Presence Of Polyp Research Articles

Renal Carcinoma Metachronous Metastases to the Gall-Bladder and Pancreas - Case Report

Renal carcinoma metastases to the gastrointestinal tract are seldom reported in medical literature. The study presented a case of a 76-year old female patient who underwent nephrectomy, due to T2N0M0 clear cell renal carcinoma and was additionally diagnosed with two metachronous metastases to the gall-bladder and pancreas. Abdominal ultrasound performed 32 months after nephrectomy demonstrated the presence of cholelithiasis and gall-bladder polyp. Laparoscopic cholecystectomy was performed. Clear cell renal carcinoma metastasis restricted to the gall-bladder mucosa was diagnosed on the basis of the histopathological examination. After surgery the patient remained under follow-up. In December, 2009 (47 months after nephrectomy) abdominal computer tomography (CT) revealed the presence of a tumor located in the tail of the pancreas. Distal pancreatic resection and splenectomy was performed. The histopathological examination confirmed the presence of clear cell renal carcinoma metastasis. The patient is in good general condition, under follow-up at the Oncological Outpatient Clinic.

Platelet Polyphosphate Enhances Factor XI Activation by Thrombin

Abstract 377Factor (f) XI deficiency is associated with a bleeding diathesis but factor fXII deficiency is not, indicating that, in normal hemostasis, fXI must be activated in vivo by a protease other than fXIIa. Several groups have identified thrombin as the most likely activator of fXI, although this reaction is slow in solution. While certain non-physiologic anionic polymers and surfaces have been shown to enhance fXI activation by thrombin, the physiologic cofactor for this reaction is uncertain. Activated platelets secrete the highly anionic polymer, polyphosphate (polyP), and our previous studies have shown that polyP has potent procoagulant activity. We now report that polyP potently accelerates fXI activation by alpha-thrombin, beta-thrombin and fXIa, and that these reactions are supported by polyP polymers of the size secreted by activated human platelets. We therefore propose that polyP is a natural cofactor for fXI activation in plasma.In reactions using purified proteins, fXI activation by alpha-thrombin was undetectable (under the conditions employed) in the absence of polyP or in the presence of polyP with polymer lengths shorter than 55mers. On the other hand, polyP of the size range secreted by human platelets (60 to 100mers) potently stimulated fXI activation by thrombin, as did longer polyP polymers. PolyP of this size also potently stimulated fXI autoactivation. Addition of EcPPXc, the isolated polyP-binding domain of E. coli exopolyphosphatase, specifically abrogated polyP-mediated fXI activation by alpha-thrombin. We further observed that releasates from activated platelets markedly accelerated the rate of fXI activation by alpha-thrombin, but this activity was inhibited by EcPPXc. Using surface plasmon resonance analyses, we found that fXI, fXIa and alpha-thrombin all bound tightly to immobilized polyP, yielding Kd values of 6.4 nM, 1.5 nM and 15.1 nM, respectively.We next examined whether polyP enhances fXI activation by thrombin in a plasma environment. To eliminate interference from fXI activation by fXIIa, we used fXII-deficient plasma and added corn trypsin inhibitor (CTI) to inhibit any remaining traces of fXIIa. Since beta-thrombin activates fXI but has greatly diminished capacity to cleave fibrinogen, we performed clotting assays using beta-thrombin and varying polyP sizes in fXII-deficient plasma containing CTI. Longer polyP polymers (65 to 445 phosphate units) shortened the clotting time in a concentration-dependent manner. FXI-deficient plasma exhibited prolonged clotting times in this assay, with clotting times that were essentially unaffected by the presence of longer polyP sizes. These results show that polyP shortens the beta-thrombin-mediated clotting time of plasma in a manner that is dependent on fXI but independent of fXII.Finally, we examined the ability of polyP to enhance thrombin-mediated thrombin generation in plasma using CAT assays. Increasing concentrations of polyP caused increasing thrombin bursts in a polymer length-dependent manner, while no thrombin generation was observed in the presence of polyP without beta-thrombin. This effect was dependent on fXI, as addition of blocking antibodies to fXI inhibited polyP-mediated thrombin generation. Consistent with this notion, there was no observable polyP-mediated thrombin generation in fXI-deficient plasma, although this was restored when fXI-deficient plasma was reconstituted with purified fXI.Our studies demonstrate that polyP polymers of the size secreted by activated platelets enhance fXI activation by thrombin and also enhance fXI autoactivation. Furthermore, platelet releasates promoted fXI activation by thrombin, an activity that was abrogated by EcPPXc. Taken together, these findings support the notion that platelet polyP may be a natural, physiological cofactor for the activation of fXI by thrombin, and may represent a previously unrecognized link between fXI and hemostasis/thrombosis. Disclosures:Choi:University of Illinois: Patents & Royalties. Smith:University of Illinois: Patents & Royalties. Morrissey:University of Illinois: Patents & Royalties.

Assessment of Patientsʼ Recollection of Polyp Findings on Colonoscopy

Purpose: Current ACG guidelines for colorectal cancer (CRC) screening and surveillance require knowledge of a patient's personal and family history of CRC and adenomas, including age of onset, size, number and pathology of polyps. Which details a patient remembers regarding their colonoscopy findings is unknown. Our aims are to determine the accuracy of patients' knowledge regarding the findings on their last colonoscopy and establish if any factors including method of communicating results influenced their ability to correctly recall the findings. Methods: A 35 question survey was administered to individuals who previously had a colonoscopy at our Center. Questions included information on demographics, absence/presence of polyps, polyp size (1-5, 6-9, >9mm), number and pathology (by specific histology). Other and unsure were response options. We compared participants' survey responses to colonoscopy and pathology reports and electronic medical records (EMR). Subjects who correctly recalled presence of polyps were studied to determine how many of the 3 key polyp features they reported correctly; number (1-2 or > 2), size of largest polyp (1-9 mm or > 9 mm) and pathology of at least 1 polyp. The effect of method of communication of results on correct recall of colonoscopy findings was assessed. Results: 233 individuals (median age 55, 49% men) participated in this IRB approved study. 82% correctly recalled the presence/absence of polyp(s) [Table]. 9% reporting polyps did not have them and 3% reporting no polyps had them. Of 118 correctly reporting polyps, 61% correctly recalled number of polyps, 26% polyp size, and 74% were unsure of pathology. 37% of individuals did not correctly recall at least one of the 3 key polyp features while 39% were correct on 1, 16% on 2 and 8% recalled 3. Neither age at last colonoscopy, current age, gender or method of communication of colonoscopy results significantly influenced accurate reporting of presence of polyp(s) or number of key polyp features (p > 0.05). Less years since last colonoscopy, 3 vs 4.3 (p=0.037) and presence of polyps on last colonoscopy (p <0.001) were associated with correct self report of presence/absence of polyps.Table: No Caption available.Conclusion: Only 82% of patients correctly remember the presence/absence of polyp(s). Key polyp features important in determining surveillance intervals are not recalled by patients. Methods to improve a patient's ability to retain details of personal colonoscopy findings is an important area of quality improvement in colonoscopy.

Inorganic polymeric phosphate/polyphosphate as an inducer of alkaline phosphatase and a modulator of intracellular Ca 2+ level in osteoblasts (SaOS-2 cells) in vitro

Inorganic polymeric phosphate is a physiological polymer that accumulates in bone cells. In the present study osteoblast-like SaOS-2 cells were exposed to this polymer, complexed in a 2:1 stoichiometric ratio with Ca 2+, polyP (Ca 2+ salt). At a concentration of 100 μM, polyP (Ca 2+ salt) caused a strong increase in the activity of the alkaline phosphatase and also an induction of the steady-state expression of the gene encoding this enzyme. Comparative experiments showed that polyP (Ca 2+ salt) can efficiently replace β-glycerophosphate in the in vitro hydroxyapatite (HA) biomineralization assay. In the presence of polyP (Ca 2+ salt) the cells extensively form HA crystallites, which remain intimately associated with or covered by the plasma membrane. Only the tips of the crystallites are directly exposed to the extracellular space. Element mapping by scanning electron microscopy/energy-dispersive X-ray spectroscopy coupled to a silicon drift detector supported the finding that organic material was dispersed within the crystallites. Finally, polyP (Ca 2+ salt) was found to cause an increase in the intracellular Ca 2+ level, while polyP, as well as inorganic phosphate (P i) or Ca 2+ alone, had no effect at the concentrations used. These findings are compatible with the assumption that polyP (Ca 2+ salt) is locally, on the surface of the SaOS-2 cells, hydrolyzed to P i and Ca 2+. We conclude that the inorganic polymer polyP (Ca 2+ salt) in concert with a second inorganic, and physiologically occurring, polymer, biosilica, activates osteoblasts and impairs the maturation of osteoclasts.

Sessile polyps and pedunculated polyps respond differently to oral contraceptives

Endometrial polyp is the lesion frequently found by hysteroscopy. The presence of endometrial polyp is associated with abnormal uterine bleeding and is probably associated with infertility. Until today, clinical guidelines for endometrial polyp remain elusive. The aim of this preliminary study was to estimate whether the shape of endometrial polyps affects the response to the treatment with an oral contraceptive (OC). We performed a retrospective case series study on 50 women diagnosed as endometrial polyps by hysteroscopy and managed by the administration of OC. Hysteroscopy was performed in the follicular phase of the menstrual cycle before medical treatment. Endometrial polyps were classified as pedunculated polyps (n = 25) or sessile polyps (n = 25). After diagnosis, OC was administered for 2–5 months (median 3 months) intermittently: To quantify the regression rate of lesions, the area index of endometrial polyps was assessed. In the study group, when comparing the efficacy of treatment with OC, there was a statistically significant difference in the regression rate between sessile polyps and pedunculated polyps (76% vs. 44%, p = 0.042). We conclude that sessile polyps are more sensitive to OC treatment than pedunculated polyps, implying usefulness of the hysteroscopic classification of the shape of polyps in the management of endometrial polyps.

Polyphosphate modifies the fibrin network and down-regulates fibrinolysis by attenuating binding of tPA and plasminogen to fibrin

AbstractActivated platelets secrete a negatively charged polymer, polyphosphate (polyP). Here, we explore the interactions of polyP with fibrin(ogen) and its effect on fibrin structure and fibrinolysis. Electrophoretic mobility and binding assays indicate that polyP interacts with fibrinogen and soluble fibrin. Clots formed in the presence of polyP exhibited reduced turbidity and permeability indicative of a tighter fibrin network, but these changes were not related to cross-linking or fibrinopeptide release. Microscopy showed a change in fibrin distribution in clots formed with polyP; with formation of tight aggregates of fibrin fibers interspaced with large pores in contrast to homogenous fiber distribution in control clots. Lysis by tissue plasminogen activator (tPA) and plasminogen or plasmin was delayed in clots formed with polyP and depended on both the activator and polyP concentration. Adding polyP to the clot after fibrin formation or to repolymerizing soluble fibrin did not affect lysis, indicating changes induced by polyP occur at the level of conversion of fibrinogen to fibrin. Surface plasmon resonance showed that the presence of polyP reduced the binding of both plasminogen and tPA to partially lysed fibrin surfaces. These data show that polyP directly influences fibrin architecture and attenuates fibrinolysis through reduced binding of fibrinolytic proteins.

Recent Discoveries on the Roles of Polyphosphates in Plants

Polyphosphate (polyP) has been abundant on Earth long before life began. In living organisms, polyphosphate can be stored in electron-dense granules that have long been referred to as volutin granules. After having being ignored for a long time, this polymer has proven to have numerous unsuspected functions in living organisms and is receiving more attention. The ubiquitous presence of polyP in nature and its structural and physico-chemical characteristics appear to be the drivers for the evolutionary selection of this versatile molecule as a component of cellular processes. Most of our knowledge about the functions of polyP comes from the microbial world. PolyP can influence the transcription and translation of specific genes, act as a metabolic regulator, provide an alternative source of energy, and modulate several stress responses. In plant systems, although the presence of polyP has long been known, its roles in cellular processes have begun to emerge only recently. The purpose of this mini-review is to provide a brief overview of the proposed biological roles of polyphosphates in plants and their roles in microbial/plant interactions.

Clinical Significance of Colonic Diverticulosis Associated with Bowel Symptoms and Colon Polyp

This study was done to evaluate prospectively the clinical significance of colonic diverticulosis. In the 1,030 consecutive outpatients undergoing colonoscopy, the information on the demographics, the patterns of bowel symptoms, and the prevalence of colon polyp were analyzed according to the presence of colonic diverticulosis. The mean age of 1,030 patients were 52.2 yr and 59.3% were male. The prevalence of diverticulosis was 19.7% (203/1,030). Of 203 diverticulosis patients 85.2% were in proximal group, 5.4% in distal group and 9.4% in both group. Six (3.0%) patients were found to have diverticulitis. Multivariate logistic regression analysis showed that an old age, diabetes and the presence of polyp were significant factors associated with proximal or both diverticulosis. A significant difference was demonstrated between the patients of distal diverticular group and the controls for the symptom frequency scores within the previous 4 weeks. The items, which showed difference, were hard stool, urgency, flatus, chest discomfort and frequent urination. In conclusion, old age, diabetes and the presence of colon polyp were associated with proximal diverticulosis. The temporal symptoms were more frequent in distal diverticulosis than in proximal diverticulosis in the study subjects.

Correlation of iron and colon adenomas

Better colon cancer screening guidelines are needed. This study was conducted to explore the relationship between serum transferrin saturation (as iron is a potential carcinogen) and presence of colon adenomas. This may aid to evolve better colon cancer screening guidelines. This study is a retrospective review of computer records. Patients who had colonoscopy and iron studies done between May 1996 and December 2003 were included in the study. The adjusted odds ratio, derived from multiple logistic regression analysis, was used to measure the association between transferrin saturation and colon adenomas. Complete data were available for 124 subjects. The adjusted odds ratio, for predicting the presence of polyp in those patients with transferrin saturation above the median was 10.9 (CI 4.0-29.5, P<0.001). A one percent increase in transferrin saturation was associated with a 1.07 increase the odds of adenoma (CI 1.03-1.11, P<0.001). Iron levels are directly linked to presence of colon polyps, and might help in evolving better screening guidelines.

Investigating Rectal Bleeding

Purpose: Few studies are available that describe the pattern of lower GI pathology in the third world. It is generally believed that such pathology including IBD is uncommon. We conducted this study with the following objectives 1) To review the etiological patterns on diagnostic evaluation of patients presenting with rectal bleeding. 2) To study the association of rectal bleeding with age and gender Methods: We conducted a retrospective chart review of existing clinical data to compare patterns of GI pathology in patients presenting with rectal bleeding and subsequently undergoing flexible sigmoidoscopies and colonoscopies. Outcomes of interest included depth examined, nature of clinical findings and association of these with rectal bleeding. Furthermore, association of rectal bleeding with age and gender were also found. Results: A total of 261 patients, 131 (51%) males and 130 (49%) females, mean age 41 years (S.D 21, Range 4–93) were included in the study. 160/261 (61%) presented with rectal bleeding (82 males and 78 females) of which majority 83/261 (32%) were examined up to the hepatic flexure followed by 79/261 (30%) till the terminal ileum. A total of 27/160 (16%) had a single or multiple polyp, 47/160 (29%) had Inflammatory bowel disease (P-value 0.000), 17/160 had malignant lesions while 37/160 (23%) had hemorrhoids (P-value 0.003). Flexible sigmoidoscopy was performed on 61/261 patients and 46 (75%) of these had presented with rectal bleeding. It was found that 4/46 (0.1%) had a single or multiple polyps with significant association found between absence of rectal bleeding and presence of polyp (P-value = 0.03). IBD was diagnosed in 16/46 (35%) (P-value = 0.047) while 5/46 (0.1%) had malignancies. Of those (200/261) who underwent colonoscopic examination, 114/200 (57%) presented with rectal bleeding. Diagnosis of polyp was made on 23/114 (20%), IBD 31/114 (27%) (P-value < 0.001) while 13/114 (11%) were found to have malignant lesions. Conclusion: 1) Rectal bleeding seems to be presenting below 40 years of age in our patient population and has a strong association with IBD. 2) Hemorrhoids are significantly associated with bleeding per rectum. 3) Polyps seem to have an inverse statistical association with rectal bleeding in the patient population that underwent flexible sigmoidoscopy. 4) Malignancy does not seem to be significantly associated with bleeding per rectum in our set-up.Table: Association of Rectal Bleeding with Major Diagnoses

Multiple Analyses of Factors Related to Intraoperative Blood Loss and the Role of Reverse Trendelenburg Position in Endoscopic Sinus Surgery

To find out the factors related to the volume of intraoperative blood loss during endoscopic sinus surgery and to validate the role of reverse Trendelenburg position (RTP) in controlling blood loss. Prospective, controlled, single-blind study. Endoscopic sinus surgeries for chronic rhinosinusitis with or without polyposis were performed in 60 patients, which were randomly categorized into two groups. The study group (RTP group) consisted of 30 patients laid on operation table with the RTP of 10 degrees during the whole surgery, and the control group with 30 patients completely laid supine. All operations were performed by the same operator (the first author) without using hemostatic agents during the operation. Intraoperative blood loss was estimated by total volume of blood loss, blood loss per minute, and surgical field scale. Multiple factors related to blood loss, such as computed tomography scores, operation time, mean arterial pressure, polyposis, fungal sinusitis, and anesthetic agents were compared. There existed significant differences in total blood loss, blood loss per minute, and surgical field between the RTP group and supine group. In multiple analyses within the two groups, presence of polyp, non-fungal sinusitis and use of microdebrider exhibited a significant higher blood loss rate in the RTP group. RTP may reduce intraoperative blood loss. Besides, fungal sinusitis and rhinosinusitis without polyposis may contribute to a lesser intraoperative blood loss.

Polyphosphate Enhances Fibrin Clot Structure.

Introduction: Inorganic polyphosphate (polyP) is a negatively charged polymer of phosphate units linked by high energy phosphoanhydride bonds. Dense granules of human platelets contain polyP which is released in response to thrombin stimulation. We recently reported that polyphosphate is a potent hemostatic regulator, accelerating blood clotting by activating the contact pathway and promoting the activation of factor V. Our previous studies found that polyP did not affect the time to clot formation when plasma was clotted with thrombin, however, suggesting that polyP exerts its procoagulant actions upstream of thrombin. We now report that polyP enhances fibrin clot structure.Methods: Purified fibrinogen and polyP were preincubated for 15 min in multiwell plates in buffer containing CaCl2, after which clotting was initiated by adding 0.1 to 8 nM thrombin and fibrin clot formation was evaluated by quantifying the change in turbidity (A405). Mass-length ratios were calculated from scans of A400 to A800. The effect of polyP on fibrinolysis was examined by adding 8 nM plasmin to the reaction mixtures immediately prior to thrombin. Scanning electron microscopy (SEM) was employed to visualize clot structure, and time courses of covalent fibrin cross-linking were assessed by SDS-PAGE.Results: PolyP had no effect on time to clot formation, but clots formed in the presence of polyP had markedly (up to threefold) higher turbidity than clots formed in the absence of polyP (see figure), irrespective of thrombin concentration. The increased turbidity in the presence of polyP was calcium-dependent and was enhanced when fibrinogen, CaCl2, and polyP were preincubated for up to 15 min prior to initiation of clotting with thrombin. PolyP increased the mass-length ratio of fibrin, and SEM confirmed that fibers formed with polyP were thicker than those formed without polyP. The ability of polyP to enhance fibrin clot turbidity was independent of factor XIIIa activity, and polyP did not alter the rate or extent of covalent fibrin cross-linking by factor XIIIa. When plasmin was included in clotting reactions containing polyP, mean times to 50% clot lysis were 28.5 ± 0.8 min for clots without polyP but 120.4 ± 5.6 min for clots with polyP.Conclusions: PolyP alters polymerization of fibrin, resulting in fibers of higher mass-length ratio that are lysed more slowly. This effect is calcium-dependent and is enhanced by preincubation of fibrinogen with calcium and polyP. Release of polyP from activated platelets or infectious microorganisms may therefore enhance fibrin clot structure. [Display omitted]

Meat and meat‐mutagen intake, doneness preference and the risk of colorectal polyps: The Tennessee colorectal polyp study

Although meat intake has been fairly consistently linked to the risk of colorectal cancer, only a few studies have evaluated meat intake by doneness level and the heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) produced by high temperature cooking of meat in relation to colorectal adenomatous and hyperplastic polyps. We evaluated these associations in a large colonoscopy-based case-control study. Included in this study were participants with adenomatous polyp only (n = 573), hyperplastic polyp only (n = 256), or both adenomatous and hyperplastic polyps (n = 199), and 1,544 polyp-free controls. In addition to information related to demographic and other lifestyle factors, meat intake by cooking method and doneness preference were obtained through telephone interviews. Polytomous logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals for the association between exposures and colorectal polyp risks. Presence of hyperplastic polyp was found to be positively associated with high consumption of total meat (p(trend) = 0.076) or red meat (p(trend) = 0.060), with an approximate 50-60% elevated risk observed in the highest vs. the lowest intake group. High intake of 2-amino-I-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-3,4,8-trimethylimidazo [4,5]quinoxaline (DiMeIQx) were associated with increased risk for hyperplastic polyp (p(trend) = 0.036 and 0.038, respectively). With a possible exception of the intake of total well-done meats (p(trend) = 0.055) or well-done red meats (p(trend) = 0.074) with the risk of large adenomas, no other positive association was found specifically for the risk of adenomas with any of the exposure variables aforementioned. This study provides additional support for a positive association of high intake of red meat with colorectal adenomas, and suggests that high intake of meats and meat carcinogens may also be associated with hyperplastic polyps.

Pregnancy outcome of uterine arterial embolization followed by selective hysteroscopic removal of a placental polyp

To evaluate the pregnancy outcome of uterine arterial embolization followed by selective hysteroscopic removal of a placental polyp. Thirteen patients of placental polyp with abundant blood flow, which was diagnosed by ultrasound with color Doppler imaging, were studied. They underwent uterine arterial embolization followed by selective hysteroscopic removal of the polyp. Uterine arterial embolization was carried out using an absorbable gelatin sponge. Selective removal via hysteroscopy was performed on the following day, using the cutting loop with or without electrical stimulation. The polyp was gradually resected to the level of the surrounding endometrium. Complete removal of the placental polyp was achieved in all patients. The presence of placental polyp was confirmed by pathologic examination. The operative time ranged from 20 to 53 min. In all cases, no complications were noted and the bleeding was minimal during and immediately after the procedure. Postoperative ultrasound demonstrated a uterine cavity free of residual mass in each case. The seven patients with complete gestation gave birth to health babies. No recurrence of placental polyp was observed. Selective removal directed via hysteroscopy after reduction of blood supply by uterine arterial embolization provides a safe and effective method to minimize bleeding, and can preserve future fertility and successful uneventful pregnancies in the treatment of placental polyp with abundant blood flow.

Antibacterial function of inorganic polyphosphate on stress induced E. coli

This study was performed to observe the antibacterial effect of inorganic polyphosphate on wild type E. coli and ppk/x(¥Ä) mutant in variable starvation. MIC of polyP for the bacterium was determined to be 1§·/§¢. PolyP added to the growing culture of wild type E. coli MG1655 at its exponential phase was as effective in inhibiting the growth of wild type E. coli MG1655 as polyP added at the very beginning of culture, however ppk/x(¥Ä) mutant CF5802 was not. More than 99% of the cell lost their viability determined by viable cell count when polyP was added to the culture of growing wild type E. coli MG1655 at concentration of 1§·/§¢, suggesting that polyP has a bactericidal effect. Antibacterial effect of polyP was shown significant effect in MOPS carbon starvation media Intracellular uncleotide release from the cell was increased by approx. 20% in the presence of polyP but was not reserved by the addition of divalent cations like Ca++ and Mg++. After polyP treatment, the transcriptional activity of possible polyP related genes observed on cell growth. Interestingly, spoT, relA, lon, ftsZ, were shown significant differences of transcriptional activity. In protein level, about 56kD, 58kD and 70kD proteins indicated different manner of expression depending on polyP treatment on variable starvation media. Wild type E. coli MG1655 shows visible filaments with increasing concentration of polyP but ppk/x(¥Ä) mutant CF5802 is not. The overall results suggest that polyP have a strong bactericidal activity against wild type E. coli.

Histopathological parameters of recurrence and malignant transformation in sinonasal inverted papilloma

Conclusions. A combination of parameters may be useful in predicting the clinical course of squamous cell carcinoma in inverted papilloma (IP). In particular, the parameters hyperkeratosis, squamous epithelial hyperplasia and high mitotic index were negative prognostic indicators. Objective. To define histopathological parameters which could predict the recurrence and development of squamous cell carcinoma in IP. Material and methods. We analyzed the histopathological characteristics of 39 cases of IP using the following parameters: site of origin of tumor; presence of bone invasion; presence of inflammatory polyp; ratio of endophytic to exophytic lesions; ratio of neoplastic epithelium to stroma; presence of hyperkeratosis; presence of squamous epithelial hyperplasia; mitotic index; number of mucin globules; and number of eosinophils. Results. Malignancy was related to the presence of bone invasion (p=0.039), the absence of inflammatory polyp (p=0.033), increase in the ratio neoplastic epithelium:stroma (p=0.037), increase in hyperkeratosis (p=0.030), the presence of squamous epithelial hyperplasia (p=0.044), increase in the mitotic index (p=0.029) and a decrease in the number of eosinophils (p=0.037). Multiple recurrences (without malignancy) were related to frontal sinus origin (p=0.042), increase in hyperkeratosis (p=0.041), the presence of squamous epithelial hyperplasia (p=0.044) and increase in the mitotic index (p=0.031). Clinically benign behavior was related to the presence of inflammatory polyp (p=0.010) and the absence of hyperkeratosis (p=0.008).

Copper tolerance of the thermoacidophilic archaeon Sulfolobus metallicus: possible role of polyphosphate metabolism

It has been postulated that inorganic polyphosphate (polyP) and transport of metal-phosphate complexes could participate in heavy metal tolerance in some bacteria. To study if such a system exists in archaea, the presence of polyP was determined by the electron energy loss spectroscopy (EELS) procedure and quantified by using specific enzymic methods in Sulfolobus acidocaldarius, Sulfolobus metallicus and Sulfolobus solfataricus. All three micro-organisms synthesized polyP during growth, but only S. metallicus greatly accumulated polyP granules. The differences in the capacity to accumulate polyP between these archaea may reflect adaptive responses to their natural environment. Thus, S. metallicus could grow in and tolerate up to 200 mM copper sulfate, with a concomitant decrease in its polyP levels with increasing copper concentrations. On the other hand, S. solfataricus could not grow in or tolerate more than 1-5 mM copper sulfate, most likely due to its low levels of polyP. Shifting S. metallicus cells to copper sulfate concentrations up to 100 mM led to a rapid increase in their exopolyphosphatase (PPX) activity which was concomitant in time with a decrease in their polyP levels and a stimulation of phosphate efflux. Furthermore, copper in the range of 10 microM greatly stimulated PPX activity in cell-free extracts from S. metallicus. The results strongly suggest that a metal tolerance mechanism mediated through polyP is functional in members of the genus Sulfolobus. This ability to accumulate and hydrolyse polyP may play an important role not only in the survival of these micro-organisms in sulfidic mineral environments containing high toxic metals concentrations, but also in their applications in biomining.

Risk of Colorectal Neoplasm in Patients with Acromegaly and its Relationship with Serum Growth Hormone Levels

Acromegalics have been reported to be at an increased risk of colorectal neoplasm. However, the magnitude of the risk is still controversial and the mechanism has not been fully investigated. In this study, we attempted to determine the magnitude of the association between acromegaly and colorectal lesions after taking into account age, gender, smoking status, and treatment status. In addition, we assessed the relationship between colorectal lesions and serum growth hormone (GH) levels in acromegalics. We conducted a case-control study by using 19 consecutive untreated patients (male:female = 11:8) who were newly diagnosed with acromegaly between 1990 and 2000. All patients underwent colonoscopy and received a histological diagnosis of colorectal lesions. Prevalence of hyperplastic polyp, adenoma, and carcinoma were compared with the prevalence in 76 controls matched for gender, age, and smoking status. Serum GH levels were compared between acromegalic patients with and without each type of colorectal lesion. The prevalence of hyperplastic polyp, adenoma, and carcinoma were significantly higher in the acromegalic patients compared to the controls (p < 0.05, odds ratios; 8.3, 4.2, and 9.8, respectively). In acromegalics, the presence of hyperplastic polyps and carcinomas were significantly associated with higher serum GH levels after adjusting for the other lesions and age (p < 0.05). After controlling for age, gender, smoking status, and treatment status, acromegaly was associated with significantly higher prevalence of colorectal hyperplastic polyp, adenoma, and carcinoma. High serum GH levels may be associated with the presence of hyperplastic polyp and carcinoma.

AN APPENDICEAL ADENOMA

A 64 years old African American Male presented after being referred for colorectal screening. Colonoscopy showed the presence of a pedunculated appendiceal and a transverse colon polyp. Biopsy of the appendiceal polyp was performed in addition to polypectomy of the transverse colon polyp. Histological evaluation showed a Tubular adenoma of the appendix. Repeat colonoscopy and snare polypectomy was performed without any complication. The presence of adenomatous polyp of the appendix is an uncommon entity. The reported incidence of appendiceal neoplasms in the available literature is 0.1%. Adenomatous polyps behave in the same manner when it comes to progression to adenocarcinoma as their counterparts in different parts of the colon (1, 2). The majority of adenocarcinomas cause symptoms and signs of appendicitis (3). Other presentations of appendiceal polyps include intussusceptions and spontaneous inversion (4). Treatment of an appendiceal polyp can be a challenge since an inverted diverticulae can have a similar picture and cause peritonitis if polypectomy isperformed. Colonoscopy with polypectomy is an option for the treatment of appendiceal polyps. If the lesion is inaccessible, laparoscopic appendectomy can be performed.

Human Platelet Dense Granules Contain Polyphosphate and Are Similar to Acidocalcisomes of Bacteria and Unicellular Eukaryotes

Inorganic polyphosphate (polyP) has been identified and measured in human platelets. Millimolar levels (in terms of Pi residues) of short chain polyP were found. The presence of polyP of approximately 70-75 phosphate units was identified by 31P NMR and by urea-polyacrylamide gel electrophoresis of platelet extracts. An analysis of human platelet dense granules, purified using metrizamide gradient centrifugation, indicated that polyP was preferentially located in these organelles. This was confirmed by visualization of polyP in the dense granules using 4',6-diamidino-2-phenylindole and by its release together with pyrophosphate and serotonin upon thrombin stimulation of intact platelets. Dense granules were also shown to contain large amounts of calcium and potassium and both bafilomycin A1-sensitive ATPase and pyrophosphatase activities. In agreement with these results, when human platelets were loaded with the fluorescent calcium indicator Fura-2 acetoxymethyl ester to measure their intracellular Ca2+ concentration ([Ca2+]i), they were shown to possess a significant amount of Ca2+ stored in an acidic compartment. This was indicated by the following: 1) the increase in [Ca2+]i induced by nigericin, monensin, or the weak base, NH4Cl, in the nominal absence of extracellular Ca2 and 2) the effect of ionomycin, which could not take Ca2+ out of acidic organelles and was more effective after alkalinization of this compartment by the previous addition of nigericin, monensin, or NH4Cl. All of these characteristics of the platelet dense granules, together with their known acidity and high density (both by weight and by electron microscopy), are similar to those of acidocalcisomes (volutin granules, polyP bodies) of bacteria and unicellular eukaryotes. The results suggest that acidocalcisomes have been conserved during evolution from bacteria to humans.