Callose deposition: a multifaceted plant defense response

Callose deposition in Arabidopsis has emerged as a popular model system to quantify activity of plant immunity. However, there has been a noticeable rise in contradicting reports about the regulation of pathogen-induced callose. To address this controversy, we have examined the robustness of callose deposition under different growth conditions and in response to two different pathogen-associated molecular patterns, the flagellin epitope Flg22 and the polysaccharide chitosan. Based on a commonly used hydroponic culture system, we found that variations in growth conditions have a major impact on the plant's overall capacity to deposit callose. This environmental variability correlated with levels of hydrogen peroxide (H₂O₂) production. Depending on the growth conditions, pretreatment with abscissic acid stimulated or repressed callose deposition. Despite a similar effect of growth conditions on Flg22- and chitosan-induced callose, both responses showed differences in timing, tissue responsiveness, and colocalization with H₂O₂. Furthermore, mutant analysis revealed that Flg22- and chitosan-induced callose differ in the requirement for the NADPH oxidase RBOHD, the glucosinolate regulatory enzymes VTC1 and PEN2, and the callose synthase PMR4. Our study demonstrates that callose is a multifaceted defense response that is controlled by distinct signaling pathways, depending on the environmental conditions and the challenging pathogen-associated molecular pattern.

Linear increase of the modal gain in 1.3 µm InAs/GaAs quantum dot lasers containing up to seven-stacked QD layers

The authors have recently demonstrated the enhancement of the quantum dot laser modal gain, linearly scaling with the number of stacked QD layers. These results allowed the achievement of multi-quantum dot (MQD) lasers, the zero-dimensional counterpart of MQW lasers, with a modal gain as high as 42 cm(-1), in a seven-layer structure. A detailed investigation of the structural and optical properties was performed on laser structures with three, five and seven QD layers. Such an investigation clearly shows that the high uniformity of QD layer features is responsible for the linear increase of the modal gain and its high value.

[Autoimmune hepatitis with elevation of CA 19-9 and normalization with immunosuppressant [corrected]treatment: case report and review of the literature]

We describe the case of an 81 year old woman that presented with jaundice, bile duct dilation, hepatic liver tests abnormalities and elevated levels of CA-19-9 (741 UI). Intestinal and pancreatic neoplasia were ruled out. Hepatic biopsy revealed chronic inflammation, cirrhosis and findings consistent with autoimmune hepatitis. The patient was given a course of corticoids and the disease as well as levels of CA-19-9 returned to normal levels.

Treatment with encapsulated Hsp60 peptide (p277) prolongs skin graft survival in a murine model of minor antigen disparity

The increased expression of heat shock protein (Hsp)60 in different kinds of graft tissues has been associated with a proinflammatory role and rejection. However, there are very few reports in which treatment with Hsp60 delays skin allograft rejection. The aim of this work was to evaluate the capacity of encapsulated human Hsp60-derived peptide p277 to delay graft rejection in two murine models of skin transplantation with minor antigen disparities. Briefly, BALB/c mice and C57BL/6 were intranasally pre-treated with five doses of Hsp60 p277 peptide encapsulated in polylactide-co-glycolide acid microspheres (PLGM), and received skin grafts from DBA2 mice and 129/B6 (F1) mice respectively. The treatment with the peptide increased skin graft survival more than 20 days in both the mouse strains, mainly in C57BL/6 recipients (P < 0.05). Also, p277-treated BALB/c and C57BL/6 mice showed IL-10 and IFN-gamma production, induced by p277 peptide. For the first time, a mucosal schedule using the Hsp60 C-terminal peptide p277 encapsulated in PLGM showed some survival prolongation of skin grafts bearing minor antigen disparities. Our results suggest a potential role for Hsp60-based therapy and the mucosal route as a useful tool to control the inflammatory response to allografts.

Organ Donation in Latin America

Recently in Latin America, there has been a strong influence of the "Spanish model" of organ procurement. In 2001, The "Punta Cana Group" was created by Latin American transplantation coordinators with the objective of registering and improving the system of donation and procurement. In many countries there is no universal financial support from the government for medical treatment, including dialysis and transplantation. In other countries there is complete financial support for all of the population, including immunosuppressive drugs. Practically all countries have transplantation laws that follow ethical concepts, such as brain death diagnosis criteria, forms of consent, criteria of allocation, and inhibition of commerce. The rate of potential donors notified in countries that perform transplantations with deceased donors varied from 6 to 47 per million population yearly (pmp/y); The rate of effective donors varied from 1 to 20 pmp. In 2004, the mean rate of effective donors in Latin America was 5.4 pmp. The family refusal rate for the donation of organs varied from 28% in Uruguay to 70% in Peru. In some countries, such as Puerto Rico, Uruguay, and Cuba, it was more than 15 pmp, whereas in others countries deceased donors were practically not used. The number of patients on the waiting list for solid organ transplants in 12 Latin American countries is 55,000. Although the donation rate has increased by 100% during the last 10 years, it is lower than that in Europe (15 pmm/y) or the United States (20 pmp/y).

Cellular autoreactivity against heat shock protein 60 in renal transplant patients: peripheral and graft-infiltrating responses

Autoreactivity to heat shock protein 60 (Hsp60) has been implicated in the pathogenesis and regulation of chronic inflammation, especially in autoimmune diseases. In transplantation, there is a lack of information regarding the cytokine profile and specificity of cells that recognize self-Hsp60 as well as the kinetics of autoreactivity following transplantation. We studied the cellular reactivity of peripheral and graft-infiltrating lymphocytes against Hsp60 in renal transplant patients. Cytokine production induced by this protein in peripheral blood mononuclear cells indicated a predominance of interleukin (IL)-10 during the late post-transplantation period, mainly in response to intermediate and C-terminal peptides. Patients with chronic rejection presented reactivity to Hsp60 with a higher IL-10/interferon (IFN)-gamma ratio compared to long-term clinically stable patients. Graft-infiltrating T cell lines, cocultured with antigen-presenting cells, preferentially produced IL-10 after Hsp60 stimulation. These results suggest that, besides its proinflammatory activity, autoreactivity to Hsp60 in transplantation may also have a regulatory role.

Evolution of Suboptimal Renal Transplantations: Experience of a Single Spanish Center

The increase in patients on dialysis awaiting transplantation has led to the use of grafts from suboptimal donors. The aim of this study was to analyze the function of suboptimal grafts. The secondary objectives were to study vascular and urological complications, as well as delayed renal function and acute rejection episodes. The study included 135 transplantations performed over 4 years with 27% of grafts being from suboptimal donors. Early graft loss was 12%, of which 69% were due to vascular thrombosis. These thromboses were more frequent among grafts from suboptimal donors (30% vs 4%, P < .001). There were no significant differences between the groups in the incidence of acute rejection episodes (17% vs 13%) or delayed graft function (14% vs 13%). A greater incidence of urologic complications was observed among recipients of grafts from older donors. The 1-year creatinine clearance was significantly lower among recipients of grafts from older donors (73 +/- 19 vs 51 +/- 14 mL/min, P < .0001). Sequential immunosuppressive therapy resulted in a lack of significant differences in creatinine clearance at 6 months, 1 year, or 2 years after transplantation between suboptimal grafts with cold ischemia greater or less than 20 hours or in warm ischemia greater or less than 60 minutes. Logistic regression analysis showed that the best determinant of graft loss was donor age older than 60 years. Accordingly, grafts from suboptimal donors were more likely to be lost during the first month after transplantation, particularly because of thrombosis, which was not due to a higher degree of technical complexity of the transplant operation.

PTFE Mesh in Renal Allograft Compartment Syndrome

We report a case of anuria in a 42-year-old female kidney transplant patient that occurred secondary to extrinsic compression from a large kidney being placed extraperitoneally in a small iliac fossa. Prompt reexploration in the immediate postoperative period resulted in salvage of the graft with restoration of kidney function. The abdominal wall was reconstructed using prosthetic mesh, which decreased the compartment pressure within the iliac fossa sufficiently to allow the renal vein patency and the kidney perfusion. We think that this tension-free surgical technique should be applied in those cases in which the retroperitoneal space is less than the size of the kidney to avoid renal allograft compartment syndrome or incisional hernia.

Intraoperative Parathyroid Hormone Monitoring During Parathyroidectomy for Hyperparathyroidism in Waiting List and Kidney Transplant Patients

This report describes the use of the intraoperative parathyroid hormone (ioPTH) assay during parathyroidectomy in waiting list and transplanted patients. ioPTH levels were determined in 40 patients on the waiting list for kidney transplantation with secondary hyperparathyroidism who underwent subtotal parathyroidectomy and 9 transplanted patients with tertiary hyperparathyroidism who underwent removal of hyperplasic glands. Rapid PTH levels decreased significantly at each time period; the percentage decrease in rapid PTH levels was 61.3% among patients with IPT II and 70.2% in patients with IPT III at 10 minutes and 86.5% in patients with IPT II and 91% in patients with IPT III at 15 minutes after excision of hypersecreting parathyroid tissue. A decrease of 50% or more from baseline PTH levels at 10 minutes and/or a decrease of 85% or more at 15 minutes predicted successful removal of abnormal parathyroid glands. The application of this technique during subtotal parathyroidectomy has proved useful for correct excision of parathyroid glands among waiting list patients with IPT II, while in kidney transplant patients with IPT III it allowed removal of only the pathological glands with a limited surgical approach.

Comparison of serological tests for the detection of ovine and caprine antibody to Brucella melitensis

The indirect enzyme-linked immunosorbent assay (IELISA), the competitive enzyme-linked immunosorbent assay (CELISA) and the fluorescence polarisation assay (FPA) were evaluated with sera from sheep experimentally infected with Brucella melitensis and negative Canadian sheep. The sensitivity and specificity of the assays were as follows: IELISA: 91.7% and 97.6%, CELISA: 75.0% and 99.8% and FPA: 91.7% and 89.5%. Sera from the same experimental population were divided according to serological reaction in the rose bengal agglutination test (RBT) and the complement fixation test (CFT). Reactivity relative to the RBT positive and CFT positive sera were as follows: IELISA: 99.7%, CELISA: 93.2% and FPA: 99.1%. Since sera from goats with proven B. melitensis infection were not available, 699 sera from goats judged positive in the buffered antigen plate agglutination test (BPAT) and CFT and 982 BPAT/CFT negative Canadian goats were used. The sensitivity and specificity of the assays relative to the BPAT and CFT positive sera were: IELISA: 99.4% and 98.0%, CELISA: 95.4% and 97.1% and FPA: 92.7% and 99.8%.

Simultaneous imbibition–heat convection process in a non-Darcian porous medium

In the present work, the nonisothermal imbibition process in a porous medium was numerically analyzed using a non-Darcian model for the momentum equation and energy equations for the wetting and dry zones. In order to show the thermal character of the problem, we assume initially that the porous medium is found at a uniform temperature T0 and suddenly begins the imbibition process into the porous medium with a penetrating fluid at temperature T1. The physical influence of nondimensional parameters such as Peclet number, Pe, effective heat capacity number, beta(w), porous Reynolds number, Re(p), and the inertial coefficient of the porous medium, F, serve us to evaluate the position and velocity of the imbibition front as well as temperature profiles in both zones. In particular, for values of Re(p)F/beta(w)>>1, we recover a type of nonisothermal Washburn law. The numerical predictions show that the imbibition front and the temperature fields strongly depend on the above nondimensional parameters, revealing a clear deviation of the simple Washburn law.

[Serum uric acid and C-reactive protein levels in patients with chronic kidney disease]

Either inflammation or hyperuricemia has been related with increased cardiovascular risk and mortality. A hypothetical relationship between serum uric acid levels (SUA) and inflammatory markers has never been tested in chronic kidney disease (CKD) patients. The purpose of this study was to determine the prevalence of increased C-reactive protein (CRP) levels in CKD patients, and to test the hypothesis of a relationship between SUA and CRP levels. The study group consisted of 337 patients (174 males, mean age 63 +/- 16 years) with advanced chronic renal failure not yet on dialysis. None of them had overt inflammatory or infectious diseases. High sensitivity CRP levels were analyzed as a binary (above or below median value), or continuous variable (log-transformed CRP), by multiple logistic or linear regression analysis, respectively. Demographics, clinical, and biochemical characteristics, including SUA levels, were the variables tested in these analysis. In a subset of 169 patients without diabetes, the same analysis were carried out, with the inclusion of fasting insulin levels and HOMA-IR as independent variables. Median CRP level was 3.25 mg/L, and mean SUA level was 7.59 +/- 1.94 mg/dl. Patients with CRP levels above the median had significantly higher mean SUA level than that of the rest of study patients (7.93 +/- 1.79 vs 7.24 +/- 2.03 mg/dl, p = 0.001). SUA levels correlated significantly with log-transformed CRP levels (r = 0. 16, p = 0.0022). The relationship between SUA and CRP levels remained statistically significant after adjustment for age, sex, comorbid index, obesity, residual renal function, diuretic and allopurinol treatment, in the multivariate logistic and linear regression models (OR: 1.296, p = 0.0003; and beta: 0.204, p = 0.0002). The significant association between SUA and CRP levels did not change when HOMA-IR and fasting insulin levels were included as independent variables in the subset of 169 patients without diabetes. In conclusion, SUA levels are related with CRP levels in CKD patients.

Detachment and diffusive-convective transport in an evolving heterogeneous two-dimensional biofilm hybrid model

Under the hypothesis of correlation between biofilm survival and nutrient availability, by considering fluid drag forces and mortality due to nutrient depletion, a biofilm detachment/breaking condition is derived. The mechanisms leading to biofilm detachment/breaking are discussed. We construct and describe a hybrid model for a heterogeneous biofilm attached to walls in a channel where liquid is flowing. The model is called hybrid because it couples conservation equations with a cellular automaton. The biofilm layer is viewed as a porous medium with variable porosity, tortuosity, and permeability. The model is solved using asymptotic and finite differences methods. Results for porosity, nutrient distribution, and average surface location are presented. The model is capable of reproducing biofilm heterogeneity as well as the typical surface fingering (mushroomlike structure).

Correlation algorithm to recover the phase of a test surface using phase-shifting interferometry

A correlation algorithm to recover the phase in phase-shifting interferometry is presented. We make numerical simulations to test the proposed algorithm and apply it to real interferograms with satisfactory results.

Ronchi test can detect piston by means of the defocusing term

We present simulated results on piston detection applying the classical Ronchi test to a segmented surface. We have found that a piston error in a test segment, induces a change in the transversal aberration, that can be analyzed by mutually comparing the fringes frequency in each segment. We propose that the piston term of the segmented surface can be recovered by geometrically relating the change in transversal aberration with the piston term. To test this, we have simulated some ronchigrams for a known piston error, and we have been able to recover this term for a dynamic range comprised among 57nm and 550 microm. For piston errors > 550 microm a change in the transversal aberration can be appreciated and measured in the ronchigrams although these large pistons are now classical defocusings. Thus we have demonstrated that the Ronchi test can be an alternative method for the piston detection with a large dynamic range.

[Laparoscopic adrenalectomy: our preliminary experience]

INTRODUCTION

In 1992, Gagner described the first laparoscopic adrenalectomy. Since then this technique has been more and more widely employed and several studies confirmed its advantages, comparing to the traditional approach, in terms of reduction of mean hospital stay and therefore of the health expense.

PATIENTS AND METHODS

The Authors' preliminary experience spreads from March to November 2003 when 4 patients were studied and thus underwent a transperitoneal laparoscopic adrenalectomy: 2 of them were affected by Cushing syndrome, 1 by pheochromocytoma in MEN and 1 by an incidentaloma. The transabdominal access in lateral decubitus with 4 trocars was performed.

RESULTS

No complication was reported with a minimal need of analgesic drugs. The mean hospital stay was 4 days and all patients were discharged 48 hours after surgery. The mean diameter of nodules was 40 +/- 30 mm. The definitive histological examination showed 2 cortical adenomas, 1 diffuse cortical hyperplasia and 1 pheochromocytoma.

CONCLUSIONS

This preliminary report confirms the optimal results of other experienced authors. Further interventions will be necessary for improvements and technical requirements.

T-Cell response to self HSP60 peptides in renal transplant recipients: a regulatory role?

T-cell responses to heat shock proteins (Hsp) have been suggested to play a role not only in inflammatory conditions, but also in various human autoimmune diseases and in the allograft response. Previous data from our group suggested that during the early posttransplantation (post-Tx) period (<6 months post-Tx), the anti-Hsp60 T-cell repertoires in renal transplant recipients were predominantly proinflammatory. In the later period, they were predominantly regulatory. In agreement with our results, diversification of the T-cell responses toward the carboxy-terminal determinants of Hsp60, related to the resolution of the inflammatory process, was shown in an experimental model of adjuvant arthritis. It has not been clarified whether this diversification is also present in transplantation. In this context, our objective was to analyze cytokine production against autologous Hsp60 peptides from different regions of the protein, using peripheral blood mononuclear cells of 9 renal transplant recipients at 2 timepoints after transplantation: early (<6 months) and late (>1 year). IFN gamma production induced by Hsp60 peptides was observed in 71% and 75% of the patients in the early and late post-Tx periods, respectively. Interleukin (IL)-10 production induced by Hsp60 peptides was observed in 28% of the patients in the early period and in 62% in the late period. Interestingly, the production of IL-10 was induced mainly by peptides of the intermediate and the C-terminal regions. This suggests a predominance of autoreactive regulatory anti-Hsp T-cell repertoire in the late post-Tx period, which predominantly recognize peptides from the intermediate and C-terminal regions of the protein.

[The surgical treatment of nodular thyroid lesions: our experience. Analysis of 462 cases]

Nodular thyroid lesions are the most frequent endocrine diseases in the general population. The surgical procedure is indicated for nodular thyroid tissue degeneration, or when the suppressive pharmacologic therapy is less efficient, even if sometimes both factors are associated. In Authors' study 462 patients were observed who underwent surgical procedures for thyroid diseases between January 1997-April 2003. In the thyroid pathology, either uninodular or multinodular, the surgical therapy adopted is total thyroidectomy, according to other Authors. The aim of total thyroidectomy is to avoid recurrence and simplify long term pharmacologic treatment. Although the question about the surgical approach (total thyroidectomy vs lobectomy) is still open in the case of single monolateral lesions, on the basis of their experience the Authors believe that the first is the best procedure. For diffused or malignant nodular thyroid pathology, on the contrary, total thyroidectomy is widely adopted.

[Obesity and mortality in advanced chronic renal failure patients]

A protective effect of obesity on the mortality of end-stage renal failure patients has been observed in several studies. Most of these studies have been based on prevalent dialysis population. The aim of the present study was to evaluate if obesity has beneficial effects on the survival of advanced chronic renal failure patients. The study group consisted of 376 patients (mean age 63 +/- 15 years) with advanced chronic renal failure not yet on dialysis. Obesity was defined as a body mass index (BMI) > or = 30 kg/m2. Grade of comorbidity was quantified by the method devised by Davies. Survival was analyzed as time from the referral to the predialysis outpatient clinic to patient death, censoring from contributing additional survival data to the analysis following transplantation. Kaplan-Meier analysis was used to test survival differences according to quartiles of BMI, and between obese and nonobese patients. Further analysis were performed, stratifying survival curves by comorbid scores, lean body mass, age, and sex. Cox proportional hazard regression models were used to investigate the best determinants of mortality, and the role of obesity adjusted for other covariates. Median survival time was 1,453 days. During the follow-up time, 158 patients (42%) died. Survival differences among quartiles of BMI were statistically significant (Breslow = 10.7, p = 0.017). Patients within the lowest and the highest quartiles of BMI had higher mortality than the rest of patients. Survival curves between obese and non-obese patients did not differ significantly. However, when patients without comorbidity were studied apart, those with obesity showed worse survival than the rest of patients (log-rank = 7.42, p = 0.0064). Since the effect of obesity on mortality did not follow a proportional hazard pattern throughout the study period, multivariable analysis for mortality was stratified by 18 months intervals. The variables which fitted the best model were: age (Hazard Ratio: 1.04), comorbid score (HR: 2.17), serum albumin (HR: 0.62), GFR at the study entry (HR: 0.91), male gender (HR: 1.48), and obesity (HR: 1.51). In conclusion, obesity had no survival benefit in patients with advanced chronic renal failure. Obesity had a noteworthy impact on early mortality of advanced chronic kidney disease patients without comorbidities.

[Progression of renal insufficiency in the pre-end-stage renal disease setting]

The rate of decline of renal function (RDRF) in the pre-end stage renal disease setting (pre-ESRD) is highly variable. Several factors have been involved as potential modifiers of renal failure progression. This retrospective study attempts to establish which were the main determinants of the RDRF in pre-ESRD patients followed in the predialysis consult. The study group consisted of 230 patients with pre-ESRD not yet on dialysis who were referred to the predialysis consult from January 1998 to July 2002. The mean follow-up time per patient was 356 days. RDRF was assessed as delta of the average of creatinine and urea clearances (CrCl-UCl). Data obtained at time of referral to the predialysis consult were analyzed as potential predictors of the subsequent RDRF. These independent variables included: demographics, comorbid conditions, main hematological and biochemical data, antihypertensive and statin treatment, mean blood pressure, and CrCl-UCl at time of referral. The predictors of delta CrCl-UCl were determined by multiple linear regression analysis. The determinants of the survival without dialysis were established by the Cox regression hazard model, adjusted to renal function at time of referral. Mean CrCl-UCl at time of referral was 10.98 +/- 2.58 ml/min/1.73 m2, and mean delta CrCl-UCl was -0.37 +/- 0.46 ml/min/1.73 m2/month. Patients with diabetic nephropathy and chronic glomerulonephritis had the fastest RDRF, while patients with ischemic nephropathy and chronic interstitial nephritis had the slowest RDRF. Seventy-five patients (46%) required EPO therapy. The best determinants of delta CrCl-UCl were: the 24-hour proteinuria (p < 0.0001), and the hematocrit at time of referral (p = 0.0024). The best determinants of the survival rate without dialysis during the study period were: the proteinuria (in g/24 hours) (R 1, 16; p < 0.0001), the hematocrit at time of referral (OR: 0.88; p < 0.0001), the treatment with EPO (OR: 0.59; p = 0.02), and the diagnosis of diabetes mellitus (OR: 1.59; p = 0.01). In conclusion, apart from the rate of proteinuria, which could represent the best marker of the RDRF in chronic renal diseases, the development of anemia was associated with faster decline in renal function.

[Differences between the glomerular filtration rate estimated by the MDRD equation and the measurement of creatinine and urea clearance in unselected patients with terminal renal insufficiency]

From the results of the Modification of Diet in Renal Disease (MDRD) study, a prediction equation for a more accurate estimate of glomerular filtration rate (GFR), was developed. The present study ais to compare the GFR estimated by MDRD formula and that calculated by the average of creatinine and urea clearances in unselected patients with advanced renal failure. The study group consisted of 320 (163 males) with advanced renal failure not yet on dialysis. Their mean age was 63 +/- 14 years. Diabetic nephropathy was the most common etiology of renal failure (25%). Significant comorbidity was observed in 115 patients. Serum creatinine (Cr), urea and albumin were determined in all patients. Creatinine (Ccr) and urea clearance (Cu) were calculated on a 24-hour urine collection. The GFR was estimated by summing Ccr and Cu, and dividing by two (Ccr-Cu). THe clearances were corrected for a body surface area of 1.73 m2. The MDRD formula for the estimation of GFR included the following parameters: serum Cr, BUN, age, gender and serum albumin. Linear regression analysis and Bland-Altmann plot were utilized to establish the degree of correlation and agreement between both estimations of GFR. The percent differences between the two estimations of GFR was especially analyzed in those subgroups of patients which were not included in the MDRD study (patients older than 70 years, diabetics and those with comorbid conditions). The mean GFR estimated by Ccr-Cu and by MDRD formula were 10.04 +/- 3.10 ml/min and 10.55 +/- 3.60 ml/min, respectively (p < 0.0001). The two parameters correlated significantly (R = 0.76, p < 0.0001). GFR by the MDRD formula tended to overestimate the highest values of Ccr-Cu. The mean percent difference between both methods was 6.5 +/- 23.6. MDRD predictive equation overestimated significantly Ccr-Cu in patients older than 70 years (mean overestimation of 15%), males (10%), diabetics (10%), and mainly in patients with comorbidity (17%). In conclusion, the GFR estimated by MDRD formula is very similar to Ccr-Cu in young uremic patients without comorbidity. However, major discrepancies between these two methods could be observed in older patients, and mainly in those with comorbidity.

Epidemic of jungle yellow fever in Brazil, 2000: implications of climatic alterations in disease spread

Seventy-seven human cases of sylvatic yellow fever were reported in Brazil during the period January-June 2000. The first cases were reported 1 week after New Year's day and originated at Chapada dos Veadeiros, a tourist canyon site in Goiás state, near Brasília, the Brazilian capital. The laboratory procedures used for diagnoses included serology with an IgM capture assay and plaque reduction neutralization test, virus isolation in suckling mice and C6/36 cells, and immunohistochemistry. All cases were diagnosed by at least two different laboratory procedures, with the exception of the first three fatal cases, which were diagnosed on the basis of clinical and epidemiological information. The cases were reported in eight Brazilian states as follows: Goiás with 64.9% (50 cases); Amazonas (1); Bahia (10); Distrito Federal (1); Mato Grosso (4); Minas Gerais (2); Pará (1); São Paulo (2); and Tocantins (6). Patient ages were within the following ranges: 13-74 years old (mean 34.3), 64 (84.4%) were male, especially agricultural workers (n = 30), but tourists (n = 11), carpenters (n = 4), fishermen (n = 4), students (n = 3), truck drivers (n = 3), and other people (n = 22) were also sickened. The case fatality rate was 50.6% (39/77). In Bahia state, a serologic survey that was carried out has suggested a symptomatic/asymptomatic coefficient of 1:4. Field studies developed in Distrito Federal, Goiás, and São Paulo states showed that Haemagogus janthinomys was the mosquito species associated with the transmission. A single strain was also obtained from Aedes scapularis in Bahia. Epizootic occurrence (monkey mortality) was observed in 49 municipalities mainly in Goiás state, where 40 municipalities made reports, 21 of which also diagnosed human cases. Data obtained by the National Institute of Meteorology in Brazil showed an increase in temperature and rain in December 1999 and the first 3 months of 2000 in Goiás and surrounding states, which perhaps has contributed to the intense and widespread transmission of the yellow fever virus. The relatively small number of cases probably reflects the extensive use of yellow fever 17D-vaccine during the last 3 years, in which about 45 million doses were used. During the last months of 1999, 16 and 11 yellow fever cases were reported in Tocantins and Goiás states, respectively. It is noteworthy that the last reported autochthonous cases of sylvatic yellow fever in São Paulo and Bahia, both states outside the endemic/enzootic area, had occurred in 1953 and 1948, respectively.

Recombinant cytochrome rC557 obtained from Escherichia coli cells expressing a truncated Thermus thermophilus cycA gene. Heme inversion in an improperly matured protein

Cytochrome rC(557) is an improperly matured, dimeric cytochrome c obtained from expression of the "signal peptide-lacking" Thermus thermophilus cycA gene in the cytoplasm of Escherichia coli. It is characterized by its Q(00) (or alpha-) optical absorption band at 557 nm in the reduced form (Keightley, J. A., Sanders, D., Todaro, T. R., Pastuszyn, A., and Fee, J. A. (1998) J. Biol. Chem. 273, 12006-12016). We report results of a broad ranging, biochemical and spectral characterization of this protein that reveals the presence of a free vinyl group on the porphyrin and a disulfide bond between the protomers and supports His-Met ligation in both valence states of the iron. A 3-A resolution x-ray structure shows that, in comparison with the native protein, the heme moiety is rotated 180 degrees about its alpha,gamma-axis; cysteine 14 has formed a thioether bond with the 2-vinyl of pyrrole ring I instead of the 4-vinyl of pyrrole ring II, as occurs in the native protein; and a cysteine 11 from each protomer has formed an intermolecular disulfide bond. Numerous, minor perturbations exist within the structure of rC(557) in comparison with that of native protein, which result from heme inversion and protein-protein interactions across the dimer interface. The unusual spectral properties of rC(557) are rationalized in terms of this structure.

Epidemic nephritis in Nova Serrana, Brazil

BACKGROUND

Outbreaks of nephritis have been rare since the 1970s. From December, 1997, to July, 1998, 253 cases of acute nephritis were identified in Nova Serrana, Brazil. Seven patients required dialysis, and three patients died. We did a case-control study to investigate the cause of the outbreak.

METHODS

Using a matched cluster design, we examined seven recent patients, their family members (n=23), and members of neighbourhood-matched control households (n=22). We subsequently interviewed 50 patients and 50 matched controls about exposure to various dairy products. We also cultured dairy foods and took udder-swab and milk samples from cows.

FINDINGS

Throat cultures indicated that nephritis was associated with group C Streptococcus equi subspecies zooepidemicus, a cause of bovine mastitis. S. zooepidemicus was detected in four of seven case households (six of 30 people) and no control households (p=0.09). Patients were more likely than matched controls to have consumed a locally produced cheese called queijo fresco (matched odds ratio 2.1, p=0.05). The nephritis attack rate was 4.5 per 1000 in Nova Serrana but 18 per 1000 in the village Quilombo do Gaia (p=0.003). The largest supplier of unpasteurized queijo fresco was a farm in Quilombo do Gaia. S. zooepidemicus was not detected in food samples or in swabs collected from cows in August, 1998, although mastitis was evident among cows on the suspected farm. Throat cultures of the two women who prepared cheese on this farm yielded the outbreak strain of S. zooepidemicus. After the cheese was removed from the distribution system, no further cases were reported.

INTERPRETATION

A large outbreak of glomerulonephritis was attributed to S. zooepidemicus in unpasteurised cheese. This outbreak highlights the dangers of consuming unpasteurized dairy products and need for global efforts to promote food safety.

Application of sulfobutylether-beta-cyclodextrin with specific degrees of substitution for the enantioseparation of pharmaceutical mixtures by capillary electrophoresis

In this research the separation of the enantiomers of the basic drug bidisomide (SC-40230) from five closely related known process impurities was investigated using several neutral and anionic sulfobutylether beta-cyclodextrins (SBE-beta-CDs) as isomer selectors. Several novel sulfobutylether derivative mixtures and purified charge types having a specific degree of substitution were used to study the effect of selector charge on the efficiency and selectivity of both chiral and achiral separations. The effects of run buffer pH, selector type, and selector concentration on the chiral separation of bidisomide and the achiral separation of the related process impurities was also investigated. The related process impurity, SC-47500, displayed significant peak tailing with SBE-beta-CD mixtures which contained mono- to deca-substituted cyclodextrins. This problem was explored using isolated SBE-beta-CD charge types having degrees of substitution from one to seven. Peak tailing increased as the charge on the selector increased, suggesting that the distortion was due to electrodispersion and the large countercurrent mobility of the negatively charged complexes. Pure charge types having a lower degree of substitution provided adequate chiral and achiral selectivity, while eliminating the severe peak distortion caused by electrodispersion. The complete analysis of the bidisomide enantiomers and the related impurities was achieved with a pH 2.5 running buffer containing 5-10 mM of the isolated sulfobutylether charge types SBE[2]ds(1)sr-beta-CD or SBE[3]ds(1)sr-beta-CD. These conditions gave baseline resolution of bidisomide enantiomers and all five impurities, thus allowing both chiral and achiral purity to be determined in a single run.

Recurrent acute scleroderma renal crisis complicated by thrombotic thrombocytopenic purpura

Acute renal crisis as an early manifestation of scleroderma is underemphasized, and its recurrence after initial successful therapy is rare. We describe a 32-year-old woman who presented with scleroderma renal crisis. A second episode of apparent renal crisis, however, was complicated by thrombotic thrombocytopenic purpura, which led to pancreatitis, a large cerebral infarction, and fatal outcome despite intensive therapy. This case illustrates the complexity and severity of diffuse systemic sclerosis presenting with multiple, major organ complications.

Active primary mirror support for the 2.1-m telescope at the San Pedro Mártir Observatory

We have designed and installed a new set of actuators for the suspension of the primary mirror of the 2.1-m telescope at San Pedro Mártir. This active optics system has allowed us to correct low-order aberrations identified by several wave-front analysis techniques.

Exercise echocardiographic correlates of transient dilatation of the left ventricular cavity on exercise thallium-201 SPECT imaging

Transient dilatation of the left ventricular cavity on exercise thallium perfusion imaging is recognized as a marker of significant coronary disease, but the mechanisms that produce this finding are not fully understood. We studied 32 patients who underwent exercise thallium imaging and exercise echocardiography to determine the changes in left ventricular cavity size that underlie transient dilatation. Left ventricular area from the apical four-chamber view was used to approximate left ventricular cavity size. There were 24 patients who did not have transient dilatation (group 1) and 8 patients who did have transient dilatation (group 2) on thallium imaging. Systolic area decreased from rest to exercise in group 1 patients but not in group 2 patients. There was no significant change in diastolic area from rest to exercise in either group 1 or group 2 patients. Thus, exercise-induced systolic dysfunction, manifested as a failure to decrease left ventricular systolic cavity size in exercise, may be an important mechanism in producing scintigraphic transient dilatation.

Identification of a novel, N7-deoxyguanosine adduct as the major DNA adduct formed by a non-bay-region diol epoxide of benzo[a]pyrene with low mutagenic potential

A metabolite of benzo[a]pyrene, 9-r,10-t-dihydroxy-7,8-c-oxy-7,8,9,10- tetrahydrobenzo[a]pyrene (BPDE-III), that is not thought to be involved in carcinogenesis has nevertheless been shown to bind extensively to DNA in vitro. The adducts formed by this non-bay-region diol epoxide in Chinese hamster ovary cells are much less mutagenic than those formed by an isomeric diol epoxide that is carcinogenic. We have isolated and characterized three major adducts formed by in vitro reaction of BPDE-III with DNA. The major adduct, accounting for over half of the total is formed by reaction of BPDE-III with the N7 position of dGuo and is recovered after enzymatic digestion as an N7-Gua adduct. A second major adduct involves the N2 position of dGuo, while the third adduct is tentatively identified as a C8-substituted dGuo. Little or no reaction with deoxyadenosine residues is detected. The N7 adduct is unstable in DNA at 37 degrees C and is released as the modified base with a half-life of about 24 h. This adduct lability apparently leads to single-strand breaks and alkali-sensitive sites in the DNA and may account in part for some of the biological properties of BPDE-III adducts. This represents the first description of an N7-dGuo adduct that is formed in DNA as the major adduct by a diol epoxide derived from a carcinogenic polycyclic aromatic hydrocarbon.

Reactive eosinophilic pulmonary vascular infiltration in patients with spontaneous pneumothorax

Prominent nonnecrotizing eosinophilic inflammation of muscular pulmonary arteries was seen in resected lung tissue from two patients with spontaneous pneumothorax. Other histologic features included reactive eosinophilic pleuritis (REP) and fibrobullous disease. Eosinophilic vascular infiltration was not contiguous to REP. In neither patient was there a specific and recognized cause of eosinophilic vasculitis. Both patients are without pulmonary symptoms 1 and 4 years after pneumothorax. Eosinophilic vascular infiltration initially suggested the diagnosis of allergic angiitis or pulmonary eosinophilic granuloma. These diagnoses were excluded by clinical and morphologic data. We subsequently reviewed 30 cases of lung tissue resected from patients with pneumothorax and found REP in 18 patients (60%) and mild pulmonary vascular and perivascular eosinophilia in five patients (17%). REP was present in all cases with eosinophilic vascular infiltration. We conclude that this eosinophilic vascular lesion is an unusual reaction in patients with REP and pneumothorax. Occasionally this lesion mimics allergic angiitis or eosinophilic granuloma. The pathogenesis is probably related to vascular transport of eosinophils to the injured pleural surface.

Disappearance of a left ventricular aneurysm on radionuclide ventriculography due to formation of a mural thrombus

Radionuclide ventriculography is an accepted method for diagnosing left ventricular aneurysms, but false-negative studies have been associated with a mural thrombus filling the left ventricular cavity. We describe a patient with a left ventricular aneurysm due to myocardial infarction whose aneurysm scintigraphically "disappeared" from serial radionuclide ventriculograms. This was documented echocardiographically and pathologically to be due to the formation of a large mural thrombus. Review of the literature suggests that radionuclide ventriculography and echocardiography may be complementary techniques in the diagnosis of left ventricular aneurysm. Echocardiography may remain diagnostic when a mural thrombus has caused the loss of the characteristic scintigraphic findings on radionuclide ventriculography.

Solution conformation of the (+)-cis-anti-[BP]dG adduct in a DNA duplex: intercalation of the covalently attached benzo[a]pyrenyl ring into the helix and displacement of the modified deoxyguanosine

This paper reports on the solution structure of the (+)-cis-anti-[BP]dG adduct positioned opposite dC in a DNA oligomer duplex which provides the first experimentally based solution structure of an intercalative complex of a polycyclic aromatic hydrocarbon covalently bound to the N2 of deoxyguanosine. The combined NMR-energy minimization computation studies were undertaken on the (+)-cis-anti-[BP]dG adduct embedded in the same d(C5-[BP]G6-C7).d(G16-C17-G18) trinucleotide segment of the complementary 11-mer duplex studied previously with the stereoisomeric trans adducts. The exchangeable and nonexchangeable protons of the benzo[a]pyrenyl moiety and the nucleic acid were assigned following analysis of two-dimensional NMR data sets in H2O and D2O solution. The solution structure of the (+)-cis-anti-[BP]dG-dC 11-mer duplex has been determined by incorporating intramolecular and intermolecular proton-proton distances defined by upper and lower bounds deduced from NOESY data sets as restraints in energy minimization computations. The benzo[a]pyrene ring of [BP]dG6 is intercalated between intact Watson-Crick dC5.dG18 and dC7.dG16 base pairs in a right-handed DNA helix. The benzylic ring is in the minor groove while the pyrenyl ring sacks with flanking dC5 and dC7 bases on the same strand. The deoxyguanosine ring of [BP]dG6 is not Watson-Crick base paired but displaced into the minor groove with its plane parallel to the helix axis and stacks over the sugar ring of dC5. The dC17 base on the partner strand is displaced from the center of the helix toward the major groove by the intercalated benzo[a]pyrene ring. This intercalative structure of the (+)-cis-anti-[BP]dG-dC 11-mer duplex exhibits several unusually shifted proton resonances which can be readily accounted for by the ring current contributions of the deoxyguanosine and pyrenyl rings of the [BP]dG6 adduct. Several phosphorus resonances are shifted to low and high field of the unperturbed phosphorus spectral region and have been assigned to internucleotide phosphates centered about the [BP]dG6 modification site. These studies define the changes in the helix at the central trinucleotide segment needed to generate the intercalation site for the covalently bound (+)-cis-anti-[BP]dG adduct.(ABSTRACT TRUNCATED AT 400 WORDS)

[Comparison of the new Granada medium and the ICON-strep B test in the detection of group B streptococci in pregnant patients]

The detection of group B streptococci by the ICON Strep-B test an enzyme immunoassay, and culture in new Granada Medium was compared in tubes and plates in a total of 200 vaginal specimens from pregnant women. The group B streptococci were cultured in new Granada medium from 33 of these specimens (incidence of 16.5%). Compared with culture in new Granada medium, the sensitivity and specificity of the ICON-Strep B test were 66.6 and 100%, respectively. Because of their poor sensitivity, we do not recommend the use of these rapid test as the only basis for GBS detection.

Use of differential scanning potentiometry in pharmaceutical analysis

The use of differential scanning potentiometry (DSP) to assay pure drugs and mixtures is illustrated through a set of model cases. The profiles obtained by scanning glycine (0.3 mmol), sulfanilamide (0.3 mmol), epinephrine (0.06 mmol), and norfloxacin (0.05 mmol) are reported, as well as the areas (A+, A-, and At) obtained in each scan. Such information is useful to assess identity and/or chemical purity and to get the pKa of the ionizing groups of the drugs. The degree of hydrolysis of a parenteral solution of procaine hydrochloride is also determined through DSP as an example of mixture assay. Comparison with conventional aqueous acid-based potentiometry shows that the new technique exhibits much better performance to assay small samples or samples carrying weak acidic and/or basic groups.

Hepatic localization of Tc-99m MAA during lower extremity venography

Hepatic localization of macroaggregated albumin particles has been observed previously in both superior and inferior vena cava obstruction. These reports have described focal regional hepatic uptake in porta hepatis or the left hepatic lobe in cases of SVC and IVC obstruction as well as global hepatic uptake in IVC obstruction. In this report of an unusual case of hepatic uptake of MAA during lower extremity venography, the entire liver and lungs were simultaneously visualized, presumably due to portal-to-systemic collateral flow pathways in the presence of inferior vena cava obstruction.

Computerized axial tomography in investigations of the rheumatoid knee

It is essential when deciding on the therapeutic approach to the rheumatoid knee--medical or surgical--to make a precise and thorough assessment of the joint situation as a whole. In order to overcome the limitations of traditional X-ray methods, the Authors used computerized axial tomography (C.A.T.) to study the knees of twenty rheumatoid arthritis patients. They analysed three particular sections: the first at the level of the subquadriceps bursa, the second through the femoral condyles, and the third through the proximal tibio-fibular joint. C.A.T. permits an assessment of the conditions of the muscles and any hypertrophy of the synovial membrane; this kind of investigation reveals them clearly. It was possible to make an accurate investigation of the femoro-patellar joint and of lesions involving the femoral condyles and tibial plate. The findings indicate that C.A.T. in the study of the rheumatoid knee provides information on the soft tissues that cannot be obtained by traditional radiological methods. It also shows with greater precision the extent and morphology of bone lesions to the joint heads, an extremely important question in planning the use of prostheses.

Effects of solvent medium on solubility IV: Comparison of the hydrophilic-lipophilic character exhibited by functional groups in ethanol-water and ethanol-cyclohexane mixtures

Solvent effects on the solubility of a set of structurally related solid compounds (Ax, Ay, etc.) in ethanol-water (system 1) and ethanol-cyclohexane (system 2) are compared by the equation, log Sy = Py log Sx + C. For a given structural change, Ax----Ay, it yields the respective medium-effects parameters, Py1 and Py2. They are used to compare the sensitivity of both solvent systems with the structural changes in the substrates by the equation, delta 12 = (Py1 - 1) - (1 - Py2). Structural changes involving the full replacement of the hydrogen atoms bonded to either O or N afford delta 12 less than 0, while those involving solely an increase in the alkyl chain of the substrates yield delta 12 greater than 0. A structural change where the donor-acceptor capacity of hydrogen bonding is maintained yields a delta 12 approaching zero.