Decline in the workload associated with the serodiagnosis of syphilis in a general hospital: 1994-2004

Syphilis re-emergence is a cause of concern. Our objective was to quantify the laboratory workload, incident cases and patient follow-up that syphilis has generated for 11 years in a large teaching hospital. An ecologic study including all samples submitted for syphilis serodiagnosis at our hospital from January 1994 to December 2004 was undertaken. Our laboratory processed 58,832 samples for syphilis serodiagnosis. From 1994 to 2004, the number of samples submitted for syphilis testing dropped by 11% (95% confidence interval [CI] 10-12, p<0.001). Syphilis was diagnosed in 443 patients. The incidences were 11, 3 and 8 per 100,000 inhabitants/year in 1994, 2000 and 2004, respectively. Only 42% (185) of patients had repeat tests and in 79% (146) of cases, the 1-year follow-up data were missing. The median follow-up was 9 months (interquartile range [IQR] 3-26). We detected a reduction in the effort to detect syphilis, despite an increase in its incidence and the low cost of syphilis screening. Efforts should be intensified to improve physician compliance with syphilis screening and follow-up guidelines.

Interaction of noise with excitable dynamics

In this paper, the interaction of noise with excitable dynamics of a three-electrode electrochemical cell is examined. Different scenarios involving both external and internal noise sources are considered. In the case of external noise, aperiodic stochastic resonance and regulation of the noise-induced spiking behaviour are investigated. In the case of internal noise, the interaction of intrinsic electrochemical noise with autonomous nonlinear dynamics is studied. The amplitude of this internal noise, determined by the concentration of chloride ions, is monotonically increased and the provoked dynamics are analysed. Our results indicate that internal noise, similar to its external counterpart, is able to induce regularity in the system response.

A Mediterranean age-comorbidity prognostic index for survival in dialysis populations

BACKGROUND

The most widely used prognostic indices for estimation of survival, including for dialysis patients, were described by Charlson, and an adaptation was proposed by Hemmelgarn for dialysis patients. We present the first age-comorbidity prognostic index (ACPI) designed in a Mediterranean incident dialysis population and examine its concordance with other prognostic indices.

METHODS

Incident dialysis patients were scored in relation to age and 11 diseases. Cox regression analysis was performed to construct multiple regression models, and diseases with a hazard ratio (HR) higher than 1.2 were included in the index. The impact of age was assessed by including it in a separate multivariate model. Scores were categorized in 3 levels of risk: low (0-1 points), medium (2-4 points) and high levels (5 or more points). The probability of survival of each group was calculated according to the Kaplan-Meier method, and receiver operating characteristic (ROC) curves were plotted to examine the concordance with other prognostic indices.

RESULTS

A cohort of 304 patients on hemodialysis (80%) and peritoneal dialysis was analyzed. Global mortality rate was 31% (93/304). The mean score was 4.41 +/- 2.84. Diseases that received the highest scores were ischemic heart disease (IHD) with chronic heart failure (CHF), and malignancies of less than 5 years of evolution. With regard to age, the maximum score was received by patients over 60 years old. The probability of survival at 3 years was 89%, 77% and 54% for low-, medium- and high-risk groups, respectively (log-rank test, 19; p=0.0001). The ROC curves showed similar areas for our index (0.749), the Charlson index (0.758) and Hemmelgarn index (0.708), but our index scored higher than Charlson in older patients, IHD with CHF, CHF, peripheral vascular disease and systemic diseases.

CONCLUSIONS

Although prospective external validation of this new index is required, this index adequately estimates the probability of survival at 3 years. The prognostic power of ACPI is similar to that of the Charlson index; however, relevant differences were found, concerning the weight of factors age, cardiovascular diseases and myocardial dysfunction. In end-stage renal disease we recommend estimating survival by indices established in incident dialysis patients, due to the particular comorbid conditions of this population.

Prevalence and management of potential candidates for simultaneous pancreas-kidney transplantation in a provincial setting

INTRODUCTION

Simultaneous pancreas-kidney (SPK) transplantation is the best therapeutic option for correctly selected diabetic patients with advanced chronic kidney disease (CKD).

OBJECTIVES

The objectives of this study were to quantify in a Spanish province the prevalence and incidence of type 1 and 2 diabetics with stage IV-V CKD who are potential candidates for SPK, and to analyze the selection for SPK in clinical practice.

MATERIALS AND METHODS

All patients with diabetic neuropathy (DN) in predialysis, hemodialysis, or peritoneal dialysis (PD) in our transplantation referral area (population, 1.8 million; data collection ended December 7, 2005) were examined for basic SPK criteria (NTO 2005 Consensus). A new assessment was performed 9 months later, including new possible recipients, and patients were classified as: follows in study, excluded after study, added to SPK waiting list, or SPK-transplanted.

RESULTS

In 2005, there were 1371 patients in dialysis or predialysis, including 179 (13%) with DN (41 type 1 and 138 type 2 DM); only 16 of these patients (8.9% of DN patients), 8.9 per million population (PMP), met the basic criteria for SPK transplantation. There were 68 with DN in predialysis, including 8 (11.7%) possible SPK candidates; 7 with DN in PD, no candidates for SPK; and 104 patients with DN in hemodialysis, including 8 (7.2%) SPK candidates. After 9 months, 7 new potential candidates were identified (incidence of 5.1 PMP/y). Of 23 possible candidates, 3 refused SPK, 7 awaited completion of study, 8 were excluded after study, 1 was on the SPK waiting list, and 7 underwent SPK transplantation.

CONCLUSIONS

In our setting, approximately 9% of DN patients with stage IV-V CKD were potential SPK candidates in 2005 and 2006. After completion of studies, less than half were eventually included on the waiting list, generating an effective demand for SPK of 2-4 new patients PMP/y.

The risk for depression conferred by stressful life events is modified by variation at the serotonin transporter 5HTTLPR genotype: evidence from the Spanish PREDICT-Gene cohort

We report results from the PREDICT-Gene case-control study nested in a prospective cohort designed to identify predictors of the onset of depression among adult primary-care attendees. We tested the potential gene-by-environment interaction between 5HTTLPR genotype at the serotonin transporter gene and previous exposure to threatening life events (TLEs) in depression. A total of 737 consecutively recruited participants were genotyped. Additional information was gathered on exposure to TLEs over a 6-month period, socio-demographic data and family history of psychological problems among first-degree relatives. Diagnoses of depression were ascertained using the Composite International Diagnostic Interview (CIDI) by trained interviewers. Two different depressive outcomes were used (ICD-10 depressive episode and ICD-10 severe depressive episode). Both the s/s genotype and exposure to increasing number of TLEs were significantly associated with depression. Moreover, the 5HTTLPR s/s genotype significantly modified the risk conferred by TLEs for both depressive outcomes. Thus, s/s homozygous participants required minimal exposure to TLE (1 TLE) to acquire a level of risk for depression that was only found among l/s or l/l individuals after significantly higher exposure to TLEs (two or more TLEs). The interaction was more apparent when applied to the diagnosis of ICD-10 severe depressive episode and after adjusting for gender, age and family history of psychological problems. Likelihood ratios tests for the interaction were statistically significant for both depressive outcomes (ICD-10 depressive episode: LR X(2)=4.7, P=0.09 (crude), LR-X(2)=6.4, P=0.04 (adjusted); ICD-10 severe depressive episode: LR X(2)=6.9, P=0.032 (crude), LR-X(2)=8.1, P=0.017 (adjusted)).

Tungstate administration improves the sexual and reproductive function in female rats with streptozotocin-induced diabetes

BACKGROUND

Diabetes induces great alterations in female reproductive function. We analyzed the effects of tungstate, an anti-diabetic agent, on the reproductive function of healthy and diabetic female rats.

METHODS

Healthy and streptozotocin-induced diabetic rats were treated with sodium tungstate (2 mg/ml in their drinking water) for 12 weeks. Markers of reproductive function and diabetes were measured in serum, and in uterus and ovaries by Western blot or RT-PCR. Reproductive function was also assessed by mating.

RESULTS

Diabetic rats showed great impairment of libido, which was accompanied by a total loss of fertility (P < 0.05) and a decrease in the serum levels of FSH (P < 0.05) and LH (P < 0.05) compared with healthy rats. Tungstate treatment of diabetic rats partially recovered libido while fertility rate increased to 66.6%. This improvement was accompanied by a recovery of serum FSH (to a level higher than healthy rats) and LH. Moreover, tungstate treatment normalized ovarian expression of GLUT 3 hexose transporter, and estrogen, progesterone and FSH receptors, whereas only GLUT 3 and FSH receptors were normalized in the uterus.

CONCLUSIONS

Our results indicate that the alterations in female reproduction in diabetes were partially reversed after tungstate treatment by a mechanism(s) involving the normalization of serum FSH and LH levels, and ovarian and uterine expression of FSH receptors and GLUT3.

Inactivation of calcium-dependent lactic acid bacteria phages by phosphates

The capacity of three phosphates to interrupt the lytic cycle of four specific autochthonal bacteriophages of lactic acid bacteria used as starters was assayed. The phosphates used (polyphosphates A and B and sodium tripolyphosphate-high solubility [TAS]) were selected on the basis of their capacity to sequester divalent cations, which are involved in the lytic cycle of certain bacteriophages. The assays were performed in culture media (deMan Rogosa Sharpe and Elliker broths) and reconstituted (10%, wt/vol) commercial skim milk to which phosphates had been added at concentrations of 0.1, 0.3, and 0.5% (wt/vol). Phosphate TAS was the most inhibitory one, since it was able to inhibit the lytic cycle of all bacteriophages studied, in both broths and milk. In broth, polyphosphates A and B inhibited the lytic cycle of only two bacteriophages at the maximal concentration used (0.5%), whereas in milk, they were not capable of maintaining the same inhibitory effect.

Genetic analysis of two influenza A (H1) swine viruses isolated from humans in Thailand and the Philippines

Influenza viruses A/Philippines/341/2004 (H1N2) and A/Thailand/271/2005 (H1N1) were isolated from two males, with mild influenza providing evidence of sporadic human infection by contemporary swine influenza. Both viruses were antigenically and genetically distinct from influenza A (H1N1 and H1N2) viruses that have circulated in the human population. Genetic analysis of the haemagglutinin genes found these viruses to have the highest degree of similarity to the classical swine H1 viruses circulating in Asia and North America. The neuraminidase gene and the internal genes were found to be more closely related to viruses circulating in European swine, which appear to have undergone multiple reassorting events. Although transmission of swine influenza to humans appears to be a relatively rare event, swine have been proposed as the intermediate host in the generation of potential pandemic influenza virus that may have the capacity to cause human epidemics resulting in high morbidity and mortality.

Experimental observation of different types of chaotic synchronization in an electrochemical cell

Chaotic synchronization for a pair of electrochemical oscillators is studied experimentally. The underlying bidirectional coupling between the two oscillators is achieved by immersing the two anodes in a common electrolytic solution. The horizontal distance between these two electrodes determines the strength of the coupling constant. On monotonically decreasing the distance between the two anodes, different domains of chaotic synchronization, namely, no, phase, lag, and complete synchronization, are identified. Furthermore, dynamics from the different transition intervals are also characterized.

Long-term outcome of acute tubular necrosis: a contribution to its natural history

As long-term outcome studies of acute renal failure (ARF) are scarce and non-homogeneous, we studied 187 consecutive acute tubular necrosis (ATN) patients without previous nephropathies, discharged alive from our hospital between October 77 and December 92 and followed-up until December 99 (range 7-22 years; median 7.2). Variables were analyzed at the time of the acute episode and during follow-up. In 2000-2001 a clinical evaluation was made in 58 of the 82 patients still alive. Ten patients were lost to follow-up and 95 died. In 59% death was related with the disease present when the ATN developed. Kaplan-Meir survival curve showed 89, 67, 50, and 40% at 1, 5, 10, and 15 years, respectively, after discharge. Survival curves were significantly better (log-rank P<0.001) among the youngest, those surviving a polytrauma, those without comorbidity and surprisingly those treated in intensive care units. The proportional Cox model showed that age (hazard ratio (HR) 1.04 per year of age; P=0.000), presence of comorbid factors (HR 4.29; P=0.006), surgical admission (HR 0.45; P=0.000), and male sex (HR 1.72; P=0.020) were the variables associated with long-term follow-up. In the evaluated patients renal function was normal in 81%. Long-term outcome after ARF depends on absence of co-morbid factors, cause of initial admission and age. Although the late mortality rate is high and related with the original disease, renal function is adequate in most patients.

[Control of the dialysis dose by ionic dialysance and bioimpedance]

INTRODUCTION

The ionic dialysance monitor allows an automated measure of Kt in each dialysis session. Bioelectrical impedance analysis (BIA) determines the total body water which it is equivalent to the urea volume of distribution (V). If the Kt, determined by ionic dialysance, is divided by the V, estimated by bioelectrical impedance, a Kt/V at the end of dialysis session (Kt/VDiBi) is obtained.

AIM OF THE STUDY

To evaluate the agreement between the Kt/VDiBi and the Kt/V obtained by two simplified formulas: the monocompartimental (Kt/Vm) and the equilibrated (Kt/Ve) Daugirdas equations.

METHODS

The Kt/VDiBi, the Kt/Vm and the Kt/Ve were determined in 38 hemodialysis patients (27 males and 11 females) in the same hemodialysis session. The patients were on dialysis three times a week for 3.5 to 4 hours. The V was determined by monofrequency bioelectrical impedance (50 kHz) at the end of the dialysis session.

RESULTS

The Kt/VDiBi, Kt/Vm and Kt/Ve were 1.29+/-0.26, 1.54+/-0.29 and 1.36+/-0.25, respectively (p<0.001 between the Kt/VDiBi and the KtVm, and p<0.001 between the KtV/DiBi and the Kt/Ve). The intraclass correlation coefficient showed better concordance between the KtV/DiBi and the Kt/Ve (coefficient 0.88) than between the Kt/VDiBi and the KtVm (coefficient 0.65). The relative difference of the Kt/VDiBi was 8.3+/-6.4% with respect to the Kt/Ve and 18.4+/-7.8 % with respect to the Kt/Vm (p<0.001). The relative difference between the Kt/VDiBi and the Kt/Ve was lower than 15% in the 84% of the patients and lower than 10% in the 64% of the patients.

CONCLUSIONS

If the V obtained by bioelectrical impedance analysis is included in the ionic dialysance monitor, we can obtain a Kt/V for each patient in real time, which is similar to the equilibrated Kt/V obtained from the Daugirdas equation.

[The Cockcroft-Gault equation is better than MDRD equation to estimate the glomerular filtration rate in patients with advanced chronic renal failure]

ABSTRACT The aim of this study was to compare the accuracy of three kidney function estimating equations: classic Cockcroft-Gault (classic CG), corrected Cockcroft-Gault (corrected CG) and simplified Modification of Diet in Renal Disease (MDRD), in patients with advanced chronic renal failure. The study was made in 84 nondialyzed patients with chronic renal disease in stage 4 or 5. The glomerular filtration rate was measured on a 24-hour urine collection as the arithmetic mean of the urea and creatinine clearances (CUrCr). In each patient, the difference between each estimating equation and the measured glomerular filtration rate was calculated. The absolute difference expressed as a percentage of the measured glomerular filtration rate indicates the intermethod variability. In the total group the glomerular filtration rate measured as the CUrCr was de 13,5+/-5,1 ml/min/1.73 m(2); and the results of the estimating equations were: classic CG 14,2+/-5 (p<0,05); corrected CG 12+/-4,2 (p<0,01) and MDRD : 12,1+/-4,8 ml/min/1.73 m(2) (p<0,01). The variability of the estimating equations was 15,2+/-12,2%, 17,1+/-13,4 % and 19,3+/-13,3% (p<0,05), for classic CG, corrected CG and MDRD respectively. The percent of estimates falling within 30% above o below the measured glomerular filtration rate was 90% for CG classic, 87% for corrected CG and 79% for MDRD. The intraclass correlation coefficients respect to CUrCr were 0,86 for classic CG, 0,81 for corrected CG and 0,77 for MDRD. The MDRD variability, but not classic CG variability or corrected CG variability, showed a positive correlation with the glomerular filtration rate (r=0,25, p<0,05). In patients with chronic renal disease in stage 5, the variability of the different estimating equations was similar. We conclude that in our population with advanced chronic renal failure the classic CG equation is more accurate than the MDRD equation. Corrected CG equation has not any advantage respect to classic CG equation.

Synchronization phenomena for a pair of locally coupled chaotic electrochemical oscillators: a survey

Chaotic synchronization of two locally coupled electrochemical oscillators is studied numerically. Both bidirectional and unidirectional couplings are considered. For both these coupling scenarios, varying the characteristics of the coupling terms (functional form and/or strength) reveals a wide variety of synchronization phenomena. Standard diagnostic tests are performed to verify and classify the different types of synchronizations observed.

The frequency of the JAK2 V617F mutation in patients with polycythemia vera and its correlation with severity of disease

6587

Background: The frequency of the JAK2 V617F mutation in patients with polycythemia vera (PV) has ranged from approximately 65–97% in published reports from different institutions. Moreover, its expression has been variably correlated with certain aspects of the disease. Therefore, we quantified its frequency in patients from our institution, and also determined if its presence correlated with severity or duration of disease. Methods: We used stringent criteria to diagnose the disease PV. This included an initial CR51 red blood cell mass (RBCM) and I131 plasma volume. All causes of secondary PV were excluded. In an earlier cohort of 61 patients, we found that an increased RBCM, exclusion of secondary PV, and the presence of 3 of the following reliably diagnosed the phenotype of PV: serum erythropoietin level ≤ 5 mU/ml, platelet count ≥ 400 × 109/L, splenomegaly, clonal cytogenetic abnormalities, and an abnormal bone marrow histology. Results: JAK2 determinations were sequentially performed on 71 treated and untreated patients. Of these, 68 (97%) were V617F positive by allele-specific PCR analysis determined by pyrosequencing peripheral blood leukocyte DNA. We then ranked 48 patients who had not been treated with either imatinib or interferon (which affects JAK2 expression) by percent mutant allele arranged in quintiles. The highest percent mutation (80–100%) was noted in 11 patients with a phenotype of advanced disease which included massive splenomegaly (7/11 patients) and marrow fibrosis (6/11 patients). In contrast, of the group expressing 0–20% JAK2, 0/5 patients had palpable splenomegaly and 0/5 had fibrosis. The patients in the 2nd, 3rd and 4th quintiles had varying degrees of splenomegaly and fibrosis. Duration of disease could not be correlated with JAK2 V617F expression in our patients. Conclusions: We conclude that the JAK2 V617F mutation is an effective marker for diagnosing patients with PV and correlates with severity, but not duration, of disease.

No significant financial relationships to disclose.

Imatinib mesylate is effective in the treatment of polycythemia vera: A multi-institutional clinical trial

6532

Background: We previously reported that the erythrocytosis of polycythemia vera (PV) was controlled with imatinib mesylate in a cohort of patients. This effect may involve inhibition of tyrosine phosphorylation of c-Kit, the stem cell factor receptor essential for erythroid progenitor cell proliferation. Methods: We report treating an expanded cohort of 37 PV patients with imatinib in a multi-institutional phase II trial. All patients had an increased 51Cr RBC mass determination at diagnosis and fulfilled the stipulated criteria for the diagnosis of PV. Men were initially phlebotomized to a hematocrit (HCT) ≤ 45%; women to HCT ≤ 42%. Imatinib was started at 400 mg qd escalating 100 mg every 2 weeks to a maximum of 800 mg for persistent phlebotomy (PHL) requirements or for platelet counts > 600 × 109/L. All patients received 81 mg of aspirin qd. Results: There were 21 men, 16 women, median age 51 years, range 29–83. Prior to imatinib, mean disease duration was 60.2 mos; average number of PHLs per year ranged from 0–23 (mean=9). After 1 year of imatinib, PHLs ranged from 0 to 9 (mean=2). There were 9 complete remissions (PHL-free, platelets ≤ 600 × 109/L, no splenomegaly) and 10 partial remissions (PHL and/or splenomegaly decreased by 50% of initial values with platelets ≤ 600 × 109/L, or platelets > 600 × 109/L but no PHL requirements or splenomegaly); 1 patient, protocol violation. Thus, of 36 evaluable patients, 19 (53%) responded. Of the remaining 17, 10 failed due to disease progression: myelofibrosis (n=2); platelets > 1,000 × 109/L with PHL and/or splenomegaly (n=2); repeated PHLs (n=1); cytogenetic abnormalities (n=1); increasing thrombocytosis (n=1); and a TIA (n=1). Seven of 17 with no remission developed toxicity: grade 3 dermatologic (n=2); grade 3 diarrhea (n=2); grade 3 bone pain (n=1), liver (n=1); heart failure (n=1). Median treatment duration: 17.2 months. Conclusions: We conclude that imatinib is useful for treating erythrocytosis and controlling splenomegaly in a significant proportion of PV patients, but is less effective for controlling thrombocytosis or splenomegaly in others. These data suggest heterogeneity of hematopoietic stem cell proliferation in PV or patient variability with respect to imatinib metabolism.

[Table: see text]

Comparative study of the new colorimetric VITEK 2 yeast identification card versus the older fluorometric card and of CHROMagar Candida as a source medium with the new card

The new VITEK 2 colorimetric card was compared to the previous fluorometric card for identification of yeast. API 20C was considered the "gold standard." The new card consistently performed better than the older card. Isolates from CHROMagar Candida plates were identified equally as well as those from Sabouraud dextrose agar.

[Temperature dialysate and hemodialysis tolerance]

In this study, the effect of dialysate temperature on hemodynamic stability, patients' perception of dialysis discomfort and postdialysis fatigue were assessed. Thirty-one patients of the morning shift were eligible to participate in the study. Three patients refused. Patients were assessed during 6 dialysis sessions: in three sessions the dialysate temperature was normal (37 degrees C) and in other three sessions the dialysate temperature was low (35.5 degrees C). To evaluate the symptoms along the dialysis procedure and the postdialysis fatigue, specific scale questionnaires were administered in each dialysis session and respective scores were elaborated. Low temperature dialysate was associated with higher postdialysis systolic blood pressure (122 +/- 24 vs. 126 +/- 27 mmHg, p < 0.05), and lower postdialysis heart rate (82 +/- 13 vs. 78 +/- 9 beats/min, p < 0.05) with the same ultrafiltration rate. Dialysis symptoms score and postdialysis fatigue score were better with the low dialysate temperature (0.7 +/- 0.9 vs. 0.4 +/- 1 vs. p < 0.05, and 1.3 +/- 1 vs. 1 +/- 0.9 p < 0.05, respectively). Furthermore, low temperature dialysate shortened the post-dialysis fatigue period (5.4 +/- 6.3 vs. 3.1 +/- 3.3 vs. hours, p < 0.05). The clinical improvement experimented with the low temperature dialysate was not universal. A beneficial effect was exclusively observed in the patients with higher dialysis symptoms and postdialysis fatigue scores or having more than one episode of hypotension in a week. The patients were asked about their temperature preference, 7 patients (23%) request a dialysate at 37 degrees C, 19 patients (61%) prefered to be dialysed with the low temperature dialysate, and 5 patients (16%) were indifferent. The later two groups of the patients continued with the low temperature dialysate during other 4 weeks. At the end of that period, the clinical improvement remained unchanged. In summary, low temperature dialysate is particularly beneficial for highly symptomatic patients.