Descriptive epidemiology of cerebral gliomas in northwest Greece and study of potential predisposing factors, 2005-2007

BACKGROUND

To investigate the epidemiologic and clinical characteristics (age, sex, tumor location, socioeconomic status) and potential predisposing factors (alcohol, tobacco, mobile phone use, severe head trauma) of cerebral gliomas in a defined area of Northwest Greece.

METHODS

The prospective study was conducted in patients with gliomas referred to all 7 hospitals of a study area with a population of 488,435 inhabitants, from June 1, 2005, to May 31, 2007. Incidence rates (IR) were calculated as new cases diagnosed among residents of the study area during the study period per 100,000 inhabitants. A case-control study was carried out in order to study the possible association of the risk of glioma with smoking, alcohol, use of mobile phone, and severe cranial trauma.

RESULTS

A total of 56 glioma incident cases were identified with IRs of glioma and glioblastoma (GBM) at 5.73/10(5)/year and 3.69/10(5)/year, respectively. A male to female ratio of 1.25 was obtained in the GBM group. IRs of glioma and GBM for both males and females were higher in the age group 60-79. The most frequent anatomic location was the frontal lobe. 46.5% of the patients originated from the low, 25% from the middle and 28.5% from the high socioeconomic class. There was no significant association between glioma and alcohol consumption, smoking and mobile phone use. A trend for a positive association between the risk of glioma and a history of severe cranial trauma was observed, but this association was not statistically significant.

CONCLUSION

The estimated IR of glioma and GBM in this study was higher compared with data from other studies carried out on European, Asian and US populations. Further studies may be needed to assess the possible association of genetic, environmental and lifestyle factors with the high occurrence of gliomas observed in this study.

Diagnostic value of vascular endothelial growth factor and endostatin in malignant pleural effusions

OBJECTIVE

To assess the value of vascular endothelial growth factor (VEGF) and endostatin in the differential diagnosis of malignant and tuberculous pleural effusions (PE).

METHODS

Effusion samples were collected from 62 patients with malignant PE caused by lung cancer and from 64 patients with tuberculous pleurisy. Concentrations of pleural fluid VEGF and endostatin were measured simultaneously using enzyme-linked immunosorbent assay (ELISA) and enzyme immunoassay, respectively. The sensitivity, specificity and accuracy were calculated.

RESULTS

PE levels of VEGF and endostatin were found to be significantly elevated in effusions with malignancy rather than in those of tuberculous origin (both P < 0.01). For VEGF, the sensitivity, specificity and accuracy in diagnosing malignant pleural effusions were respectively 71%, 61% and 66%, while for endostatin the values were respectively 69%, 83% and 76%. A combination of VEGF and endostatin can increase these to respectively 81%, 97% and 89%.

CONCLUSIONS

Elevated levels of VEGF and endostatin in pleural effusions may be helpful in diagnosing malignant pleural effusions, while a combination of VEGF and endostatin can increase the sensitivity, specificity and accuracy of differentiating malignant from tuberculous pleural effusions.

Onset of pi(0) suppression studied in Cu+Cu collisions at sqrt S NN=22.4, 62.4, and 200 GeV

Neutral pion transverse momentum (p(T)) spectra at midrapidity (|y| less than or approximately 0.35) were measured in Cu+Cu collisions at sqrt[s(NN)]=22.4, 62.4, and 200 GeV. Relative to pi_(0) yields in p+p collisions scaled by the number of inelastic nucleon-nucleon collisions (N(coll) the pi_(0) yields for p(T) more than or approximately 2 GeV/c in central Cu+Cu collisions are suppressed at 62.4 and 200 GeV whereas an enhancement is observed at 22.4 GeV. A comparison with a jet-quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.

Radical therapy for muscle-infiltrating bladder cancer (cystectomy or radiotherapy): does age affect the final therapeutic benefit for the patient?

PURPOSE

To evaluate the therapeutic outcome of radical cystectomy and radical radiotherapy in patients with T2N0M0 clinical stage bladder cancer in relation to their age.

PATIENTS AND METHODS

Between 1995-2006, 119 patients with clinical stage T2N0M0 bladder cancer were treated with radical radiotherapy (group A) and were divided in 2 subgroups: >70 years old (A1) and <or=70 years old (A2). Between 1998-2006, 26 patients with the same clinical stage were treated with radical cystectomy (group B) (>70 years old/B1 subgroup and <or=70 years old/B2 subgroup). The following parameters were evaluated in both groups and subgroups: therapeutic outcome (overall survival/OS, local control, development of metastases) and tolerance (side effects and complications of each method). Kaplan-Meier method and log-rank test were used for statistical analyses.

RESULTS

All group B patients tolerated their treatment very well, without interruptions. The 3-year OS of groups A and B was 39 and 69%, respectively (p=0.032). The 3-year OS of subgroups A1 and A2 was 37.3 and 43.3%, respectively (p=0.085). In the cystectomy group B, 3-year OS of the subgroups was the same (B1: 68.6% and B2: 69.3%; p=0.10). Local control rate for the subgroups A1, A2, B1, B2 was 43, 40, 90 and 84%, respectively. Distant metastatic rate was 14.1, 20, 7.6 and 7.4% for subgroups A1, A2, B1, B2, respectively.

CONCLUSION

The results of both therapeutic methods in both age groups seem satisfactory. Very good tolerance was also observed. It seems that if a patient is not completely suitable for radical cystectomy or radical radiotherapy age should not be considered as an exclusion factor.

Emissions of the indirect greenhouse gases NH3 and NOx from Australian beef cattle feedlots

Emissions of indirect greenhouse gases, notably the nitrogen gases ammonia (NH3) and the odd oxides of nitrogen (NOx), play important roles in the greenhouse story. Feedlots are intense, but poorly quantified, sources of atmospheric NH3 and although production of NOx is to be expected in feedlots, rates of NOx emission are virtually unknown. In the atmosphere, these gases are involved in several transformations, but eventually return to the earth in gaseous or liquid form and can then undergo further transformations involving the formation and emission of the direct greenhouse gas nitrous oxide (N2O). The IPCC Phase II guidelines estimate that indirect N2O emissions due to atmospheric deposition of N compounds formed from NH3 and NOx could be ~14% of the direct emissions from agricultural soils or from animal production systems. IPCC recommends that these indirect emissions be accounted for in making inventory estimates of N2O emission. This paper is a preliminary report of emissions of NH3 and NOx from two Australian feedlots determined with micrometeorological techniques. Emissions of nitrogen gases from both feedlots were dominated by emissions of NH3. The average NH3 emission rate over both feedlots in winter was 46 g N/animal.day, while that of NOx was less than 1% of that rate at 0.36 g N/animal.day. It was apparent that NH3 release was governed by the wetness of the surface. Rates of emission from the feedlot with the wetter surface were almost three times those from the other. The IPCC default emission factor for the combined emission of NH3 and NOx from livestock is 0.2 kg N/kg N excreted, but in our work, the emission factor was 0.59 kg N/kg N excreted. Potential emissions of N2O due to NH3 and NOx deposition were estimated to be of the same magnitude as the direct N2O emissions, the sum of direct and potential indirect amounting to ~3 g N2O-N/animal.day. If applied nationally, this would represent a contribution of N2O from Australian feedlots of 533Gg CO2-e or 2.2% of all Australian N2O emissions.

Overcoming depolarizing resonances with dual helical partial Siberian snakes

Acceleration of polarized protons in the energy range of 5 to 25 GeV is challenging. In a medium energy accelerator, the depolarizing spin resonances are strong enough to cause significant polarization loss but full Siberian snakes cause intolerably large orbit excursions and are also not feasible since straight sections usually are too short. Recently, two helical partial Siberian snakes with double pitch design have been installed in the Brookhaven Alternating Gradient Synchrotron (AGS). With a careful setup of optics at injection and along the energy ramp, this combination can eliminate the intrinsic and imperfection depolarizing resonances otherwise encountered during acceleration to maintain a high intensity polarized beam in medium energy synchrotrons. The observation of partial snake resonances of higher than second order will also be described.

Air quality improvement estimation and assessment using contingent valuation method, a case study in Beijing

The aim of the paper is to estimate and assess residents' willingness to pay to improve air quality in the urban area of Beijing using the Contingent Valuation Method (CVM). The mean willingness to pay (WTP) for a 50% reduction of harmful substances in the air was 143 CNY per household per year, and the total WTP of the residents in the study area was 336 million CNY per year. As a proportion of household annual income, the mean WTP amounted to 0.7%. Four socio-economic variables were found to have significant impacts on residents' willingness to pay. The analysis results illustrated that WTP increases with income and education level, and decreases with household population and age. The willingness was larger for residents in the urban districts than those in the suburban districts. It was found that most of the protest bids lay on interviewees' incomplete perception of the values of environmental amenity. The influence of household income on people's willingness to pay illustrated in this study reflects a causal force of Beijing's transition to market economy that households created to have disposable income are more likely to care about environmental quality. The results of this study strike an optimistic note on the possibility of measuring the total economic value of environmental quality improvement by using the CVM in China. Suggestions on implication of the CVM for both academics and policy makers are provided in the paper.

Polarized proton collisions at 205 GeV at RHIC

The Brookhaven Relativistic Heavy Ion Collider (RHIC) has been providing collisions of polarized protons at a beam energy of 100 GeV since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the intrinsic spin resonances beyond 100 GeV are about a factor of 2 stronger than those below 100 GeV making it important to examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were first accelerated to the record energy of 205 GeV in RHIC with a significant polarization measured at top energy in 2005. This Letter presents the results and discusses the sensitivity of the polarization survival to orbit distortions.

Psychological distress and personality traits in early rheumatoid arthritis: a preliminary survey

OBJECTIVES

To investigate psychiatric manifestations, personality traits, and ego mechanisms of defense involved in early rheumatoid arthritis (RA).

METHODS

Twenty-two unselected early RA outpatients with disease duration less than 1 year participated in the study. The majority of participants were females (72.7%), married (81.8%), aged 51.0+/-14.6 years. Thirty-four subjects matched for age, sex and educational level served as "healthy" controls. General Heath Questionnaire, Symptom Distress Checklist, Defense Style Questionnaire and Hostility and Direction of Hostility Questionnaire were used; disease activity was estimated by disease activity for 28-joint indices score.

RESULTS

Seven patients (31.8%) presented psychological distress scores indicative of possible psychiatric caseness, expressing obsessive-compulsive symptoms and depression, as compared to six (17.6%) of controls. Social dysfunction distress and somatization were prominent psychiatric manifestations in early RA group. Early RA patients tend to adopt a less adaptive defense style than controls. Although disease activity was not correlated to psychological distress, a significant association between disease activity and patients' defensive style was observed: as the disease is exacerbated, there was a shift from "non-adaptive" to "immature image distorting or borderline" defense style, suggesting a rather fragile underlying personality structure.

CONCLUSION

Psychological distress is a relatively common experience in early RA. Social dysfunction, along with the less adaptive defense style, which under the stress of the disease exacerbation turns to "borderline", underlines the importance of a careful assessment and consultation in early RA patients in order to face the distress shortly after diagnosis and highlights potential risk factors for future adaptation to exacerbations of the disease.

Clinical correlation of bone marrow microvessel density in essential thrombocythemia

The aim of this study was to investigate the prognostic relevance of angiogenesis expressed as bone marrow microvessel density (MVD) in 40 patients with essential thrombocythemia (ET). Bone marrow MVD was visualized in paraffin tissue sections using immunohistochemical staining for CD34 protein. Increased MVD of bone marrow specimens was not significantly correlated with clinical (sex, age, microvascular disturbances, liver and spleen size, complications, treatment or no before biopsy), laboratory (peripheral blood count), bone marrow histopathological parameters (cellularity, megakaryocyte clumping and reticulin fibrosis) and overall survival. These preliminary findings suggest that angiogenesis has no prognostic value in patients with ET.

Multiple brown tumors of the ribs simulating malignancy

Bone disease associated with primary hyperparathyroidism, known as osteitis fibrosa cystica, is now very rarely encountered, since the parathyroid disorder is most often diagnosed at the early stage of asymptomatic hypercalcemia. Here, we report the case of a patient with multiple pleural-based masses and hypercalcemia, which led to the presumptive diagnosis of malignancy. However, histological and laboratory data were consistent with the development of brown tumors of the ribs due to underlying severe hyperparathyroidism.

Laryngeal involvement in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease affecting the synovial membrane, which causes joint damage and bone destruction. Extra-articular manifestations are numerous, involving multiple organ systems. Rheumatoid nodules are common extra-articular findings occurring in 20% RA patients. They develop most commonly in pressure areas (elbows and finger joints) and may occasionally affect internal organs including pleura, lungs, meninges, larynx, and others. Furthermore, RA affects the ear, nose, and throat, causing various otorhinolaryngological symptoms. In this report we describe two patients with RA and laryngeal involvement, mostly rheumatoid nodule formation, with a review of the literature.

Sinus histocytosis with massive lymphadenopathy (Rosai-Dorfman disease) in a patient with primary Sjogren's syndrome

Sinus histocytosis with massive lymphadenopathy is a rare disease that has been described by Rosai and Dorfman. It is characterized by massive, cervical lymphadenopathy, with extranodal manifestations in about 40% of patients. It occurs as a distinct entity, never associated with other diseases, and in most cases the prognosis is good. Lymphadenopathy is also a frequent sign of patients with primary Sjogren's syndrome (SS), usually associated with disease activity or concurrent infection. However, excessive lymphadenopathy in SS patients is a sign of lymphoproliferative disorder development. In this report, we describe a patient with primary SS, and excessive lymphadenopathy and splenomegaly who developed Rosai-Dorfman disease, and we discuss the possible aetiopathophysiological mechanism linking these two entities.

Angiogenesis in chronic myeloproliferative diseases detected by CD34 expression

Increased bone marrow angiogenesis estimated as bone marrow microvessel density (MVD), or as serum angiogenic factor levels and/or immunohistochemical expression of these factors in bone marrow biopsy has been demonstrated in a variety of hematological disorders including chronic myeloproliferative diseases (MPDs). The aim of this study was to investigate the MVD in 25 cases of myelofibrosis with myeloid metaplasia (MMM). MVD was estimated by CD34 immunohistochemical expression in bone marrow biopsies. A control group of 27 patients without bone marrow disease, eight cases of polycythemia vera (PV), 41 cases of essential thrombocythemia (ET) and nine cases of chronic myeloid leukemia (CML) were also studied. Moreover, in cases with MMM, MVD was correlated with clinical, laboratory, histological parameters and the outcome of the patients. Our study confirmed a significantly higher degree of angiogenesis in MMM, PV, ET and CML compared with controls (P < 0.001, P = 0.0007, P < 0.001 and P = 0.0008, respectively). Angiogenesis was higher in MMM than PV, ET and CML cases (P < 0.001, P < 0.001 and P = 0.008). Increased angiogenesis was correlated with hypercatabolic symptoms in MMM patients (P = 0.009). No correlation with other clinicopathological parameters or clinical outcome was found. However, definitive conclusions regarding the prognostic value of increased angiogenesis may require additional follow-up and a larger group of patients.

Expression and characterization of the extracellular Ca(2+)-sensing receptor in melanotrope cells of Xenopus laevis

The extracellular Ca(2+)-sensing receptor (CaR) is expressed in many different organs in various species, ranging from mammals to fish. In some of these organs, this G protein-coupled receptor is involved in the control of systemic Ca(2+) homeostasis, whereas in other organs its role is unclear (e.g. in the pituitary gland). We have characterized the CaR in the neuroendocrine melanotrope cell of the intermediate pituitary lobe of the South African clawed toad Xenopus laevis. First, the presence of CaR mRNA was demonstrated by RT-PCR and in situ hybridization. Then it was shown that activation of the CaR by an elevated extracellular Ca(2+) concentration and different CaR-activators, including L-phenylalanine and spermine, stimulates both Ca(2+) oscillations and secretion from the melanotrope. Furthermore, it was revealed that activation of the receptor stimulates Ca(2+) oscillations through opening of voltage-operated Ca(2+) channels in the plasma membrane of the melanotropes. Finally, it was shown that the CaR activator L-phenylalanine could induce the biosynthesis of proopiomelanocortin in the intermediate lobe. Thus, in this study it is demonstrated that the CaR is present and functional in a defined cell type of the pituitary gland, the amphibian melanotrope cell.

Increased expression of the bcl6 and CD10 proteins is associated with increased apoptosis and proliferation in diffuse large B-cell lymphomas

There is increasing evidence that bcl6 and CD10 expression may be related to apoptosis and cell cycle progression. Therefore, 79 cases of de novo diffuse large B-cell lymphomas were studied for the expression of bcl6 and CD10 proteins in relation to 1) the apoptotic index; 2) the proliferation-associated proteins Ki67, cyclin A, and cyclin B1; and 3) the expression of the bcl2, p53, Rb, p16, and p27 proteins. Expression of bcl6, CD10, and bcl2 proteins was found in 54/79 (68%), 28/79 (35%), and 47/74 (63%) cases, respectively. The bcl6/CD10 patterns were as follows: bcl6+/CD10+ (26 cases, 32%), bcl6+/CD10- (28 cases, 33%), bcl6-/CD10- (23 cases, 31%), and bcl6-/CD10+ (2 cases, 4%). Significant positive correlations were found between bcl6/Ki67 (r =.328, P =.003), bcl6/cyclin A (r =.265, P =.018), bcl6/apoptotic index (r =.327, P =.010), CD10/Ki67 (r =.296, P =.008), and CD10/apoptotic index (r =.397, P =.001). In addition, high expression of bcl6 showed significant correlation with negative (null/low) bcl2 expression (chi(2) test, P =.002). The above findings indicate that increased expression of the bcl6 and CD10 proteins is associated with increased apoptosis and proliferation in diffuse large B-cell lymphomas. The association between increased bcl6 expression and enhanced apoptosis might be due, at least in part, to the null/low bcl2 expression because previous in vitro data showed that bcl6 overexpression induces apoptosis accompanied by bcl2 and bcl-xl downregulation. Moreover, significant correlation was found between increased apoptotic index and the bcl6+/CD10+ pattern (t test: P =.014, Mann-Whitney test: P =.046). This finding and the positive correlation of the apoptotic index with bcl6 and CD10 expression may be related to previous results showing that the expression of these proteins has favorable effects on the clinical outcome of diffuse large B-cell lymphomas.

Expression of cyclin D3 and cyclin E and identification of distinct clusters of proliferation and apoptosis in diffuse large B-cell lymphomas

In the present study 79 cases of de novo Diffuse Large B-cell Lymphomas (DLBCL) were studied in order: a) to analyse the expression of cyclin D3, cyclin E and cyclin D1 in relation to other proliferative features (expression of Ki67, cyclin A and cyclin B1), the apoptosis status and the expression of p53, Rb, p16 and p27; and b) to determine whether distinct clusters of proliferation and apoptosis could be identified in DLBCL. Overexpression of cyclin D3 and cyclin E was found in 35/79 (43%) and 18/79 (22%) cases, respectively, whereas overexpression of cyclin D1 was not detected in any case. In most cases (39/46) overexpression of cyclin D3 and cyclin E was mutually exclusive possibly reflecting different underlying pathways inducing deregulated expression of these cyclins. In most cases (29/35) overexpression of cyclin D3 was mutually exclusive with Rb/p16 aberrant expression status supporting an oncogenic role for cyclin D3 and suggesting that the pathogenetic effect of cyclin D3 overexpression occurs through perturbation of the Rb1 pathway. Combined alterations of the P53 and the Rb/p16/cyclin D3 expression status were significantly associated with higher mean values of cyclin A (p=0.023) and cyclin B1 (p=0.033) indicating that concurrent impairment of the p53 and Rb1 pathways induces increased tumour cell proliferation in DLBCL. Cluster analysis of the apoptosis and the proliferation status permitted separation of DLBCL into distinct groups with low (44 cases) and high (18 cases) apoptotic activity and into distinct groups with low (32 cases), intermediate (36 cases) and high (11 cases) proliferative activity. The identification of distinct clusters with respect to the proliferation and the apoptosis status indicates that groups with distinct cellular kinetic properties can be defined in the histological group of DLBCL.

Solitary extramedullary plasmacytoma of the maxillary sinus. Case report

Solitary extramedullary plasmacytomas are rare tumors that often affect head and neck region. Because of the non-specific associated symptomatology, they frequently are misdiagnosed. We briefly describe a 69-year-old woman who developed solitary plasmacytoma in the left maxillary sinus and was initially treated as having sinusitis. We also report the diagnostic work-up that is necessary to establish a correct diagnosis in such cases. This case highlights that an appropriate investigation for neoplastic disease should be performed in patients presenting with persistent symptoms that resemble those of sinusitis, especially if these do not resolve after conservative medical treatment.

Measurement of analyzing power for proton-carbon elastic scattering in the coulomb-nuclear interference region with a 22-GeV/c polarized proton beam

The analyzing power for proton-carbon elastic scattering in the Coulomb-nuclear interference region of momentum transfer, 9.0x10(-3)<-t<4.1x10(-2) (GeV/c)(2), was measured with a 21.7 GeV/c polarized proton beam at the Alternating Gradient Synchrotron of Brookhaven National Laboratory. The ratio of hadronic spin-flip to nonflip amplitude, r(5), was obtained from the analyzing power to be Rer(5)=0.088+/-0.058 and Imr(5)=-0.161+/-0.226.

Polyvalent cation receptor proteins (CaRs) are salinity sensors in fish

To determine whether calcium polyvalent cation-sensing receptors (CaRs) are salinity sensors in fish, we used a homology-based cloning strategy to isolate a 4.1-kb cDNA encoding a 1,027-aa dogfish shark (Squalus acanthias) kidney CaR. Expression studies in human embryonic kidney cells reveal that shark kidney senses combinations of Ca(2+), Mg(2+), and Na(+) ions at concentrations present in seawater and kidney tubules. Shark kidney is expressed in multiple shark osmoregulatory organs, including specific tubules of the kidney, rectal gland, stomach, intestine, olfactory lamellae, gill, and brain. Reverse transcriptase-PCR amplification using specific primers in two teleost fish, winter flounder (Pleuronectes americanus) and Atlantic salmon (Salmo salar), reveals a similar pattern of CaR tissue expression. Exposure of the lumen of winter flounder urinary bladder to the CaR agonists, Gd(3+) and neomycin, reversibly inhibit volume transport, which is important for euryhaline teleost survival in seawater. Within 24-72 hr after transfer of freshwater-adapted Atlantic salmon to seawater, there are increases in their plasma Ca(2+), Mg(2+), and Na(+) that likely serve as a signal for internal CaRs, i.e., brain, to sense alterations in salinity in the surrounding water. We conclude that CaRs act as salinity sensors in both teleost and elasmobranch fish. Their tissue expression patterns in fish provide insights into CaR functions in terrestrial animals including humans.

Low expression of p27 protein combined with altered p53 and Rb/p16 expression status is associated with increased expression of cyclin A and cyclin B1 in diffuse large B-cell lymphomas

The expression of the cyclin-dependent kinase inhibitor (CDKI) p27 protein was investigated in relation to (1) the expression of the cell cycle regulators p53, Rb and p16 and (2) the proliferation profile as determined by the expression of Ki67, cyclin A, and cyclin B1 in 80 cases of de novo diffuse large B-cell lymphomas (DLBCL). P27 expression was low/null in large tumor cells in 58/80 cases and intermediate/high in 22/80 cases. Increased expression of p53 protein was observed in 39/80 cases. Decreased expression of Rb and p16 proteins was mutually exclusive and was observed in 5/80 and 14/80 cases, respectively. The analysis of the p27 expression status (low/null versus intermediate/high) with respect to the p53 and/or Rb/p16 expression status showed that low/null p27 expression was significantly correlated with increased p53 expression (P =.018) and showed a strong trend for correlation with concurrent increased p53 expression and decreased Rb or p16 expression (P =.050). These findings suggest a tendency for concurrent alterations of the cell cycle regulators p27, p53, and Rb or p16 in DLBCL, which might result in impaired tumor growth control. Indeed, the analysis of the combined p27/p53/Rb/p16 expression status with respect to the proliferation profile showed that (1) three alterations in the combined p27/p53/Rb/p16 status (i.e., low/null P27 expression, increased expression of p53, and decreased expression of Rb or p16) were significantly correlated with increased expression of cyclin B1 (P =.005) and (2) two or three alterations were significantly correlated with increased expression of cyclin A (P =.014). These findings suggest combined impairment of a complex cell-cycle control network involving the CDK inhibitor p27, the P53 pathway, and the Rb1 pathway, which exerts a cooperative effect resulting in enhanced tumor cell proliferation.

Activating mutations of the calcium-sensing receptor: management of hypocalcemia

Activating mutations of the calcium-sensing receptor (CaR) can cause isolated hypoparathyroidism. Treatment of hypocalcemia in these patients remains to be optimized, because the use of 1-hydroxylated vitamin D3 derivatives can cause hypercalciuria and nephrocalcinosis. We identified activating CaR mutations in 8 (42%) of 19 unrelated probands with isolated hypoparathyroidism. The severity of hypocalcemic symptoms at diagnosis was independent of age, mutation type, or mode of inheritance but was related to the degree of hypocalcemia; serum Ca was 1.97 +/- 0.08, 1.82 +/- 0.14, and 1.54 +/- 0.22 mmol/liter, respectively, in asymptomatic (n = 7), mildly symptomatic (n = 8), and severely symptomatic patients (n = 6). Hypocalcemia segregated with the CaR mutation, but no phenotype-genotype relationships were identified. Fourteen patients received regular 1-hydroxylated vitamin D3 treatment (mean duration, 7.2 +/- 4.9 yr). Nine had hypercalciuric episodes, which were associated with nephrocalcinosis in eight cases. Serum Ca during treatment predicted hypercalciuria and nephrocalcinosis poorly, because either or both of the latter could develop in hypocalcemic patients. Thus, mutational analysis of the CaR gene should be considered early in the work-up of isolated hypoparathyroidism. Treatment options should be weighed carefully in patients with serum Ca below 1.95 mmol/liter. The risk of nephrocalcinosis during treatment can be minimized by carefully monitoring urinary Ca excretion.

Immunohistochemical expression of p53, p21/waf1, rb, p16, cyclin D1, p27, Ki67, cyclin A, cyclin B1, bcl2, bax and bak proteins and apoptotic index in normal thymus

The immunohistochemical expression of p53, p21, Rb, p16, cyclin D1, Ki67, cyclin A, cyclin B1, p27, bcl2, bax, and bak proteins and the apoptotic index (Al) were investigated in 20 normal thymuses (8 adults, 3 adolescents, 5 infants and 4 newborns). The expressions of Rb, Ki67, cyclin A and cyclin B1 were overlapping, being high in the cortex with a tendency for decreased expression toward the medulla. Apoptotic cells were mainly detected in the cortex and the corticomedullary junction, rarely being present in Hassall's corpuscles. The mean values of Ki67, cyclin A, and cyclin B1 expression in thymuses were 77.2%, 32.2% and 21.4% (newborns), 62.4%, 33.7% and 18.5% (infants), 56.9%, 23.4% and 18.9% (adolescents) and 38.7%, 21.7% and 14.6% (adults), respectively. The mean values of AI in thymuses from newborns, infants, adolescents and adults were 1.4%, 2.9%, 2.7% and 3.8%, respectively. This decrease in proliferation and increase in apoptosis may account for the process of thymic involution. P16 expression was widespread with most of Hassall's corpuscles being p16-positive. P16-positive cells and Hassall's corpuscles increased with the increase in age, in keeping with the suggested role of p16 in cellular senescence. P27 expression was undetectable in subcapsular thymocytes with a tendency for increased expression toward the medulla. The expressions of Ki67, cyclin A and cyclin B1 were inversly related with that of p27, consistent with previous evidence that p27 concentration is reduced when the cell-cycle progresses. P21 and much less frequently p53 proteins were mainly detected in a part of the subcapsular cortical epithelial cells. These findings suggest that a) in thymocytes, the apoptotic pathway is mostly p53-independent and the function of p21 as a negative regulator of the cell cycle must be redundant to other negative regulators, such as p16 and p27 which were abundantly detected in thymocytes and b) in some thymic epithelial cells, the p21 expression may be induced by p53, but in most of them seems to be p53-independent. Most of Hassall's corpuscles were p21-positive, consistent with previous evidence that these structures represent end stages of maturation of thymic medullary epithelium and that p21 protein is involved in the process of terminal differentiation. Cyclin D1 positivity was found in some macrophages. Bcl2 expression was mainly seen in medullary thymocytes, reflecting the surviving thymocytes in this region. The expressions of Bax and bak were more widespread in both the medulla and cortex, suggesting that these proteins play a broader role than bcl2 in the regulation of thymic apoptosis.

[Influence of suppressor gene p16 on retinoic acid inducing lung cancer cell A549 differentiation]

OBJECTIVE

To investigate the role of suppressor gene p16 in the process of differential regulation of retinoic acid (RA) on the A549 lung cancer cells.

METHODS

Tumor suppressor gene p16 was transfered into A549 cells and the cells were treated with all-trans retinoic acid (ATRA) at the dosage of 5 x 10(-6) mol/L for 4 d. After that, the proliferation and differentiation of A549 cells were examined by growth curve and cytometry analysis, the change of lung lineage-specific marker MUC1 was tested by immunohistochemical staining. Meanwhile, Western blot was used to observe the change of p16 protein expression in A549 cells treated with ATRA.

RESULTS

ATRA could obviously inhibit the growth and induce the differentiation of A549 cells that were transfered with p16 gene. There were more cells arrested in G1/G0 phase and the expression of MUC1 was markedly down-regulated than in control cells. The expression of p16 protein was up-regulated in A549 cells treated with ATRA.

CONCLUSION

Suppressor gene p16 could enhance the effects of RA on proliferative suppression and differential induction of A549 cells.

Skin and gingival lesions in a young woman with B-prolymphocytic leukemia (B-PLL)

B-PLL has not been often associated with diffuse skin involvement or oral lesions. We present a 32 year-old woman in whom skin and gingival manifestations were the prominent clinical signs of disease relapse.

Near-absolute expression of the bcl-2 protein identifies a subgroup of stage II breast cancer patients with a most favorable outcome. Results of a clinicopathological study

The clinical relevance of quantitative assessment of tumor-tissue expression of the bcl-2 protein in operated stage II breast cancer was investigated in this study. Thirty-five cases were studied by immunohistochemistry for the expression of bcl-2 protein and analyzed for disease outcome. One fourth (25%) of the cases were negative and 57% demonstrated near-absolute expression of the bcl-2 protein. No association was found between immunohistochemical detection of the protein with age, hormonal receptor status and tumor grading other than between bcl-2 and estrogen receptor expression (p=0.01). An impressively positive impact of near-absolute expression of bcl-2 on clinical outcome was identified. Our results provide evidence that quantitative assessment of bcl-2 expression constitutes a new approach in early breast cancer with potential clinical implications. We consider that molecular sub-staging of patients with stage II breast cancer by level of bcl-2 expression provides additional important prognostic information and prompts for investigation of its clinical significance on the issue of adjuvant systemic therapy.

[Effect of exogenous p16 gene on biological behaviors of human lung cancer]

OBJECTIVE

To evaluate the biological effects of tumor suppressor gene p16 on human lung cancer cells with p16 gene deletion.

METHODS

p16-pcDNA3 was transfected into lung cancer cell line A549 using lipofectin, in which p16 gene was homozygously deleted. Biological behaviors of the transfected cell line were investigated both in vitro and in vivo. The expressions of p16 mRNA and protein were detected by RT-PCR and immunohistochemistry.

RESULTS

There was stable expression of p16 in the transfected cell line A549. Exogenous p16 gene significantly slowed down the growth of A549 cells as compared with the control. Flow Cytometry showed that the transfected cells were stagnated in G1 phage of cell cycle accompanying with apoptosis. In addition, clonogenic assay showed that the number of colony in soft agar was decreased in transfected cells as well. In vivo, a suppressed tumorigenicity and significantly decreased growth rate were shown in nude mice injected with A549 cells transfected with p16-pcDNA3, as compared with those in mice injected with either original A549 or A549 transfected with pcDNA3.

CONCLUSION

Exogenous p16 gene can express stably in human lung cancer A549 cell line; exogenous p16 gene transfection induces apoptosis in lung cancer cells with p16 deletion and inhibits growth of the tumor in nude mice.

Interleukin 18 transfection enhances antitumor immunity induced by dendritic cell-tumor cell conjugates

Dendritic cell (DC)-based tumor vaccine represents a promising approach to the immunotherapy of malignant tumors. We prepared a novel type of DC-based vaccine, stable conjugates of DCs and EL4 cells transduced with cDNA of OVA (E.G7). Immunization with DC-E.G7 conjugates led to generation of T helper (Th) 1 cytokine-producing cells, antigen-specific CD8(+) T cells, and strong antitumor immunity that is dependent on both CD4(+) T cells and CD8(+) T cells. To further increase the potency of the vaccine, interleukin 18-transfected DCs were used to prepare the IL18DC-E.G7 conjugates. Immunization with such conjugates significantly increased the production of Th1 cytokine-producing cells and the number of antigen-specific CD8(+) T cells, as well as stronger antitumor immunity. Furthermore, the increased Th1 cytokine production and stronger antitumor effect were not observed in mice depleted of IFN-gamma. These data indicated that DC-tumor cell conjugates are a potent tumor vaccine. Interleukin 18 can be administrated using gene-transfected cells and enhances antitumor immunity, which is mainly mediated by IFN-gamma.

Immunohistochemical expression of the p53, mdm2, p21/Waf-1, Rb, p16, Ki67, cyclin D1, cyclin A and cyclin B1 proteins and apoptotic index in T-cell lymphomas

Fifty-seven cases of T-cell lymphomas (TCL) including 5 lymphoblastic (T-LBL) and 52 peripheral TCL (PTCL) were analyzed by immunohistochemistry for the expression of p53, mdm2, p21, Rb, cyclin D1, cyclin A, cyclin B1, and Ki67/MIB1 proteins and 39/52 PTCL were also analyzed for the expression of p16 protein and for the presence of apoptotic cells by the TUNEL method. The aim was to search for abnormal immunoprofiles of p53 and Rb growth control pathways and to determine the proliferative activity and the apoptotic index of TCL. Abnormal overexpression of p53, p21 and mdm2, in comparison to normal lymph nodes, was found in 12/57, 10/57 and 2/57 cases of TCL, respectively. Abnormal loss of Rb and p16 expression was found in 1/57 and 2/39 cases, respectively, whereas abnormal overexpression of cyclin D1 was not detected in any of the 57 cases. Our data revealed entity-related p53/p21/mdm2 phenotypes. Indeed, most nodal and cutaneous CD30+ anaplastic large cell lymphomas (ALCL) showed concomitant overexpression of p53 and p21 proteins (7/8 cases), and mdm2 was overexpressed in 2 p53-positive nodal ALCL. In contrast, overexpression of p53 was found in 3/17 cases of nodal peripheral TCL unspecified (PTCL-UC) and 2/7 non-ALCL cutaneous pleomorphic TCL. Overexpression of p21 protein was detected in 2/3 p53-positive PTCL-UC and in 1/2 p53-positive non-ALCL cutaneous pleomorphic TCL. Finally, all the remaining 25 cases of TCL did not show p53 and p21 overexpression. Overall, the p53+/p21+ phenotype in 10/57 TCL suggests wild-type p53 capable of inducing p21 expression. The highest apoptotic index (AI) was found in ALCL and a positive correlation between apoptotic index and Ki67 index (p<0.001) was detected. Ki67, cyclin A and cyclin B1 expression was found in all 57 TCL and on the basis of the combined use of these 3 variables, 3 groups of proliferative activity could be determined: a) high in ALCL and T-LBL, b) low in mycosis fungoides (MF) and gammadelta hepatosplenic TCL, and c) intermediate in the remaining TCL entities. The proliferative activity in the 12 p53 overexpressing cases was higher in comparison to the 45 p53-negative cases. Ki67 expresion in more than 25% of tumour cells showed significant correlation with p53 overexpression (p<0.001). Rb expression tended to be parallel to Ki67, cyclin A and cyclin B1 expression in all but one case of nodal PTCL-UC which displayed loss of RB expression. Interestingly, this case was p53-negative, whereas the p53-positive cases were Rb-positive. These findings suggest that different pathogenetic routes may function in some TCL, involving either the p53 or, less frequently, the Rb pathways.

FHIT gene expression in human urinary bladder transitional cell carcinomas

BACKGROUND

Our purpose was to investigate the expression of FHIT (Fragile Histidine Triad) gene product in a series of 110 urinary bladder TCCs, and its eventual relationship with histological grade, clinical stage, recurrences and patients' survival.

MATERIALS AND METHODS

We performed immunohistochemistry in archival material of formalin-fixed, paraffin-embedded tissues, using the anti-Fhit antibody and the Streptavidin-biotin peroxidase method.

RESULTS

In 30 out of 110 cases (27.27%) Fhit protein was absent whereas in 32 cases (29.08%) it was abnormally expressed. In 48 cases (43.63%) Fhit protein was diffusely expressed in all tumor cells. A statistically highly significant correlation (p < 0.001) was noticed between Fhit protein absence or reduction and clinically advanced tumors. Conversely, abnormal Fhit protein expression was not associated with age, histological grade, tumor size, number of recurrences, and clinical outcome in terms of patients' survival.

CONCLUSIONS

These results confirm that FHIT gene inactivation is a late event in urinary bladder carcinogenesis. Fhit protein reduced expression or complete absence correlates with advanced clinical stage of the disease, and does not seem to correlate with tumor recurrences and patient survival.

The extracellular calcium-sensing receptor dimerizes through multiple types of intermolecular interactions

Recent studies have shown that the G protein-coupled, extracellular calcium ([Ca(2+)](o))-sensing receptor (CaR) forms disulfide-linked dimers through cysteine residues within its extracellular domain and that dimerization of the CaR has functional implications. In this study, we have investigated which of these disulfide linkages are essential for dimerization of the CaR and whether they are required for these functional interactions. Our results confirm the key roles of Cys(129) and Cys(131) in CaR dimerization. However, utilizing cross-linking of the CaR or immunoprecipitation of a non-FLAG-tagged CaR with a FLAG-tagged CaR using anti-FLAG antibody, we demonstrate that CaRs with or without these two cysteines form dimers on the cell surface to a similar extent. In addition, reconstitution of CaR-mediated signaling by cotransfection of two individually inactive mutant CaRs is nearly identical in the presence or absence of both Cys(129) and Cys(131), showing that covalent linkage of CaR dimers is not needed for functional interactions between CaR monomers. These findings suggest that the CaR has at least two distinct types of motifs mediating dimerization and functional interactions, i.e. covalent interactions involving intermolecular disulfide bonds and noncovalent, possibly hydrophobic, interactions.

Regulation of MAP kinase by calcium-sensing receptor in bovine parathyroid and CaR-transfected HEK293 cells

Regulation of the extracellular signal-regulated kinase 1 and 2 (ERK1/2) pathway by the extracellular calcium (Ca2+o)-sensing receptor (CaR) was investigated in bovine parathyroid and CaR-transfected human embryonic kidney (HEKCaR) cells. Elevating Ca2+o or adding the selective CaR activator NPS R-467 elicited rapid, dose-dependent phosphorylation of ERK1/2. These phosphorylations were attenuated by pretreatment with pertussis toxin (PTX) or by treatment with the phosphotyrosine kinase (PTK) inhibitors genistein and herbimycin, the phosphatidylinositol-specific phospholipase C (PI-PLC) inhibitor U-73122, or the protein kinase C (PKC) inhibitor GF109203X and were enhanced by the PKC activator phorbol 12-myristate 13-acetate. Combined treatment with PTX and inhibitors of both PKC and PTK nearly abolished high Ca2+o-evoked ERK1/2 activation in HEKCaR cells, demonstrating CaR-mediated coupling via both Gq and G(i). High Ca2+o increased serine phosphorylation of the 85-kDa cytosolic phospholipase A2 (cPLA2) in both parathyroid and HEKCaR cells. The selective mitogen-activated protein kinase (MAPK) inhibitor PD98059 abolished high-Ca2+o)-induced ERK1/2 activation and reduced cPLA2 phosphorylation in both cell types, documenting MAPK's role in cPLA2 activation. Thus our data suggest that the CaR activates MAPK through PKC, presumably through Gq/11-mediated activation of PI-PLC, as well as through G(i)- and PTK-dependent pathway(s) in bovine parathyroid and HEKCaR cells and indicate the importance of MAPK in cPLA2 activation.

Serum levels of IL-6 and its soluble receptor (sIL-6R) in Waldenström's macroglobulinemia

BACKGROUND

Interleukin-6 (IL-6) is a multifunctional cytokine that plays roles in the immune response, inflammation and hematopoiesis. Serum IL-6 levels have reported to reflect disease severity and high tumor burden in multiple myeloma (MM) patients and to correlate with several other laboratory parameters. Serum-soluble IL-6 receptor (sIL-6R) plays an agonist role in IL-6 signaling, enhancing its biological activity tenfold. PURPOSE-METHODS: We measured IL-6 and sIL-6R levels in 11 patients (7 male, 4 female, mean age 66.9 yr) with Waldenström's macrobulinemia (WM) using a commercially available enzyme-linked immunoassay in order to investigate their biological role and to find any possible relationship with disease severity, tumor burden or response to treatment.

RESULTS

Serum IL-6 and sIL-6R concentrations at diagnosis were significantly higher than in healthy controls (Mann Whitney U-test, p < 0.001 and p < 0.01, respectively). Patients who were effectively treated had a significant reduction in IL-6 levels (p = 0.017). With regard to sIL-6R levels, no specific tendency was observed. In some of the responsive patients the levels increased whereas in others they decreased. No correlation was found between IL-6 and sIL-6R levels at diagnosis (p = 0.9, r = 0.036) or after treatment (p = 0.083, r = 0.3).

CONCLUSIONS

Our results suggest that IL-6 may be a marker reflecting tumor burden, disease severity and response to treatment in WM. With regard to sIL-6R, we believe that it does not seem to be of much value, and its role remains to be clarified. However, future studies are needed to confirm and further extend the present results.

Up-regulation of the parathyroid calcium-sensing receptor after burn injury in sheep: a potential contributory factor to postburn hypocalcemia

OBJECTIVE

To test the hypothesis that the hypocalcemia and hypoparathyroidism that follow severe burn injury are related to up-regulation of the parathyroid gland calcium-sensing receptor (CaR), which may reduce the set-point for suppression of circulating parathyroid hormone by blood calcium.

DESIGN

A controlled but unblinded study.

SETTING

An investigational intensive care unit.

SUBJECTS

Female range ewes.

INTERVENTION

Sheep were subjected to a 40% total body surface area burn under anesthesia (n = 9) or sham burn receiving anesthesia and fluid resuscitation only (n = 8) and were killed 48 hrs postburn.

MEASUREMENTS AND RESULTS

Blood ionized calcium, magnesium, and creatinine, and urinary calcium, magnesium, and creatinine were monitored for 48 hrs. After the sheep were killed, parathyroids (burn group, n = 3; sham group, n = 4) and kidneys (n = 4, each group) were harvested, snap frozen in liquid nitrogen, and analyzed for CaR messenger ribonucleic acid (mRNA) by Northern blot, and were analyzed for CaR cell-surface staining by immunocytochemistry with a polyclonal CaR-specific antiserum (parathyroids only). Bumed sheep were hypocalcemic and hypomagnesemic compared with sham-burned control sheep. CaR mRNA was increased by 50% (p < 0.005, analysis of variance) with a corresponding increase in the intensity of CaR immunoreactivity associated with the cell surface in parathyroids obtained from burned (n = 3) compared with sham-burned (n = 2) sheep. These findings are consistent with up-regulation of the parathyroid CaR and a related decrease in set-point for calcium suppression of parathyroid hormone secretion that may contribute to the previously reported postburn hypoparathyroidism and hypocalcemia.

Immunohistochemical expression of the p53, p21/Waf-1, Rb, p16 and Ki67 proteins in multiple myeloma

The aim of this study was to investigate the immunohistochemical expression of the proteins p53, Waf-l/p21, Rb, p16 and Ki67 in 38 cases of multiple myelomas (MM) and 4 cases of solitary extramedullary plasmacytomas in relation to the tumor histological grade and stage. In bone marrow (BM) biopsies from MM, overexpression of p53 and p21 proteins, in comparison to plasma cell infiltrates in non-pathological bone marrow, was detected in 13 out of 38 and 21 out of 38 cases, respectively. The combined immunoexpression of p53 and p21 proteins in the 38 cases of MM showed the following patterns: a) p53+/p21+ (13 cases) b) p53-/p21+ (8 cases) and c) p53-/p21- (17 cases). Rb, p16 and Ki67 proteins were detected in tumor cells in all 38 cases and their expression increased proportionally to tumor grade. The 4 cases of solitary extramedullary plasmacytomas showed the p53+/p21+ pattern in 2 cases and the p53-/p21+ pattern in 2 cases, all of them displaying Rb, p16 and Ki67 expression in tumor cells. The pattern p53+/p21+ might represent cases with wild-type p53 able to induce p21 expression. However, in previous studies p53 mutations were reported in about 3-10% of MM, and they were strongly associated with advanced disease. Thus, in some p53+/p21+ cases associated with high p53 expression and advanced disease, p53 gene cannot be excluded and up-regulation of p21 expression may be p53- independent. P53 overexpression correlated with increased tumor grade (p < 0.005), advanced histological stage (p < 0.001) and Ki67 expression in more than 10% of tumor cells (p < 0.001). Since increase in Ki67 expression also correlated with increased tumor grade (p < 0.001) and advanced histological stage (p < 0.001), these findings suggest that impairment of the p53 growth control pathway is associated with tumor progression in MM. Thus, p53 and Ki67 immunostaining in routine BM biopsies may be helpful for the detection of MM with potentially aggressive behavior. Overexpression of p21 in MM correlated with higher Ki67 expression (p < 0.005), suggesting that the p21 function of arresting cell-cycle is impaired. Ki-67 expression in MM increased in parallel with p16 (p < 0.001) and Rb expression (p < 0.001). Rb expression could represent a growth control response which, however, might not be able to induce growth arrest in view of the parallel increase in Ki67 expression and of previous findings showing that Rb protein in MM cells is expressed mostly in its phosphorylated form.

Familial hypercalcemia and hypercalciuria caused by a novel mutation in the cytoplasmic tail of the calcium receptor

Familial hyperparathyroidism (HPT), characterized by hypercalcemia and hypercalciuria, and familial benign hypocalciuric hypercalcemia (FHH) are the most common causes of hereditary hypercalcemia. The calcium-sensing receptor (CaR) regulates PTH secretion and renal calcium excretion. Heterozygous inactivating mutations of the gene cause FHH, whereas CaR gene mutations have not been demonstrated in HPT. In a kindred with 20 affected individuals, the hypercalcemic disorder segregated with inappropriately higher serum PTH and magnesium levels and urinary calcium levels than in unaffected members. Subtotal parathyroidectomy revealed parathyroid gland hyperplasia/adenoma and corrected the biochemical signs of the disorder in seven of nine individuals. Linkage analysis mapped the condition to markers flanking the CaR gene on chromosome 3q. Sequence analysis revealed a mutation changing phenylalanine to leucine at codon 881 of the CaR gene, representing the first identified point mutation located within the cytoplasmic tail of the CaR. A construct of the mutant receptor (F881L) was expressed in human embryonic kidney cells (HEK 293), and demonstrated a right-shifted dose-response relationship between the extracellular and intracellular calcium concentrations. The hypercalcemic disorder of the present family is caused by an inactivating point mutation in the cytoplasmic tail of the CaR and displays clinical characteristics atypical of FHH and primary HPT.

A large homozygous or heterozygous in-frame deletion within the calcium-sensing receptor's carboxylterminal cytoplasmic tail that causes autosomal dominant hypocalcemia

Autosomal dominant hypocalcemia (ADH) can result from heterozygous missense activating mutations of the calcium-sensing receptor (CaSR) gene, a G-protein-coupled receptor playing key roles in mineral ion metabolism. We now describe an ADH kindred of three generations caused by a novel CaSR mutation, a large in-frame deletion of 181 amino acids within its carboxylterminal-tail from S895 to V1075. Interestingly, the affected grandfather is homozygous for the deletion but no more severely affected than heterozygous affected individuals. Functional properties of mutant and wild-type (WT) CaSRs were studied in transiently transfected, fura-2-loaded human embryonic kidney (HEK293) cells. The mutant receptor exhibited a gain-of-function, but there was no difference between cells transfected with mutant complementary DNA alone or cotransfected with mutant and WT complementary DNAs, consistent with the similar phenotypes of heterozygous and homozygous family members. Therefore, this activating deletion may exert a dominant positive effect on the WT CaSR. The mutant receptor's cell surface expression was greater than that of the WT CaSR, potentially contributing to its gain-of-function. This novel mutation in the CaSR gene provides the first known examples of a large naturally occurring deletion within a G-protein-coupled receptor's carboxylterminal-tail and of a homozygous, affected individual with ADH.

Observation of a hybrid spin resonance

A new type of spin depolarization resonance has been observed at the Brookhaven Alternating Gradient Synchrotron (AGS). This spin resonance is identified as a strong closed-orbit sideband around the dominant intrinsic spin resonance. The strength of the resonance was proportional to the 9th harmonic component of the horizontal closed orbit and proportional to the vertical betatron oscillation amplitude. This "hybrid" spin resonance cannot be overcome by the partial snake at the AGS, but it can be corrected by the harmonic orbit correctors.

Structure and function of the extracellular calcium-sensing receptor (Review)

The extracellular calcium-sensing receptor (CaR) originally cloned from bovine parathyroid gland is a G protein-coupled receptor. The physiological relevance of the cloned CaR for sensing and regulating the extracellular calcium concentration has been established by identifying hyper- and hypocalcemic disorders resulting from inactivating and activating mutations, respectively, in the CaR. The cloned CaR has been stably or transiently expressed in human embryonic kidney cells and significant progress has been made in elucidating its biochemical and functional features using physiological, biochemical and molecular biological methods. A large collection of naturally occurring CaR mutations offers a valuable resource for studies aimed at understanding the structure-function relationships of the receptor, including receptor-receptor interactions. In turn, characterization of these naturally occurring mutations has clarified the pathogenesis of clinical conditions involving abnormalities in the CaR, such as familial hypocalciuric hypercalcemia and neonatal severe hyperparathyroidism, and the physiology of certain cell types, such as keratinocytes.

Sicca syndrome in patients with sarcoidosis

Out of 134, 12 sarcoidosis patients with symptoms of mucosal dryness as the first clinical manifestation were identified and compared with 30 consecutive unselected Sjögren's syndrome (SS) patients. Sicca manifestations were similar among the two groups, while parotid gland enlargement (PGE) was more frequently found in sarcoidosis patients (P < 0.05). Patients with sarcoidosis had mainly pulmonary (P < 0.001) and skin involvement (P < 0.05), while SS patients presented more frequently with Raynaud's phenomenon (P < 0.05). Autoantibody profile was more often found in SS patients compared to sarcoidosis (P < 0.0025). The histopathological findings of minor salivary gland biopsy (MSGB) revealed noncaseating granulomas (NCG) in 58% of patients with sarcoidosis, while in SS, MSGB showed focal sialadenitis in the majority of the patients. Transbronchial lung biopsy (TBLB), which was performed in 10 sarcoidosis patients, revealed the presence of NCG in all patients. In patients with sarcoidosis and sicca symptoms as the presenting syndrome, PGE is a useful clinical finding. Searching for pulmonary involvement is a determining factor to differentiate sarcoidosis from SS. The absence of autoantibodies is another useful tool for the diagnosis of sarcoidosis. Finally, MSGB is very helpful to discriminate between sarcoidosis and SS and when MSGB is not specific, then TBLB is valuable to confirm the diagnosis.

Alteration in enterocyte gene expression may explain structural and functional changes following glutamine supplemented parenteral nutrition

Following extensive bowel resection, the intestinal tract undergoes a variety of adaptive responses to enhance bowel function. The purpose of this study was to determine the effect of glutamine-supplemented parenteral nutrition on mucosal cellularity and gut function. In addition, enterocyte gene expression of two relevant systems was also characterized and related to the structural and functional changes that occurred. Male Wistar rats underwent a 60% small bowel resection and jugular vein catheterization and were randomized into two groups. The control group (n = 10) received a standard intravenous nutritional solution and the study group (n = 10) received a similar solution but enriched with alanylglutamine dipeptide. After 7 days blood was taken for amino acid analysis, and bowel was harvested to determine mucosal morphology and expression of mucosal cell glutaminase and IGF-I mRNA. Mesentery lymphnodes were cultured to determine the presence of bacteria and thus access bacteria translocation. Serum glutamine concentration and mucosal architecture were maintained in the study group compared to the controls. Seventy percent of lymphnodes were cultured positive in control vs. only 20% in the study group (P < 0.05). Jejunal mucosal glutaminase and ileum mucosal IGF-I mRNA increased twofold and threefold respectively compared to control animals. Parenteral nutrition supplemented with alanyl-glutamine dipeptide supports mucosal cellularity and regional immune function in rodents following intestinal resection, These alterations are associated with enhanced enterocyte expression of glutaminase and IGF-I. These changes may facilitate the structural and functional alterations which were observed in the glutamine treated animals.

Tissue distribution and metabolism of gamma-linolenoyl-3-eicosapentaenoyl propane diol enterally or intravenously administered to mice bearing human pancreatic carcinomas

Synthetic propane diol lipids have been proposed as novel compounds to deliver cytocidal polyunsaturated fatty acids (PUFA) such as gamma-linolenic (GLA) and eicosapentaenoic (EPA) acids. To assess the biodistribution and metabolism of these PUFA in immunodeficient mice bearing human pancreatic carcinomas (AsPC-1), gamma-linolenoyl-3-eicosapentaenoyl propane diol (GE diol) was provided in a fat-free diet (5% w:w) for 6 weeks or parentally administered as 14C-GE diol (1 or 3 consecutive doses of 1.66 g/kg/day) in an innovative non-ionic-digalactosyldiacylglycerol emulsion. In tumor, liver, brain, kidney, plasma and fat tissue of mice fed GE diol, PUFA were increased over 25-fold, except for arachidonic acid (AA) levels, which were reduced or remained constant when compared to mice fed control corn oil diet. GLA and EPA were mainly stored in fat tissue. The recovery of radioactivity from the i.v. infected 14C-GE diol was dose and time dependent. Ten days after the i.v. infusion, GLA was only detected in substantial concentrations in tumor and in fat tissue (21 and 202 micrograms/g, respectively). Overall, these studies showed that: GE diol emulsions provide 640-fold higher doses of both GLA and EPA without causing hemolysis or adverse effects in the host mouse when compared to free PUFA infusions; GE diol is metabolized after oral or i.v. administration; tumor concentrations of GLA and EPA from the enterally administered diol were 4 to 13-fold higher than the in vitro cytotoxic levels; EPA, competes with AA and probably inhibits the activity of delta 5 desaturase without affecting the elongation of GLA in the host and tumor tissue; the change in PUFA profile modifies the substrates for eicosanoid synthesis. In short, a potentially desirable cytotoxic PUFA pattern can be achieved in host tissues and, in particular, in a human pancreatic tumor by providing GLA and EPA in the form GE-diol. These findings guarantee further investigations in oncology with this neutral diol lipid.

Intermolecular interactions between dimeric calcium-sensing receptor monomers are important for its normal function

We recently demonstrated that the G protein-coupled, extracellular calcium-sensing receptor (CaR) forms disulfide-linked dimers. The functional significance of dimerization of this receptor was suggested by our earlier observations that CaRs carrying certain point mutations exert dominant negative effects on the function of the coexpressed wild-type receptor both in vivo and when cotransfected in human embryonic kidney cells. In this study, we explored the functional consequences of CaR dimerization. Coexpression in human embryonic kidney cells of specific pairs of mutant CaRs, each with reduced or absent activity because of distinct loss-of-function mutations, results in the formation of heterodimers and partially reconstitutes extracellular calcium-dependent signaling. Moreover, our results suggest that the CaR has at least two functionally separable domains. However, the presence of an abnormal domain in each mutant monomer substantially impairs the function of the CaR heterodimer, resulting in the reconstituted CaRs having characteristics distinct from those of the wild-type CaR. Our study suggests that intermolecular interactions within the dimeric CaR are important for the receptor's function.

Dimerization of the extracellular calcium-sensing receptor (CaR) on the cell surface of CaR-transfected HEK293 cells

The extracellular calcium (Ca2+o)-sensing receptor (CaR) is a G protein-coupled receptor that plays important roles in calcium homeostasis. In this study, we employed epitope tagging, cell-surface biotinylation, and immunoprecipitation techniques to demonstrate that the CaR is expressed mostly in the form of a dimer on the surface of transfected human embryonic kidney (HEK293) cells. Western analysis of cell-surface proteins under nonreducing conditions showed that the CaR exists in several forms with molecular masses greater than 200 kDa. Most of these high molecular mass forms of the receptor could be converted to a single monomeric species at 160 kDa under reducing conditions. This result suggests that the CaR forms dimers or even higher oligomers on the cell surface through intermolecular disulfide bonds that are sensitive to reducing agents. Consistent with this hypothesis, use of a cell-surface cross-linking agent substantially increases the proportion of the putative dimeric CaR at 280 kDa relative to the monomeric form of the receptor at 160 kDa under reducing conditions. Dimerization of the CaR in intact cells was further demonstrated when we co-transfected and co-immunoprecipitated the wild type, full-length receptor and a truncated form of the CaR lacking its cytoplasmic tail. Taken together, we conclude from these results that the functional CaR resides on the cell surface of transfected HEK293 cells in the form of a dimer.