Methylation Analysis of Urinary Sample in Non-Muscle-Invasive Bladder Carcinoma: Frequency and Management of Invalid Result.

BACKGROUND: Numerous studies showed that methylation analysis represents a newly developed urinary marker based on DNA methylation changes in a panel of genomic biomarkers and it could represent a valid tool in terms of the diagnosis and prediction of high-grade urothelial carcinoma recurrences. One of the limits of the use of this new molecular method during a follow-up is represented by the number of invalid tests in routine practice. METHOD: A total of 782 patients with a diagnosis of non-muscle-invasive high-grade carcinoma (NMIBC) was studied. The Bladder EpiCheck test (BE) was performed together with cytology in all cases within 1 year after the end of treatment. In 402 patients, the urinary samples were voided urine (UV), while, in 380 cases, the samples were collected after bladder washing (IU). For all the patients with invalid BE results, a second BE test was performed following the instructions for use that indicated the test should be repeated with a new urinary sample in the case of an invalid result. RESULTS: Analyzing the two different groups (UV and IU), we found the invalid BE results seemed to be not related to urinary samples (p = 0.13 Fisher's exact test), suggesting that the collection method was not relevant in order to reduce the number of invalid tests. CONCLUSIONS: In the follow-up for NMIBC, for patients for whom a BE test is planned, a combined approach of cytology and a methylation test is recommended in order to repeat the BE test with an invalid result only in those cases with a cytological diagnosis of atypical urothelial cells (AUC) suspicious for high-grade urothelial carcinoma (SHGUC) and high-grade urothelial carcinoma (HGUC).

Apoptotic volume decrease (AVD) in A549 cells exposed to water-soluble fraction of particulate matter (PM10).

Exposure to atmospheric particulate matter (PM) is recognized as a human health risk factor of great concern. The present work aimed to study the cellular mechanisms underlying cytotoxic effects of airborne particulate matter <10 µm in size (PM10), sampled in an urban background site from January to May 2020, on A549 cells. In particular, the study addressed if PM10 exposure can be a main factor in the induction of the Apoptotic Volume Decrease (AVD), which is one of the first events of apoptosis, and if the generation of intracellular oxidative stress can be involved in the PM10 induction of apoptosis in A549 cells. The cytotoxicity of PM10 samples was measured by MTT test on cells exposed for 24 h to the PM10 aqueous extracts, cell volume changes were monitored by morphometric analysis of the cells, apoptosis appearance was detected by annexin V and the induction of intracellular oxidative stress was evaluated by the ROS sensitive CM-H2DCFDA fluorescent probe. The results showed cytotoxic effects ascribable to apoptotic death in A549 cells exposed for 24 h to aqueous extracts of airborne winter PM10 samples characterized by high PM10 value and organic carbon content. The detected reduced cell viability in winter samples ranged from 55% to 100%. Normotonic cell volume reduction (ranging from about 60% to 30% cell volume decrease) after PM10 exposure was already detectable after the first 30 min clearly indicating the ability of PM10, mainly arising from biomass burning, to induce Apoptotic Volume Decrease (AVD) in A549 cells. AVD was prevented by the pre-treatment with 0.5 mM SITS indicating the activation of Cl- efflux presumably through the activation of VRAC channels. The exposure of A549 cells to PM10 aqueous extracts was able to induce intracellular oxidative stress detected by using the ROS-sensitive probe CM-H2DCFDA. The PM10-induced oxidative stress was statistically significantly correlated with cell viability inhibition and with apoptotic cell shrinkage. It was already evident after 15 min exposure representing one of the first cellular effects caused by PM exposure. This result suggests the role of oxidative stress in the PM10 induction of AVD as one of the first steps in cytotoxicity.

Commissioning of pencil beam and Monte Carlo dose engines for non-isocentric treatments in scanned proton beam therapy.

This work describes the dosimetric commissioning of the treatment planning system (TPS) RayStation v6.1 from RaySearch Laboratories (Stockholm, Sweden) for a synchrotron-based scanned proton beam delivery with isocentric and non-isocentric setups at MedAustron. Focus was on the comparison of the pencil beam (PBv4.1) and Monte Carlo (MCv4.0) calculation algorithms. Commissioning of dose calculations was done first for 1D/2D dose delivery where the performance of the beam model in reproducing dosimetric properties for the delivery of single static pencil beams and mono-energetic layers with multiple spots was evaluated. The commissioning for 3D beam delivery employed test cases with increasing complexity: from box-shaped fields in homogeneous phantoms to the introduction of oblique incidences and inhomogeneities. Dose calculations were compared to the measured data for different air gaps and using beams with and without range shifter (RaShi). Depth-dose curves and spot shape comparisons showed good agreement of the results obtained with PBv4.1 and MCv4.0 algorithms at isocentric setup for open beam configurations (without RaShi). Comparison of transverse dose profiles for lateral heterogeneities at different depths showed better performance of the MCv4.0 algorithm in comparison to the PBv4.1 algorithm. In the case of 3D delivery comparisons of measured and TPS-calculated dose with MCv4.0 algorithm in box-shaped fields in water showed an average agreement within 2%. The results for dose calculations with the PBv4.1 algorithm showed larger deviations for beams with RaShi at all evaluated air gaps (from 64.8 cm to 14.8 cm). Our results suggest that the MCv4.0 algorithm shall be used in clinics for final dose calculation when beams with RaShi are used especially in the presence of large air gaps, inclined patient surface and lateral inhomogeneities. The detailed stepwise methodology implemented for the RayStation commissioning in this work could serve as further guidance for other facilities introducing a new TPS for proton beam therapy.

Characterization of PTW-31015 PinPoint ionization chambers in photon and proton beams.

The increased use of complex forms of radiotherapy using small-field photon and proton beams has invoked a growing interest in the use of micro-ionization chambers. In this study, 48 PTW-TM31015 PinPoint-type micro-ionization chambers that are used in the commissioning and patient specific QA of a proton pencil beam scanning (PBS) delivery system have been characterized in proton and high-energy photon beams. In both beam modalities, the entire set of PinPoint chambers was characterized by imaging them, by evaluating their stability using check source measurements, by experimentally determining the ion recombination, polarity effect and by cross calibrating them in terms of absorbed dose to water against Farmer-type ionization chambers. Beam quality correction factors were theoretically derived for both beam modalities. None of the chambers' check source readings drifted by more than 0.5% over a one year period. Beam quality correction factors for the 6 MV photon with reference to 60Co were on average 1.0 ± 0.5% lower than the theoretical values calculated according to the data and procedures outlined in IAEA TRS-398. While this difference is within the overall dosimetric uncertainty, it is significant considering only uncorrelated uncertainties indicating inconsistencies in the theoretical data. Beam quality correction factors for the 179.2 MeV proton beam with reference to 60Co were in good agreement with the theoretical data. Ion recombination and polarity correction factors were very consistent for all chambers with standard deviations of 0.2% or below show that findings from more comprehensive investigations in the literature can be considered as representative for all the chambers of this type. The characterization of 48 PinPoint-type micro-ionization chambers performed in this study provided a unique opportunity to investigate chamber-to-chamber variations of calibration, beam quality correction factors, ion recombination and polarity correction factors for an unprecedented sample size of chambers for both high-energy photon and proton beams.

End-to-end tests using alanine dosimetry in scanned proton beams.

This paper describes end-to-end test procedures as the last fundamental step of medical commissioning before starting clinical operation of the MedAustron synchrotron-based pencil beam scanning (PBS) therapy facility with protons. One in-house homogeneous phantom and two anthropomorphic heterogeneous (head and pelvis) phantoms were used for end-to-end tests at MedAustron. The phantoms were equipped with alanine detectors, radiochromic films and ionization chambers. The correction for the 'quenching' effect of alanine pellets was implemented in the Monte Carlo platform of the evaluation version of RayStation TPS. During the end-to-end tests, the phantoms were transferred through the workflow like real patients to simulate the entire clinical workflow: immobilization, imaging, treatment planning and dose delivery. Different clinical scenarios of increasing complexity were simulated: delivery of a single beam, two oblique beams without and with range shifter. In addition to the dose comparison in the plastic phantoms the dose obtained from alanine pellet readings was compared with the dose determined with the Farmer ionization chamber in water. A consistent systematic deviation of about 2% was found between alanine dosimetry and the ionization chamber dosimetry in water and plastic materials. Acceptable agreement of planned and delivered doses was observed together with consistent and reproducible results of the end-to-end testing performed with different dosimetric techniques (alanine detectors, ionization chambers and EBT3 radiochromic films). The results confirmed the adequate implementation and integration of the new PBS technology at MedAustron. This work demonstrates that alanine pellets are suitable detectors for end-to-end tests in proton beam therapy and the developed procedures with customized anthropomorphic phantoms can be used to support implementation of PBS technology in clinical practice.

Melanoma detection in Italian pigmented lesion clinics.

AIM: Accuracy in melanoma detection is important to recognize early curable melanomas and to minimize the unnecessary excision of benign lesions. The aim of this paper was to evaluate melanoma screening accuracy of Italian pigmented lesion clinics in terms of number needed to excise (NNE), melanoma thickness, and number of melanomas diagnosed during patient follow-up. METHODS: Information on all skin tumors excised in 2011 were extracted from the databases of the participating centers. Information whether the lesion was excised at the baseline examination or during patient follow-up was recorded, as well as the overall number of patients examined in each center in 2011. RESULTS: After e-mail solicitation, 22 of 40 centers agreed to participate. A total of 8229 excised lesions were collected. The overall number of examined patients was 86.564, thus 9.5% of screened patients had a lesion removed. Of the excised lesions, 866 were diagnosed as melanoma (1% of examined patients) and 5311 (88.9%) were melanocytic nevi. Three NNE were calculated giving values of 7.9 excised lesions to find 1 melanoma, 7.1 melanocytic lesions to find 1 melanoma, and 3.7 lesions to find 1 skin malignancy. The median melanoma thickness was 0.6 mm, with only 15.1% of melanomas ≥ 1 mm of thickness. Melanomas detected over time were 96 (11.1%; mean thickness, 0.3 mm), with 15.6% of lesions excised after short-term follow-up and 84.4% after long-term follow-up. CONCLUSION: The NNE values comparable to those achieved in specialized clinical settings and the high number of early melanomas diagnosed at the baseline examination or during patient follow-up indicate a high level of accuracy in melanoma screening achieved by Italian pigmented lesion clinics.

EPR/alanine pellets with low Gd content for neutron dosimetry.

This paper reports on results obtained by electron paramagnetic resonance (EPR) measurements and Monte Carlo (MC) simulation on a blend of alanine added with low content of gadolinium oxide (5 % by weight) to improve the sensitivity to thermal neutron without excessively affecting tissue equivalence. The sensitivity is enhanced by this doping procedure of more an order of magnitude. The results are compared with those obtained with the addition of boric acid (50 % by weight) where boron is in its natural isotopic composition in order to produce low-cost EPR dosemeters. The gadolinium addition influences neutron sensitivity more than the boron addition. The presence of additives does not substantially change the fading of the EPR signal induced by neutrons. The MC simulations agree the experimental results in case of gadolinium addition.

A retrospective analysis of early and late outcome of biodegradable stent placement in the management of refractory anastomotic colorectal strictures.

BACKGROUND: Benign colorectal strictures are treated conventionally by endoscopic dilation. Experience using SEMS for benign colonic strictures is limited, and outcomes to date have been disappointing. Refractory colorectal strictures remain challenging to be treated with surgery. Polydioxanone-based stent are biodegradable (BD) stent CE approved for esophageal strictures. This study was designed to investigate retrospectively the safety and the efficacy of these stents for the management of strictures refractory to multiple sessions of dilation. METHODS: Patients with postsurgical benign strictures located within 20 cm from anal verge, refractory to mechanical or pneumatic dilation (at least 3 sessions) were included in this analysis. Clinical success was defined as the absence of occlusive symptoms and the ability to pass through the stricture with a regular size colonoscope. All patients were predilated before stent placement. Stents were released under fluoroscopic control. All patients were under stool softeners for 3 months. Follow-up was scheduled with endoscopic and fluoroscopic controls within 90 days from stent deployment and afterwards by telephone interview and/or ambulatory consultation. RESULTS: Eleven patients (7 males, mean age 62.3 ± 8.5 years) were included. Technical success was achieved in all the patients. Stent migration was observed in four patients within the first 2 weeks after stent placement. Stent migration was followed by recurrence of stricture and obstructive symptoms in all the cases. Among the seven patients who completed the process of stent biodegradation, five of them had complete resolution of the stricture and relief of symptoms. Two of 11 patients required surgical treatment during the follow-up period (mean 19.8 (range 42-15) months). The overall success rate of the BD stent was 45 %. CONCLUSIONS: This retrospective analysis of a limited number of patients demonstrated that nondedicated esophageal BD stents are associated with high risk of migration and clinical success in less than 50 % of patients. Dedicated stents with large diameter and antimigration findings could potentially improve the outcome of patients with refractory benign colorectal strictures.

Safety of cold polypectomy for <10mm polyps at colonoscopy: a prospective multicenter study.

BACKGROUND: Cold polypectomy techniques (without electrocautery) by means of biopsy forceps or snare are widely adopted for the removal of subcentimetric polyps. However, few data are available on the safety of this approach. The aim of this study was to assess the safety of cold polypectomy for subcentimetric polyps, as well as the rate of advanced neoplasia in these lesions. PATIENTS AND METHODS: In a prospective multicenter trial, consecutive patients with at least one < 10-mm polyp at colonoscopy were prospectively included. All of the < 10-mm polyps detected within the study period were removed by cold polypectomy. The rates of immediate or delayed bleeding and other complications were assessed at 7 and 30 days after cold polypectomy by telephone calls. The rate of advanced histology was also assessed. Predictive variables of postpolypectomy bleeding or advanced neoplasia were identified by multivariate analysis. RESULTS: A total of 1015 < 10-mm polyps in 823 patients (15.5 % on antiplatelet agents) were removed. Of these, 822 (81 %) were ≤ 5 mm and 193 (19 %) were 6 - 9 mm. Immediate postpolypectomy bleeding occurred in 18 patients, corresponding to a per-patient and per-polyp bleeding rate of 2.2 % (95 % confidence interval [CI] 1.2 % - 3.2 %) and 1.8 % (95 %CI 1 % - 2.6 %), respectively. Therapy with antiplatelet agents (odds ratio [OR] 4; 95 %CI 1.5 - 10.6) and larger polyp size (OR 2; 95 %CI 1.1 - 6.9) were independent predictors of bleeding. Bleeding was successfully treated by endoscopic hemostasis in all cases and required no further medical intervention. Advanced neoplasia prevalence in polyps ≤ 5 mm was as high as 8.7 %. CONCLUSIONS: The results from this study showed the high safety of a cold polypectomy approach for subcentimetric polyps. This was due to the low rate of postpolypectomy bleeding and to the high efficacy of endoscopic hemostasis in its treatment. The high rate of advanced neoplasia in polyps ≤ 5 mm should prompt some caution on the management of these lesions following detection at computed tomography colonography or colon capsule endoscopy.

Balanced Propofol Sedation in Patients Undergoing EUS-FNA: A Pilot Study to Assess Feasibility and Safety.

Introduction and aims. Balanced propofol sedation (BPS) administered by gastroenterologists has gained popularity in endoscopic procedures. Few studies exist about the safety of this approach during endosonography with fine needle aspiration (EUS-FNA). We assessed the safety of BPS in EUS-FNA. Materials and methods. 112 consecutive patients, referred to our unit to perform EUS-FNA, from February 2008 to December 2009, were sedated with BPS. A second gastroenterologist administered the drugs and monitorized the patient. Results. All the 112 patients (62 males, mean age 58.35) completed the examination. The mean dose of midazolam and propofol was, respectively, of 2.1 mg (range 1-4 mg) and 350 mg (range 180-400). All patients received oxygen with a mean flux of 4 liter/minute (range 2-6 liters/minute). The mean recovery time after procedure was 25 minutes (range 18-45 minutes). No major complications related to sedation were registered during all procedures. The oxygen saturation of all patients never reduced to less than 85%. Blood systolic pressure during and after the procedure never reduced to less than 100 mmHg. Conclusions. In our experience BPS administered by non-anaesthesiologists provided safe and successful sedation in patients undergoing EUS-FNA.

Endoscopic flexible treatment of Zenker's diverticulum: a modification of the needle-knife technique.

BACKGROUND AND STUDY AIM: Endoscopic treatment of Zenker's diverticulum has been successfully reported over the last 10 years using different approaches. The hook-knife is a new device originally developed for endoscopic submucosal dissection procedures. This study aimed to investigate the safety and efficacy of endoscopic myotomy performed with the hook-knife. PATIENTS AND METHOD: From July 2005, 32 consecutive patients (23-male, mean age 74.8 years) with dysphagia secondary to the presence of Zenker's diverticulum were prospectively enrolled. Myotomy was performed using a straight-end transparent hood to the tip of the scope and the hook-knife for the incision of the bridge between the Zenker's diverticulum and the esophagus. Clinical outcome was evaluated assigning a dysphagia symptom score from 0 (symptoms absent) to 4 (inability to swallow saliva). RESULTS: General anesthesia was used in 4 patients, deep sedation with propofol in 23 patients, while midazolam was used in 5 patients. The mean procedural time was 28 minutes. Complications occurred in 2 patients (6.25 %). At 1 month follow-up, the mean dysphagia score was significantly improved from 2.9 to 0.6 ( P < 0.001) with 87.5 % of patients free of symptoms and 4 patients with dysphagia that was persistent but milder than before the treatment. Three of these 4 patients underwent a successful second endoscopic treatment with complete relief of dysphagia; one was not re-treated because of advanced age (92 years). During the follow-up period (23.87 +/- 9.6 months), 2 patients developed dysphagia recurrence. The overall success rate was 90.6 %. CONCLUSIONS: Diverticulectomy with a flexible scope and the hook-knife may represent a safe and effective alternative treatment for patients with Zenker's diverticulum.

Prevalence of thyroid disorders in untreated adult celiac disease patients and effect of gluten withdrawal: an Italian multicenter study.

OBJECTIVES: Many afflictions have been associated with celiac disease, but chance associations may exists. The aim of this study was to establish, by means of a multicenter prospective study, the prevalence of thyroid impairment among adult patients with newly diagnosed celiac disease and to evaluate the effect of a 1-yr gluten withdrawal on thyroid function. METHODS: A total of 241 consecutive untreated patients and 212 controls were enrolled. In 128 subjects a thorough assessment, including intestinal biopsy, was repeated within 1 yr of dietary treatment. Thyroid function was assayed by measuring the levels of TSH, free T3, free T4, thyroperoxidase, and thyroid microsome antibodies. RESULTS: Thyroid disease was 3-fold higher in patients than in controls (p < 0.0005). Hypothyroidism, diagnosed in 31 patients (12.9%) and nine controls (4.2%), was subclinical in 29 patients and of nonautoimmune origin in 21. There was no difference regarding hyperthyroidism, whereas autoimmune thyroid disease with euthyroidism was present in 39 patients (16.2%) and eight controls (3.8%). In most patients who strictly followed a 1-yr gluten withdrawal (as confirmed by intestinal mucosa recovery), there was a normalization of subclinical hypothyroidism. Twenty-five percent of patients with euthyroid autoimmune disease shifted toward either a subclinical hyperthyroidism or subclinical hypothyroidism; in these subjects, dietary compliance was poor. In addition, 5.5% of patients whose thyroid function was normal while untreated developed some degree of thyroid dysfunction 1 yr later. CONCLUSIONS: The greater frequency of thyroid disease among celiac disease patients justifies a thyroid functional assessment. In distinct cases, gluten withdrawal may single-handedly reverse the abnormality.

Autoimmune thyroid diseases and coeliac disease.

BACKGROUND: Coeliac disease may be associated with a wide variety of diseases of known or suspected immunological aetiology. OBJECTIVE: To screen for both (a) the prevalence of coeliac disease in adults with autoimmune thyroid diseases, and (b) thyroid impairment among adults with coeliac disease, as compared to sex- and age-matched controls. DESIGN: Prospective cohort study. SETTING: University teaching hospital. PATIENTS: A total of 152 consecutive adults with autoimmune thyroid diseases, 185 consecutive coeliac disease patients (53 newly diagnosed and 132 already on a gluten-free diet) and 170 sex- and age-matched controls. METHODS: Screening for coeliac disease was done by means of IgA anti-endomysium antibodies, detected by indirect immunofluorescence on monkey oesophagus. Patients with positive sera underwent duodenal biopsy for diagnostic confirmation. Thyroid function was assessed by measuring the levels of serum thyroid-stimulating hormone, free T3, free T4, thyroperoxidase and thyroid microsome antibodies. Autoimmune thyroid diseases were classified according to the American Thyroid Association guidelines. RESULTS: Anti-endomysium antibodies were positive in five of 152 autoimmune thyroid disease patients (3.3%) and coeliac disease was histologically confirmed in all: this prevalence is 10-fold higher than expected. Only one patient presented with gastrointestinal complaints, but iron deficiency was found in three and alterations at bone mineralometry in all. The overall prevalence of autoimmune thyroid diseases was significantly higher (38/185, 20.5%) in coeliac patients than in controls (19/170, 11.2%). The prevalence of both hypo- and hyperthyroidism was not different from that of controls, while the prevalence of autoimmune thyroid disease with euthyroidism was 13% in patients and 4.7% in controls. CONCLUSIONS: The association of coeliac disease with autoimmune thyroid disease is not surprising as they share common immunopathogenetic mechanisms. It is advisable to screen autoimmune thyroid disease patients for coeliac disease as there is an increased risk for gluten intolerance. In contrast, thyroid function assessment in coeliac disease patients is probably less justified, although the need for a strict clinical follow-up of those patients with euthyroidism and autoimmune thyroid disease, who could develop overt thyroid impairment, remains an open question.

Bath-5-methoxypsoralen-UVA therapy for psoriasis.

BACKGROUND: After oral intake, 5-methoxypsoralen (5-MOP) is as effective as 8-MOP for PUVA therapy for psoriasis, with a lower incidence of acute cutaneous side effects. OBJECTIVE: We compared bath-water delivery of 5-MOP and 8-MOP for photochemotherapy of psoriasis. METHODS: Twenty-two patients underwent phototesting with 0.0003% 5-MOP or 8-MOP aqueous solutions. Twelve patients with palmar psoriasis were studied with a side-to-side comparison, and 10 patients with recurrent plaque-type psoriasis were treated with one therapy or the other. RESULTS: Minimal phototoxic dose (MPD) values were 2.8 +/- 1.2 J/cm2 with 8-MOP and 2.0 +/- 1.2 J/cm2 with 5-MOP (p < 0.01). Both therapies cleared palmar lesions but 8-MOP required more UVA irradiation (46.3 +/- 21.0 J/cm2 vs 30.2 +/- 21.5 J/cm2; p < 0.01) and more exposures (21.0 +/- 6.0 vs 17.0 +/- 5.0; p = 0.02). Bath-5-MOP-UVA was also more effective in the treatment of plaque-type psoriasis (cumulative UVA doses, 56.8 +/- 39.2 vs 59.1 +/- 27.9 J/cm2; number of exposures, 20.0 +/- 5.7 vs 21.6 +/- 4.7), but these differences were not significant (p = NS). Patients developed an intense tan significantly earlier with 5-MOP than with 8-MOP (3.5 +/- 0.5 weeks vs 4.4 +/- 0.5 weeks; p < 0.01). CONCLUSION: Bath-5-MOP-UVA was more phototoxic than bath-8-MOP-UVA. It was more effective in the treatment of palmar psoriasis, whereas its greater pigmentogenic activity appeared to have an adverse effect on therapeutic effectiveness in the treatment of plaque-type psoriasis.

ATP hydrolysis is not required for the dissociation of a substance P.BiP complex.

BiP is a member of the hsp70 family of proteins that is present in the endoplasmic reticulum where it functions as a molecular chaperone. Rapid quantitative assays have been used to study the effect of mutating BiP residue 229, located in the ATP binding site, from threonine to glycine. Although binding of ATP to the mutant BiP was not affected, the mutant protein possessed 10-20% of the wild-type BiP ATPase activity. Binding to a model peptide substrate, substance P (Brot et al. (1994) Proc. Natl. Acad. Sci. USA 91, 12120-12124), was twofold higher with mutant BiP at 4 degrees C than with wild-type BiP, and was ATP dependent. Under these conditions the substance P that was bound to mutant BiP, but not the wild-type, could be released by higher levels of ATP (5-10 microM), and the ratio of substance P released to ATP hydrolyzed was greater than 10. These results suggest that stoichiometric ATP hydrolysis is not required for release of a chaperone from its substrate.

Angiokeratoma corporis diffusum and arteriovenous fistulas with dominant transmission in the absence of metabolic disorders.

BACKGROUND: A three-generation family with members affected by angiokeratoma corporis diffusum (ACD) and arteriovenous fistulas of the legs is described. Our purpose was to investigate possible lysosomal storage defects previously described in association with ACD. OBJECTIVE: Results of physical examination of both affected and unaffected family members were otherwise normal as was the life span. The inheritance pattern of both ACD and arteriovenous fistula traits was autosomal dominant, with variable expressivity and incomplete penetrance. Microscopic examination of ACD lesions showed dilated capillaries without vacuolation of cells. Ultrastructural studies failed to reveal lysosomal abnormalities. Normal levels of alpha-galactosidase, beta-galactosidase, alpha-fucosidase, and alpha-sialidase were detected in peripheral blood leukocytes and skin fibroblasts. CONCLUSIONS: The association of autosomal dominant ACD and arteriovenous fistulas might represent a novel syndrome. However, pathogenesis of these lesions remains unknown.

Interaction of BiP with substance P and nucleotides.

A rapid and simple spin column assay has been used to study interactions of BiP with substance P (SP) and ATP. At 4 degrees C, the binding of SP to BiP requires ATP and a stable SP-BiP.ATP complex is formed. Nonhydrolyzable ATP analogues or ADP cannot replace ATP. Although ATP converts BiP dimers to monomers, the requirement for ATP for SP binding is not solely due to BiP dissociation, because purified BiP monomers also require ATP for peptide binding. At 37 degrees C, there is rapid binding of SP to BiP even in the absence of ATP and, in fact, ATP at concentrations above 5 microM causes release of SP from BiP. At this higher temperature, there is also rapid hydrolysis of ATP bound to BiP. These results extend our previous results (Brot et al., 1994) that indicated the formation, at low ATP concentrations, of a labile SP.BiP.ATP complex that, after ATP hydrolysis, resulted in a stable SP.BiP.ADP complex.

Similarity of nucleotide interactions of BiP and GTP-binding proteins.

BiP is a member of the Hsp70 heat shock protein family found in the lumen of the endoplasmic reticulum, that binds to a variety of proteins destined to be secreted. Substance P (SP) has been used as a model peptide to study the interaction of BiP with protein substrates. SP stimulates BiP ATPase activity and forms a stable complex with BiP that is dissociated in the presence of levels of ATP > 50 microM. At lower concentrations of ATP, the SP remains bound to BiP, and the results are consistent with the view that a BiP-ATP complex is initially formed that reacts with SP to form a ternary complex, SP-BiP-ATP. Hydrolysis of ATP in this complex yields a SP-BiP-ADP complex. An exchange of ATP with ADP bound to BiP has also been demonstrated, and the results suggest that the interactions of BiP with ATP resemble those seen with GTP-binding proteins and GTP.