[Primary lung paraganglioma. A case report]

Primary lung paragangliomas are rare. They are 1-2% of the paragangliomas, and most of them occur in patients of 43-61 years. They clinically appear as solitary tumors and are in general asymptomatic. These tumors show a nesting pattern (Zellballen) of chief polygonal cells locked by fibrovascular trabeculae with subtenticular cells. The main cells have uniform nuclei with granular eosinophilic cytoplasm, and they are positive for neuroendocrinal markers (Neuron Specific Enolase, sinaptofisine and cromogranine A). Sustentacular cells are positive for protein S-100 and neurofibrilar protein. A differential diagnosis with the carcinoid tumor can be very difficult. The surgical treatment is mandatory , specially high blood pressure and the chances of malignization.

Pathogenesis of haemophilic synovitis: experimental studies on blood-induced joint damage

Hemarthrosis is a common manifestation of haemophilia, and joint arthropathy remains a frequent complication. Even though the exact mechanisms related to blood-induced joint disease have not yet been fully elucidated, it is likely that iron deposition in the synovium induces an inflammatory response that causes not only immune system activation but also stimulates angiogenesis. This process ultimately results in cartilage and bone destruction. Investigating the processes that occur in the early stages of blood-induced joint disease in humans has been very limited. Therefore, the use of haemophilic animal models is critical to augment the understanding of this phenomenon. This article discusses three cellular regulators (p53, p21 and TRAIL) induced in synovial tissue that are important for iron metabolism. A cartilage remodelling programme induced by the release of cytokines and growth factors that result in articular damage is also discussed. Full elucidation of the pathogenesis of haemophilic joint disease is required to identify new avenues for prevention and therapy.

[Small intestinal plasmacytoid lymphoma. Clinical presentation with acute abdominal pain]

Primary tumors of the small intestine are rare; 15-20% of the cases are extranodal lymphomas from B or T cells. Higher Incidence occurs in patients between 21 and 50 years. The clinical symptoms are pain, intestinal obstruction, diarrhea, bleeding or perforated peritonitis. In high-grade lymphomas, the cells are large and pleomorphic, with immunoblastic and plasmacytoid features, and immunopositive for alpha chain immunoglobulins. We reported the case of a 56-year-old patient presented with abdominal pain associated with intestinal perforation. Resections of a 9-centimetres-long segment in the small intestine was performed, which was covered by purulent plaques, with a perforation of 5 mm, surrounded by a greyish-white thick intestinal wall. It can be observed in the microscopy a proliferation of neoplastic cells arranged diffusely and with frequent mitosis. Large areas of immunoblastic and plasmacytoid configuration were evident. The immunomarcation was consistent with a lymphoma of large cells, immunophenotype B, with plasmacytoid development. We highlighted the clinical presentation like acute abdominal pain and its clinical and pathological characteristics, especially in the plasmacytoid development that should differ of the true plasmocytoma.

Pathogenesis of haemophilic synovitis: clinical aspects

Arthropathy remains a major cause of morbidity in patients with haemophilia. Frequent bleeding into the joints leads to joint damage with resultant contractures, joint deformities and arthritis. This in turn leads to muscle atrophy, limited physical activity, osteoporosis and disability. Even though several studies of prophylactic factor replacement for persons with severe haemophilia demonstrate improved joint function, this therapy is still not readily available to most people with haemophilia around the world and a universal treatment protocol has not been used. In this article, we discuss key issues in the treatment of severe haemophilia: the optimal timing of initiation and termination of therapy, dosing options and goals of therapy. The options for countries where prophylaxis is not readily available are also discussed. Most studies are small and not randomized making consensus treatment recommendations difficult to formulate. Randomized, clinical trials are needed to provide the answers regarding the optimal treatment of patients with severe haemophilia.

Prevalence of Osteoporosis, Osteopenia, and Vertebral Fractures in Long-Term Renal Transplant Recipients

BACKGROUND

Osteopenia and osteoporosis are frequent complications early after transplantation. Their long-term prevalences and associations with the risk of fractures are not well known. The objective of the present work was to determine the incidence of osteopenia and osteoporosis versus vertebral fractures in renal transplant recipients with stable graft function and with a follow-up of at least 10 years.

PATIENTS AND METHODS

Forty renal transplant recipients, 24 men and 16 women, were included in the study. The mean age was 41.8 years and the follow-up was 130 +/- 14 months. Initial immunosuppression consisted of cyclosporine with or without an antiproliferative agent. Measurements of bone mass density (BMD) were performed by dual-energy X-ray absorptiometry (DEXA). The assessment of vertebral fracture using conventional radiography was evaluated by semiquantitative criteria.

RESULTS

Eleven patients (27.5%) displayed lumbar spine osteoporosis (T-score < -2.5); 21 (52.5%), osteopenia (T-score > -2.5 and < -1) and 8 (20.0%), normal BMD. However, BMD was better preserved at the femoral neck: 14 patients (35.0%) had normal BMD; 20 (50.0%) osteopenia, and 6 (15.0%), osteoporosis. When analyzed together, patients with osteoporosis or osteopenia showed worse graft function at 1 and 8 years compared with normal BMD patients (1.75 +/- 0.634 vs 1.32 +/- 0.33 mg/dL at 1 year; P < .014) and (1.7 +/- 0.4 vs 1.2 +/- 0.2 mg/dL at 5 years; P < .01) and a greater number were prescribed vitamin D (50% vs 23%). Mild vertebral fractures were observed in 60.0% patients with osteoporosis; 70% with osteopenia; and 43% with normal lumbar BMD. Peripheral fractures were more common in patients with osteoporosis (P = .053).

CONCLUSIONS

Osteoporosis and osteopenia are common among long-term renal transplant recipients are associated with poorer graft function. Lumbar spine BMD osteoporosis is associated with peripheral fractures. However, mild vertebral deformities are not associated with the presence of osteopenia or osteoporosis.

High Body Mass Index and Posttransplant Weight Gain Are Not Risk Factors for Kidney Graft and Patient Outcome

BACKGROUND

High body mass constitutes a significant risk factor for morbidity and mortality in the general population, but it has been associated with an increased survival among dialysis patients. Its effects on renal transplant outcomes are controversial. The aim of our present work was to investigate the impact of high body mass and posttransplant weight gain on patient and graft outcomes.

PATIENTS AND METHODS

One thousand consecutive renal transplant recipients (631 men and 369 women) were included in the study. Their mean age was 42.9 years and the follow-up was at least 2 years. Basal immunosuppression was azathioprine (Aza) and steroids in 196 patients, cyclosporine (CsA) without or with antiproliferative agent in 557, and 239 were presented tacrolimus (Tac).

RESULTS

At the time of transplantation the body mass index (BMI) was 23.7 +/- 3.9 kg/m2, namely, <18.5 kg/m2 in 6.3%; 18.5 to 25 in 61.7%; 25 to 30 in 25.4%; and >30 in 6.5%. Pretransplant obesity was associated with old age and female gender. Obese patients experienced a greater risk of delayed graft function (P < .01) and surgical wound complications (P < .01). After 1 year, 299 patients (29.9%) displayed weight gain >10% (mean 8.6% +/- 10.4% or 5.0 +/- 6.1 kg). Patients on Aza showed increased body weight by 11.9% +/- 10.9%; CsA patients by 9.5% +/- 10.3%, and Tac patients by 4.9% +/- 9.1% (P < .001). Univariate and multivariate analysis showed that pretransplant BMI had no effect on graft or patient survival either in the whole group or in the patients treated with CsA or TAC. Posttransplant weight gain above 5% or 10% did not influence graft or patient outcomes.

CONCLUSIONS

The new immunosuppressive regimes reduce posttransplant weight gain. Pretransplant high body mass and 1-year posttransplant weight gain were not risk factors for graft or patient survival in our experience.

Cost structure of a postcombustion CO2 capture system using CaO

This paper presents the basic economics of an emerging concept for CO2 capture from flue gases in power plants. The complete system includes three key cost components: a full combustion power plant, a second power plant working as an oxy-fired fluidized bed calciner, and a fluidized bed carbonator interconnected with the calciner and capturing CO2 from the combustion power plant. The simplicity in the economic analysis is possible because the key cost data for the two major first components are well established in the open literature. It is shown that there is clear scope for a breakthrough in capture cost to around 15 $/t of CO2 avoided with this system. This is mainly because the capture system is generating additional power (from the additional coal fed to the calciner) and because the avoided CO2 comes from the capture of the CO2 generated by the coal fed to the calciner and the CO2 captured (as CaCO3) from the flue gases of the existing power plant, that is also released in the calciner.

Correlation between the EGFR intron 1 CA dinucleotide repeat and skin toxicity in lung cancer patients treated with erlotinib

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Background: Acneiform rash is the main toxicity of erlotinib, an epidermal growth factor receptor (EGFR) inhibitor. The length of the CA dinucleotide repeat in EGFR intron 1 has been suggested to predict the biological effects of tyrosin kinase inhibitors. Thus, we compared this polymorphism with the rash severity in non-small cell lung cancer (NSCLC) patients treated with erlotinib. Methods: Toxicity was evaluated in 18 metastatic or locally advanced unresectable NSCLC patients treated orally with 150 mg/d of erlotinib: 7 retrospectively and 11 prospectively. Rash was graded according to a modified scale based on the Common Toxicity Criteria v.3.0, which subclassified grade II rash into IIA (topic intervention indicated) and IIB (oral intervention indicated). Genomic DNA was isolated from each patient; the length of the EGFR intron 1 CA dinucleotide repeat was measured by PCR amplification and analyzed on a capillary sequencer. Results: The most common EGFR genotypes were: 16, 20, 17 and 18 CA repeats (with 50, 25, 8 and 8% frequency, respectively). 33% of the subjects with a total amount of CA repeats <34 had grade IIB-III rash vs 11% of the subjects with =34 CA repeats. In addition, all patients with 0 grade toxicity belonged to the =34 CA group. When the only patient with a previous dermatological disease (psoriasis) was excluded from the analysis, the difference between both groups increased, reaching statistical significance (p=0.047). Conclusions: This data suggests that NSCLC patients with long EGFR intron 1 CA alleles present lower grades of skin toxicity when treated with erlotinib than patients with short CA alleles. Further studies are required to confirm this data.

[Table: see text]

No significant financial relationships to disclose.

Flexible communication and control protocol for injectable neuromuscular interfaces

BION2 is a system based on injectable neuromuscular implants whose main goal is to restore the functional movement of paralyzed limbs. To achieve this objective, the functional requirements of the implanted interfaces include not only stimulation but also integrated sensors in order to detect patient intention, to provide servocontrol of muscle activation and to sense posture to inform more global motor planning and coordination. The technical constraints for managing the system include the efficient use of forward and reverse telemetry channels with limited capacity, minimization of adverse consequences from errors in data transmission or intermittent loss of power to the implants, and ability to adjust stimulation rates and phases to achieve efficient fine control of muscle force while minimizing fatigue. This paper describes a communication and control architecture with several novel features that address these requirements.

Indirect evidence of submicroscopic pores in giant unilamellar [correction of unilamelar] vesicles

Formation of pore-like structures in cell membranes could participate in exchange of matter between cell compartments and modify the lipid distribution between the leaflets of a bilayer. We present experiments on two model systems in which major lipid redistribution is attributed to few submicroscopic transient pores. The first kind of experiments consists in destabilizing the membrane of a giant unilamellar vesicle by inserting conic-shaped fluorescent lipids from the outer medium. The inserted lipids (10% of the vesicle lipids) should lead to membrane rupture if segregated on the outer leaflet. We show that a 5-nm diameter pore is sufficient to ease the stress on the membrane by redistributing the lipids. The second kind of experiments consists in forcing giant vesicles containing functionalized lipids to adhere. This adhesion leads to hemifusion (merging of the outer leaflets). In certain cases, the formation of pores in one of the vesicles is attested by contrast loss on this vesicle and redistribution of fluorescent labels between the leaflets. The kinetics of these phenomena is compatible with transient submicroscopic pores and long-lived membrane defects.

Phylogenetic relationships between Puerto Rico and continental USA HIV-1 pol sequences: a shared HIV-1 infection

In order to investigate the existing notion that the human immunodeficiency virus type 1 (HIV-1) infection in Puerto Rico (PR) was imported from the continental United States of America (USA) we sequenced and analyzed 900 bases of the HIV-1 pol sequence from individuals in PR for comparison with pol sequences from the USA mainland. The sequences were derived by direct sequencing of reverse transcription-polymerase chain reaction products generated from plasma virus. The products were sequenced in both directions and the complementary strands were compared prior to analysis. These processed sequences and GenBank sequences from the continental USA were subjected to phylogenetic analyses. The PR and USA sequences did not form independent clusters, indicating a shared HIV-1 infection. This may be due to the continuous human traffic or, less likely, may indicate a similar evolution of a common source virus. Analysis of drug resistance mutations, fairly similar in frequency in the PR and USA sequences analyzed here, supports human traffic as a rationale for the common infection. This work indicates that an efficacious vaccine developed for use in the USA mainland will also be effective in prevention in PR and perhaps the other countries of the Caribbean region.

Death at the border

"Debates about United States border control policies have generally ignored the human costs of undocumented migration. We focus attention on these costs by estimating the number, causes and location of migrant deaths at the southwest border of the United States between 1993 and 1997.... Deaths from hyperthermia, hypothermia and dehydration increased sharply from 1993 to 1997 as intensified border enforcement redirected undocumented migration flows from urban crossing points to more remote crossing areas where the migrants are exposed to a greater risk of death."

Prevalence of erectile dysfunction in Colombia, Ecuador, and Venezuela: a population-based study (DENSA)

The purpose of this study was to estimate the prevalence of erectile dysfunction (ED) in Colombia, Ecuador, and Venezuela. A 49-item questionnaire was completed by 1946 men aged 40 years and older. The age-adjusted combined prevalence of minimal, moderate, and complete ED for all three countries was 53.4%, with 19.8% of all men reporting moderate to complete ED. Age was the variable most strongly linked to ED; the prevalence of complete ED increased markedly in men older than 79 y of age (31.9%) and 70-79 y (17.2%) compared with men aged 40-49 y (<3%). Several medical conditions, such as hypertension, benign prostatic hyperplasia, and diabetes, and the use of medications to treat these conditions were correlated with the prevalence of ED. This study corroborates earlier studies demonstrating that ED is very common, increases dramatically with age, and has multiple correlates, including some that are also risk factors for cardiovascular disease.

Development of thrombocytosis in HIV+ drug users: impact of antiretroviral therapy

With the exception of hemolytic anemia, the potential hematological toxicity of antiretrovirals (ARV) and combination treatments in HIV treated individuals has not been well established. We report, for the first time, hematological toxicity defined as thrombocytosis in 9% of the HIV+ patients receiving highly active antiretroviral treatment (HAART) being followed in a nutritional clinical trial. Participants were evaluated every 6 months during a 2-year period (1998-2000) and blood drawn for biochemical, hematological and immunological parameters. NK cells were negatively correlated with platelet counts in the total cohort (P = 0.018) and persistently elevated with ARVT. Chronic thrombocytosis was associated with significantly lower NK percentages (P = 0.005). Twenty-five percent of the patients with thrombocytosis developed a cardiovascular disease. Together, these results support the proposal that HAART may increase the risk of hematological dysfunction and impact the risk of cardiovascular disease.

Involvement of gntS in the control of GntI, the main system for gluconate metabolism in Escherichia coli

The initial steps of gluconate metabolism in E. coli, transport and phosphorylation, occur through duplicate activities. These activities have been included in two systems designated as GntI (main) and GntII (subsidiary), encoded by differently regulated operons located at the 76.4-77 and 95.3-96.9 regions on the map respectively. Despite recent molecular advances related to genetics and physiology of these systems, there is no information about the coordination of their expression when E. coli grows on gluconate. Under these conditions, the subsidiary gluconokinase (gntV gene, min 96.8) as well as the GntI activities are expressed in inducible form. Therefore it was of interest to find out if GntS, the positive regulator of gntV has a similar effect on GntI activities expression. Our results agree with this hypothesis. GntS, in addition to its regulatory action on the gntV gene, seems to assist, direct or indirectly, the expression of the GntI activities. A gntS E. coli mutant does not grow on gluconate but spontaneously pseudoreverts to a gluconate growing phenotype at high rate per cell generation when cultivated in rich media with or without gluconate or mineral medium containing any other suitable carbon source. In the pseudorevertants, the thermosensitive gluconokinase remains repressed while the GntI activities are inducibly expressed. At present, the location and nature of the gntS suppressor mutation are not known. Phage P1Kc mediated transductions have ruled out that it alters the gntT gene. This is the first report on GntI activities alteration due to a lesion located out of the bioH-asd region.

Effect of sequence length, sequence frequency, and data acquisition rate on the performance of a Hadamard transform time-of-flight mass spectrometer

Various factors influencing the performance of a Hadamard transform time-of-flight mass spectrometer (HT-TOFMS) have been investigated. Using a nitrogen corona discharge to produce an ion stream of N2+, N3+, and N4+, it is found for spectra containing only N4+ that the signal-to-noise ratio (SNR) closely approaches the value calculated from the ion background by assuming that the ion background follows a Poisson distribution. In contrast, for a more intense beam containing N2+, N3+, and N4+, the SNR is less than its theoretical value because of the appearance of discrete spikes in the mass spectrum caused by deviations in the actual modulation sequence from the ideal one. These spikes can be reduced, however, by decreasing the modulation voltage. Under these optimized conditions, the pseudo-random sequence length is varied to understand how it alters SNR, mass resolution, and scan speed. When the length of the pseudo-random sequence is doubled, the SNR increases by the square root of 2 while the time necessary to record a mass spectrum also doubles. Mass resolution can be varied between 500 and 1200 at m/z = 609 as the sequence length, modulation speed (10 MHz, 25 MHz), and acquisition rate (up to 50 MHz) are changed. Scan speeds of 6000 passes per s can be obtained using a sequence containing 4095 elements modulated at 25 MHz. The capability to tailor the HT-TOFMS to increase the scan speed and resolution with a constant 50% duty cycle makes the technique extremely appealing as a mass analyzer for measuring rapid changes in the composition of an ion stream.