Periodate oxidized ATP (oATP) reduces hyperalgesia in mice: involvement of P2X7 receptors and implications for therapy.

Some inflammatory mediators play an important role not only in the pathogenesis of the inflammatory pain, but also in that of neuropathic and visceral pain. We previously showed the antihyperalgesic effect of oATP, the inhibitor of the P2X7 receptors for the pro-nociceptive ATP, in experimental inflammation. Here we show the antihyperalgesic effect of oATP in mouse models of neuropathic and visceral pain, other than in a model of arthritic pain mimicking rheumatoid arthritis in humans. We also show that mice lacking P2X7 receptors (KO) are resistant to hyperalgesic thermal stimuli following the induction of arthritic, neuropathic and visceral pain. Local (injection into the right hind paw) pre-treatment with oATP is able to prevent the successive induction of ATP-dependent hyperalgesia in wild type mice. In addition, KO mice are not insensitive to intraplantar treatment with ATP. Our data suggest that, even if oATP is able to inhibit purinoceptors different from P2X7, the latter are the more important involved in pain transmission.

Cancer arising after pancreas and/or kidney transplantation in a series of 99 diabetic patients.

OBJECTIVE: Recipients of solid organ transplants have an increased risk of developing certain types of malignancies as compared with the general population. The majority of the literature has reported on neoplasms in kidney and heart transplant recipients. RESEARCH DESIGN AND METHODS: We describe 9 neoplasms occurring in 7 out of 73 IDDM patients after simultaneous pancreas and kidney transplantation. No cases were recorded among 26 IDDM recipients of kidney transplantation. RESULTS: Among the neoplasms found were 2 cases of posttransplant lymphoproliferative disorder (PTLD), malignant melanoma, basal-cell and squamous-cell carcinoma of the skin in the same patient, squamous-cell carcinoma in situ of the vulva, hepatocarcinoma, small-cell lung cancer, and ductal carcinoma of the breast. Four patients died. Among immunological risk factors, over-immunosuppression for steroid-resistant kidney rejection was administered only in the 2 cases of PTLD. CONCLUSIONS: Increased dosage of immunosuppressive agents may be necessary in some patients of prevent or treat rejection in view of their reduced survival on hemodialysis.

Oxidative injury in reoxygenated and reperfused hearts.

In this study, we separated the effects of low oxygen supply and low coronary flow in isolated perfused rat hearts to focus on the genesis of free radicals-induced reperfusion injury. Hearts were exposed to either hypoxemia/reoxygenation or ischemia/reperfusion in various sequences, with hypoxemia and ischemia matched for duration (20 min), temperature (37 degrees C), and oxygen supply (10% of baseline). Hypoxemia/reoxygenation (n = 7) resulted in lower (developed pressure) x (heart rate) (p < 0.001) and higher end-diastolic pressure (p < 0.001) than ischemia/reperfusion (n = 9). The presence of 40 IU/ml superoxide dismutase and 104 IU/ml catalase nearly blunted the rise of the end-diastolic pressure (p = 0.02 vs. baseline), but could only partially prevent the depression of myocardial contractility (p < 0.001 vs. baseline, n = 7). Similar patterns were observed when hearts were made ischemic after hypoxemia, eliminating the intermediate reoxygenation step. We conclude that the major determinant of the reperfusion injury is associated with low oxygen supply rather than low coronary flow. Part of the injury is mediated by oxygen-derived free radicals, but a substantial portion of it is associated with energetic processes.

Amyloid neuropathy simulating lower motor neuron disease.

We report a 57-year-old man with progressive symmetric weakness and fasciculation affecting the legs. Electromyography revealed fibrillations and neurogenic motor unit potentials in the leg muscles. Biopsy of a motor branch of the obturator nerve revealed axonal degeneration, loss of myelinated nerve fibers, and amyloidosis with deposits of lambda light chains. At 6-month follow-up, the patient manifested sensory and autonomic symptoms, and lambda light chains were first detected in the serum. In this case, diagnosis of amyloidosis remained elusive until motor nerve biopsy.

"Striped" pattern of medullary ray fibrosis in allograft biopsies from kidney transplant recipients maintained on tacrolimus.

BACKGROUND: A striped pattern of fibrosis has been described in the kidneys of patients undergoing long-term cyclosporine or tacrolimus therapy. This lesion is frequently misconstrued as being specific for drug toxicity. METHODS: We performed clinicopathologic correlation on 18 patients with striped fibrosis identified by reviewing 61 biopsies from kidney transplant recipients maintained with tacrolimus. RESULTS: Acute rejection was identified in 14 of 18 patients, chronic rejection in 9 of 18 patients, potential diabetic microvascular injury in 8 of 18, and pre-existing donor disease in 2 of 18. In only one patient could striped fibrosis be ascribed primarily to tacrolimus. Striped fibrosis could also be demonstrated in 6 of 10 late allograft biopsy specimens from patients maintained with only azathioprine, and 8 of 10 native biopsies from patients with advanced diabetes mellitus. CONCLUSION: Multiple insults contribute to the pathogenesis of striped fibrosis in the kidney. This lesion can be attributed entirely to chronic drug toxicity in only a minority of allografts.

Primary cardiac sarcoma in pregnancy: a case report and review of the literature.

Primary cardiac sarcoma (PCS) is a rare disease with a poor prognosis, because of diagnostic delay, therapeutic difficulties, and high metastatic potential. Surgery is the standard treatment. A case of PCS in pregnancy is reported, with a review of published surgical series of PCSs, focusing on the role of surgery and adjuvant therapy. Prompt surgery improved cardiac function and patients' outcome in comparison with untreated cases. The role of adjuvant treatment was analyzed only in a few series, mainly without distinction between postoperative chemotherapy and radiotherapy; adjuvant therapy improved survival in the larger series of resected PCSs. Only three other cases of PCS in pregnancy were reported. In the present case, resection was performed with no major complication for the mother and the infant. Even if the patient's survival was short, cardiac surgery allowed prolonging of pregnancy until an acceptable possibility of fetal survival was reached. Although resection is not curative in most cases, surgery remains the treatment of choice for PCS and has a definite palliative significance. The role of postoperative chemotherapy and radiotherapy is difficult to ascertain; however, adjuvant chemotherapy seems advisable in high-grade tumors.

Mixed germ cell tumour of the mediastinum (seminoma, embryonal carcinoma, choriocarcinoma and teratoma). Light and electron microscopic cytology and histological investigation.

A mixed germ cell tumour of the mediastinum was found in a 27-year-old subject. It had four components: seminoma, embryonal carcinoma, choriocarcinoma and teratoma. Material for light microscopy (L.M.) and ultrastructural studies were obtained with computerized tomography (CT) guided fine needle aspiration. Three histotypes were identified with ultrastructural studies while only seminoma was identified with L.M. The slides prepared for L.M. were reexamined in the light of findings with electron microscopy (E.M.) and previously unidentified cellular elements were found to be characteristic of choriocarcinoma and teratoma. Histological examination of surgical and autopsy material confirmed the cytological findings. Because of the singularity of this case, the rarity of this type of neoplasm and the difficulty in arriving at a differential diagnosis from other neoplastic and non neoplastic lesions, only the ultrastructural cytological examination allowed us to identify the mixed nature of the tumour. Such an identification is not always possible with L.M. but it is a determining factor in the prognosis and therapy.

Heterogeneity and susceptibility to apoptosis of human renal carcinoma cells in vitro.

Tumors are heterogeneous in terms of morphology and susceptibility to drugs or radiation. Among primary and metastatic cells of a human renal carcinoma, a population (type II) of larger cells with prominent nucleoli, eosinophilic globules of intermediate filaments in paranuclear bundles, margination of subcellular organelles and peripheral pools of glycogen was evident. Paranuclear structures were recognized by monoclonal antibodies specific for cytokeratin 8, 18 and 19, but not by vimentin specific antibodies. We propagated a cell line in vitro (referred to as BKR cells), and observed culture in vitro, the almost complete disappearance of the type II cells. Pharmacological agents that influence cell differentiation, such as retinoic acid, rescued the expression of type II cells in vitro. Long-term treatments with insulin or alpha-interferon, but not with the epithelial growth factor (EGF), similarly differentiated BKR cells and abated their susceptibility to spontaneous and actinomycin-D induced apoptosis. These data support the contention that differentiation of tumor cells is actively maintained in vivo and further strengthen the caveat on tumor lines stabilized in vitro, that poorly represent the morphologic and antigenic heterogeneity of neoplasms in vivo.

Electron microscopy of fine-needle aspiration biopsy from extragonadal germ cell tumors.

We describe five cases of extragonadal germ cell tumor (EGCT) diagnosed by the electron microscope (EM) on cytological material. The clinical diagnosis was incorrect in all cases and EGCT was suspected in two cases; cytological diagnosis by light microscopy confirmed the presence of malignant tumor cells, but did not identify the cytotype/s correctly except in one case. Ultrasonography, laparoscopy, and autopsy (in case 3) excluded a primitive germ cell tumor (GCT). Histology confirmed the EM diagnosis in all cases. EM, even of scanty or necrotic cytological material, is particularly useful for mediastinal and retroperitoneal masses. In case of EGCT, EM can identify the different cytotypes and the different ultrastructural subcellular cytotypes and demonstrates a close relation between seminomatous and nonseminomatous GCT, which could influence their classification and prognosis.

Electron microscopy of fine needle aspiration biopsies of mediastinal and paramediastinal lesions.

The ultrastructural cytologic study of fine needle aspiration (FNA) biopsies from eight cases with mediastinal and paramediastinal lesions is reported. In these cases, electron microscopy (EM) was essential in cytologically determining the correct type of the cancer cells. The results in these cases suggest that portions of FNA biopsies from deep sites, where aspiration is difficult or requires computed tomographic scanning, should be routinely processed for plastic embedding, so that EM examination can be performed if the cells are undifferentiated, scanty or poorly preserved by light microscopic examination. The proper cytologic identification of the cell might, in fact, have a major bearing on the therapeutic choices and on the prognosis.

Cardiac papillary fibroelastoma: report of two cases.

We report 2 cases of cardiac papillary fibroelastoma in aortic position that were successfully treated by complete surgical excision, without damage to the aortic valve. This rare cardiac tumor can be associated with serious embolic or hemodynamic complications and therefore, prompt surgical intervention is required.

Evaluation of histological and ultrastructural aspects of endometrium during treatment with gestrinone in women with amenorrhea or spotting.

Nineteen patients with a laparoscopic diagnosis of endometriosis were treated with gestrinone at a dosage of 2.5 mg twice a week for 6 months. In 7 who reported spotting in the first 3 months, the dose was increased to 2.5 mg three times a week during the second trimester. An endometrial sample was obtained from each patient at the time of laparoscopy (basal) and at 3 and 6 months of treatment. Endometrial structure and ultrastructure were studied. Areas of hemorrhage and of loss of surface epithelium and a lesser degree of involution of the surface epithelium were observed in the 3-month samples of 7 patients with spotting, compared with 12 with amenorrhea. It is hypothesized that incomplete endometrial involution could be due to differences in gestrinone pharmacokinetics in individual patients, in the quality and/or quantity of endometrial cytosolic receptors for sex steroids, or in endocrine compensation to administration of the drug.

Heterogeneous subcellular morphology of lung adenocarcinoma cells: identification of different cytotypes on cytological material.

We performed an electron microscopic study of cytologic material from 20 cases of primary lung adenocarcinoma (pleural effusion, 13 cases; fine needle aspiration biopsy, 7 cases). Ultrastructural characteristics related to secretory and storing activity of adenocarcinoma cells were evaluated semiquantitatively. Data analysis identified three basic cell types (secretory, well or poorly differentiated; storing; and indifferent). We could classify our cases in five groups of pure or mixed cytotypes. Our results demonstrated a subcellular morphological heterogeneity manifested by the presence of different basic cell types: secretory, storing or indifferent features (or both); and different secretory and storage products in the same cell. This heterogeneity of lung adenocarcinoma cells suggests that the neoplasm could arise from a single cell type capable of differentiating along different lines. Cases lacking secretory differentiation seemed to be characterized by more aggressive biologic behavior. A clear correlation between the ultrastructural cytotypes identified and the clinical and prognostic data on the patients was not observed. This may be due to the fact that 75% of the patients were in clinical stage III at the time of diagnosis; also, in this series only five cases did not have characteristics that indicated secretory activity.

Chromogranin A as a marker of neuroendocrine histogenesis of tumours: an immunoelectron microscopic study with considerations about the influence of fixation and embedding media on immunolabelling.

The ultrastructural localization of chromogranin A (Chr A) was studied in eleven neoplasias of the diffuse neuroendocrine system (3 pancreatic islet-cell tumours, 1 medullary carcinoma of the thyroid, 1 large bowel and 1 small bowel carcinoid tumours, 2 carcinoid tumours of the lung, 1 adenoma of the parathyroid gland, 2 pheochromocytomas of the adrenal gland). On account of the great influence of the technical treatment of the samples on the immunolocalization of Chr A, the effect of the following variables was studied in a case of pheochromocytoma: fixation in glutaraldehyde versus paraformaldehyde, postfixation in osmium tetroxide versus omission, embedding in epoxy resin versus acrylic resin. The method of choice for the better preservation of the antigenic character of the tissue was found to be fixation in 4% paraformaldehyde, omission of osmium postfixation and embedding in LRWhite acrylic resin; by this procedure we were able to find Chr A in the neurosecretory granules of all the studied cases, using three commercially available antibodies directed against Chr A. These findings further confirm that Chr A is a reliable marker for the study of neuroendocrine neoplasias by electron microscopy.

[Primary neuroendocrine carcinoma of the skin: histologic, immunohistochemical and ultrastructural study of a case with highly aggressive biological behavior]. / Carcinoma neuroendocrino primitivo della cute: studio istologico, immunoistochimico ed ultrastrutturale di un caso a comportamento biologico altamente aggressivo.

We report a histological, immunohistochemical and ultrastructural study of a case of neuroendocrine carcinoma of the skin, which occurred in a 52 years old woman in the dermal, subcutis and soft tissues of the left buttock. Clinically this neoplasm, which was related to intramuscular injections and a to a following abscess, had rapidly reached unusual dimension compared with other cases of neuroendocrine carcinoma of the skin reported in the literature. The patient died three months after presentation with distant metastases. A variable percentage of the neoplastic cells was positive for low molecular weight cytokeratins (CK), neurofilaments (NF), neuron specific enolase (NSE) and occasionally for vaso-intestinal polypeptide (VIP). Ultrastructural investigations showed two types of neoplastic cells, identified for some features of the nucleus and of the cytoplasm; these two groups of cells are, in our opinion, related to different stages of cellular development. Our results, in agreement with some observations reported in the literature, give evidence of a possible origin of neuroendocrine carcinoma of the skin from an undifferentiated cell which is capable of neuroendocrine or ectodermal differentiation.

Culture of human endometrial cells: a new simple technique to completely separate epithelial glands.

In vitro studies on dispersed human endometrial cells are still difficult to perform as the techniques employed do not allow an optimal separation of the cells. In particular, epithelial glands tend to maintain their tubular structure even after enzymatic dispersion. This could be a disadvantage when monolayers of single well dispersed cells are needed. In this paper we describe a new technique to establish monolayer cultures of isolated endometrial stromal and epithelial cell populations. After a first collagenase digestion, stromal and epithelial cells were separated by differential sedimentation at unity gravity. The epithelial glands obtained were further dispersed in single cells using a short incubation with low amount of trypsin. Morphologic characterization was performed using immunohistochemistry for vimentin and cytokeratins. Compared to previous described methods, this procedure is shorter and could better preserve cell surface structures. Thus, it could be successfully employed for in vitro studies of human endometrial pathophysiology.

Effects of trimetazidine on metabolic and functional recovery of postischemic rat hearts.

The objective of this study was to test the hypothesis that the beneficial effect of trimetazidine during reflow of ischemic hearts is mediated by energy sparing and ATP pool preservation during ischemia. Isolated rat hearts (controls and rats treated with 10(-6) M trimetazidine, n = 17 per group) underwent the following protocol: baseline perfusion at normal coronary flow (20 minutes), low-flow ischemia at 10% flow (60 minutes), and reflow (20 minutes). We measured contractile function, O2 uptake, lactate release, venous pH and PCO2, and the tissue content of high-energy phosphates and their metabolites. During baseline, trimetazidine induced higher venous pH and lower PCO2 without influencing performance and metabolism. During low-flow ischemia, trimetazidine reduced myocardial performance (P = 0.04) and ATP turnover (P = 0.02). During reflow, trimetazidine improved performance (91 +/- 6% versus. 55 +/- 6% of baseline), prevented the development of diastolic contracture and coronary resistance, and reduced myocardial depletion of adenine nucleotides and purines. ATP turnover during low-flow ischemia was inversely related to recovery of the rate-pressure product (P = 0.002), end-diastolic pressure (P = 0.007), and perfusion pressure (P = 0.05). We conclude that trimetazidine-induced protection of ischemic-reperfused hearts is also mediated by energy sparing during ischemia, which presumably preserves the ATP pool during reflow.