Activation by ACA induces pluripotency in human blood progenitor cells.

Reprogramming of human somatic cells by transcription factors to pluripotent state holds great promise for regenerative medicine. However, low efficiencies of current reprogramming methods, immunogenicity and lack of understanding regarding the molecular mechanisms responsible for their generation, limits their utilization and raises questions regarding safety for therapeutic application. Here we report that ACA signaling via PI3K/Akt/mTor induces sustained de-differentiation of human blood progenitor cells leading to generation of ACA pluripotent stem cells. Blood-derived pluripotent stem cells differentiate in vitro into cell types of all three germ layers, exhibiting neuronal, liver, or endothelial characteristics. Our results reveal insight into the molecular events regulating cellular reprogramming and also indicate that pluripotency might be controlled in vivo through binding of a natural ligand(s) to ACA receptor enabling reprogramming through defined pathway(s) and providing a safe and efficient method for generation of pluripotent stem cells which could be a breakthrough in human therapeutics.

A novel human glycoprotein ACA is an upstream regulator of human hematopoiesis.

A central issue in stem cell biology is a better understanding of the molecular mechanisms that regulate self-renewal of human hematopoietic stem cells (HSCs). Control of the specific function of HSCs like self-renewal and differentiation might be regulated by a common set of critical genes. However, the regulation among these genes is yet to be elucidated. Here, we show that activation by a novel human GPI-linked glycoprotein ACA at the surface of human peripheral blood progenitor cells induces via PI3K/Akt/mTor/PTEN upregulation of WNT, Notch1, Bmi-1 and HoxB4 genes thus, promoting self-renewal and generation of primitive HSCs. ACA-generated self-renewing cells retained their lympho-myeloid repopulating potential in NOD/SCID mouse xeno-transplantation model with long term functional capacity. We conclude that ACA is an essential regulator of the genes involved in maintaining hematopoiesis and its use in clinical praxis could overcome many of the barriers present so far in transplantation medicine.

[Diagnostic and therapeutic impact of 18F-FDG-PET/CT in patients with suspected breast cancer recurrence]. / Impacto diagnóstico y terapéutico de la (18)F-FDG-PET/TAC en pacientes con sospecha de recidiva de cáncer de mama.

Breast cancer is a tumor with high prevalence in our environment. Thus, it is essential to make an early diagnosis in both the primary disease and its recurrence, given the high mortality of the cases with the advanced disease. Our study has aimed to evaluate the impact of (18)F-FDG-PET/CT in patients with suspected breast cancer recurrence and their therapeutic management. This study analyzed the PET/CT of 70 patients with a background of breast cancer and suspicion of recurrence, either because of elevation of tumor markers (n=28), doubtful findings on other imaging techniques (n=56) and/or suspicious symptoms (n=1). All the patients underwent a standard FDG-PET study acquired in combination with low-dose CT. The studies were considered pathological in 34 of the 70 patients, with 29 true positive, 32 true negative, 5 false positive and 4 false negative results. The final diagnosis was established either by histopathologic confirmation (n=17), other imaging techniques (n=26) and/or clinical radiological follow-up (n=27, mean 12.7 months). The sensitivity, specificity, positive predictive value and negative predictive values obtained were 87.8%, 86.4%, 85.2% and 88.8%, respectively. Therapeutic management was modified in 41% of the patients. In conclusion, PET/CT is a technique with high diagnostic yield in patients with suspected breast cancer recurrence.

[Utility of PET-CT on radiotherapy planning of head and neck cancer. Our initial experience]. / Utilidad de la PET-TAC en la planificación radioterápica en el cáncer de cabeza y cuello. Nuestra experiencia inicial.

OBJECTIVE: To describe the methods used for the incorporation of FDG-PET-CT on radiotherapy planning of patients with head and neck cancer and also to evaluate the impact of FDG-PET-CT on staging and tumor volume definition. MATERIAL AND METHODS: A prospective study in which 20 patients with head and neck tumor submitted for radiotherapy treatment were included. All underwent a whole body PET- CT (GE DSTE 16) for staging and restaging, also acquiring an additional 3h delayed PET image with diagnostic CT parameters for planning. A CT scan with diagnostic protocol, tabletop available for radiotherapy treatment and the same personalized head-shoulder mask were used in the latter. Lymph node involvement and/or distant involvement were evaluated, considering the changes in staging. We also evaluated the differences in volumes obtained between the different techniques. The threshold value used for delineating PET gross tumor volume (GTV) was empirically established and ranged from 20-40% of the maximum SUV. RESULTS: Radiotherapy planning was performed with PET-CT in 20 patients between October 2007 to September 2008. A total of 29 lesions (18 primary lesions because 2 patients were excluded as no tumor was observed on the PET CT images, and 11 nodes). The most frequent location was oropharynx (5 patients). Mean maxSUV of the 29 lesions was 14.4 (range 5.0 and 26.4). No statistically significant differences were found between the GTV PET and GTV CT (mean 21.9cm³ and 19.3cm³, respectively). PET-CT modified the staging in 20% of the patients, with a diagnostic and therapeutic impact of 50 and 25%, respectively. CONCLUSION: The incorporation of PET-CT in routine radiotherapy planning is a promising technique that requires close collaboration between the nuclear medicine and radiotherapy oncology departments. PET-CT achieves better staging in patients and has a significant diagnostic and therapeutic impact. The use of the hybrid technique avoids problems arising from co-registry as well as a second examination for planning with the consequent advantage for the patient. Nonetheless, more prospective and randomized studies with pathology specimens are needed to evaluate the real impact in the tumor volume definition.

[PET-CT with intravenous contrast in the evaluation of patients with lymphoma. Contribution to diagnostic indications]. / PET-TAC con contraste intravenoso en la valoración de pacientes con linfoma. Aproximación hacia las indicaciones diagnósticas.

AIM: To define the utility of intravenous contrast administration in the PET-CT (PET-CTc) in patients with lymphoma in order to determine its possible indications. MATERIAL AND METHODS: 78 patients with lymphoma were prospectively evaluated. All underwent simultaneous PET-CTc scans in a hybrid system for staging (8), evaluation of response to treatment (29), suspicion of recurrence (9) and complete remission control (48). The PET scan was acquired by a conventional method and the diagnostic CT scan was performed according to radiological protocol. Both examinations were evaluated blinded and independently, analyzing 28 anatomical locations in order to determine the degree of agreement. Final diagnosis was established by the clinician based on the histological study, results of other diagnostic techniques or clinical follow-up. RESULTS: The final result of both techniques were concordant in 87/94 studies (92.5%). A total of 158 (36 FP) pathological locations were detected with PET-CT and 189 (71 FP) with CTc, with 72 locations being discordant between both techniques. Global sensitivity, specificity, PPV and NPV were 93%, 98%, 77% and 99%; and 94%, 97%, 62% and 99%, respectively. CONCLUSIONS: Administration of intravenous contrast does not seem to provide any advantage in the determination of nodal and extranodal disease in lymphoma patients. The low prevalence of disease probably accounts for the limited PPV of both techniques. An increase of our sample size, with a greater homogeneity of the groups, should offer more reliable results.

[Study of physician satisfaction as a quality criterion in Nuclear Medicine]. / Estudio de satisfacción de facultativos como criterio de calidad en Medicina Nuclear.

OBJECTIVE: To determine the perception and satisfaction level of referring physicians requesting scans as final users of the Nuclear Medicine Department. MATERIAL AND METHODS: A self-administered questionnaire was designed; it was composed of 10 closed questions (5 categorised and 5 with numerical scale) and 3 open questions. The indicators evaluated were: physician's information about available tests, test indications and diagnostic information, accessibility, delay in the examination and reception of the diagnostic report, usefulness of diagnostic information and overall satisfaction with the department. Two hundred and fifteen questionnaires were sent. RESULTS: Seventy eight questionnaires were returned, so the response index was 36.3 %. The 44.6 % of physicians surveyed considered that they had sufficient information about the tests and 59.5 % were satisfied with the indications and diagnostic information. The accessibility was 7 or more out of 10 for 78.5 %. The 64.9 % of physicians considered the delay in performing examinations to be correct but the satisfaction was lower in the delay between performance and reception of the diagnostic report. The diagnostic information was considered useful by 81.9 % and relevant in the management of patients by 70.5 % of the participants surveyed. The overall satisfaction was > or = 7 out of 10 in 86.8 %. CONCLUSIONS: Overall satisfaction was high, although the level of knowledge about available tests and the delay between test performance and report reception could be improved.

[Value of 99mTc-labelled red cells in the detection of pulmonary haemorrhage]. / Valor de la gammagrafía con hematíes marcados con 99mTc en la detección de hemorragia pulmonar.

The use of 99mTc-labelled red cells is very extensive in the detection of haemorrhages of gastrointestinal origin. However, not only is it useful in haemorrhages in this location, but it may also be of use in other locations such as pulmonary haemorrhage. We should not forget that this is a non-invasive diagnostic method, useful in localising possible pulmonary bleeding which causes symptoms of haemoptysis, without having to resort to invasive tests such as angiography, or prior to this, to have approximate knowledge of the location of the bleeding area. We present the case of a patient with a haemoptysis picture where the use of scintigraphy with labelled red cells detected the location of the bleeding site, directing towards subsequent surgery, and a final diagnosis of haemoptysis due to pulmonary carcinoma.

18F-FDG PET/contrast enhanced CT in the standard follow-up of patients with lymphoma. / 18F-FDG PET/TC con contraste intravenoso en el seguimiento estandarizado de pacientes con linfoma.

AIM: To assess the diagnostic accuracy of 18F-FDG PET/contrast enhanced computed tomography (ceCT) in the detection of asymptomatic recurrences in patients with lymphoma. MATERIAL AND METHODS: Patients with lymphoma and clinical complete remission underwent 18F-FDG PET/ceCT for standard follow-up.18F-FDG PET and ceCT were evaluated blindly by two independent observers, and classified as positive or negative for recurrence. Additionally a combined evaluation of both techniques was performed. The final diagnosis was established by histopathological analysis or a clinical follow-up longer than 6 months. Statistical diagnostic parameters and concordance levels between both diagnostic techniques were calculated. RESULTS: A total of 114 explorations on 90 patients were analyzed. Only 4 patients were diagnosed as asymptomatic recurrence during the follow-up. 18F-FDG PET/ceCT, 18F-FDG PET and ceCT showed an association with the final diagnosis (p=0.002 and χ2=11.96; p<0.001 and χ2=15.60; p=0.001 and χ2=11.96, respectively). The concordance between 18F-FDG PET and ceCT was moderate/high and significant (kappa=0.672; p<0.001). A sensitivity and specificity of 50% and 88% was obtained for the 18F-FDG PET/ceCT civ, 50% and 93% for the 18F-FDG PET, and 50% and 91% for the ceCT. CONCLUSION: The combined use of 18F-FDG PET/ceCT did not offer any advantage compared to any isolated diagnostic technique in the detection of asymptomatic lymphoma recurrence.

[Are bone scintigraphy examinations requested in oncologic patients according to established indications?]. / Se solicitan las gammagrafías óseas en pacientes oncológicos según criterios clínicos reconocidos?

OBJECTIVE: To determine the percentage of bone scintigraphy examinations (BS) requested according to established indications and to assess the clinical impact of the scintigraphic results. MATERIAL AND METHODS: A retrospective study was performed including BS in 117 patients (70 women and 47 men) carried out in our department during the year 2001. All patients had a primary extraosseous malignancy. The correctness of the indication of each study requested was analyzed according to established criteria from the literature. BS results were classified as positive, negative, and equivocal for metastatic disease. RESULTS: 96 out of the 117 BS were performed in patients affected with the most prevalent primary malignancies: breast (57), prostate (21), and lung (18). The remaining studies were included in a miscellaneous group (gynecological [3], colorectal [4], oropharyngeal [4], and renal malignancies [4]; lymphoma [2], melanoma [2], hemangioendothelioma [1]; and cancer of the bladder [1] or pancreas [1]). Ninety-nine (85 %) of the 117 BS performed met the criteria for appropriate indication. The indication was correct in 75 % of breast, 90 % of prostate (19/21), and 100 % of lung cancers. The indication was correct in 90 % of the cases in the miscellaneous group. BS were positive in 21 patients (20 of which were confirmed). BS were equivocal in 24 patients (in 5 of whom bone metastases were confirmed). BS were negative in 72 patients (one of whom had bone metastases). The BS findings changed staging in 9 % (9/99) of the correctly indicated cases. CONCLUSION: Most BS (85 %) were indicated according to the established criteria and the clinical impact was greater in this group.

[Assessment of cortical brain blood flood by brain perfusion spect in patients with a diagnosis of eating behavior disorders]. / Valoración del flujo cortical cerebral mediante SPECT de perfusión cerebral en pacientes con diagnóstico de trastornos de la conducta alimentaria.

OBJECTIVE: To evaluate cortical brain blood flow by 99mTc-HMPAO SPECT in patients with Eating Disorders (ED): restrictive anorexia (RA) and purgative bulimia (PB). MATERIAL AND METHOD: The study included 7 women with diagnostic criteria of RA and 12 with PB. The control group was made up of 12 healthy women. All subjects underwent brain 99mTc-HMPAO SPECT. The SPECT studies were quantified, yielding semiquantitative indexes relating to cerebellar activity in different regions. Body dissatisfaction was assessed by means of the BSQ (Body Shape Questionnaire). The results were analyzed with the ANOVA variance and had a statistical significance of p < 0.05. RESULTS: Mean BSQ scores were 98.28 (range 71-159) in the RA group, 145.05 (range 73-191) in the PB group, and 57.4 (range 37-88) in the control group. All patients in the sample (i.e., both RA and PB) showed global cerebral hypoperfusion versus the controls, although the difference only reached statistical significance in the RA group in the left parietal lobe (p = 0.02) and in the right (p = 0.004) and left temporal lobes (p = 0.015). In the PB group, the significantly hypoperfused regions were the right (p < 0.001) and left (p = 0.008) superior frontal lobe, the right inferior frontal lobe (p = 0.042), the right (p = 0.042) and left (p = 0.002) parietal lobes, and the right temporal lobe (p = 0.002). CONCLUSION: The results obtained showed that patients with ED had cerebral hypoperfusion compared with healthy subjects. This pattern is common in parietotemporal regions for both PB and AR although with temporal and parietal predominance in RA and PB, respectively. In addition, patients with PB had frontal region involvement.

[Patient satisfaction as quality indicator in a nuclear medicine department]. / La satisfacción del usuario como indicador de calidad en un servicio de Medicina Nuclear.

OBJECTIVE: To assess patient satisfaction and dissatisfaction with a Nuclear Medicine department. MATERIAL AND METHODS: A questionnaire was designed with 9 closed questions, 1 with a numerical scale (1-10) and 1 with an open question for suggestions. The questions included different quality dimensions of the department related with waiting time for the scan, information, facilities, attention manner with department staff and global satisfaction (numerical scale, 1-10). Dissatisfaction was determined by analyzing the written complaints for the last 6 years. RESULTS: A total of 671 questionnaires were obtained, 58 % of those surveyed being women. The mean age of patients was 56.5 (+/- 16.26). The information provided was correct in 81.7 % of cases. Equipment and facilities were correct for 74.5 % of patients. Waiting list and waiting time were correct for 70 % and 66.4 % respectively. The attention manner of the department staff was the most satisfactory dimension (98.7 %). Global satisfaction was positive (> or = 7 out of 10) in 82.8 % of the patients. 29 complaints were received. Most of them were based on waiting list (12) and disagreement with assistance (9). CONCLUSIONS: Global satisfaction was high in most of patients. Waiting time was the dimension with the lowest level of satisfaction and subsidiary of improvement plans. The primary spontaneous complain by our patients was due to the waiting list.

18F-FDG PET/CT as predictor of tumour biology and prognosis in epithelial ovarian carcinoma. / PET/TC con 18F-FDG como predictor de la biología tumoral y del pronóstico en el cáncer epitelial ovárico.

OBJECTIVE: To investigate the relationship between maximum standardised uptake value (SUVmax) of ovarian lesions and histopathology subtypes, and their involvement in the response and prognosis of patients with epithelial ovarian carcinoma (EOC). MATERIAL AND METHODS: A retrospective analysis of 31 patients with EOC and 18F-FDG-PET/CT before treatment, including an assessment of the SUVmax of ovarian lesion. Histopathological diagnosis and follow-up was performed. A study was made on the relationship between the SUVmax and histological type (type I and II) and tumour stage, as well as the role of various parameters (SUVmax, histology, stage) on the patient outcomes (complete response [CR], overall survival [OS], disease-free survival [DFS], and disease-free [DF] status, at 12 and 24 months). RESULTS: The medium SUVmax in type I lesions was lower than in type II (6.3 and 9.3, respectively; P=.03). A 7.1 cut-off was set for SUVmax in order to identify type II EOC (sensitivity: 77.8%, specificity: 69.2%; AUC=0.748; P=.02). No significant relationship was found between tumour stage and SUVmax. CR was more common in early stages; relative risk (RR) of 1.64; P=.003, as well as in type I tumours and a lower SUVmax. Tumour stage was decisive in DFS (P=.04), LE24m (0.07) and OS (P=.08). Longer DFS and a higher percentage of DF 24m were observed in type I tumours (RR: 1.32; P=.26). CONCLUSIONS: SUVmax was related to EOC histology, so could predict the response and prognosis of these patients. No association was found between glycolytic activity of the primary tumor with the response and prognosis.

Role of 18F-Choline PET/CT in guiding biopsy in patients with risen PSA levels and previous negative biopsy for prostate cancer.

OBJECTIVES: To study 18F-Choline PET/CT in the diagnosis and biopsy guide of prostate cancer (pCa) in patients with persistently high prostate-specific antigen (PSA) and previous negative prostate biopsy. To compare the clinical risk factors and metabolic variables as predictors of malignancy. METHODS: Patients with persistently elevated PSA in serum (total PSA >4ng/mL) and at least a previous negative or inconclusive biopsy were consecutively referred for a whole body 18F-Choline PET/CT. Patient age, PSA level, PSA doubling time (PSAdt) and PSA velocity (PSAvel) were obtained. PET images were visually (positive or negative) and semiquantitatively (SUVmax) reviewed. 18F-Choline uptake prostate patterns were defined as focal, multifocal, homogeneous or heterogeneous. Histology on biopsy using transrectal ultrasound-guided approach was the gold standard. Sensitivity (Se), specificity (Sp) and accuracy (Ac) of PET/CT for diagnosis of pCa were evaluated using per-patient and per-prostate lobe analysis. Receiver-operating-characteristic (ROC) curve analysis was used to assess the value of SUVmax to diagnose pCa. Correlation between PET/CT and biopsy results per-prostate lobe was assessed using the Chi-square test. Univariate and multivariate logistic regression analysis were applied to compare clinical risk factors and metabolic variables as predictors of malignancy. RESULTS: Thirty-six out of 43 patients with histologic confirmation were included. In 11 (30.5%) patients, pCa was diagnosed (Gleason score from 4 to 9). The mean values of patient age, PSA level, PSAdt and PSAvel were: 65.5 years, 15.6ng/ml, 28.1 months and 8.5ng/mL per year, respectively. Thirty-three patients had a positive PET/CT; 18 had a focal pattern, 7 multifocal, 4 homogeneous and 4 heterogeneous. Se, Sp and Ac of PET/CT were of 100%, 12% and 38% in the patient based analysis, and 87%, 29% and 14% in the prostate lobe based analysis, respectively. The ROC curve analysis of SUVmax showed an AUC of 0.568 (p=0.52). On a lobe analysis, poor agreement was observed between PET/CT findings and biopsy results (p=0.097). In the univariate/multivariate analysis, none of clinical and metabolic variables were statistically significant as predictor of pCa. CONCLUSION: Choline PET/CT is a suitable procedure for the detection of pCa in highly selected patients, however, a high rate of false positive should be expected.

P-glycoprotein, HER-2/neu, and mutant p53 expression in human gynecologic tumors.

BACKGROUND: Overexpression of P-glycoprotein has been associated with a worse prognosis for some groups of patients not receiving chemotherapy. Recently, it has been demonstrated that in vitro both c-Ha-Ras overexpression and mutant p53 overexpression do activate the MDR1 gene (also known as PGY1) in murine NIH 3T3 cells. This direct connection between oncogenic activation, antioncogenic malfunctioning (presence of mutant instead of wild-type p53 protein), and MDR1 gene expression constitutes a fundamental conceptual model that could provide an explanation for the obscure prognostic role, in the absence of chemotherapy, of the MDR1 gene. PURPOSE: Our goal was to test whether the relationship between MDR1 (P-glycoprotein) expression, oncogenic activation, and mutant p53 protein expression demonstrated in vitro is also reproducible in vivo for two groups of human gynecologic tumors. METHODS: Fifty tumor specimens (31 mammary, 11 endometrial, and eight cervical) were analyzed. They had been obtained from previously untreated patients. Aliquots of these specimens had been frozen and stored at -70 degrees C since surgical collection or routinely fixed in formalin and embedded in paraffin. DNA was extracted from routinely fixed specimens for single-strand conformation polymorphism (SSCP) analysis. Immunohistochemical techniques were used on frozen material to determine: 1) P-glycoprotein expression using two different monoclonal antibodies (c219 and JSB1); 2) HER-2/neu (c-erb-B2; also known as ERBB2) expression using the NCL-CB11 monoclonal antibody; and 3) mutant p53 protein expression using the PAb 1801 monoclonal antibody. Polymerase chain reaction (PCR)-SSCP was used to confirm recognition of the mutated isoform of p53. Endometrial and cervical carcinomas were studied by both PCR-SSCP DNA analysis and immunohistochemical analysis. Only when there was full concordance between both methods were endometrial and cervical tumors considered to express mutant p53. RESULTS: A statistically significant (P = .009; Fisher's exact test) association between HER-2/neu and MDR1 expression was found for the more aggressive form of inoperable, locally advanced mammary carcinoma. Expression of HER-2/neu or mutant p53 was similar in both tumor groups studied--mammary carcinoma with a low basal expression of P-glycoprotein compared with endometrial and cervical carcinomas with significantly (P = .0002; chi-square test) higher levels of expression. CONCLUSIONS: The highly statistically significant coexpression of P-glycoprotein and HER-2/neu took place only in the subgroup of aggressive, locally advanced, inoperable mammary carcinomas, whereas no statistically significant association could be found for operable tumors. No association between mutant p53 expression and MDR1 activation was found in the human tumors analyzed.

The putative glioma tumor suppressor gene on chromosome 19q maps between APOC2 and HRC.

The frequent allelic loss of chromosome 19q in human gliomas suggests that 19q harbors a tumor suppressor gene that is integral to glioma tumorigenesis. Our initial deletion mapping of this gene localized the common region of deletion to the distal long arm, 19q13.2-13.4. To bracket the putative tumor suppressor gene further, we have studied this region in 55 gliomas, using loss of heterozygosity studies for 11 well mapped, highly informative microsatellite polymorphisms that cover this area: D19S178; BCL3; APOC2; ERCC1; DM; D19S112; HRC; D19S246; KLK; D19S180; and D19S254 (from centromeric to telomeric). Twenty astrocytic, oligodendroglial, and mixed gliomas had deletions affecting this region. Of nine partial deletions, two cases maintained heterozygosity at APOC2 while showing allelic loss at the more telomeric markers, ERCC1 and DM, while five cases maintained heterozygosity at HRC but lost the more centromeric markers, D19S112 and DM. Nine cases lost the entire D19S178 to D19S254 region. Three astrocytic gliomas, including one with an interstitial deletion, had terminal deletions of 19q13.4. The minimum area of overlap shared by the interstitial deletions is between APOC2 and HRC, including ERCC1, DM, and D19S112. These findings suggest that the glioma tumor suppressor gene maps to an approximately 8-cM/5-megabase region on 19q13.2-13.3 between the proximal marker APOC2 and the distal marker HRC. Among the DNA repair/DNA metabolism genes on chromosome 19q, ERCC1, LIG1, and perhaps ERCC2 are within the common area of deletion; XRCC1 is centromeric and is therefore excluded as a candidate.

Accumulation of wild type p53 protein in human astrocytomas.

We have previously described 10 astrocytomas with accumulation of p53 protein but no mutations in p53 exons 5-8, and we have suggested that they might represent overexpression of wild type protein or mutations in less conserved regions of the gene. To investigate these possibilities further, we studied the tumors with immunohistochemistry for wild type and mutant p53 protein and showed that all cases stained with the wild type PAb 1801 antibody but only one case stained with the mutant-specific PAb 240 antibody. To support the hypothesis that the accumulated p53 protein is wild type in most cases, we used single-strand conformation polymorphism analysis and DNA sequencing to evaluate p53 exons 4, 9, and 10 and did not detect mutations at these loci. Although the product of the MDM2 oncogene binds wild type p53 and may account for p53 accumulation, slot-blot analysis of these astrocytomas did not detect MDM2 gene amplification. Thus, evidence suggests that some astrocytomas may accumulate wild type p53 protein but not as a result of MDM2 gene amplification. Furthermore, PAb 1801 immunohistochemistry may not be an adequate method of screening astrocytomas for p53 mutations.

[Myocardial perfusion SPECT with 99mTc-tetrofosmin and thoracic SPECT with Gallium-67 SPECT in a patient with chest pain and a history of sarcoidosis]. / SPECT de perfusión miocárdica con 99mTc-Tetrofosmin y SPECT torácica con Galio-67 en paciente con dolor torácico y antecedente de sarcoidosis.

We present the case of a 54-year-old male patient, with history of diagnosed sarcoidosis some years ago and myocardial involvement, who being asymptomatic, shows chest pain because of which he goes to the emergency room of the hospital. During the first hours of his admission the pain relieves with nonsteroidal antiinflammatory medication, an electrocardiogram demonstrates changes of early repolarisation with pericardial involvement, the enzymes don't rise and the echocardiogram reveals a slight pericardial effusion. The differential diagnosis is between a chest pain due to ischemia, and the secondary to myopericarditis in the clinical context of a sarcoidosis. Myocardial perfusion rest SPECT is required which is compatible with lateral acute myocardial infarction (AMI) with extension to inferior wall. A coronary angiography was carried out and showed two vessels disease (RCA and Cx), PTCA and stent were carried out successfully. During the admission a thoracic scintigraphy and SPECT with gallium -67 showed an uptake in lateral wall of left ventricle (LV). Nothing about active sarcoidosis was found.

Analysis of the neurofibromatosis 2 gene in human ependymomas and astrocytomas.

Ependymomas and astrocytomas commonly have allelic losses of chromosome 22q, which suggests the presence of a glioma tumor suppressor gene on 22q. A candidate tumor suppressor gene on 22q is the neurofibromatosis 2 (NF2) gene since NF2 patients have an increased susceptibility to ependymomas and astrocytomas. Using single strand conformation polymorphism analysis and direct DNA sequencing, we screened 8 ependymomas and 30 fibrillary astrocytomas from non-NF2 patients for mutations in the coding sequence and portions of the 3' untranslated region of the NF2 gene. Only one mutation was detected, a single base deletion in NF2 exon 7 from a spinal ependymoma, which had also lost the wild-type allele. These results suggest that the NF2 gene may be important in the formation of some ependymomas but the NF2 gene is probably not the critical chromosome 22q tumor suppressor gene involved in astrocytoma tumorigenesis.

Loss of the p16INK4a and p15INK4b genes, as well as neighboring 9p21 markers, in sporadic melanoma.

Although homozygous deletions of the cyclin-dependent kinase inhibitor 2 gene p16INK4a on 9p21 have been reported frequently in metastatic melanoma cell lines, and intragenic mutations within the p16INK4a gene have been detected in familial melanoma kindreds, specific targeting of this gene in the development of sporadic melanoma in vivo remains controversial. Southern analyses were performed in this study to initially assess the frequency of hemi- or homozygous losses of p16INK4a, as well as its neighboring family member, p15INK4b, and other candidate regions within 9p21, in sporadic melanoma. Overall, 22 of 40 (55%) uncultured sporadic melanoma DNAs were determined to harbor deletions of 1-11 markers/genes located on 9p21. This included 10 tumors (25%; 10 of 40) with homozygous deletions limited to either the p16INK4a gene only (20%; 2 of 10), both the p16INK4a and p15INK4b genes (10%; 1 of 10), another novel 9p21 gene, FB19 (10%; 1 of 10), or all three of these genes plus surrounding markers (60%; 6 of 10). In subsequent single-strand conformation polymorphism and sequencing analyses, intragenic mutations in the p16INK4a gene were also revealed in two (10%; 2 of 21) melanoma DNAs that retained one copy of this locus. By comparison, the frequency of pl6INK4a and p15INK4b homozygous deletions, as well as p16INK4a mutations, in melanoma cell lines (analyzed in parallel) was 2-3-fold higher at 61 (23 of 38) and 24% (9 of 38), respectively. These findings indicate that (a) p16INK4a is inactivated in vivo in over one-fourth (27.5%; 11 of 40) of sporadic melanomas; (b) mutation/deletion of p16INK4a may confer a selective growth advantage in vitro; and (c) other 9p21 tumor suppressor genes could be targeted during the development of melanoma.

Chromosome 17 allelic loss and NF1-GRD mutations do not play a significant role as molecular mechanisms leading to melanoma tumorigenesis.

Allelic loss in human cutaneous melanoma has been detected on chromosomes 1p, 6q, 9p, 10q, and 11q. Chromosome 17 contains important tumor suppressor genes such as p53, NM23, and neurofibromatosis type 1 (NF1), which have been implicated in melanoma tumorigenesis. The role of p53 has already been studied by a number of laboratories, showing contrasting results. In the present study, two restriction fragment length polymorphism (RFLP) probes for the NM23 and NF1 genes, together with five other RFLP and four variable number of tandem repeat chromosome 17 probes, were investigated at the loss of heterozygosity (LOH) level in a Southern blot-based assay. The NF1 gene was also tested for LOH by a polymerase chain reaction (PCR)-based approach in two different experiments, using a dinucleotide repeat polymorphic probe at locus D17S250 (17q11.2-q12), and an Alu probe intragenic to the NF1 gene (17q11.2). A PCR single-strand conformation polymorphism assay was included in the study for mutation detection at the NF1-GTPase-activating protein-related domain (GRD). A total of 68 melanocytic tumors were analyzed. LOH was detected in 9 of 87 informative cases (10%). LEW301 (17p11.2-pcen) presented the highest LOH frequency (22%). NM23 showed LOH in 17% of the informative cases, while NF1 did not show either LOH in the Southern blot- and PCR-based experiments or mutations at the NF1-GRD. These results are in concordance with those of previous smaller studies, but when compared with higher LOH frequencies obtained from other chromosomes, these findings indicate that the LOH values found in our study can most likely be attributed to background effect. Thus, chromosome 17 LOH is likely to play and unimportant role as a genetic event in melanoma tumorigenesis. Nevertheless, NF1 merits further study, since homozygous deletions have been detected at this locus in melanoma cell lines.