Paroxysmal nocturnal hemoglobinuria: molecular pathogenesis and molecular therapeutic approaches

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal hematologic stem cell disorder classified as an intravascular hemolytic anemia. Abnormal blood cells are deficient in glycosylphosphatidyl inositol (GPI)-anchored proteins. Deficiencies of GPI-anchored complement regulatory proteins, such as decay accelerating factor (DAF) and CD59, render red cells very sensitive to complement and result in complement-mediated hemolysis and hemoglobinuria. In the affected hematopoietic cells from patients with PNH, the first step in biosynthesis of the GPI anchor is defective. Three genes are involved in this reaction step and one of them, an X-linked gene termed PIG-A, is mutated in affected cells. Granulocytes and lymphocytes from the same patient have the same mutation, indicating that a somatic PIG-A mutation occurs in hematopoietic stem cells. The PIG-A gene is mutated in all patients with PNH reported to date. We review these recent advances in the understanding of the molecular pathogenesis of PNH. Furthermore, we present an hypothesis regarding the predominance of the PNH clone, caused by positive selection by hematopoietic suppressive cytokines, such as transforming growth factor (TGF)-beta. In addition, we discuss the possibility of cure for PNH through molecular therapeutic strategy using gene transfer techniques. (Key words: paroxysmal nocturnal hemoglobinuria, glycosylphosphatidylinositol-anchored proteins, PIG-A, clonal dominance, growth advantage, transforming growth factor-beta, gene therapy, molecular therapeutic approach).     

Novel clinical approaches in monoclonal antibody-based management in colorectal cancer patients: radioimmunoguided surgery and antigen augmentation

In animals, changes in brain temperature induce a shift in frequencies in the electroencephalogram (EEG). Given the large decreases in body and brain temperature that occur during hibernation, putative functions that were previously ascribed to certain EEG frequencies are no longer valid because of the progressive shift away from the original frequency. In the present review it is proposed that even moderate temperature changes in humans and animals, such as those across the circadian or menstrual cycle, or induced by drugs, have a significant effect on EEG frequencies and the corresponding power spectrum. Alterations in the relative EEG power spectrum, in studies where body temperature also changes, may not be a direct cause of the treatment under investigation, but a consequence of effects on body or brain temperature. However, these effects on the EEG power spectrum are usually interpreted to result directly from the experimental treatment.     

Diagnosing basal cell carcinoma by dermatoscopy

BACKGROUND: Dermatoscopy (DS) has been used primarily to evaluate pigmented skin lesions. Little information is available on DS findings of basal cell carcinoma (BCC). Dermatoscopy is a noninvasive technique that allows visualization of cutaneous features from the skin surface to the papillary dermis. Basal cell carcinoma, the most common cutaneous malignancy, is traditionally diagnosed clinically and confirmed with biopsy. OBJECTIVE: To determine the dermatoscopic features of nonpigmented basal cell carcinomas. Methods: The dermatoscopic findings of 27 lesions that clinically were suspicious for BCC were analyzed. RESULTS: Of these 27 clinically suspect lesions, the biopsies revealed BCC in 20 specimens and squamous cell carcinoma (SCC) in two specimens. Twenty of these 22 specimens had dermatoscopic findings of BCC: diffusely distributed, branching blood vessels, asymmetric, and narrow blood vessels distributed deeper in the dermis, or a milky-red corona with superficial wide blood vessels. One nodular BCC in our study showed no distinct findings. CONCLUSIONS: Many BCCs have characteristic DS findings; however, dermatoscopic examination of some tumours will not demonstrate any known characteristic findings. As such, the DS criteria we propose for BCC are best utilized as an adjunctive study of clinical impressions. Biopsy remains the definitive diagnostic tool.     

Affect regulation: Two clinical approaches.

The panel on affect was presented in the Spring 2001 Meeting of Division 39 (Psychoanalysis) of the American Psychological Association. Judith Levene and Kenneth Barish presented a theoretical framework and clinical experiences indicating how their work attempts to facilitate affect regulation. David Landau discussed several similar qualities shared in these papers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Retinoblastoma: clinical and molecular diagnostic aspects

Retinoblastoma, a tumor of the immature retina concerns babies and young infants in particular. They make up for 14% of malignomas in the first years of life. There are two types of retinoblastoma: In the first two alleles of the gene Rb1 must be inactivated sequentially in the same retinoblast cell until this may escape control. In this case the retinoblastoma is always unilateral and unifocal. This is explained by the lower frequency of two mutations in one retinoblast. The other type, however, is inherited: One allele Rb1 is inactivated in all cells of the organism by mutation. The probability that a second mutation arrives in different retinoblasts is thus high. In this case bilateral multifocal tumors develop. Characterization of the Rb1 gene has permitted identification or at least determination of a haplotype in persons at risk. This knowledge is decisive for early recognition of babies at risk and for genetic counselling.     

Chemotherapy of colorectal carcinoma

The benefit of adjuvant therapy in colorectal cancer (CRC) has been provided in clinical studies that have demonstrated reduction of up to 30% in a 5-year overall mortality in patients (pts.) with TNM stage III (Dukes' stage C) carcinoma. Patients with metastatic CRC are usually in a relatively good condition despite their advanced disease. Therefore, some clinicians wished to withheld the toxicity of chemotherapy until the disease became symptomatic. Others, however, felt it appropriate to treat patients early in the course of the disease. Four clinical trials may be cited addressing this clinical uncertainty (Table 1). Patients receiving chemotherapy had a significantly longer median survival in comparison with only best supportive care. The delay of the carrying out of systemic chemotherapy in patients with metastatic disease decreases the symptom free interval (2 vs. 10 months, p < 0.001), time to disease progression (3 vs. 8 months, p < 0.001) and median survival (14 versus 9 months, p < 0.02) compared to an early start of therapy [7C. Patients with metastatic colorectal cancer benefit from early chemotherapy in terms of survival and quality of life. It is clear that survival is determined by prognostic factors, mainly the performance status, which is a highly significant predictor of therapeutic response and overall survival in advanced colorectal cancer patients. Some authors suggests that the response is a potent and independent prognostic factor of survival, and that response can be used as surrogate marker of survival. Stable disease is a category in therapy response evaluation which is not included in the overall response rate. In many studies with a response rate below 20%, chemotherapy almost doubles the survival of patients. In most chemotherapy trials in advanced colorectal cancer patients, about 30-50% had stable disease. One of the possible reasons may be that in colorectal cancer stabilization of disease is a clinically relevant effect of chemotherapy. If we accept that disease stabilization is a clinically relevant effect of chemotherapy, should we continue with chemotherapy after 3 or 4 courses, and for how long, or should we stop treatment according to rules for stable disease, i.e. following 4 courses? The results of on study, which we performed in 99 patients with advanced colorectal cancer, indicate that under category of "stable disease" there are two different subpopulations of patients with quite different symptom responses as an effect of chemotherapy, different time to progression and possible different survival (Graph 1 and Graph 2). It seems that stable disease patients with clinical benefit could be a target group for policy "to treat until disease progression". The tumour response is likely to be positively correlated with improvement in quality of life when a patient is a symptomatic from cancer before the treatment. Stable disease patients without symptom improvement have no benefit from further chemotherapy and in these patients treatment should be stopped. Such selection would spare from toxicity stable disease patients without clinical benefit. We have no data whether different number of chemotherapy cycles in the groups of patients with and without clinical benefit could lead to a bias in survival estimation. Patients who achieved also a stable disease, but who were asymptomatic from the beginning of chemotherapy, and who are still asymptomatic after 4 chemotherapy courses, make a group for which is hard to make decision either to continue or to stop chemotherapy. We have treated and followed-up these stable disease patients as patients without clinical benefit. We have no answer if they could reach better time to progression and/or survival if they had been treated for more than 4 courses. Careful studies in the evaluation of the quality of life in connection with treatment effects for all stable disease subpopulations of patients are warranted. (ABSTRACT TRUNCATED)     

Lymphadenectomy in colorectal carcinoma

Recurrence of colorectal carcinomas occurs in about 50% of the cases with localized neoplasia. It is understood that the tumor recurrence is due to residual micrometastases not found during surgery or extraregional (peripheral blood or bone marrow). We developed a procedure to detect non-visible, abdominal metastases using a radiolabeled anti-tumor cell antibody injected before the operation (radioimmunoguided surgery RIGS). However, even with the best technique, it is not possible to remove all micrometastasis if a hematogenic dissemination happens. Based on the knowledge of disturbing humoral immune reaction is mounted against shed tumor associated antigens (TAA), we developed a new method to reduce and correct the B cell response and B cell recruitment due to chronic TAA immun complex presentation on follicular dendritic cells (immune corrective surgery, ICS). This method is based on a selective lymphadenectomy. The target lymph nodes were those loaded with TAA-immune complex. The detection method used was the injection of radiolabeled antibody able to recognize the immune complex. From 20 patients (stage I, II and III) treated with ICS, 17 survived more than 5 years 'showing a statistically significant increase of survival compared to patients treated with standard procedures. In conclusion, these data show that surgery of colorectal cancer should be selectively extended to specific anatomical regions in order to remove hidden micrometastases, and more importantly, correct postoperative immune processes that could suppress the T cell response against residual tumor cells.     

Optical mapping approaches to molecular genomics

Gunshot injury causes a complex of changes in perinecrotic area covering all tissue structures of skin which is discussed as a systemic organ disintegration, including disintegration of dermal differons. Connective tissue regeneration is reflected by a determined process. Replacement of a defect with granulation tissue should be considered as a reparative regeneration. Peculiarities of fibroblasts proliferation and differentiation in perinecrotic area indicate the prevalence of regenerative histogenesis features.     

Flat adenoma as a precursor of colorectal carcinoma in hereditary nonpolyposis colorectal carcinoma

BACKGROUND: Because flat adenoma shows a higher malignancy rate compared with other types of polyps, it is considered to play an important role in the carcinogenesis of colorectal carcinoma. In the present study, we examined flat adenomas in hereditary nonpolyposis colorectal carcinoma (HNPCC) patients. METHODS: Nine HNPCC patients who presented with flat adenomas were examined. All patients underwent either surgery or endoscopic polypectomy for colorectal carcinoma and/or adenoma. In all patients, annual colonoscopy had been performed once a year throughout the follow-up period after the initial treatment. When colorectal polyps were detected during follow-up colonoscopy, all lesions were endoscopically excised. Clinicopathologic features and microsatellite instability of both malignant lesions and adenomas were examined. RESULTS: Thirteen malignant lesions were detected: seven advanced carcinomas and six early carcinomas. Among 4 early carcinomas with submucosal invasion, 3 lesions (75%) were categorized as superficial type, with a configuration similar to flat adenoma. The frequency of flat adenoma was strikingly high in HNPCC patients in the present study. Among 73 polyps detected, 37 (50.7%) were flat adenomas. Both malignant lesions and flat adenomas had proximal predominance, 61.5% and 59.5%, respectively. Eleven of 15 lesions (73.3%) showed replication error. CONCLUSIONS: These results suggest the importance of flat adenoma as a precursor of colorectal carcinoma in some groups of HNPCC patients. Further study is essential to elucidate the natural history of flat adenomas in HNPCC patients.     

Nasopharyngeal carcinoma: clinical trends

Nasopharyngeal carcinoma (NPC) is one of the most difficult diseases to diagnose at an early stage. The clinical presentation of 122 patients with confirmed NPC is described and the findings analysed. The common modes of presentation and cases where detailed nasopharyngeal examination need to be performed are highlighted. We emphasize the importance of health education and training for primary care physicians for early detection of these cases.     

S-adenosylmethionine synthesis: molecular mechanisms and clinical implications

Methionine adenosyltransferase (MAT) is an ubiquitous enzyme that catalyzes the synthesis of S-adenosylmethionine from methionine and ATP. In mammals, there are two genes coding for MAT, one expressed exclusively in the liver and a second enzyme present in all tissues. Molecular studies indicate that liver MAT exists in two forms: as a homodimer and as a homotetramer of the same oligomeric subunit. The liver-specific isoenzymes are inhibited in human liver cirrhosis, and this is the cause of the abnormal metabolism of methionine in these subjects.     

Serum and tissue CEA in colorectal cancer: clinical relevance

PURPOSE: This article is an analysis of the information derived from the determination of tumor-tissue concentration of CEA in patients with colorectal cancer. To ascertain the relationship between tumor marker content with the histologic aspects and serologic levels of CEA of this neoplam. MATERIALS AND METHODS: 136 patients with colorectal adenocarcinoma and 41 with colorectal benign processes are analyzed and followed during an average time of 27 months. The CEA of the serum were obtained preoperatively and postoperatively and measured by radioimmunoassay (RIA). Tissular CEA levels were determined with RIA. The histological characteristics are analyzed (Dukes classification, grade of differentiation, index of atypia, microscopic vascular and lymphatic involvement. RESULTS: 1) The cut off point of the tissular CEA with the best sensitivity and specificity for the diagnosis of normal mucosa is 386 ng/mg and for tumoral tissue is 1160 ng/mg. 2) There is no correlation between tissue and serologic CEA value. 3) The tissular level of CEA have a significant statistical correlation with Dukes stage (p < 0.003); other histological characteristics were no significative. 4) There are significant statistical correlations between serologic CEA and relapse but no with survival rates. CONCLUSIONS: 1) Serologic CEA levels depend on numerous factors. 2) There aren't correlations between preoperative serologic levels and tissular CEA levels. 3) Tissular CEA do not predict what patients will have an elevated serologic CEA level in relapse.     

Probe-guided surgery of colorectal carcinoma

Anti-CEA-scintigraphy turned out very reliable in detecting primary and recurrent colorectal cancer, its overall accuracy being more than 90 p.c. The intraoperative application of this technology should provide similar results when focussing at extrahepatic tumor deposits, for example in lymph nodes, thus allowing accurate staging of the underlying disease. To test this hypothesis we lauched the following feasibility-study the results of which are compared to those reported in the recent literature. We investigated 20 patients-six with rectum-, 14 with colon cancer, 24 hours before surgery they were intravenously given 1 ml of an fab-fragment-antibody to CEA, labeled with 25mCi of 99mTc (CEA-Scan). During surgery the radioactivity in lymph glands regionary for the tumors was measured and compared to the-much lower-activity in healthy nodes. For this we used a scintillation-probe (C-Trak). All lymph nodes of interest were-then excised and submitted to frozen section pathology. In 7/20 cases scintimetry led to an up-staging of the disease. In addition we found metastatic spread to lymph nodes that were basically not regionary for the primary tumor. Our results are confirmed by those of other investigators. Scintimetry can precisely identify even very small tumor deposits. So it leads to accurate staging when surgery is still on-going. In a next step the concept of sentinel-node-diagnosis, which is right now being clinically evaluated, may be applied is colorectal surgical oncology.     

Preoperative and postoperative colonoscopy for colorectal carcinoma

A patient with documented ZE syndrome responded to intravenous magnesium infusion by increased gastric acid output and increased serum gastrin concentration. A patient with acid hypersecretion but no gastrinoma had no substantial alteration in acid output or serum gastrin concentration following magnesium administration. This suggests that magnesium caused gastrin to be released from a gastrinoma.     

Genetic alterations and molecular mechanisms underlying colorectal tumorigenesis

Tumor cells are cells that have acquired damage to genes that directly regulate their cell cycles. In the multistep process leading to colorectal carcinoma, the adenoma-carcinoma sequence is characterized by progressive accumulation of genetic abnormalities (K-ras oncogene mutation, allelic deletion on chromosome 5q, 18q, 17p). In a hereditary non-polyposis syndrome (Lynch syndrome II) and in about a quarter of the cases of sporadic colorectal cancer there is a DNA micro-instability which contributes to the acquisition of mutations that cause loss of tumor-suppressor function. The p53 tumor-suppressor gene is the most frequently mutant gene in human cancer. In colorectal cancer cells missense p53 mutations and allelic deletion on chromosomal locus 17p13.1 are found with very high frequency. One of biological roles of p53 gene is to ensure that, in response to genotoxic damage, cells arrest in G1 and attempt to repair their DNA before it is replicated. In addition, p53 is required for apoptosis in response to severe DNA damage, included the damage induced by chemotherapeutics drugs and ionizing radiation. The loss of p53 function results in genomic instability and has been implicated in the evolution of normal cells into cancer cells.     

Diagnosing and monitoring the clinical course of chronic obstructive pulmonary disease

COPD is an extremely common, chronic disorder characterized by a reduction in airflow after the administration of an inhaled bronchodilator as measured by the FEV1. The diagnosis is suspected in patients with a history of several decades of cigarette smoking who present with nonspecific respiratory symptoms. The diagnosis is established by simple forced expiratory spirometry. Baseline evaluation usually includes a chest radiograph and some assessment of functional capacity, either by history or with some form of exercise testing. In patients whose initial FEV1 is more severely reduced or who have significant dyspnea, an arterial blood gas is indicated at baseline. Dyspnea, hypoxemia, or hypercarbia that is out of proportion to the measured FEV1, at either presentation or follow-up, should prompt a thorough evaluation for complicating conditions. There are important roles in health care delivery and chronic disease management strategies for RCPs, primary care providers, and specialty trained pulmonary physicians. The need for repeated, extensive, or expensive testing will be largely driven by patients symptoms but disease monitoring with periodic assessments of dyspnea, functional capacity, and spirometry can be performed without great expense.     

Vitamin D-retinoid association: molecular basis and clinical applications

BACKGROUND AND PURPOSE: The role of single-photon emission CT (SPECT) in the prognosis of cerebral infarction is controversial, but most studies report that SPECT using a variety of radiopharmaceutical agents gives useful prognostic information. Only one study has questioned whether acute perfusion deficits independently add to a valid clinical prognostic score. This study was limited to middle cerebral artery territory infarcts and was negative. We present data on the prognostic utility of SPECT using 99mTc-hexamethylpropyleneamine oxime (HMPAO) in cerebral infarction, unselected by site. METHODS: Fifty consecutive unselected patients admitted to the hospital with acute cerebral infarction, of whom 10 died and 7 withdrew, had SPECT performed serially at onset and at 1 week and 3 months after stroke onset using 99mTc-HMPAO and the NOVO 810 dedicated high-resolution head tomograph. Clinical severity at presentation and outcome was measured with the Canadian Neurological Scale and the Barthel Index. Infarct volumes were measured from both the SPECT and CT scans. The data for the 43 subjects who completed the study or died were evaluated to determine the most powerful prognostic measures. Predictors were the Canadian Neurological Scale score at onset and 1 week, the Barthel Index at 1 week, the CT infarct volume typically done between 3 and 7 days after stroke onset, and the infarct volumes at the first and second SPECT. Outcome measures were the Canadian Neurological Scale score and Barthel Index score at 3 months, scored as zero for those patients who died. RESULTS: The clinical prognostic indicators correlated with the outcome measures, with coefficients between .617 and .821 (P < .0006 in all cases). The Canadian Neurological Scale score measured at 1 week was the best of these. Infarct volumes measured from SPECT correlated less well (coefficients between -.518 and -.683, P < .0019 in all cases). CT infarct volume was the poorest predictor. Although SPECT infarct volumes predicted outcome, they did so less well than clinical examination. Spontaneous infarct reperfusion did not affect outcome. CONCLUSIONS: Although the measurement of infarct volume on SPECT using 99mTc-HMPAO provides a predictor of stroke outcome, it is not a better predictor than the Canadian Neurological Scale score.