An enhanced antigen-retrieval protocol for immunohistochemical staining of formalin-fixed, paraffin-embedded tissues

Formalin is the most commonly used fixative for light microscopy because of its preservation of -morphological details. A major adverse effect of formalin fixation is formation of cross-linkages between epitopes (amino acid residues) and unrelated proteins by formaldehyde groups. The great majority of monoclonal and polyclonal antibodies used for immunohistochemical (IHC) staining of formalin-fixed, paraffin-embedded (FFPE) tissues necessitate unmasking antigens for antigen retrieval. There are currently two major antigen-retrieval procedures based on treatment of deparaffinized tissue sections with heat or, less commonly, with enzymatic digestion. The use of various antigen-retrieval solutions and heating sources does not allow standardization of IHC staining and minimalization of interlaboratory discrepancies. We developed a novel modified antigen-retrieval protocol for reversing the effect of -formalin fixation. The key feature of this protocol is treatment of deparaffinized tissue sections at reduced constant heat (97(o)C in a water bath) for 40 min in 25 mM Tris-HCl (pH 8.5), 1 mM EDTA, and 0.05% SDS (Tris-EDTA-SDS) buffer. Sections are then immunostained with primary and secondary antibodies conjugated with polymer-labeled Horse Radish Peroxidase. Compared to conventional antigen-retrieval procedures, this protocol more efficiently reverses the effect of formalin fixation of a wide variety of cellular antigens and in most instances decreases the use of primary antibody by 2-40 times, resulting in cost savings. Moreover, this protocol eliminates the need for using different antigen-retrieval methods in the laboratory, which reduces both time and labor for medical technologists.

Ecthyma gangrenosum mimicking acute invasive fungal sinusitis in an immunocompromised patient

Ecthyma gangrenosum is a rare necrotizing cutaneous infection usually caused by Pseudomonas aeruginosa. We report a case of ecthyma gangrenosum presenting as a sinonasal eschar and mimicking acute invasive fungal sinusitis in an immunocompromised 39-year-old man with a hematologic malignancy. To the best of our knowledge, this represents the first case of ecthyma gangrenosum affecting the sinonasal mucosa to be reported in the literature.

Ecthyma Gangrenosum Mimicking Acute Invasive Fungal Sinusitis in an Immunocompromised Patient

Ecthyma gangrenosum is a rare necrotizing cutaneous infection usually caused by Pseudomonas aeruginosa. We report a case of ecthyma gangrenosum presenting as a sinonasal eschar and mimicking acute invasive fungal sinusitis in an immunocompromised 39-year-old man with a hematologic malignancy To the best of our knowledge, this represents the first case of ecthyma gangrenosum affecting the sinonasal mucosa to he reported in the literature.

Dystroglycan is not required for maintenance of the luminal epithelial basement membrane or cell polarity in the mouse prostate

BACKGROUND

Dystroglycan is a cell-surface receptor for extracellular matrix proteins including laminins and perlecan. Prior studies have shown its involvement in assembly and/or maintenance of basement membrane structures, cell polarity and tissue morphogenesis; and its expression is often reduced in prostate and other cancers. However, the role of dystroglycan in normal epithelial tissues such as the prostate is unclear.

METHODS

To investigate this, we disrupted dystroglycan expression in the prostate via a conditional gene targeting strategy utilizing Cre recombinase expressed in luminal prostate epithelial cells.

RESULTS

Contrary to expectations, deletion of dystroglycan in luminal epithelial cells resulted in no discernable phenotype as judged by histology, basement membrane ultrastructure, localization of dystroglycan ligands, cell polarity or regenerative capacity of the prostate following castration. Dystroglycan expression remains in keratin-5-positive basal cells located in the proximal ducts where dystroglycan expression is elevated in regenerating prostates.

CONCLUSIONS

Our results show that dystroglycan in luminal epithelial cells is not required for the maintenance of basement membranes, cell polarity or prostate regeneration. However, it is possible that persistent dystroglycan expression in the basal cell compartment may support these or other functions.

Abstract 421: Dystroglycan glycosylation status predicts Gleason grade and influences prostate tumor growth

Dystroglycan, an extracellular matrix receptor, is expressed in many tissues including muscle, neural, adipose and epithelial where its function includes roles in polarity, basement membrane formation and tissue morphogenesis. Loss of dystroglycan expression has been shown in many epithelial cancers including prostate cancer yet the underlying mechanism remains unclear. Here, we investigate the role of DG in prostate cancer progression. We show that staining for the extracellular αDG subunit with the glycosylation-sensitive IIH6 anti-αDG antibody as well as the transmembrane βDG subunit are independent predictors of Gleason score in clinical prostate cancer specimens. In addition, increased αDG glycosylation due to expression of LARGE, a putative glycosyltransferase, in prostate cancer cell lines results in decreased tumor growth in prostate cancer xenografts. We determined that this reduction in growth is specific to the effect of LARGE on dystroglycan. Therefore our work has shown that the extent of αDG glycosylation predicts Gleason scores in prostate cancer and that LARGE dependent glycosylation of αDG regulates tumor growth.

This work is supported by a grant from the National Institutes of Health R01-CA130916

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 421.

Runx2 regulates survivin expression in prostate cancer cells

Previously we described that bone morphogenetic protein-7 (BMP7) could protect prostate cancer C4-2B cells from serum starvation-induced apoptosis via survivin induction. Here, for the first time, we identify Runx2 as a key regulator of survivin transcription. In C4-2B cells grown normally, suppression of Runx2 reduced survivin expression. Using ChIP assays, two regions of the survivin promoter, -1953 to -1812 (I) and -1485 to -1119 (II) encompassing consensus Runx-binding sites were examined. Runx2 was found to be associated with both regions, with a stronger affinity to region-I. In serum-starved cells neither region was occupied, but BMP7 restored association to region-II and not region-I. In reporter assays, transcription activity by BMP7 was significantly reduced when sequences including binding sites of region-II were deleted. Additionally, Runx2 expression was enhanced by BMP7 in these cells. Along with a strong survivin expression, a trend in increased Runx2 expression in human prostate cancer cells and tissues was noted. In the conditional Pten-knockout mouse, Runx2 level increased with growth of prostate tumor. The data define a novel role of Runx2 in regulating survivin expression in malignant epithelial cells and identify it as a critical factor in BMP signaling that protects cancer cells against apoptosis.

Commentary: Mentoring the mentor: executive coaching for clinical departmental executive officers

Departmental executive officers (DEOs), department chairs, and department heads in medical schools are often hired on the basis of their accomplishments in research as well as their skills in administration, management, and leadership. These individuals are also expected to be expert in multiple areas, including negotiation, finance and budgeting, mentoring, and personnel management. At the same time, they are expected to maintain and perhaps even enhance their personal academic standing for the purposes of raising the level of departmental and institutional prestige and for recruiting the next generation of physicians and scientists. In the corporate world, employers understand the importance of training new leaders in requisite skill enhancement that will lead to success in their new positions. These individuals are often provided with extensive executive training to develop the necessary competencies to make them successful leaders. Among the tools employed for this purpose are the use of personal coaches or executive training courses. The authors propose that the use of executive coaching in academic medicine may be of benefit for new DEOs. Experience using an executive coach suggests that this was a valuable growth experience for new leaders in the institution.

Clinical correlation between irrigation bottle contamination and clinical outcomes in post-functional endoscopic sinus surgery patients

BACKGROUND

Sinonasal irrigation after endoscopic sinus surgery (ESS) is a common practice, but the role irrigation bottles play in iatrogenic contamination of the operated sinuses is unknown. Therefore, we investigated whether irrigation bottles used postoperatively become contaminated and have any potential association with immediate postsurgical infection and outcomes.

METHODS

Patients irrigated twice daily after ESS. Bottle cleaning was performed as recommended by the manufacturer. New bottles were distributed at the time of the operation and at each postoperative visit. During postoperative weeks 1, 2, and 4, bottles were cultured. Medical charts were reviewed for the presence of postsurgical infection and changes in management.

RESULTS

Twenty post-ESS patients were enrolled and examined at weeks 1, 2, and 4. A total of 51 bottles were collected and cultured. Overall, 15 of 51 (29%) bottles demonstrated bacterial growth when cultured. During the first two collection periods, 10 of 40 (25%) bottles demonstrated bacterial growth when cultured; however, five of 11 (45%) bottles collected at the last postoperative visit demonstrated bacterial growth when cultured. During the study, Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae were frequently recovered during the collection periods. Other organisms isolated included Escherichia coli and Enterobacter spp. Although positive bottle cultures were more common at weeks 2 and 4, no postoperative infections occurred.

CONCLUSIONS

Irrigation bottles used postoperatively have a measurable incidence of contamination. Contamination rate increases when bottles are used for longer than 1 week, but this does not appear to result in postsurgical infection.

Effects of an LL-37-derived antimicrobial peptide in an animal model of biofilm Pseudomonas sinusitis

BACKGROUND

LL-37, an innate immunity protein expressed within sinonasal mucosa, has in vitro antibacterial and antifungal properties as well as efficacy against preformed Pseudomonas aeruginosa biofilms. We hypothesize that a 24 amino acid peptide derivative of LL-37 will show efficacy against biofilm-forming P. aeruginosa in an established animal model of sinusitis.

METHODS

Five groups of six New Zealand rabbits were each infected with P. aeruginosa (PAO-1) and fitted with irrigating catheters 7 days later. Each group was instilled with either one of three different concentrations of peptide, a positive control of topical tobramycin, or the carrier solution without the peptide once a day for 10 days. Nasal diluent was collected throughout the irrigation period to assess for persistence or resolution of infection by determining colony-forming units (CFU). At study end, sinus mucosa was harvested for histological assessment of inflammation and SEM evaluation for ciliary integrity and presence of biofilms.

RESULTS

Topical tobramycin at 400x minimum inhibitory concentration and 2.5 mg/mL of peptide were effective in significantly lowering CFUs after 10 days of irrigation. Histological evaluation showed increased signs of inflammation in a dose-dependent manner within mucosa and bone of the groups receiving the peptide. SEM analysis showed ciliary loss in a dose-dependent manner. Biofilms were present in all groups except for the highest concentration of peptide and tobramycin.

CONCLUSION

High concentrations of LL-37-derived peptide showed in vivo ability to eradicate Pseudomonas biofilms and decrease bacterial counts. However, increasing concentrations of peptide showed proinflammatory and ciliotoxic effects on sinus mucosa.

Mechanisms of prostate cancer cell survival after inhibition of AR expression

Recent reports have shown that the AR is the key determinant of the molecular changes required for driving prostate cancer cells from an androgen-dependent to an androgen-independent or androgen depletion-independent (ADI) state. Several recent publications suggest that down-regulation of AR expression should therefore be considered the principal strategy for the treatment of ADI prostate cancer. However, no valid data is available about how androgen-dependent prostate cancer cells respond to apoptosis-inducing drugs after knocking down AR expression and whether prostate cancer cells escape apoptosis after inhibition of AR expression. This review will focus on mechanisms of prostate cancer cell survival after inhibition of AR activity mediated either by androgen depletion or by targeting the expression of AR by siRNA. We have shown that knocking down AR expression by siRNA induced PI3K-independent activation of Akt, which was mediated by calcium/calmodulin-dependent kinase II (CaMKII). We also showed that the expression of CaMKII genes is under AR control: active AR in the presence of androgens inhibits CaMKII gene expression whereas inhibition of AR activity results in an elevated level of kinase activity and in enhanced expression of CaMKII genes. This in turn activates the anti-apoptotic PI3K/Akt pathways. CaMKII also express anti-apoptotic activity that is independent from the Akt pathway. This may therefore be an important mechanism by which prostate cancer cells escape apoptosis after androgen depletion or knocking down AR expression. In addition, we have found that there is another way to escape cell death after AR inhibition: DNA damaging agents cannot fully activate p53 in the absence of AR and as a result p53 down stream targets, for example, microRNA-34, cannot be activated and induce apoptosis. This implies that there may be a need for re-evaluation of the therapeutic approaches to human prostate cancer.

Shared flowering phenology, insect pests, and pathogens among wild, weedy, and cultivated rice in the Mekong Delta, Vietnam: implications for transgenic rice

Many varieties of transgenic rice are under development in countries where wild and weedy relatives co-occur with the crop. To evaluate possible risks associated with pollen-mediated transgene dispersal, we conducted a two-year survey in Vietnam to examine overlapping flowering periods of rice (Oryza sativa L.), weedy rice (O. sativa), and wild rice (O. rufipogon Griff.), all of which are inter-fertile. We surveyed populations in two regions of the Mekong Delta, northern and southern, and at three sites in each of three habitats per region: fresh water, saline water, and acid sulfate soil. Weedy rice frequently flowered simultaneously with neighboring cultivated rice plants. Flowering was more seasonal in wild rice and often peaked in November and December. Peak flowering times of wild rice overlapped with adjacent rice fields at all of the saline sites and half of the acid sulfate sites. The longer flowering season of wild rice ensured that crop-to-wild gene flow was possible in fresh water habitats as well. Our second objective was to determine whether wild and weedy rice populations are exposed to pests that could be targeted by future transgenes, which may then provide fitness benefits. These populations shared many pathogen and insect herbivore species with cultivated rice (leaffolder, locust, cricket, planthoppers, rice bug, stem borer, sheath blight, blast, bacterial leaf blight, and brown spot). Damage by leaffolders and locusts was the most frequently observed insect feeding damage on all three rice types. Indicator species analysis revealed that most of the insect herbivores were associated with particular habitats, demonstrating the importance of broad geographic sampling for transgenic rice risk assessment. These survey data and the strong likelihood of gene flow from cultivated rice suggest that further studies are needed to examine the effects of transgenic traits such as resistance to pests on the abundance of wild and weedy rice.

A Web-based database for pathology faculty effort reporting

To ensure appropriate mission-based budgeting and equitable distribution of funds for faculty salaries, our compensation committee developed a pathology-specific effort reporting database. Principles included the following: (1) measurement should be done by web-based databases; (2) most entry should be done by departmental administration or be relational to other databases; (3) data entry categories should be aligned with funding streams; and (4) units of effort should be equal across categories of effort (service, teaching, research). MySQL was used for all data transactions (http://dev.mysql.com/downloads), and scripts were constructed using PERL (http://www.perl.org). Data are accessed with forms that correspond to fields in the database. The committee's work resulted in a novel database using pathology value units (PVUs) as a standard quantitative measure of effort for activities in an academic pathology department. The most common calculation was to estimate the number of hours required for a specific task, divide by 2080 hours (a Medicare year) and then multiply by 100. Other methods included assigning a baseline PVU for program, laboratory, or course directorship with an increment for each student or staff in that unit. With these methods, a faculty member should acquire approximately 100 PVUs. Some outcomes include (1) plotting PVUs versus salary to identify outliers for salary correction, (2) quantifying effort in activities outside the department, (3) documenting salary expenditure for unfunded research, (4) evaluating salary equity by plotting PVUs versus salary by sex, and (5) aggregating data by category of effort for mission-based budgeting and long-term planning.

Long-term, tumor-free survival after radiotherapy combining hepatectomy-Whipple en bloc and orthotopic liver transplantation for early-stage hilar cholangiocarcinoma

This retrospective study reviews our experience in surveillance and early detection of cholangiocarcinoma (CC) and in using en bloc total hepatectomy-pancreaticoduodenectomy-orthotopic liver transplantation (OLT-Whipple) to achieve complete eradication of early-stage CC complicating primary sclerosing cholangitis (PSC). Asymptomatic PSC patients underwent surveillance using endoscopic ultrasound and endoscopic retrograde cholangiopancreatography (ERCP) with multilevel brushings for cytological evaluation. Patients diagnosed with CC were treated with combined extra-beam radiotherapy, lesion-focused brachytherapy, and OLT-Whipple. Between 1988 and 2001, 42 of 119 PSC patients were followed according to the surveillance protocol. CC was detected in 8 patients, 6 of whom underwent OLT-Whipple. Of those 6 patients, 4 had stage I CC, and 2 had stage II CC. All 6 OLT-Whipple patients received combined external-beam and brachytherapy radiotherapy. The median time from diagnosis to OLT-Whipple was 144 days. One patient died 55 months post-transplant of an unrelated cause, without tumor recurrence. The other 5 are well without recurrence at 5.7, 7.0, 8.7, 8.8, and 10.1 years. In conclusion, for patients with PSC, ERCP surveillance cytology and intralumenal endoscopic ultrasound examination allow for early detection of CC. Broad and lesion-focused radiotherapy combined with OLT-Whipple to remove the biliary epithelium en bloc offers promising long-term, tumor-free survival. All patients tolerated this extensive surgery well with good quality of life following surgery and recovery. These findings support consideration of the complete excision of an intact biliary tree via OLT-Whipple in patients with early-stage hilar CC complicating PSC.

Baby Shampoo Nasal Irrigations for the Symptomatic Post-functional Endoscopic Sinus Surgery Patient

Background

Symptoms of postnasal drainage and thickened mucus are commonly seen in patients with chronic rhinosinusitis (CRS) recalcitrant to sinus surgery and conventional medical therapies. Chemical surfactants can act as a mucolytic by reducing water surface tension and have the potential to serve as an antimicrobial agent. Baby shampoo is an inexpensive, commercially available solution containing multiple chemical surfactants. This is an in vitro study of its antimicrobial effects on Pseudomonas biofilms with translation to a clinical study for use as an adjuvant nasal wash in patients with CRS who remain symptomatic despite adequate sinus surgery and conventional medical therapies.

Methods

In vitro testing was performed to determine the optimal concentration of baby shampoo that disrupted preformed bacterial biofilms and inhibited biofilm formation. This concentration was then used in a prospective study of symptomatic post–functional endoscopic sinus surgery (FESS) patients who irrigated twice a day for 4 weeks. Validated outcome forms and objective smell testing was performed before and after therapy.

Results

One percent baby shampoo in normal saline was the optimal concentration for inhibition of Pseudomonas biofilm formation. Baby shampoo had no effect on the eradication of preformed Pseudomonas biofilms. Eighteen patients with CRS with an average of 2.8 surgeries were studied after irrigating with 1% baby shampoo solution. Two patients discontinued use because of minor nasal and skin irritations; 46.6% of patients experienced an overall improvement in their subjective symptoms, and 60% of patients noted improvement in specific symptoms of thickened mucus and postnasal drainage.

Conclusion

Baby shampoo nasal irrigation has promise as an inexpensive, tolerable adjuvant to conventional medical therapies for symptomatic patients after FESS. Its greatest benefit may be in improving symptoms of thickened nasal discharge and postnasal drainage.

A review of the association between congestive heart failure and cognitive impairment

Heart failure is a growing epidemic with an estimated 5 million Americans suffering from this condition. Several clinical trials have demonstrated a high correlation between congestive heart failure (CHF) and cognitive impairment. The severity of cognitive impairment correlates positively with the degree of CHF. The underlying mechanism for cognitive impairment remains unclear but appears to be related to cerebral hypoperfusion and impaired cerebral reactivity with selective impairment of verbal memory and attention domains. Furthermore, cognitive dysfunction represents one aspect of frailty, a novel concept that encompasses a range of clinical conditions that results in functional impairment in patients with heart failure. In addition, frailty independently predicts mortality in CHF patients. Cognitive impairment is a common and predictable effect of CHF that contributes with social and behavioral problems to decreased compliance to prescribed therapy and increased hospital readmissions. A multidisciplinary approach is necessary to deal with the complexity of this clinical syndrome.