Yoav Sherman

Identification of dying cells--in situ staining.

Publisher Summary The basic requirements for any methodology of programmed cell death (PCD) detection include (1) resolution at the individual cell level, and (2) in situ applicability while preserving the tissue architecture. To investigate PCD in its physiological context, the chapter develops a method that satisfies both criteria that is referred to as “terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL).” This technique is based on the observation that PCD is associated with DNA degradation. Researchers have come to consider the appearance of the ladder of nucleosomal DNA on agarose gels as the hallmark of PCD. The TUNEL method relies on the in situ labeling of DNA breaks in individual nuclei in tissue sections processed through the routine procedures of histopathology. TUNEL relies on the specific binding of TdT to exposed 3′-OH ends of DNA followed by the synthesis of a labeled polydeoxynucleotide molecule. Nuclear DNA on histological sections is first exposed by proteolytic treatment; then TdT is used to incorporate biotinylated deoxyuridine into the sites of DNA breaks. The signal is amplified by avidin-peroxidase, enabling conventional histochemical identification of PCD by light microscopy.

Heparanase powers a chronic inflammatory circuit that promotes colitis-associated tumorigenesis in mice.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease that is closely associated with colon cancer. Expression of the enzyme heparanase is clearly linked to colon carcinoma progression, but its role in UC is unknown. Here we demonstrate for what we believe to be the first time the importance of heparanase in sustaining the immune-epithelial crosstalk underlying colitis-associated tumorigenesis. Using histological specimens from UC patients and a mouse model of dextran sodium sulfate-induced colitis, we found that heparanase was constantly overexpressed and activated throughout the disease. We demonstrate, using heparanase-overexpressing transgenic mice, that heparanase overexpression markedly increased the incidence and severity of colitis-associated colonic tumors. We found that highly coordinated interactions between the epithelial compartment (contributing heparanase) and mucosal macrophages preserved chronic inflammatory conditions and created a tumor-promoting microenvironment characterized by enhanced NF-κB signaling and induction of STAT3. Our results indicate that heparanase generates a vicious cycle that powers colitis and the associated tumorigenesis: heparanase, acting synergistically with the intestinal flora, stimulates macrophage activation, while macrophages induce production (via TNF-α-dependent mechanisms) and activation (via secretion of cathepsin L) of heparanase contributed by the colon epithelium. Thus, disruption of the heparanase-driven chronic inflammatory circuit is highly relevant to the design of therapeutic interventions in colitis and the associated cancer.

Detection of bladder tumors by immunostaininc of the lewis x antigen in cells from voided urine

OBJECTIVES A study was made to determine the sensitivity and specificity of immunostaining of the Lewis X antigen in exfoliated urothelial cells from voided urine, for the detection and surveillance of bladder tumors. METHODS Three consecutive voided urine specimens were obtained from 101 patients, 78 of whom were under surveillance because of a history of bladder tumors, and 23 were being evaluated because of hematuria or irritative urinary symptoms. Indirect immunoperoxidase staining of two urine samples was done on cytocentrifuge slides, using the P12 monoclonal antibody against the Lewis X antigen. The diagnosis of the presence of urothelial tumor was made if more than 5% of the cells showed a typical red-brown staining. Cytopathologic examination of the third urine specimen was done according to Papanicolaou. Each patient underwent cystoscopy, and biopsies were obtained whenever there was endoscopic evidence of bladder tumors or carcinoma in situ. RESULTS Cystoscopy and biopsies revealed transitional cell carcinoma in 32 patients, whereas 69 patients had no evidence of bladder tumors. Immunocytology of one urine sample showed true-positive results in 26 of the 32 patients with bladder tumors, corresponding to a sensitivity of 81.25%. When two samples were examined, a sensitivity of 97% and a specificity of 85.5% were obtained. When the results of cytology and immunocytology were combined, sensitivity reached 100%. High-grade and low-grade transitional cell tumors were detected with equal efficiency. CONCLUSIONS The use of P12 monoclonal antibody for evaluation of Lewis X reactivity in cytologic preparations from multiple voided urine specimens can improve the sensitivity of noninvasive detection of bladder cancer. The technique may ultimately replace cystoscopy in monitoring therapeutic response and tumor recurrence.

IMMUNOSTAINING OF LEWIS X IN CELLS FROM VOIDED URINE, CYTOPATHOLOGY AND ULTRASOUND FOR NONINVASIVE DETECTION OF BLADDER TUMORS

PURPOSE We examined the use of immunostaining of the Lewis X antigen in exfoliated cells from voided urine samples, cytopathology and bladder ultrasound for noninvasive detection of bladder tumors as a potential substitute for cystoscopy. MATERIALS AND METHODS A total of 260 patients were included, of whom 80 were evaluated because of irritative symptoms or hematuria and 180 were examined during followup visits after resection of bladder tumors. Voided urine samples were obtained from each patient for immunocytology and cytopathology. Bladder ultrasound and cystoscopy were performed. Biopsies were obtained whenever a bladder tumor was seen or if carcinoma in situ was suspected. Indirect immunoperoxidase staining was done on cytocentrifuge slides, using the P12 monoclonal antibody against the Lewis X antigen. RESULTS Cystoscopy and biopsies revealed bladder tumors in 84 patients. Immunocytology of 1 urine sample resulted in a sensitivity of 79.8% and a specificity of 86.4%. The diagnosis of primary carcinoma in situ by immunocytology was correct in 100% of the cases. The examination of 2 consecutive urine samples detected 95.1% of the tumors. False-negative results occurred in a few cases with small, superficial, low grade tumors. Cytopathology and bladder ultrasound resulted in a sensitivity of 47.6 and 66.7%, and a specificity of 97.7 and 97.2%, respectively. The results of immunocytology of 2 urine samples were equivalent to the combination of immunocytology of a single urine sample, cytology and ultrasound. CONCLUSIONS Immunostaining of the Lewis X antigen is significantly more sensitive than cytopathology for the detection of low grade as well as high grade tumor cells in voided urine. Immunocytological evaluation of 2 consecutive voided urine specimens for the Lewis X antigen is the most sensitive method currently available for noninvasive detection of transitional cell tumors. This assay may replace cystoscopy for detection of bladder cancer.

T-2 toxin effect on bacterial infection and leukocyte functions.

The effects of T-2 toxin on bacterial infection and leukocyte function and structure were examined in vivo and in vitro. Rats were innoculated with staphylococci after pretreatment with or without T-2 toxin. The T-2 pretreated rats failed to mount a cellular response to the bacteria. Blood and bone marrow cells were markedly suppressed by the T-2 toxin, the myeloid series being the most affected. In vitro studies with human leukocytes showed that small, nonkilling doses of T-2 toxin inhibited chemotaxis, chemiluminescence stimulated by bacteria, and phagocytosis of bacteria. It was concluded that this inhibition may contribute towards sepsis and rapid onset of death in T-2 toxin poisoning.

A safety and tolerability study of differently-charged nanoparticles for local pulmonary drug delivery

Nanoparticle (NP) based drug delivery systems provide promising opportunities in the treatment of lung diseases. Here we examined the safety and tolerability of pulmonary delivered NPs consisting of PEG-PLA as a function of particle surface charge. The rationale for such a comparison should be attributed to the differential pulmonary toxicity of positively and negatively charged PEG-PLA NP. Thus, the local and systemic effects of pulmonary administered NPs were investigated following 5days of daily endotracheal instillation to BALB/c mice that were euthanized on the eighth or nineteenth day of the experiment. We collected bronchoalveolar lavages and studied hematological as well as histochemistry parameters. Notably, the cationic stearylamine based PEG-PLA NPs elicited increased local and systemic toxic effects both on the eighth and nineteenth day. In contrast, anionic NPs of similar size were much better tolerated with local inflammatory effects observed only on the eighth experimental day after pulmonary instillation. No systemic toxicity effect was observed although a moderate change was noted in the platelet count that was not considered to be of clinical significance. No pathological observations were detected in the internal organs following instillation of anionic NPs. Overall these observations suggest that anionic PEG-PLA NPs are useful pulmonary drug carriers that should be considered as a promising therapeutic drug delivery system.

Spatial and temporal heparanase expression in colon mucosa throughout the adenoma-carcinoma sequence

Heparanase is a mammalian endo-β-D-glucuronidase that cleaves heparan sulfate side chains at a limited number of sites. Such enzymatic activity is thought to participate in degradation and remodeling of the extracellular matrix and to facilitate cell invasion associated with tumor metastasis, angiogenesis and inflammation. Traditionally, heparanase activity was well correlated with the metastatic potential of a large number of tumor-derived cell types. More recently, heparanase upregulation has been documented in an increasing number of primary human tumors, correlating with poor postoperative survival and increased tumor vascularity. Here, we employed anti-heparanase 733 polyclonal antibody that preferentially recognizes the 50 kDa active heparanase subunit over the 65 kDa proenzyme, as well as anti-heparanase 92.4 monoclonal antibody that recognizes both the latent and the active enzyme, to follow heparanase expression, processing and localization throughout the adenoma–carcinoma transition of the colon epithelium. Normal (nondysplastic) mucosa of the large bowel near epithelial neoplasms, as well as areas of mild dysplasia in adenomas, exhibited a strong reactivity with antibody 733 that became even stronger in foci of moderate dysplasia. Interestingly, although reactivity with antibody 733 was markedly reduced in severe dysplasia and in colorectal carcinoma, response to antibody 92.4 exhibited the opposite trend and staining intensities increased in parallel with tumor stage, the highest being in carcinoma cells. Involvement of latent heparanase (detected by 92.4, but not by 733 antibody) in tumor progression was suggested by activation of the Akt/PKB signal transduction pathway upon heparanase overexpression or exogenous addition to HT29 human colon carcinoma cells. These results suggest that heparanase expression is induced during colon carcinogenesis, and that its processing, conformation and localization are tightly regulated during the course of colon adenoma–carcinoma progression.

Osteoporosis in the Cohen Diabetic Rat: Correlation Between Histomorphometric Changes in Bone and Microangiopathy

Osteoporosis is well documented in type I diabetes, but its occurrence is controversial in type II diabetes. Microangiopathy is a major complication of type I and type II diabetes. We studied bone and microvascular changes in the Cohen diabetic rat, a unique nonobese model of noninsulin-dependent diabetes mellitus. The aim of this study was to find whether there is a temporal correlation between the onset of these two complications. The diabetic rats were divided into three groups (A, B, and C) according to duration of diabetes (2 months, 3 months, and 7 to 8 months, respectively). Trabecular bone area was assessed by computerized image analysis and microangiopathy by means of renal function tests, histologic examination of the kidneys, and ultrastructural measurement of the width of capillary basement membranes. Bone density of the distal femur and vertebra was significantly reduced in the diabetic rats relative to the control rats in all three groups (Group A femur: 11.5 ± 1.6% versus 21.8 ± 3.0%, p < 0.02; Group A vertebra: 15.9 ± 1.6% versus 28.5 ± 2.0%, p < 0.02; Group C femur: 7.9 ± 1.1% versus 29.6 ± 3.5%, p < 0.001; Group C vertebra: 11.4 ± 0.7% versus 37.1 ± 1.9%, p < 0.002). Renal function tests were normal in the Group A diabetic rats and there was marked albuminuria in the Group C diabetic rats. Histologic changes in the kidneys were seen only in the Group C diabetic rats. Five of 15 Group C diabetic rats showed no albuminuria or histologic evidence of kidney damage. The bone density in this subgroup was reduced relative to controls to the same degree as that of the rats with renal damage. There was no evidence of capillary basement membrane thickening in the Group A diabetic rats. Our findings indicate that in the Cohen diabetic rat, osteoporosis precedes the onset of microangiopathy. Microangiopathy probably does not play an important role in the pathogenesis of osteoporosis in this animal model.

Intravascular Lymphomatosis-An Indolent or Aggressive Entity?

Intravascular lymphomatosis (IVL) is a rare malignancy characterized by neoplastic proliferation of lymphoid cells within the lumens of arteries, small veins and capillaries. We report four patients with IVL and review the recent world literature, relating to incidence, clinical features and possible therapy. In these cases diagnosis was established coincidentally in one patient after prostatectomy. This patient eventually had central nervous system involvement. In two other patients IVL was diagnosed from skin lesions. In the fourth case the diagnosis was established at post-mortem examination, where involvement of most organs was evident but particularly kidneys, myocardium, gastrointestinal tract and lymph nodes. Therapy was given to three patients, but the disease progressed in two and they both died with evidence of central nervous system involvement, while the third patient has had a good partial response to combination chemotherapy but has relapsed within two months of completing chemotherapy. As evident from our patients and the literature review IVL has a variable clinical course and currently, there appears to be no effective therapy for this rare disorder.

Image-guided cutting-edge-needle biopsy of peripheral lymph nodes and superficial masses for the diagnosis of lymphoma.

Objective: To evaluate the diagnostic efficacy of image-guided cutting-edge-needle biopsy of peripheral lymph nodes and superficial masses for the diagnosis of lymphoma, for which many still advocate open surgical resection. Methods: A retrospective analysis was performed of the medical records of 114 lymphoma patients who presented with peripheral lymphadenopathy and superficial masses and who underwent diagnostic image-guided biopsy. There were 69 non-Hodgkin lymphoma patients, 38 Hodgkin lymphoma patients, and 7 patients who were evaluated for histologic transformation of CLL or high grade lymphoma. Results: Image-guided needle biopsy was diagnostic in 96/114 (84.2%) patients. The procedure was diagnostic in 59/69 (85.5%) of NHL patients and in 30/38 of Hodgkin disease patients (79%). Diagnoses were achieved for all 7 cases where histologic transformation was suspected. Conclusion: Percutaneous image-guided needle biopsy is a safe and reliable procedure with a high diagnostic yield. It can be used as a first step in patients suspected of having lymphoma presenting with enlarged peripheral lymph nodes and superficial masses.