointestinal malignancy, although the incidence is increasing. Current treatment employs definitive chemoradiation, 5-fluorouracil, mitomycin C and a radiation dosage of 54–59 Gy for T3/T4 tumors, but not for T1 and T2 disease. Surveillance after completion of treatment is required. One acceptable strategy includes physical examinations every 3–6 months for 5 years and serial CT scans to detect advanced disease. A total of 40% of patients with T4 disease or immunosuppressed status may recur within the first 2 years after completion of treatment. Salvage therapy includes radical abdominoperineal resection. The most significant prognosticator after salvage surgery is the resection margin. Generally, patients with anal cancer should be treated by a multidisciplinary physician team and be assigned to clinical research trials, if feasible.

Surgical management of Crohn's disease

Although medical management can control symptoms in a recurring incurable disease, such as Crohn's disease, surgical management is reserved for disease complications or those problems refractory to medical management. In this article, we cover general principles for the surgical management of Crohn's disease, ranging from skin tags, abscesses, fistulae, and stenoses to small bowel and extraintestinal disease.

Effect of surgical approach on 30-day mortality and morbidity after elective colectomy: a NSQIP study

PURPOSE

The aim of this study was to evaluate the laparoscopic approach and pre- and postoperative conditions as predictors of 30-day mortality and morbidity in elective colectomy.

METHODS

Elective colectomies were identified in the 2005-2008 American College of Surgeons National Surgical Quality Improvement Program database. Multivariate logistic regression was used to model 30-day mortality and morbidity following elective colectomy. Propensity scores were calculated to decrease selection bias.

RESULTS

During the period studied, 14,321 patients underwent open colectomy and 10,409 underwent laparoscopic colectomy. Factors that significantly influenced mortality included male gender [odds ratio (OR) 1.4, confidence interval (CI) 1.07-1.9]; age (OR 1.07, CI 1.05-1.08); comorbidities including dyspnea, ascites, congestive heart failure, dialysis, or disseminated cancer; and postoperative conditions including reintubation (OR 2.6, CI 1.6-4.0), renal failure (OR 3.8, CI 2.1-6.9), stroke (OR 6.44, CI 2.4-17.6), and septic shock (OR 13.1, CI 8.76-19.4). While laparoscopy was not independently associated with mortality, it was associated with decreased postoperative morbidity including reintubation (OR 0.74, CI 0.59-0.91), renal failure (OR 0.60, CI 0.4-0.91), septic shock (OR 0.74, CI 0.59-0.92), wound infection (OR 0.58, CI0.44-0.77), and pneumonia (OR 0.71, CI 0.59-0.86).

CONCLUSIONS

Based on this analysis, laparoscopy was associated with a decrease in 30-day postoperative morbidity for colectomy. However, after adjusting for preoperative comorbidities and postoperative morbidities, laparoscopy did not independently influence mortality after colectomy.

Use and outcomes of emergent laparoscopic resection for acute diverticulitis

BACKGROUND

The use and outcomes of laparoscopic sigmoid resection during emergency admissions for diverticulitis are unknown.

METHODS

The Nationwide Inpatient Sample was queried for colorectal resections performed for diverticulitis during emergent hospital admissions (2003-2007). Univariate and multivariate analyses including patient, hospital, and outcome variables were performed.

RESULTS

A national estimate of 67,645 resections (4% laparoscopic) was evaluated. The rate of conversion to open operation was 55%. Ostomies were created in 66% of patients, 67% open and 41% laparoscopic. Laparoscopy was not a predictor of mortality (odds ratio [OR] =.70; confidence interval [CI], .32-1.53). Laparoscopy predicted routine discharge (OR = 1.31; CI, 1.06-1.63) and a decreased length of stay (absolute days = -.78; CI, -1.19 to -.37). There was no difference in the cost of hospitalization between the 2 groups (P = .45).

CONCLUSIONS

In acute diverticulitis, urgent laparoscopic resection decreases the length of stay. However, it is associated with a high conversion rate, no cost savings, and no difference in mortality.

Dramatic decreases in mortality from laparoscopic colon resections based on data from the Nationwide Inpatient Sample

OBJECTIVE

To determine the mortality rate and associated factors for laparoscopic and open colectomy as derived from the Nationwide Inpatient Sample database.

DESIGN

Retrospective cohort.

SETTING

Nationwide Inpatient Sample database.

PATIENTS

Between 2002 and 2007, the Nationwide Inpatient Sample estimated 1,314,696 patients underwent colectomy in the United States. Most (n = 1,231,184) were open, but 83,512 were laparoscopic. Patients who underwent a laparoscopic procedure that was converted to open were analyzed within the laparoscopic group on an intention-to-treat basis.

MAIN OUTCOME MEASURE

Mortality rate. Using a logistic regression model, patient and institutional characteristics were analyzed and evaluated for significant associations with in-hospital mortality.

RESULTS

In a multivariate analysis, significant predictors of increased mortality included older age, male sex, lower socioeconomic status, comorbidities, and emergency or transfer admission. Additionally, a laparoscopic approach was an independent predictor of decreased mortality when compared with open colectomy (relative risk, 0.51; P < .001).

CONCLUSION

Even when controlling for comorbidities, socioeconomic status, practice setting, and admission type, laparoscopy is an independent predictor of decreased mortality for colon resection.

Laparoscopic converted to open colectomy: predictors and outcomes from the Nationwide Inpatient Sample

BACKGROUND

Early in their learning curve, surgeons need to appropriately select patients to avoid conversion from laparoscopic to an open colectomy.

METHODS

Using the Nationwide Inpatient Sample, laparoscopic and laparoscopic converted to open colectomies performed between 2002 and 2007 were compared. We evaluated patient and institutional characteristics to find significant predictors and outcomes of conversion.

RESULTS

Between 2002 and 2007, the rate of conversion was high, ranging from 35.7% to 38.0%. Multivariate predictors of conversion included obesity, diverticulitis, inflammatory bowel disease, constipation, metastatic disease, nonelective admission, left or transverse colectomy, intraoperative complication, lower socioeconomic status, uninsured status, and rural hospital location. A colectomy for benign colon polyps was less likely to be converted. Conversion to an open colectomy did not increase inpatient mortality.

CONCLUSIONS

Predictors of conversion from open to laparoscopic colectomy were found from a national database reflecting all US laparoscopic colectomies. Conversion did not increase inpatient mortality.

Specialized practice reduces inpatient mortality, length of stay, and cost in the care of colorectal patients

OBJECTIVE

This study aimed to determine whether specialized surgeon practice improves clinical outcomes for major inpatient adult colorectal resections.

DESIGN

The Nationwide Inpatient Sample was queried for elective colorectal resections performed from 2001 through 2007. Specialization was determined by first identifying surgeons' procedures as either colorectal or noncolorectal. Surgeons were then stratified as either a specialized surgeon, if colorectal cases comprised more than 75% of their caseload, or a nonspecialized surgeon if colorectal cases comprised less than 75%.

MAIN OUTCOME MEASURES

The data points collected for these cases were: cost, length of stay, mortality, demographics, comorbidities, acuity of admission, hospital region, hospital location and teaching status, and primary payer information. Cost and length of stay were analyzed using a linear regression model with a log transformation for length of stay. A logistic regression analysis was performed for mortality. These models were adjusted for all other covariates including surgeon volume.

RESULTS

A total of 13,925 surgeons performing 115,540 procedures were analyzed. Specialized surgeons comprised 4.6% of surgeons and performed 17.0% of resections. In multivariate analysis, specialized surgeons had a lower risk of mortality (OR 0.72; CI 0.57-0.90, P = .0044), decreased length of stay (absolute difference in days 0.23; CI 0.11-0.49, P = .0022), and similar hospital cost (absolute cost difference $420 less; CI $238 more to $1079 less, P = .211) compared with nonspecialized surgeons. Although cost was not significant at a 75% specialization cutoff, a relationship exists between lower hospitalization cost and increased surgeon specialization even when controlled for surgeon volume.

CONCLUSIONS

Surgical specialization leads to reductions in mortality, hospital days, and cost for inpatient colorectal care.

Growth of multiple metal/semiconductor nanoheterostructures through point and line contact reactions

Forming functional circuit components in future nanotechnology requires systematic studies of solid-state chemical reactions in the nanoscale. Here, we report efficient and unique methods, point and line contact reactions on Si nanowires, fabricating high quality and quantity of multiple nanoheterostructures of NiSi/Si and investigation of NiSi formation in nanoscale. By using the point contact reaction between several Ni nanodots and a Si nanowire carried out in situ in an ultrahigh vacuum transmission electron microscopy, multiple sections of single-crystal NiSi and Si with very sharp interfaces were produced in a Si nanowire. Owing to the supply limited point contact reaction, we propose that the nucleation and growth of the sugar cane-type NiSi grains start at the middle of the point contacts between two Ni nanodots and a Si nanowire. The reaction happens by the dissolution of Ni into the Si nanowire at the point contacts and by interstitial diffusion of Ni atoms within a Si nanowire. The growth of NiSi stops as the amount of Ni in the Ni nanodots is consumed. Additionally, without lithography, utilizing the line contact reaction between PS nanosphere-mediated Ni nanopatterns and a nanowire of Si, we have fabricated periodic multi-NiSi/Si/NiSi heterostructure nanonowires that may enhance the development of circuit elements in nanoscale electronic devices. Unlike the point contact reaction, silicide growth starts at the contact area in the line contact reaction; the different silicide formation modes resulting from point and line contact reactions are compared and analyzed. A mechanism on the basis of flux divergence is proposed for controlling the growth of the nano-multiheterostructures.

Management of colonic injuries in the combat theater

PURPOSE

Combat injuries are more often associated with blast, penetrating, and high-energy mechanisms than civilian trauma, generating controversy about the management of combat colonic injury. Despite implementation of mandatory colostomy in World War II, recent civilian data suggest that primary repair without diversion is safe and feasible. This study describes the modern management of battle-related colonic injuries and seeks to determine whether management strategy affects early complications.

METHODS

Records from the combat theater (downrange) and tertiary referral center in Germany were retrospectively reviewed from 2005 to 2006. Patient characteristics, management strategy, treatment course, and early complications were recorded. Comparison groups by management strategy were as follows: primary repair, diversion, and damage control.

RESULTS

A total of 133 (97% male) patients sustained colonic injuries from penetrating (71%), blunt (5%), and blast (23%) mechanisms. Average injury severity score was 21 and length of stay in the referral center was 7.1 days. Injury distribution was 21% ascending, 21% descending, 15% transverse, 27% sigmoid, and 25% rectum. Downrange complications for primary repair, initial ostomy, and damage control groups were 14%, 15%, and 30%, respectively. On discharge from the center, 62% of patients had undergone a diversion. The complication rate was 18% overall and was unrelated to management strategy (P = .16). Multivariate analysis did not identify independent predictors of complications.

CONCLUSION

Early complications were similar by mechanism, anatomic location, severity of injury, and management strategy. More diversions were performed for rectosigmoid injury. Good surgical judgment allows for low morbidity and supports primary repair in selected cases. Damage control surgery is effective in a multinational theater of operations.

Anal fissure

Anal fissure is a common disorder that is effectively treated and prevented with conservative measures in its acute form, whereas chronic fissures may require medical or surgical therapy. This article discusses the nonoperative and operative management strategies, reviews the current literature on expected outcomes, and provides guidance on dealing with fissures in special situations, such as patients with inflammatory bowel disease or hypotonic sphincters.

Apoptotic markers on lymphocytes and monocytes are unchanged during single hemodialysis sessions using either regenerated cellulose or polysulfone membranes

BACKGROUND

There is an increased rate of apoptosis of peripheral blood mononuclear cells (PBMCs) in patients undergoing hemodialysis (HD), but little is known about how different dialysis membranes may contribute to the process. We, therefore, studied the influence of two different dialysis membranes on apoptotic markers during HD.

METHODS

8 healthy controls and 8 patients on regular HD 3 times per week were enrolled in this cross-controlled study. Patients received HD using polysulfone and then regenerated cellulose dialysis membranes for one week each, sequentially. Serum was collected for C-reactive protein (CRP) detection; flow cytometry with dual antibody staining was used to measure the apoptotic markers Fas (CD95), FasL (CD 178) and TNF-R2 (CD120b) in T cells (CD3+), B cells (CD19+), and monocytes (CD14+) at 0, 15, 120 and 240 min after starting HD. We also measured total leukocyte numbers and differential white cell counts.

RESULTS

Hemodialysis patients revealed lymphocytopenia, monocytopenia, higher CRP levels and higher Fas and TNF-R2 expression on lymphocytes and monocytes at baseline when compared with normal controls. Leukocyte numbers, including neutrophils, lymphocytes and monocytes, dropped significantly after 15 min of dialysis. There were no significant differences in Fas levels during hemodialysis on T and B lymphocytes or on monocytes. T lymphocyte FasL (CD 178) levels remained unchanged throughout the process. There was a significantly lower overall level of CD120b at 15 min of HD, whereas this marker was higher on monocytes after dialysis. There were no significant differences in the levels of apoptotic markers between the two membranes.

CONCLUSION

Our results suggest that uremia itself contributes to PBMC apoptosis. The two different dialysis membranes used in this study did not influence apoptotic markers on PBMCs significantly, but increased TNF-R2 expression on monocytes during a single dialysis session.

Concomitant allorecognition of mismatched donor HLA class I- and class II-derived peptides in pediatric lung transplant recipients with bronchiolitis obliterans syndrome

BACKGROUND

The authors' previous studies with 2 different adult patient populations demonstrated a correlation between indirect allorecognition of mismatched donor HLA Class I- and Class II-derived peptides and the development of bronchiolitis obliterans syndrome (BOS) after lung transplantation. The aim of this study was to determine whether a parallel allorecognition of mismatched donor HLA Class I- and Class II-derived peptides occurs after lung transplantation and to determine its correlation with the development of BOS after lung transplantation in a group of pediatric patients.

METHODS

Peripheral blood mononuclear cells from 7 BOS-positive and 6 BOS-negative pediatric lung transplant recipients (age, 11.5 +/- 4.4 years) were cultured in the presence of synthetic peptides corresponding to the alpha-chain hypervariable regions of a mismatched donor HLA Class I molecule and the beta-chain hypervariable region of a mismatched donor HLA-DR molecule. The frequencies of HLA Class I and Class II alloreactive T cells were determined using limiting dilution analysis.

RESULTS

A significant increase (p = 0.025) in HLA Class I-alloreactive T cells was observed in BOS-positive patients (7.1 x 10(-5) +/- 4.3 x 10(-5)) compared with BOS-negative patients (2.1 x 10(-5) +/- 1.8 x 10(-6)). In addition, a significant increase (p = 0.033) in HLA Class II-alloreactive T cells also was observed in BOS-positive patients (9.6 x 10(-5) +/- 7.9 x 10(-5)) compared with BOS-negative patients (1.3 x 10(-5) +/- 2.1 x 10(-6)).

CONCLUSIONS

This study indicates that a parallel CD4+ T-cell alloreactivity to both donor HLA Class I and Class II molecules may play a role in the pathogenesis of BOS both in adult and pediatric lung transplant recipients.

Interleukin-6 and interferon-gamma gene polymorphisms in the development of bronchiolitis obliterans syndrome after lung transplantation

BACKGROUND

A number of genetic polymorphisms have been shown to regulate the production and secretion of tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1, interferon (IFN)-gamma, interleukin (IL)-6, and IL-10. Several of these genetic polymorphisms have been shown to be associated with either acute or chronic rejection of kidney, liver, and heart allografts and with development of allograft fibrosis after lung transplantation. The aim of this study was to assess the effect of these genetic polymorphisms on the development of bronchiolitis obliterans syndrome (BOS) after lung transplantation.

METHODS

Genetic polymorphisms were detected by means of polymerase chain reaction in 93 lung allograft recipients for functional polymorphisms in the TNF-alpha (-308), TGF-beta1 (+869 and +915), IL-6 (-174), IFN-gamma (+874), and IL-10 (-1082, -819, and -592) genes. Then, a correlation between BOS development and the presence of these cytokine genotypes was determined using Kaplan-Meier actuarial analysis.

RESULTS

A significant correlation was detected between the presence of high-expression polymorphisms of the IL-6 and IFN-gamma genes and BOS development after lung transplantation (P =0.045 and 0.039, respectively). Also, patients with high-expression polymorphisms in both genes developed BOS significantly earlier than patients with low-expression polymorphisms in one or both genes, suggesting a synergistic effect of the alleles during BOS pathogenesis (P =0.016). No correlation was detected between polymorphisms of the TNF-alpha, TGF-beta1, and IL-10 genes and development of BOS after lung transplantation.

CONCLUSIONS

The presence of high-expression polymorphisms at position -174 of the IL-6 gene and position +874 of the IFN-gamma gene significantly increases the risk for BOS development after lung transplantation.

In vitro T cell proliferation from kidney allograft biopsies with unremarkable pathology: new strategies for an old problem

Acute rejection of renal allografts is mediated by infiltrating alloreactive T cells. The goals of this study were to correlate T cell proliferation with rejection and to determine whether T cell proliferation in the absence of rejection would predict future rejection episodes. Toward this, kidney biopsies (n=100) were cultured in the presence of interleukin-2. Cultures were examined at 4, 24, and 48 hr for T cell proliferation. A strong correlation was observed between T cell proliferation at any time point and rejection. There was not a significant correlation between T cell proliferation in biopsies with no rejection and the occurrence of a rejection episode within 2 months. However, T cell proliferation after 4 hr was a better predictor of the occurrence of rejection within 2 months compared with observations after 24 and 48 hr. Therefore, a subgroup of patients with unremarkable biopsies but T cell proliferation may be at risk for rejection and warrant closer observation and possible tailoring of immunosuppression.

Prevention of obliterative airway disease in HLA-A2-transgenic tracheal allografts by neutralization of tumor necrosis factor

BACKGROUND

Inflammatory cytokines play an important role in the development of experimental obliterative airway disease (OAD) after transplantation. To further determine the immunologic mechanisms associated with OAD development, we used a murine tracheal transplant model in which a single mismatched HLA-A2-transgenic molecule is indirectly recognized by the recipient CD4+ T cells and then determined whether neutralization of several inflammatory cytokines affected the development of OAD.

METHODS

Tracheas from HLA-A2+ C57BL/6 mice were heterotopically transplanted into C57BL/6 mice. Recipients were treated with neutralizing antibodies against tumor necrosis factor (TNF), interferon-gamma (IFN-gamma), or interleukin-1 (IL-1). Allograft histology as well as anti-HLA-A2 antibody development and T cell proliferative responses were determined at days +5, +15, +28, and +60.

RESULTS

Allografts in untreated and anti-IFN-gamma-treated recipients demonstrated full development of OAD by day +28. Allografts in anti-TNF-treated recipients showed no evidence of OAD, even at day +60. Allografts in anti-IL-1-treated recipients showed airway epithelium changes by day +28 but minimal evidence of OAD by day +60. Spleen cells from untreated and anti-IFN-gamma-treated recipients showed significantly higher proliferative responses to HLA-A2+ cells, compared with syngeneic recipients (negative controls). In contrast, anti-TNF and anti-IL-1-treated recipients showed significantly lower proliferative responses to HLA-A2+ cells, compared with untreated recipients. Development of anti-HLA-A2 antibodies was detected in all recipients by day +15, with the exception of those treated with anti-TNF.

CONCLUSION

Among the inflammatory cytokines, TNF seems to play a crucial role in the immunopathology of OAD developed after transplantation.

Acute correction of metabolic acidosis increases serum procollagen type I carboxyterminal propeptide in patients with chronic renal failure

BACKGROUND AND PURPOSE

Previous in vitro study has shown that an acidic medium increases osteoclastic and inhibits osteoblastic activity. The present study sought to determine the role of alkali therapy in osteoblast function in patients with chronic renal failure by assessing the serum concentration of procollagen type I carboxyterminal propeptide (PICP), a marker of bone formation, before and after bicarbonate infusion.

PATIENTS AND METHODS

Eighteen patients with chronic renal failure (creatinine clearance 12 +/- 6.6 mL/min) associated with mild to moderate metabolic acidosis were enrolled in this study. None had undergone dialysis. Metabolic acidosis was corrected by continuous bicarbonate infusion while plasma ionized calcium was clamped at the preinfusion level by calcium gluconate infusion throughout the procedure.

RESULTS

After bicarbonate infusion, there were significant increases in plasma pH (7.31 +/- 0.04 to 7.40 +/- 0.03, p < 0.001), bicarbonate concentration (18.46 +/- 2.49 to 23.66 +/- 2.72, p < 0.001), serum total calcium concentration (2.01 +/- 0.24 to 2.12 +/- 0.24 mmol/L, p < 0.001), and PICP concentration (137.3 +/- 56.25 to 159.6 +/- 57.30 micrograms/L, p < 0.05), whereas serum parathyroid hormone concentrations assessed by radioimmunoassay decreased significantly (153.7 +/- 88.6 to 111.5 +/- 78.7, p < 0.001). Serum ionized calcium concentrations showed no significant difference before and after bicarbonate infusion.

CONCLUSION

These results suggest that acute correction of metabolic acidosis improves osteoblast function and appear to underline the importance of maintaining normal acid-base homeostasis in chronic renal failure.

Western and Chinese antirheumatic drug-induced T cell apoptotic DNA damage uses different caspase cascades and is independent of Fas/Fas ligand interaction

Spontaneous or therapeutic induction of T cell apoptosis plays a critical role in establishing transplantation tolerance and maintaining remission of autoimmune diseases. We investigated the mechanisms of apoptosis induced by Chinese and Western antirheumatic drugs (ARDs) in human T cells. We found that hydroxychloroquine, Tripterygium wilfordii hook F, and tetrandrine (Tet), but not methotrexate, at therapeutic concentrations can cause T cell death. In addition, Tet selectively killed T cells, especially activated T cells. Although ARD-induced cytotoxicity was mediated through apoptotic mechanisms, Fas/Fas ligand interaction was not required. We further demonstrated that the processes of phosphatidylserine externalization and DNA damage along the ARD-induced T cell apoptotic pathway could operate independently, and that selective inhibition of DNA damage by caspase inhibitors did not prevent T cells from undergoing cell death. Moreover, we found that Tet- and Tripterygium wilfordii hook F-induced T cell DNA damage required caspase-3 activity, and hydroxychloroquine-induced T cell DNA damage was mediated through a caspase-3- and caspase-8-independent, but Z-Asp-Glu-Val-Asp-fluomethyl ketone-sensitive, signaling pathway. Finally, the observation that ARD-induced activation of caspase-3 in both Fas-sensitive and Fas-resistant Jurkat T cells indicates that Fas/Fas ligand interaction plays no role in ARD-induced T cell apoptosis. Our observations provide new information about the complex apoptotic mechanisms of ARDs, and have implications for combining Western and Chinese ARDs that have different immunomodulatory mechanisms in the therapy of autoimmune diseases and transplantation rejection.

Energy metabolism in exertional heat stroke with acute renal failure

BACKGROUND

Heat stroke is the clinical syndrome produced when the body overheats. It can develop in the army and in healthy civilian populations who physically exert themselves in a hot and humid environment during the summer, and may result in a significant number of heat-related deaths. Since strenuous exercise is one of the major exacerbating and precipitating factors, the incidence of exertional heat stroke (ExHS) is high among military personnel undergoing military training. Furthermore, acute renal failure (ARF) may occur in 25% of patients with ExHS and it can cause metabolic alterations that affect amino acid, carbohydrate, and lipid metabolism. Adequate nutritional support is essential for the treatment of ARF. The most important determinant of nutrient requirement in ARF is the degree of hypercatabolism caused by disease associated with renal function impairment. Indirect calorimetry (IDCM) is the method by which metabolic rate is estimated from measurements of oxygen consumption and carbon dioxide production. It can also provide information about the type and rate of substrate utilization in vivo (protein, carbohydrate, and fat).

METHOD

The present clinical study is a comprehensive analysis of metabolic changes which includes energy expenditure (EE) and substrate utilization in 10 patients with ExHS with ARF and 10 patients with exertional heat exhaustion (ExHE) by the use of IDCM.

RESULTS

Serum urea nitrogen, creatinine, peak creatine phosphokinase levels and heart rate were significantly increased in ExHS patients during ARF stage. Serum albumin levels were significantly decreased in ExHS patients with ARF. Resting energy expenditure (REE) was increased in patients with ExHS induced ARF and was not correlated with body temperature (r = 0.421). The average increase in EE during ARF stage was about 24%. The respiratory quotient in patients with ExHS induced ARF was lower than that in normal subjects and also in patients with ExHE. Urea nitrogen appearance rate increased in patients with ExHS induced ARF and in patients with ExHE without ARF. The percentage of total REE derived from fat in ExHS induced ARF and ExHE increased, while in patients with ExHS induced ARF and ExHE, the percentages of total REE derived from carbohydrate and protein were lower than those in control subjects.

CONCLUSIONS

The present results suggest that patients with exertional heat injury (both ExHS and ExHE) have hypermetabolism during the acute stage. Furthermore, patients with exertional heat-induced rhabdomyolysis and ARF have a moderately higher hypermetabolism than those without ARF during the acute stage. We believe that this mainly reflects a more pronounced reduction of the vital cell mass (muscle) in relation to body weight, and/or a compromised substrate oxidation in ExHS with ARF. Whether or not this subgroup of patients will require a higher energy/caloric support merits further investigation.

Infective endocarditis complicated with rapidly progressive glomerulonephritis: a case report

A 26-year-old man who had suffered from intermittent chills and fever over a two month period was quite clear of heart or kidney involved developed acute deterioration of renal function. A new pansystolic murmur over the apex of the heart was heard on auscultation, and echocardiography clearly showed a vegetation about 0.7-0.9 cm in size on the atrial site of the mitral value. Laboratory investigation displayed normochromic anemia with negative Coombs' test. Immunological studies were positive for rheumatoid factor and circulating immune complex. High serum levels of erythrocyte sedimentation rate and C-reactive protein, nephritic sediment of urinalysis and negative blood cultures for bacteria, tuberculosis or fungus were also noted. Abdominal sonography showed normal kidney size, bilaterally. Renal biopsy revealed typical crescentic glomerulonephritis. After intravenous penicillin therapy for two weeks, the serum creatinine level recovered from 6.7 mg/dl to 2.0 mg/dl and circulating immune complex disappeared. In consideration of cardiac insufficiency and the potential risk for complications of the vegetation, the patient underwent mitral valve replacement. Four weeks after operation, all the abnormal data had resolved completely. These data suggested that infective endocarditis with rapidly progressive glomerulonephritis is curable by antibiotic therapy and surgical intervention.

Cytokine production during hemodialysis: effects of dialytic membrane and complement activation

Interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) are closely associated with acute and chronic inflammatory processes in hemodialytic patients. However, the mechanisms concerning cytokine production by monocytes during hemodialysis are still conflicting. With the use of the more specific monoclonal antibody ELISA method, contamination detection and crossover protocol of complement-activating and noncomplement-activating hollow fibers, we were able to confirm augmented II-1 beta production by zymosan-stimulated monocytes with complement-activating hollow fiber as compared to noncomplement-activating hollow fiber before (1,411.9 +/- 865.7 +/- 149.9 pg/ ml/2 x 10(6) monocytes, p < 0.01). at the 15th minute (530.6 +/- 89.1 vs. 247.3 +/- 45.2 pg/ml/2 x 10(6) monocytes, p < 0.01) and at the end of dialysis (1,201.8 +/- 135.1 vs. 707.4 +/- 109.3 pg/ml/2 x 10(6) monocytes, p < 0.01). Similar results were observed with TNF-alpha production. IL-1 beta as well as TNF-alpha production decreased significantly at the 15th min of dialysis, thereafter they increased and approached the baseline levels towards the end of hemodialysis with both hollow fibers. Plasma C3a at the 15th minute correlated positively with postdialysis IL-1 beta and TNF-alpha production, while plasma C3a did not change in patients dialyzed with noncomplement-activating hollow fiber. Complement activation with complement-activating hollow fiber as well as monocyte-membrane interaction with complement-activating and noncomplement-activating hollow fiber might be involved in the pathogenesis of cytokine production during hemodialysis. Uremic toxin removal as well as stimulation of cytokine production inhibitor might contribute to the decreased cytokine production at the 15th minute of hemodialysis and monocyte-membrane interaction with or without complement activation resulted in augmented cytokine production toward the end of hemodialysis with both hollow fibers. We thus concluded that hollow fiber of bioincompatibility triggered much more cytokine production throughout the dialysis procedure.

Effect of calcitriol treatment on psoriasis in hemodialysis patient: a case report

The case of a 67-year-old man who has had psoriasis with multiple joints involvement for 30 years and renal failure for 1 year is described. He was admitted because of uremic symptoms and exacerbation of psoriasis. Hypocalcemia and low serum active 1.25(OH)2D3 were also observed. Hemodialysis, oral 1.25(OH)2D3 and CaCO3 supplement were employed. Interestingly, the psoriasis strikingly improved. The relationships among psoriasis, renal failure, 1.25(OH)2D3, serum calcium level and dialysis are discussed.

Influence of metabolic acidosis on serum 1,25(OH)2D3 levels in chronic renal failure

Metabolic acidosis has been shown to alter vitamin D metabolism. There is also evidence that calcium may modulate 1,25(OH)2D3 by a parathyroid hormone (PTH)-independent mechanism. To investigate the effect of rapid correction of chronic metabolic acidosis on serum 1,25(OH)2D3 levels by free calcium clamp in chronic renal failure, 20 patients with mild to moderate metabolic acidosis (mean pH 7.31 +/- 0.04) and secondary hyperparathyroidism (mean intact PTH 156.47 +/- 84.20 ng/l) were enrolled in this study. None had yet received any dialysis therapy. Metabolic acidosis was corrected by continuous bicarbonate infusion for 3-4 h until plasma pH was around 7.4, while plasma ionized calcium was held at the preinfusion level by calcium solution infusion during the entire procedure. The plasma pH, bicarbonate, total CO2, sodium, and serum total calcium levels were significantly increased while serum concentrations of alkaline phosphatase and albumin were significantly decreased after bicarbonate infusion. The plasma ionized calcium, potassium, serum magnesium, inorganic phosphorus, and 25(OH)D levels showed no significant change before and after bicarbonate infusion. The serum 1,25(OH)2D3 levels were significantly increased (38.66 +/- 11.77 vs. 47.04 +/- 16.56 pmol/l, p < 0.05) after correction of metabolic acidosis. These results demonstrate that rapid correction of metabolic acidosis raises serum 1,25(OH)2D3 levels in vitamin D-deficient chronic renal failure patients, and may underline the importance of maintaining normal acid-base homeostasis in the presence of secondary hyperparathyroidism in chronic renal failure.

A prospective study of calcium metabolism in exertional heat stroke with rhabdomyolysis and acute renal failure

Intensive training in a humid and warm environment can cause exertional heat stroke (ExHS) and rhabdomolysis (RBD) in military recruits. To investigate the role of vitamin D and monomeric calcitonin (CT) on the calcium metabolism in ExHS with RBD and acute renal failure (ARF), we studied 21 recruits with ExHS (mean age 21.4 years), 7 of which had ARF. Another 11 age-matched recruits with heat exhaustion (HE) and 11 healthy subjects were selected as controls. Our results showed that in 14 ExHS patients without ARF, mean serum creatinine (Cr) levels were significantly higher (151.16 vs. 106.08 mumol/l, p < 0.01), whereas serum osteocalcin (OC) levels were significantly lower (2.22 vs. 4.65 micrograms/l, p < 0.01) than in healthy controls. In 7 patients with ExHS and ARF, the mean serum Cr (774.38 vs. 105.20 mumol/l, p < 0.01), phosphorus (P) (2.26 vs. 1.26 mmol/l, p < 0.05), creatine phosphokinase (CPK) 274,143.97 vs. 85.78 IU/l, p < 0.05), intact parathyroid hormone (I-PTH) (299.81 vs. 18.66 ng/l, p < 0.05) and CT (13.58 vs. 6.63 ng/l, p < 0.01) levels on admission were significantly higher while the mean ionized calcium (iCa) levels were significantly lower than the healthy controls (0.9 vs. 1.18 mmol/l, p < 0.01). The mean serum 25-hydroxyvitamin D [25(OH)D] levels were not significantly different from healthy controls. However, mean serum 1,25-dihydroxyvitamin D [1,25(OH)2D] levels and the ratio of 1,25(OH)2D to 25(OH)D were significantly lower than healthy controls throughout the whole course of ARF. None of the 7 patients with ExHS and ARF developed hypercalcemia during the diuretic phase. Their mean serum I-PTH levels decreased significantly from 299 to 18 ng/l during the recovery phase (p < 0.05). Our study seems to suggest that the abnormal calcium metabolism in this unique patient group is in part caused by persistently decreased renal production of 1,25(OH)2D, although increased monomeric CT levels were associated with hypocalcemia. However, whether or not a causal relationship exists merits further investigation.

Effects of intravenous calcitriol on lipid profiles and glucose tolerance in uraemic patients with secondary hyperparathyroidism

1. Secondary hyperparathyroidism in chronic renal failure may contribute to abnormalities of lipid metabolism and glucose tolerance. Amelioration of secondary hyperparathyroidism has been reported to mitigate the hyperlipidaemia and improve glucose tolerance experimentally. 2. The effect of the partial suppression of hyperparathyroidism by intravenous calcitriol on lipid levels and glucose tolerance was studied in 15 haemodialysis patients with secondary hyperparathyroidism. All received intravenous calcitriol 1 microgram at the end of haemodialysis thrice weekly for eight weeks. Oral glucose tolerance test and plasma lipid profiles including triglyceride, total cholesterol, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), apoprotein A-I and apoprotein B were determined simultaneously before and after eight weeks of therapy. 3. Before calcitriol treatment, uraemic patients with secondary hyperparathyroidism displayed a significant higher triglyceride and a significant lower HDL-C and apoprotein A-I as well as marked glucose intolerance with an increment of the area below the glucose curve when compared with healthy control subjects. 4. After eight weeks of calcitriol treatment, there was a significant decrement in serum intact parathyroid hormone (476.45 +/- 48.33 versus 191.37 +/- 30.17 ng/l, P < 0.001) and plasma triglyceride (2.24 +/- 0.34 versus 1.80 +/- 0.29 mmol/l, P < 0.05) as well as a significant increment of plasma apoprotein A-I (38.13 +/- 2.14 versus 44.19 +/- 2.18 mumol/l, P < 0.05), whereas there was no significant change in serum total cholesterol, LDL-C, HDL-C, and apoprotein B.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of intravenous calcitriol on platelet intracellular calcium in uremic hemodialysis patients with secondary hyperparathyroidism

BACKGROUND

To investigate the effect of the reversal of hyperparathyroidism on platelet intracellular free calcium ([Ca2+]i) by pharmacological parathyroidectomy with intravenous calcitriol in uremic patients with secondary hyperparathyroidism (2 degrees HPT).

METHODS

Serum concentrations of intact parathyroid hormone (I-PTH) were measured by two-site immunometric assay, and platelet [Ca2+]i was assessed using the fluorescent indicator fura-2. Fifteen hemodialysis patients with 2 degrees HPT and serum I-PTH 4 times greater than the normal upper limits, were selected for treatment with intravenous calcitriol 1 microgram thrice weekly for one month.

RESULTS

An increase of serum I-PTH (449.17 +/- 52.35 vs 32.52 +/- 1.95 pg/ml) and elevated platelet [Ca2+]i (139.49 +/- 8.78 vs 74.70 +/- 6.48 nM/L) was observed in uremic patients with 2 degrees HPT. Serum I-PTH levels were significantly correlated with platelet [Ca2+]i in uremic patients with 2 degrees HPT (r = 0.736, p = 0.002). The serum I-PTH levels decreased from 449.17 +/- 52.35 to 221.27 +/- 35.66 pg/ml (p < 0.001) and platelet [Ca2+]i fell from 139.49 +/- 8.78 to 97.86 +/- 7.25 nM/L (p < 0.001) after treatment. Fall in platelet [Ca2+]i was related to concomitant reduction in PTH levels (r = 0.572, p = 0.026).

CONCLUSIONS

It was concluded that an increase in cytosolic calcium in uremia may be at least in part induced by PTH. Besides, intravenous calcitriol can provide an effective way to suppress elevated serum I-PTH and attenuate platelet free calcium in uremia with 2 degrees HPT.

Imerslund-Grasbeck syndrome in a Chinese family with distinct skin lesions refractory to vitamin B12

Two brothers in a Chinese family with selective malabsorption of vitamin B12 associated with proteinuria (Imerslund-Grasbeck syndrome) presented with widespread mottled skin pigmentation, termed poikiloderma. In contrast to anaemia, this pigmentary disturbance remained unresponsive to vitamin B12 replacement. This is different from the reported hyperpigmentation sometimes seen in vitamin B12 deficiency which is reversible following treatment. As far as is known, an irreversible and persistent skin disorder has not been reported in this syndrome before.

Influence of rapid correction of metabolic acidosis on serum osteocalcin level in chronic renal failure

Metabolic acidosis induces a combination of inhibited osteoblastic and stimulated osteoclastic activity. To determine the role of alkali therapy in osteoblast function in chronic renal failure, serum bone isoenzyme of alkaline phosphatase (BAP) and osteocalcin were assessed before and after bicarbonate infusion. Eighteen patients with mild to moderate metabolic acidosis, none of whom had received dialysis therapy, were enrolled in this study. Metabolic acidosis was corrected by continuous bicarbonate infusion while plasma ionized calcium was monitored at 5 min intervals and held at the preinfusion level by calcium solution infusion during the entire procedure. The end-point of the study was reached when the plasma bicarbonate was approximately 24 mmol/l or pH was approximately 7.4 and plasma ionized calcium was clamped at the preinfusion level with only a 0.01 mmol/l fluctuation. The plasma pH (7.31 +/- 0.04 vs. 7.40 +/- 0.03, P < 0.001), bicarbonate (18.46 +/- 2.49 vs. 23.66 +/- 2.72 mmol/l, P < 0.001), serum total calcium, and osteocalcin (15.61 +/- 6.45 vs. 18.79 +/- 6.71 mg/l, P < 0.05) levels were significantly increased, whereas serum concentrations of alkaline phosphatase and albumin levels were significantly decreased after bicarbonate infusion. The serum BAP (1.85 +/- 1.29 vs. 1.79 +/- 1.18 mukat/l, P = 0.252), and inorganic phosphorus levels showed no significant differences before and after bicarbonate infusion. These results demonstrate that rapid correction of metabolic acidosis improves osteoblast function and may underline the importance of maintaining normal acid-base homeostasis in chronic renal failure.

Hyperparathyroidism, glucose tolerance and platelet intracellular free calcium in chronic renal failure

Disturbance in the vitamin D/parathyroid hormone (PTH) axis may be important in the pathogenesis of glucose intolerance and insulin resistance in uraemia. To investigate possible relationships between hyperparathyroidism, intracellular free calcium ([Ca2+]i), and glucose tolerance in chronic renal failure, we measured serum intact PTH (I-PTH) by two-site immunometric assay, platelet [Ca2+]i using the fluorescent indicator fura-2, and plasma glucose and insulin after 14 h overnight fast and at 30, 60 and 120 min following a 75 g oral glucose load, in 18 chronic haemodialysis patients with elevated serum I-PTH. Calcitriol (1 microgram) was administered parenterally at the end of each dialysis session for four weeks. This significantly decreased serum I-PTH (p < 0.001) and platelet [Ca2+]i (p < 0.01). Uraemic patients initially showed marked glucose intolerance, with increased area below the glucose curve compared to healthy controls, but after 4 weeks of calcitriol treatment, this effect was significantly decreased, and there was a significant rise in the area under the insulin curve after glucose load. The insulinogenic index also increased significantly after calcitriol treatment. These data suggest that calcitriol treatment of haemodialysis patient with secondary hyperparathyroidism is associated with increased insulin secretion in response to glucose challenge, and that this change is linked to the decrease in intracellular free calcium.

Rapid correction of metabolic acidosis in chronic renal failure: effect on parathyroid hormone activity

To investigate the effect of rapid correction of chronic metabolic acidosis on circulating intact parathyroid hormone (I-PTH) activity by free calcium clamp in chronic renal failure, 18 patients were enrolled in this study. Metabolic acidosis was corrected by continuous bicarbonate infusion while plasma ionized calcium was clamped at the preinfusion level throughout the entire procedure. The plasma pH, bicarbonate, total CO2, sodium, serum total calcium and 1,25(OH)2 vitamin D3 levels increased significantly while serum concentrations of I-PTH, alkaline phosphatase and albumin showed significant decreases after bicarbonate infusion. The plasma ionized calcium, potassium, serum magnesium and inorganic phosphorus levels showed no significant difference before and after bicarbonate infusion. These results demonstrate that rapid correction of metabolic acidosis attenuates circulating PTH activity in chronic renal failure and may underline the importance of maintaining normal acid-base homeostasis particularly in the presence of secondary hyperparathyroidism.

Role of plasma catecholamines, autonomic, and left ventricular function in normotensive and hypotension prone dialysis patients

The current study looked at plasma catecholamines, clinical autonomic function tests, and hemodynamic parameters in 10 ESRD patients (five men and five woman, aged 56.4 +/- 3.6) with dialysis hypotension and 10 patients (five men and five women, aged 58.6 +/- 4.2) without dialysis hypotension. Catecholamines were measured using high performance liquid chromatography--electrochemical detection (HPLC-ECD). Dialysis led to a significant decrease in mean arterial pressure (MAP) in the hypotensive group as compared with the normotensive group. Significantly higher basal (predialysis) plasma norepinephrine (NE) and dopamine levels (DA) were found in the hypotensive uremic group as compared with the normotensive group. Levels of plasma epinephrine (EP) were not significantly different between the normotensive and hypotensive groups. In response to postural stimulation, blood pressure fell in both groups, but the fall in the hypotensive group was significantly greater. Percentage increments of plasma catecholamines in response to postural stimulation in both groups were similar, however. Among the measured hemodynamic parameters, including total peripheral vascular resistance and left ventricular function (cardiac index and fractional shortening), only the cardiac index showed significantly lower values in the hypotensive group after dialysis, as compared with the normotensive group. Results of four tests of autonomic function indicated that although both groups responded similarly to hand-grip and cold-pressor tests, impaired responses to orthostasis and Valsalva maneuver after dialysis were observed in the hypotensive group. The MAP changes in dialysis in the hypotension prone group correlated inversely with predialysis plasma NE, but not with EP and DA.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of creatine phosphokinase in predicting acute renal failure in hypocalcemic exertional heat stroke

Recruits frequently develop hypocalcemia in exertional heat stroke (ExHS) with rhabdomyolysis and acute renal failure (ARF) from intensive training. It usually indicated severe skeletal muscle damage. However, the relative risk of ARF in ExHS patients complicated with hypocalcemia was unknown. The present study was undertaken to evaluate the value of peak serum creatine phosphokinase (CPK) level in predicting ARF in ExHS patients with hypocalcemia. Sixty-eight army recruits with ExHS were hospitalized at the Tri-Service General Hospital, Taiwan: 17 with ARF and hypocalcemia (group A); 7 with ARF but without hypocalcemia (group B); 20 without ARF but with hypocalcemia (group C); and 24 without ARF or hypocalcemia (group D). In the 24 patients with ARF (groups A and B) the serum phosphate and peak CPK levels were significantly higher than in patients without ARF (groups C and D; p < 0.001), serum calcium levels were also significantly lower in the former (p < 0.001). In the 37 patients with hypocalcemia (groups A and C), the peak serum CPK levels were significantly higher than in those without hypocalcemia (groups B and D; p < 0.001). There was a higher proportion of hypocalcemic patients with peak serum CPK levels greater than 10,000 U/l among ARF compared with patients without ARF (chi 2 = 12.48, p < 0.001). In 24 patients with ARF, there was a negative correlation between serum Ca and peak CPK levels (t = 3.37, r = -0.58, p < 0.01). However, a positive correlation was found between serum creatinine and peak serum CPK levels in 37 patients with hypocalcemia (t = 2.47, r = 0.39, p < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)