Poster Session II: Alternating orientation of the chromatic pattern VEP improves signal even in the absence of contrast adaptation

The visual evoked potential (VEP) to chromatic pattern reversal is greatly reduced compared to VEPs to pattern onsets. Chromatic pattern onsets produce large and stereotypical waveforms that reliably differ from standard achromatic pattern reversal VEP waveforms used in clinical applications. Rapid contrast adaptation for sustained chromatic but not transient achromatic mechanisms has been suggested as one explanation for these observations. Here we first examined changes in the magnitude of response during recordings to reversing and onset grating patterns that preferentially modulate the L-M, S, and achromatic pathways. Given the evidence for both chromatic and achromatic orientation-selective mechanisms, we then hypothesized that contrast adaptation may be reduced by changing the orientation of the pattern for each reversal or onset. VEPs were recorded for 60 s with 2 onsets/reversals per second using both fixed and alternating (horizontal/vertical) orientations. FFT amplitudes for 6-second windows did not reveal evidence of adaptation for chromatic or achromatic onsets or reversal patterns over the 60-second recording period. Despite this, alternating pattern orientation increased the signal for all chromatic but not achromatic conditions. Although alternating the orientation for reversals increased the signal, the onset responses were still larger, even for non-alternating orientations. Mechanisms other than contrast adaptation must be invoked to explain the results.

Dynamic properties and the roton mode attenuation in liquid 3He: ab initio study within the self-consistent method of moments

The dynamic structure factor and the eigenmodes of density fluctuations in liquid ³He are studied using a novel non-perturbative approach. This new version of the self-consistent method of moments invokes up to nine sum rules and other exact relations, the two-parameter Shannon information entropy maximization procedure, and the ab initio path integral Monte Carlo simulations which provide necessary reliable input information on the system static properties. Detailed analysis is performed of the collective excitations dispersion relations, the modes' decrements and the static structure factor of ³He at the saturated vapour pressure. The results are compared to available experimental data by Albergamo et al. (Albergamo et al. 2007 Phys. Rev. Lett. 99, 205301. (doi:10.1103/PhysRevLett.99.205301)) and Fåk et al. (Fåk et al. 1994 J. Low Temp. Phys. 97, 445-487. (doi:10.1007/BF00754303)). The theory reveals a clear signature of the roton-like feature in the particle-hole segment of the excitation spectrum with a significant reduction of the roton decrement in the wavenumber range [Formula: see text]. The observed roton mode remains a well-defined collective mode even in the particle-hole band, where it is strongly damped. The existence of the roton-like mode in the bulk liquid ³He is confirmed like in other quantum fluids. The phonon branch of the spectrum is in a reasonable agreement with the same experimental data. This article is part of the theme issue 'Dynamic and transient processes in warm dense matter'.

Cetylpyridinium Chloride Mouthwash to Reduce Shedding of Infectious SARS-CoV-2: A Double-Blind Randomized Clinical Trial

The airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) via respiratory fluids and droplets suggests that mouthwashes containing substances with virucidal activity can help reduce viral spread. We conducted a multicenter, double-blind, placebo-controlled, randomized trial to assess the virucidal activity of cetylpyridinium chloride (CPC) mouthwashes. Outpatients who tested positive for SARS-CoV-2 infection with or without symptoms were randomized to perform washes and gargles for 1 min with 15 mL of either colored distilled water or 0.07% CPC (Vitis CPC Protect) mouthwash. The study outcomes were the SARS-CoV-2 log₁₀ viral RNA load and the nucleocapsid protein levels, both in saliva at 1 and 3 h after the intervention. In total, 118 patients were enrolled and randomized (mean [SD], age 46 [14] y). Thirteen of 118 participants (11%) did not complete follow-up or had insufficient sample volume for testing and were excluded from the analysis. The assessment of the viral load showed no significant differences between groups at any of the investigated points. However, the levels of SARS-CoV-2 nucleocapsid protein of lysed viruses were significantly higher in the CPC group compared with the control group at 1 h (adjusted difference 269.3 pg/mL; 95% confidence interval [CI], 97.1-441.5) and at 3 h postintervention (561.1 pg/mL; 95% CI, 380.0-742.2). In nonhospitalized patients with asymptomatic or mild symptomatic SARS-CoV-2 infection, a 0.07% CPC mouthwash, compared to placebo, was associated with a significant increase of nucleocapsid protein levels in saliva, indicating enhanced disruption of viral particles.

Correlation of eGFR By MDRD and CKD-EPI Formula with Creatinine Clearance Estimation in CKD Patients and Healthy Subjects

This cross sectional comparative study was conducted in the Nephrology and Medicine outdoor and in-patients department of Mymensingh Medical College Hospital, Bangladesh from April 2014 to March 2015. A total of 100 patients with CKD and 100 healthy subjects were included in the study. Data were collected by interview of the patients, clinical examination and laboratory investigations using a semi-structured case record form. Among all subjects, 50.0% had no CKD and 50.0% patients had CKD: Stage 3 CKD were 8.5%, CKD Stage 4 CKD were 21.0%, CKD Stage 5 CKD were 20.5%. Serum creatinine was 4.32±3.08mg/dl in patients with CKD and 1.00±0.22mg/dl was in healthy subjects. Mean±SD of CCR/ml/min was found 17.67±11.63ml/min in patients with CKD and 79.31±13.31ml/min was found in healthy subjects. On the other hand, Mean±SD CCCR/ml/m/1.73m² was found 19.79±12.85 ml/m/1.73m² in patient with CKD and healthy subjects had 83.83±13.33 ml/m/1.73m². Urinary creatinine was 45.59±15.63 & 57.66±11.45mg/dl respectively. CKD-EPI eGFR was 22.10±15.02 & 90.61±23.27ml/m/1.73m²; MDRD eGFR was 22.15±14.18 & 89.35±26.19 ml/m/1.73m² respectively. Difference between all the variables between CKD group and healthy group was found statistically significant (p<0.001). CKD-EPIeGFR and MDRDeGFR were increased both in CKD patients and healthy subjects in respect to CCR and CCCR. There was a strong positive correlation between CCCR (ml/m/1.73m2) and CKD-EPI (ml/m/1.73m²) among all patients (r=0.934 and p<0.001) and also a positive correlation of CCCR with MDRD among all patients (r=0.913 and p<0.001). A positive correlation of CCCR was found with CKD-EPIeGFR among CKD patients (r=0.848 and p<0.001). A positive correlation of CCCR was also found with MDRDeGFR among CKD patients (r=0.841, p<0.001). There are positive correlations between CCCR and CKD/EPI among healthy subjects (r=0.616 and p<0.05) and between CCCR with MDRD among healthy subjects (r=0.568 and p<0.05). Various formulae were used to calculate GFR on the basis of serum creatinine levels. The Overall correlation of population (healthy and CKD patients) between CCCR and CKD EPI and MDRD formula was (r=0.93 and 0.91) respectively, among CKD patients it was (r=0.848 and r=0.841) in healthy subjects it was (r=0.616 and r=0.568) respectively. CKD EPI eGFR and MDRD eGFR formula had fairly good correlation with conventional 24 hours creatinine clearance in both CKD patient and healthy subjects, there was even more strong correlation especially in CKD patients. The performance of CKD-EPI equation is better than MDRD equation to estimate the eGFR in both CKD patients and healthy subjects.

Acute Kidney Injury in Patients with Acute Viral Hepatitis: A Study in a Tertiary Care Hospital

This cross sectional observational study was done in the Department of Medicine, Mymensingh Medical College Hospital (MMCH), Mymensingh, Bangladesh from May 2013 to April 2014 to find out the proportion of acute kidney injury among patients with acute viral hepatitis and to identify risk factors associated with development of acute kidney injury (AKI). A total of 100 patients with acute viral hepatitis were included purposively as study subjects. Among them 61 were male and 39 were female. They were divided into AKI group (n=6) and non-AKI group (n=94) on the basis of development of AKI. There was no significant difference in mean age (39.0±13.1 years vs. 32.2±10.8 years, p=0.335) and sex (67% vs. 61% & 33.0% vs. 39.0%) p=0.769) between AKI group and non-AKI group. There were 27% acute viral hepatitis A, 21% acute viral hepatitis B and 52% acute viral hepatitis E but no case of acute viral hepatitis C was found in this study. Acute kidney injury (AKI) developed in 6 of 27 patients with acute viral hepatitis A. This study showed that 22.2% patients with acute viral hepatitis A developed acute kidney injury but patients with acute viral hepatitis B (HBV) and hepatitis E (HEV) did not develop acute kidney injury. Majority of the patients with acute kidney injury were smokers and hypertensive with elevated mean arterial pressure (p=0.0001) at presentation and had higher total bilirubin (p=0.0001), alanine aminotranseferase values (p=0.040), prolonged prothrombin time (INR) {p=0.0001}, lower albumin (p=0.0001), lower haematocrit level (p=0.0001), high CRP concentration (p=0.0001), leucocytosis (p=0.0001) and thrombocytopenia (p=0.0001) at presentation than patients without acute kidney injury. It is evident from the study that acute kidney injury is not a rare complication in patients with acute viral hepatitis.

Outcome of Pregnancy Related Acute Kidney Injury Observed in a Tertiary Care Hospital

This prospective case control study was carried out in Mymensingh Medical College Hospital (MMCH) from April 2011 to March 2012. The main objective of the study was to determine the short term maternal outcome of pregnancy related Acute Kidney Injury and to identify aetiological factors and to observe clinical features of pregnancy related Acute Kidney Injury. Total 60 pregnant women with AKI were included in the study as sample and equal (60) number of pregnant women with normal renal function was taken as control. Mean ages (±SD) of study and control group were observed 31.6±6.9 years and 25.5±4.7 years respectively. It was observed that most patients were from rural area with low income group. Most women were multiparous and presented in third trimester and postpartum period. Majority of the study subjects did not receive antenatal care at any stage of pregnancy. Fifty (86.7%) of the study subjects were oligo-anuric, forty-nine (81.7%) were edematous and fifty one (85%) were anaemic. Twenty-five (41.7%) patients presented with abnormal vaginal bleeding. Sepsis (including septic abortion and puerperal sepsis) was responsible for of Pregnancy Related AKI (PR-AKI) in more than two fifths of cases. Haemorrhage (APH & PPH combined) was the next common cause of Pregnancy Related AKI (PR-AKI). Toxemia of Pregnancy was responsible in one fourth of cases. Dialysis (HD & IPD combined) was required for two fifths of the patients. Rest patients were treated conservatively with antibiotics, blood transfusion, maintenance of fluid and electrolytes balance etc. Maternal outcome of Pregnancy related acute kidney injury was considered for the period of patient's hospital staying. 56.6% patients recovered completely, 15.0% patients recovered partially, 6.7% did not recover at the time of hospital discharge; while 21.7% died. So it can be concluded that, pregnancy related acute kidney injury is a critical condition, associated with worse prognosis.

Mycophenolate as induction therapy in lupus nephritis with renal function impairment

BACKGROUND

Mycophenolate (MF) is effective as induction therapy for lupus nephritis (LN) in patients with normal renal function; however, little is known about its role in patients with impaired renal failure. The purpose of this study was to evaluate the response to MF in LN and its association with baseline renal function.

METHODS

Data were obtained for 90 patients from 12 Spanish renal units who were receiving MF as induction therapy for LN. Patients were classified into 2 groups: group 1 (estimated glomerular filtration rate [eGFR] ≥60 ml/min/1.73 m(2)) and group 2 (eGFR <60 ml/min/ 1.73 m(2)). The primary outcome measure was the percentage of patients who achieved any response and its relationship with initial eGFR. The secondary outcome measures were the percentage of patients who achieved a complete response (CR) or partial response (PR) and the appearance of relapses during treatment and side effects.

RESULTS

At initiation of MF treatment, there were no differences in the main parameters between group 1 (n = 63; eGFR 87 ± 23 ml/min/ 1.73 m(2)) and group 2 (n = 27; eGFR 44 ± 12 ml/min/1.73 m(2)). Exposure to prednisone and MF was similar. The percentages of patients who achieved a response in groups 1 and 2 were, respectively, 69.2 and 43.8% at 6 months and 81.3 and 73.7% at 12 months. CR was more frequent in group 1, whereas PR was similar in both groups. Four patients relapsed and side effects were unremarkable.

CONCLUSIONS

MF is effective and safe as induction therapy for LN, and response is even achieved in patients with baseline renal impairment.

Axonal loss in the retinal nerve fiber layer in patients with multiple sclerosis

Objective

To quantify axonal loss in the retinal nerve fiber layer (RNFL) in patients with multiple sclerosis (MS), with and without a history of optic neuritis, by means of ocular imaging technologies.

Methods

This cross-sectional study enrolled 50 patients with MS and 25 age- and sex-matched healthy controls. All patients underwent neurologic assessment and a complete ophthalmic examination that included visual acuity, visual field examination, optical coherence tomography (OCT), scanning laser polarimetry (GDx) and visual evoked potentials (VEPs). Visual parameters and RNFL measurements were evaluated in MS eyes with a prior optic neuritis episode (MS-ON), with no prior episode (MS-NON) and control subjects.

Results

There were significant differences ( p < 0.05, analysis of variance) between MS-ON ( n = 25 eyes) and healthy eyes ( n = 25 eyes) for all RNFL parameters measured by OCT and GDx. Significant differences between MS-NON ( n = 75 eyes) and healthy eyes were also found for most of these parameters. RNFL thickness in the temporal quadrant was the parameter with the greatest differences between groups (71.79 μm in healthy eyes, 60.29 μm in MS-NON and 53.92 μm in MS-ON, p < 0.0005). Although there was a highly significant but moderate correlation between RNFL thickness and duration of the disease, no correlation was observed between RNFL thickness and neurologic impairment (Expanded Disability Status Scale).

Conclusions

Axonal loss was detected not only in MS eyes with a previous acute optic neuritis, but also in MS eyes with no known optic neuritis episode. Structural abnormalities correlate with functional assessments of the optic nerve.

[Renal involvement in benign monoclonal gammopathies: an underdiagnosed condition]

Renal involvement is observed frequently in association with malignant gammopathies, mainly those related to light chain deposition, although has also been described in non-malignant monoclonal gammopathy. This study reports the clinicopathological findings and outcome in 9 patients with nephropaty secondary to monoclonal immunoglobulin deposit in absence of malignancy. They were three men and six women and they were 59.2+/-12 years old. All patients presented proteinuria and different levels of renal insufficiency (mean creatinin = 315+/-187 micromol/L) at the moment of diagnostic. Two patients required dialysis at the time of renal biopsy. The pathology studies revealed a nodular sclerosing glomerulopathy in four cases, mesangiocapilary glomerulonephritis in three cases, only tubular lesions in one and mesangial lesions in the other one. The treatment applied was: Prednisone alone (two cases), with chemotherapy associated (melfalan in two, clorambucil in one and ciclophosphamide in another one). One patient received plasmapheresis and mycophenolate and another patient undergone a bone marrow authotransplant associated to mycophenolate and prednisone. One of the two patients who required dialysis at the moment of presentation was not treated. After a follow-up of more than 4 years (4.89 +/-DE: 3.69) renal function improved or remained stable in three patients and proteinuria was disappeared in more than 50% of patients. Four patients had a worsening of renal function and they required dialysis during the time of follow-up (in 2,4 years +/- DE: 4,3). In any case malignitation was observed. Chemotherapy stabilized or improved renal function in 3 of nine patients (33%) with non-malignant monoclonal gammopathy. Non-malignant monoclonal gammopathy could go unnoticed. Appearance of abnormalities in renal routine tests deserves more in-depth diagnostic procedures, including renal biopsy. Evolution to end stage renal disease could probably be avoided or reduced in severity with early detection and treatment of this entity.

[Advances in primary glomerular disease in 2007]

The most relevant articles published in the field of glomerular disease in 2008 are reviewed in this study. They mostly deal with membranous nephropathy and IgA nephropathy. Regarding treatment of membranous nephropathy presenting with nephrotic syndrome and normal renal function, the good remission rates and excellent long-term renal survival of cyclophosphamide and prednisone are confirmed. Cyclosporine A and tacrolimus are less aggressive options. Cyclosporine A was shown to be an effective alterative compared to alkylating agent and prednisone, whereas tacrolimus emerged as a solid alternative. Both share few side effects and high relapse rates. In cases of membranous nephropathy presenting with nephrotic syndrome and incipient renal failure, mycophenolate mofetil has a response rate comparable to cyclophosphamide and prednisone, but with a higher relapse rate. With regard to IgA nephropathy, the prognostic importance of histology and proteinuria was confirmed. Thus, the risk of progression can be well stratified by subdivision of Lee's classification from 5 to 3 classes. Proteinuria is another very important risk factor for progression and its reduction (partial remission) improves the prognosis. Over this last year, advances have been published in the field of noninvasive diagnosis of this entity and in this regard sub-galactosidate IgA levels are important. Regarding treatment, ACEIs (benazepril) have been shown to improve the prognosis in IgA nephropathy with proteinuria between 1-3 g/day.

[Histoplasmosis in a renal transplant patient]

The case of a Spanish kidney transplant patient who developed disseminated histoplasmosis approximately one year and a half after transplantation without having previously visited or travelled to endemic areas of histoplasmosis is presented. To our knowledge this is the first case of this disease in a kidney transplant patient in Spain without epidemiologic antecedent. The study of anti-histoplasm antibodies by complement fixation of the donor and recipient did not safely clarify the mechanism of contagion.

[IgA nephropathy with crescentic glomerulonephritis and ANCA positive]

We present a case of IgA nephropathy diagnosed by renal biopsy that presents after 2 years of folow-up an impairment of the renal function associate histoligically to a crescentic glomerulonephritis. The immunologic determinations showed of high titers of antineutrophil cytoplamic antibodies (ANCA) (P-ANCA IgG antiMPO and P-ANCA IgA anti-MPO). The patient began treatment with haemodyalisis and one year later she received a cadaveric kidney transplantation with good result. Two years later she had normal urine sediment, negative proteinuria, normal renal function but high titers of IgG and IgA PANCA anti-MPO. In summary, we believe that the determination ANCA in acute renal failure due to IgA nephropathy can indicate the existence of a IgA crescentic glomerulonephritis superimposed or an associated small vessel vasculitis and it confers a worse prognosis. The positive maintenance of IgG P-ANCA anti-MPO IgG anti-MPO titers during the course suggests that the sequential determination of ANCA in this entity is not useful to the monitoring of the clinical activity.

Schwann cell-autonomous role of neuropilin-2

Neuropilins and group A plexins are components of receptor complexes for class 3 semaphorins, gradients of which help to guide migration of neural progenitor cells and axonal growth cones during development. We demonstrated previously that neuropilins and class 3 semaphorins are induced in sciatic nerve by crush or transection. We now report that in cultured rat Schwann cells, expression of mRNA encoding neuropilin-2 (NRP2) and plexin-A3 (PlexA3), proteins involved in semaphorin-3F (Sema3F) signal transduction, is diminished markedly by forskolin, an adenylate cyclase activator that, like axonal contact, induces Schwann cell synthesis of myelin lipids and proteins. Interestingly, Schwann cell expression of mRNA encoding NRP1, which participates in Sema3A signaling, is not downregulated by forskolin. Antibodies that recognize ectodomains of NRP2 but not control antibodies prevented cultured Schwann cells from aligning in parallel and forming columns. These results are consistent with the view that in nerves undergoing Wallerian degeneration, Schwann cell NRP2 facilitates assembly of Schwann cells into the tubular aggregates (bands of Büngner) that guide regenerating axons.

Comparison of anti-PR3 capture and anti-PR3 direct ELISA for detection of antineutrophil cytoplasmic antibodies (ANCA) in long-term clinical follow-up of PR3-ANCA-associated vasculitis patients

A total of 118 sera from 11 patients with anti-neutrophil cytoplasmic antibodies against proteinase-3- (PR3-ANCA) associated vasculitis were retrospectively screened by anti-PR3 capture and anti-PR3 direct ELISA tests. We studied the relationship between capture and direct ELISA scores and the clinical activity of PR3-ANCA-associated vasculitis patients during follow-up. We also studied the ability of the anti-PR3 capture ELISA to detect positive values of PR3-ANCA in clinical vasculitis relapses. Only capture ELISA presented a significant relationship (p < 0.05) with clinical activity of PR3-ANCA-associated vasculitis patients over time. Capture ELISA appears to be a reliable method for detecting clinical relapses in this group of patients. Our results indicate that the new capture ELISA test is more effective than direct ELISA in the follow-up of patients with PR3-ANCA-associated vasculitis and in the detection of relapses.

[Rapid-detection GBM-ANCA ELISA. An emergency tool for the early diagnosis of type I and II rapidly progressive glomerulonephritis]

Rapidly progressive glomerulonephritides (RPGN) are forms of necrotizing glomerulonephritis associated with anti-glomerular basement membrane (anti-GBM) and anti-neutrophil cytoplasmic antibodies (ANCA) against the antigens proteinase-3 (anti-PR3) and myeloperoxidase (anti-MPO). RPGN have a course of rapid progression to renal failure. We compared the results from the semiquantitative ELISAs for anti-GMB antibodies, PR3-ANCA and MPO-ANCA and the indirect immunofluorescence technique (IIF) against a new rapid assay (30 minutes) for the same antibodies in patients with clinically suspected RPGN. The semiquantitative ELISAs for anti-GBM antibodies and PR3-ANCA and MPO-ANCA have a proven diagnostic significance in patients with RPGN I and III. There were no significant differences between the ANCA-GBM screening test and the results from the semiquantitative ELISAs (p > 0.05). We did not find significant differences between the results for PR3-ANCA and MPO-ANCA from the ANCA-GBM screening test with C-ANCA and P-ANCA IIF values (p > 0.05). We also corroborated that the ANCA-GBM screening test is a diagnostic tool for RPGN I and III as useful as the semiquantitative ELISAs and the IFF technique. The ANCA-GBM ELISA screening test is a tool as useful as the semiquantitative ELISA against anti-GBM antibodies for diagnosis of RPGN I. The comparison of the screening ELISA with the IIF technique and the semiquantitative ELISAs against PR3-ANCA and MPO-ANCA showed similar utility for diagnosis of RPGN III. The advantages of the new screening assay are that three antibodies are tested at the same time, yielding results in only 30 minutes.

Circulating soluble adhesion molecules in ANCA-associated vasculitis

BACKGROUND

To evaluate whether changes in concentrations of soluble (s) E-selectin, sP-selectin, sL-selectin, intercellular adhesion molecule 1 (sICAM-1), and vascular cell adhesion molecule 1 (sVCAM-1) reflect disease activity in patients with ANCA-associated vasculitis and whether serum levels of these adhesion molecules are related to the degree of renal failure in patients with chronic renal failure (CRF).

SUBJECTS AND METHODS

A sandwich ELISA was used to measure these soluble adhesion molecules in (i) sera from 20 patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (10 patients with Wegener's granulomatosis (WG) and 10 patients with microscopic polyangiitis (MPA)), obtained at the time of diagnosis and during the remission period; (ii) sera from 40 patients with CRF not undergoing haemodialysis.

RESULTS

At the time of diagnosis, serum levels of sE-selectin, sICAM-1 and sVCAM-1 (88+/-42 ng/ml, 437+/-184 ng/ml, 1720+/-1174 ng/ml respectively) were significantly higher in patients with ANCA-associated vasculitis than in healthy controls (P<0.0001, P=0.002 and P=0.001 respectively). Serum sP-selectin values did not differ from those obtained in normal donors. In contrast, sL-selectin levels (940+/-349 ng/ml) were significantly lower in patients than those recorded in healthy controls (P<0.0001). A significant decrease in concentrations of sE-selectin, sP-selectin, sICAM-1, and sVCAM-1 was observed between active and remission phases (P<0.0001, P=0.002, P=0.001 and P=0.001 respectively). No significant differences were observed in sL-selectin levels between active and remission phases. sL-selectin concentrations (802+/-306 ng/ml) during the remission phase remained lower than those observed in healthy controls (P<0.0001). No correlation was observed between serum creatinine and sE-selectin, sP-selectin, sICAM-1 and sVCAM-1 in patients of the CRF group. A slight negative correlation was established between creatinine and sL-selectin concentration.

CONCLUSIONS

Increased serum levels of sE-selectin, sICAM-1, and sVCAM-1 and decreased levels of sL-selectin in active ANCA-associated vasculitis, and the normalization of sE-selectin, sICAM-1, and sVCAM-1 during the remission phase suggest that the concentration of soluble levels of these adhesion molecules reflects disease activity. The decrease in sP-selectin levels between active and inactive phases also suggest that this receptor may reflect clinical activity. The lack of correlation between serum levels of sE-selectin, sP-selectin, sICAM-1, and sVCAM-1 and the degree of renal failure in patients with CRF suggests that the mechanism of clearance of these molecules is not renal.

Proteolytic degradation of tyrosine nitrated proteins

Tyrosine nitration is a covalent posttranslational protein modification that has been detected under several pathological conditions. This study reports that nitrated proteins are degraded by chymotrypsin and that protein nitration enhances susceptibility to degradation by the proteasome. Chymotrypsin cleaved the peptide bond between nitrated-tyrosine 108 and serine 109 in bovine Cu,Zn superoxide dismutase. However, the rate of chymotryptic cleavage of nitrated peptides was considerably slower than control. In contrast, nitrated bovine Cu,Zn superoxide dismutase was degraded at a rate 1. 8-fold faster than that of control by a gradient-purified 20S/26S proteasome fraction from bovine retina. Exposure of PC12 cells to a nitrating agent resulted in the nitration of tyrosine hydroxylase and a 58 +/- 12.5% decline in the steady-state levels of the protein 4 h after nitration. The steady-state levels of tyrosine hydroxylase were restored by selective inhibition of the proteasome activity with lactacystin. These data indicate that nitration of tyrosine residue(s) in proteins is sufficient to induce an accelerated degradation of the modified proteins by the proteasome and that the proteasome may be critical for the removal of nitrated proteins in vivo.

Proteolytic degradation of tyrosine nitrated proteins

Tyrosine nitration is a covalent posttranslational protein modification that has been detected under several pathological conditions. This study reports that nitrated proteins are degraded by chymotrypsin and that protein nitration enhances susceptibility to degradation by the proteasome. Chymotrypsin cleaved the peptide bond between nitrated-tyrosine 108 and serine 109 in bovine Cu,Zn superoxide dismutase. However, the rate of chymotryptic cleavage of nitrated peptides was considerably slower than control. In contrast, nitrated bovine Cu,Zn superoxide dismutase was degraded at a rate 1. 8-fold faster than that of control by a gradient-purified 20S/26S proteasome fraction from bovine retina. Exposure of PC12 cells to a nitrating agent resulted in the nitration of tyrosine hydroxylase and a 58 +/- 12.5% decline in the steady-state levels of the protein 4 h after nitration. The steady-state levels of tyrosine hydroxylase were restored by selective inhibition of the proteasome activity with lactacystin. These data indicate that nitration of tyrosine residue(s) in proteins is sufficient to induce an accelerated degradation of the modified proteins by the proteasome and that the proteasome may be critical for the removal of nitrated proteins in vivo.

Caulerpin

The crystal structure of caulerpin (dimethyl 6,13-dihydrodibenzo[b,i]phenazine-5,12-dicarboxylate, C(24)H(18)N(2)O(4)), an indole alkaloid, reported in space group Cc with an acute beta angle, has been redetermined in the correct space group, C2/c. The molecule has twofold crystallographic symmetry and is composed of two essentially planar indole groups fused to an eight-membered cyclooctatetraene ring which adopts a boat conformation. The molecular dimensions are normal. The structure is stabilized by intermolecular and intramolecular interactions involving the indole N-H atom and carbonyl O atom [N.O 3.211 (4) and 2.836 (4) A].

High prevalence of antithyroid antibodies in anti-glomerular basement membrane antibody-mediated disease

Anti-glomerular basement membrane antibody (anti-GBM Ab)-mediated disease and autoimmune thyroiditis are characterized by the presence of organ-specific antibodies. The diagnosis of autoimmune thyroiditis is usually based on the presence of serum antithyroid antibodies. Few studies have addressed the relationship between anti GBM-Ab mediated disease and autoimmune thyroid pathology. Given that this disorder is often asymptomatic, associations of the two pathologies may be under-diagnosed. This study investigated the prevalence of serum antithyroid antibodies (antithyroglobulin (anti-TG) and anti-thyroid peroxidase (anti-TPO)) in patients with anti-GBM Ab-mediated disease. Antithyroid antibodies presence was investigated in sera from 35 patients in whom anti-GBM Ab-mediated disease had been diagnosed. Anti-glomerular basement membrane antibodies and anti-thyroid antibodies (anti-TG and anti-TPO) were assayed using an enzyme-linked immunosorbent assay. Forty-five percent of patients with anti-GBM Ab-mediated disease (16/35) had positive antithyroid antibody titers. Eighteen percent (3/16) suffered from subclinical hypothyroidism. In conclusion, the high prevalence of antithyroid antibodies in these patients suggests a possible pathogenic link between autoimmune thyroiditis and anti GBM Ab-mediated disease.

Serum levels of soluble interleukin-2 receptor in patients with ANCA-associated vasculitis

Serum soluble interleukin-2 receptor (sIL-2R) concentrations were determined using the ELISA method in 19 cases of ANCA-associated vasculitis. These patients were classified as 7 cases of Wegener's granulomatosis (WG) and 12 cases of microscopic polyangiitis (MPA). Elevated levels of sIL-2R were present in the sera of these patients. Levels of serum sIL-2R were not significantly different in patients with WG and MPA either in the active or inactive phase, so the results were expressed as a unified ANCA associated vasculitis group. Concentrations of serum sIL-2R were significantly higher in ANCA-associated vasculitis during the active phase than during the inactive phase (p<0.05), and serum sIL-2R levels were significantly increased in these patients, in the active or inactive stage, compared with a group of healthy subjects (p<0.05). In patients with vasculitis, serum sIL-2R levels correlated with serum levels of C-reactive protein (p<0.05). In the active phase, concentrations of serum sIL-2R correlated to creatinine concentrations. No correlation was found between sIL-2R and ANCA levels in any of the stages of the disease. These findings suggest cellular immune activation in ANCA associated vasculitis.

[Anti-glomerular basement membrane disease: a new disease causing fever of unknown origin?]

Antiglomerular basement membrane disease is an autoimmune disorder characterized by the presence of antibodies directed against glomerular basement membrane. Pyrexia of unknown origin (PUO) is defined as temperatures higher than 38.3 degrees C on several occasions, with a duration of more than 3 weeks, and failure to reach a diagnosis despite 1 week of in-patient investigation. There is a large list of causes of PUO including infections, malignancies and autoimmune diseases, but antiglomerular basement disease has not been described as a cause. We present the first case of antiglomerular basement disease which presented with PUO.

Relationship between ANCA and disease activity in small vessel vasculitis patients with anti-MPO ANCA

BACKGROUND

We analysed the usefulness of antineutrophil cytoplasmic antibodies (ANCA) as a marker of clinical activity in patients with small vessel vasculitis associated with anti-myeloperoxidase (MPO) ANCA.

METHODS

We studied a group of 25 patients, 15 with microscopic polyangitis and 10 with renal limited vasculitis, so-called rapidly progressive glomerulonephritis type III. The clinical and serological follow-up was accomplished quarterly over an average of 2.79 +/- 2.08 years (range 0.25-6 years). ANCA was analysed by indirect immunofluorescence and enzyme-linked immunosorbent assays (ELISAs).

RESULTS

At the time of diagnosis, all patients were ANCA positive (P-ANCA and anti-MPO). Following a standardized treatment, all patients except one achieved complete remission of vasculitis in <3 months. One patient suddenly died during the active phase (1 month of follow-up) and with positive ANCA. Seroconversion from positive to negative occurred in 24/25 patients (96%). Eighteen of these 24 patients (75%) achieved the seroconversion within the first 6 months. During the follow-up, two patients had four major relapses, all of them associated with positive ANCA. ANCA seroconversion from negative to positive was observed in one patient with microscopic polyangitis without clinical relapse of vasculitis.

CONCLUSION

ANCA should be used in conjunction with other markers of disease activity in the management of microscopic polyangitis and renal limited vasculitis patients with anti-MPO ANCA.

Cytotoxic activity of marine macro-algae on Artemia salina (brine shrimp)

A total of 22 ethanol extracts of seaweed species (13 brown, 6 green and 3 red) collected from the Karachi coast were investigated for brine shrimp cytotoxicity. Of all the species, only six namely Stoechospermum marginatum, Sargassum swartzii, S. binderi, Spatoglossum asperum, Stokeyia indica (brown) and Caulerpa racemosa (green) showed significant activity. n-Hexane-soluble fractions of the ethanol extract of S. marginatum and S. swartzii were found to be responsible for the activity, whereas the methanol-soluble fractions of S. asperum and S. binderi were most active. The water extract of S. indica and C. racemosa exhibited the most prominent activity (LC50 value below 70 micrograms/mL) when compared with the ethanol extracts and their fractions. Cytotoxic activity may be due to the compounds differing in polarity.

Hypertrophic cardiomyopathy and systemic lupus erythematosus

We report the case of a 45 year-old woman with systemic lupus erythematosus (SLE), who developed clinical and echocardiographic signs of hypertrophic cardiomyopathy. Neither a family history of cardiomyopathy or sudden death nor a personal history of hypertension or valvular lesions were present. The association of SLE with hypertrophic cardiomyopathy has been previously described in only 2 patients.

[Usefulness of anti-neutrophil cytoplasmic antibodies, anti-proteinase 3 and anti-myeloperoxidase in management of small vessel vasculitis]

BACKGROUND

Analysis of usefulness of antineutrophil cytoplasmic antibodies (AN-CA) as a marker of clinical activity in small vessel vasculitis.

PATIENTS AND METHODS

33 patients, 10 patients with Wegener's granulomatosis (WG) and 23 with microscopic polyangiitis (MPA) and rapidly progressive glomerulonephritis type III (RPGN III). The clinic and serologic follow-up was accomplished every 3 months during an average of 19 (SD, 24) months (range 3-52 months. The serologic follow-up included the determination of ANCA by indirect immunofluorescence (IFI) and ELISA, as well as the serum level of C reactive protein (RCP).

RESULTS

At the time of diagnosis all patients were ANCA positive by IFI and ELISA. The seroconversion of ANCA from positive to negative was produced in 30/33 patients (90%). Twenty-six out of these 30 patients (87%) achieved the seroconversion within the first 6 months. During the follow-up 4 patients had a major relapse, all with positive ANCA. In 2 patients, one of each group, seroconversion from negative to positive was not associated with clinical relapse of vasculitis.

CONCLUSION

ANCA should be used in conjunction with other indices of disease activity in patients with small vessel vasculitis.

Inactivation of tyrosine hydroxylase by nitration following exposure to peroxynitrite and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)

The decrement in dopamine levels exceeds the loss of dopaminergic neurons in Parkinson's disease (PD) patients and experimental models of PD. This discrepancy is poorly understood and may represent an important event in the pathogenesis of PD. Herein, we report that the rate-limiting enzyme in dopamine synthesis, tyrosine hydroxylase (TH), is a selective target for nitration following exposure of PC12 cells to either peroxynitrite or 1-methyl-4-phenylpyridiniun ion (MPP+). Nitration of TH also occurs in mouse striatum after MPTP administration. Nitration of tyrosine residues in TH results in loss of enzymatic activity. In the mouse striatum, tyrosine nitration-mediated loss in TH activity parallels the decline in dopamine levels whereas the levels of TH protein remain unchanged for the first 6 hr post MPTP injection. Striatal TH was not nitrated in mice overexpressing copper/zinc superoxide dismutase after MPTP administration, supporting a critical role for superoxide in TH tyrosine nitration. These results indicate that tyrosine nitration-induced TH inactivation and consequently dopamine synthesis failure, represents an early and thus far unidentified biochemical event in MPTP neurotoxic process. The resemblance of the MPTP model with PD suggests that a similar phenomenon may occur in PD, influencing the severity of parkisonian symptoms.

Pakistan national diabetes survey: prevalence of glucose intolerance and associated factors in Shikarpur, Sindh Province

The prevalence of diabetes mellitus and impaired glucose tolerance (IGT) and their relationship to age and obesity was estimated in the rural town of Shikarpur in Sindh Province, Pakistan by a population-based survey in 1994. Oral glucose tolerance tests were performed in a stratified random sample of 967 adults (387 men, 580 women) aged 25 years and above. The diagnoses of diabetes and IGT were made on the basis of WHO criteria. The response rate was 71% for men and 80% for women. The prevalence of diabetes was 16.2% (9.0% known, 7.2% newly diagnosed) in men, and 11.7% (6.3% known, 5.3% newly diagnosed) in women. The prevalence rose with age to a peak of 30% and 21% in 65-74 year-old men and women respectively. IGT was detected in 8.2% of men and 14.3% of women. Thus, total glucose intolerance (diabetes and IGT combined) was present in 25% of subjects examined. These results indicate that glucose intolerance in South Asians can no longer be regarded as a problem confined to migrant communities. Of the 72 subjects previously known to have diabetes, none was using insulin treatment, but 57 (79%) took oral hypoglycaemic agents. Central obesity and positive family history were strongly associated with diabetes, as was prevalence of hypertension. The association with central obesity was greater for women than for men, and suggests important, modifiable risk factor(s) related to lifestyle.

Antigenic specificity of anti-ROS DNA antibodies: involvement of lysyl residues in antigen binding

The antigenicity of native DNA modified with reactive oxygen species was examined. Goats were immunized with the modified polymer and the antibody response was estimated by direct binding and competition ELISA. The induced antibodies bound ROS-DNA and showed considerable binding to native DNA as well. Specificity analysis of the purified antibodies revealed the recognition of native B-, A- and allied conformations presented by various synthetic polynucleotides. The contribution of lysine residues to the immunochemical binding of purified IgG was investigated by modifying the free amino groups of lysine residues. The modification of lysine residues paralleled loss in IgG binding to ROS-DNA to the extent of 50%, suggesting that such residues might be involved in the antigen binding site of immunoglobulin molecule.

Dot-ELISA for the rapid detection of gentamicin in milk

A dipstick dot-ELISA for the detection of gentamicin in milk of dairy cattle is reported for the first time. The test is based on a sandwich ELISA using high affinity monoclonal antibodies to gentamicin. Antibodies were adsorbed to nitrocellulose filters, blocked, dried, and stored for several weeks before use. The dipstick ELISA detected gentamicin at a concentration of 0.1 microgram/ml and produced strongly positive results at 0.2 microgram-0.3 microgram/ml. This ELISA is highly specific and no false positives were detected when tested against various aminoglycoside analogs including streptomycin, kanamycin, bekanamycin, amikacin, neomycin, and tobramycin. Further, the elimination in cow milk of gentamicin residues following intramammary administration of the drug was studied in two dairy cattle using dot-ELISA. Milk gentamicin levels were detected at post injection hours up to 120 hr in each of the two dairy cattle. It therefore, appears that gentamicin residues can still be detected in milk after 5 days using dot-ELISA. Based on the simplicity of performance and the economical nature of the test system, dipstick is recommended as a suitable method for wide scale use in field studies and diagnostic laboratories.

Modulation of glucose and growth hormone responses to meals and exercise in type 1 diabetes by cholinergic muscarinic blockade

Anticholinergic drugs suppress nocturnal and exercise-related growth hormone (GH) secretion in Type 1 diabetes; nocturnal GH suppression is associated with a fall in fasting plasma glucose levels. The aim of this study was to assess the effect of GH suppression on glucose levels following a period of meals and exercise in physiological pattern. Six Type 1 diabetic men recruited from the outpatient clinic were studied in random order at least 1 week apart. After an overnight fast subjects received two-thirds of their usual subcutaneous insulin and either 200 mg oral pirenzepine or placebo at time 0 min. Between 90 and 120 min subjects exercised continuously on an ergometric cycle. Standard meals or snacks were eaten at 30, 150, 270, and 390 min. Venous blood was collected from an indwelling cannula between 0 and 570 min. The mean incremental rise in plasma glucose after breakfast (delta peak/90 min) was 2.6 +/- 0.5 (mean +/- SEM mmol l-1 (pirenzepine) vs 4.5 +/- 0.8 (placebo)), p < 0.05. Following exercise the fall in plasma glucose (delta gluc90-240 min) was 6.4 +/- 1.9 (pirenzepine) vs 2.0 +/- 1.3 (placebo), p < 0.005. The exercise-related peak rise in GH was 12.6 +/- 3.3 (pirenzepine) vs 28.5 +/- 6.0 mU l-1 (placebo), p = 0.08. Excluding one outlying result there was an inverse correlation between the integrated exercise-related increase in GH between 90 and 240 min and the fall in glucose over the corresponding time period (n = 11, r = -0.75, p = 0.008).(ABSTRACT TRUNCATED AT 250 WORDS)

Polynucleotide specificity of anti-reactive oxygen species (ROS) DNA antibodies

Hydrogen peroxide in the presence of short wavelength UV light was able to induce alterations in native DNA fragments of 300 bp (ROS-DNA), thereby rendering it immunogenic in experimental animals. The specificity of induced antibodies was investigated by direct binding and competition ELISA. Inhibition studies revealed nearly 89% inhibition in the antibody binding by the immunogen and recognition of native B-, A- and allied conformations presented by various synthetic polynucleotides. Gel retardation assay reiterated the formation of immune complexes between induced antibodies and native and ROS-DNA fragments. It was observed that naturally occurring anti-DNA autoantibodies from systemic lupus erythematosus (SLE) sera recognize ROS-DNA. The comparison of the specificities of anti-DNA autoantibodies from 10 SLE patients showed a 20-50-fold preference for ROS-DNA over native DNA. These results demonstrate that anti-DNA antibodies can be induced by ROS-DNA, and that some of the autoimmune DNA binding antibodies found in SLE may result from response to reactive oxygen species.

Assay of antinuclear antibodies by ELISA using nuclei as antigen

An enzyme-linked immunosorbent assay to detect antinuclear antibodies in the sera of patients with autoimmune diseases is described. Goat liver nuclei were immobilized on polystyrene plates and antinuclear antibodies were used to standardize the assay. The effects of variables, such as the nuclei concentration, conditions of nuclei storage, and the length of the incubation period were investigated on the assay. Prototype sera with known antibody specificity were used to evaluate the assay. The method described is highly sensitive, autoantibodies being detectable at serum dilutions of 1:1000 or higher. According to the intra- and inter-assay coefficient of variation, the results were highly reproducible.

Reactive oxygen species modified DNA fragments of varying size are the preferred antigen for human anti-DNA autoantibodies

In vitro studies were carried out to determine if reactive oxygen species modified DNA molecules are the preferred antigen for anti-DNA antibodies found in SLE sera. Reactive oxygen species were generated by 254 nm irradiation of hydrogen peroxide. Single stranded breaks, decrease in Tm and modification of adenine (21.7%) and thymine (48%) were the major effects observed on native DNA fragments of 300 bp in length. The ROS-modified DNA showed increased binding with naturally occurring anti-DNA autoantibodies as compared to unmodified DNA fragments. These results were substantiated by competition ELISA. Measurement of binding with DNA fragments of varying size revealed considerably increased binding as the fragment size increased from 50 bp to 800 bp. The relative affinity of anti-DNA IgG for ROS-modified and native DNA fragments of 300 bp were in the order of 6.26 x 10(-8) M and 4.07 x 10(-8) M, respectively.

Antibodies against free radical modified native DNA recognize B-conformation

Hydroxyl radical, a prominent entity of reactive oxygen species, is known to modify cellular DNA and has been implicated in several human diseases. In the present studies, the radical was generated by exposure of hydrogen peroxide to 254 nm light in the presence of native calf thymus DNA. Single strand breaks, decrease in Tm and modification of adenine and thymine were some of the modifications observed in nDNA. Antibodies induced in experimental animals against the modified DNA were immunogen specific. These antibodies also recognize native B-conformation. It was observed that naturally occurring anti-native DNA autoantibodies from SLE sera recognize modified DNA in direct binding and competition ELISA. Gel retardation assay reiterated the formation of immune complexes between induced antibodies and DNA fragments of around 300 bp (B-conformation). The possible significance of these findings in the etiology of SLE has been discussed.

Cholinergic blockade with pirenzepine induces dose-related reduction in glucose and insulin responses to a mixed meal in normal subjects and non-insulin dependent diabetics

OBJECTIVE

The aim of the study was to assess the effects of cholinergic blockade with pirenzepine on glucose and insulin responses to a mixed meal in normal subjects and patients with non-insulin dependent diabetes (NIDDM). Further, to assess in normal subjects the relative importance of nocturnal GH suppression by pirenzepine.

DESIGN

Placebo, 100 or 200 mg pirenzepine were given to the normal subjects 1 hour before a standard mixed meal. The effects of placebo or 200 mg pirenzepine at night on nocturnal GH secretion and subsequent breakfast carbohydrate tolerance were also studied. NIDDMs were given placebo or 200 mg pirenzepine before the meal.

SUBJECTS

We studied six healthy male volunteers (ages 20-22, body mass indices 20.3-23.3) and ten NIDDMs (eight men, ages 42-74); five obese (BMI 25.5-31.8) and five non-obese (BMI 21.2-24.8).

MEASUREMENTS

Serial plasma glucose and insulin concentrations were measured for 3 hours after a standard mixed meal.

RESULTS

Acute pretreatment of normal male volunteers with pirenzepine produced a dose-related improvement in carbohydrate tolerance. Peak post-prandial plasma glucose levels were delayed and significantly reduced following 200 mg orally (6.5 +/- 0.1 mmol/l), but not following 100 mg (7.3 +/- 0.3), compared with placebo (7.6 +/- 0.3). Peak insulin levels were similarly delayed and reduced by the 200 mg dose only (36.5 +/- 6.1 mU/l, compared with 49.8 +/- 8.7). Suppression of nocturnal GH by 200 mg pirenzepine at night produced a small reduction in fasting plasma glucose (5.0 +/- 0.1 mmol/l, compared with 5.3 +/- 0.1, P less than 0.02) but did not improve subsequent breakfast carbohydrate tolerance. Peak plasma glucose in NIDDMs was reduced following pirenzepine (12.4 +/- 0.9 mmol/l) compared with placebo (14.3 +/- 1.0, P less than 0.01). This reduction was equally significant in obese and non-obese groups. Peak plasma insulin was also reduced by pirenzepine (22.4 +/- 3.9 mU/l) compared with placebo (42.4 +/- 5.3, P less than 0.01). Insulin suppression was quantitatively greater in obese than in non-obese patients.

CONCLUSIONS

Improvement in carbohydrate tolerance after pirenzepine in normal subjects is dose related and largely independent of GH suppression. Cholinergic blockade can also improve meal carbohydrate tolerance with simultaneous reduction in plasma insulin concentrations in non-insulin dependent diabetics, particularly those with obesity.