Reactivation of Systemic Lupus in three Patients Undergoing CAPD

Generally patients with end-stage renal disease (ESRD) due to lupus nephritis, have minimal extrarenal disease activity <Juring hemodialysis. This may be related to immunological changes secondary to chronic renal failure or the dialysis procedure itself, or both. This paper describes three patients with lupus nephritis undergoing continuous ambulatory peritoneal dialysis (CAPD) in whom we observed reactivation of SLE, by both clinical and serological criteria. This may suggest that in patients undergoing CAPD the immune system is more nearly intact than in hemodialysis. These cases should heighten awareness that patients may suffer flare-ups of SLE during CAPD even long after the onset of renal failure.

Effect of the Peritoneal Dialysate Buffer on UL TRafil Tration: Studies in Normal Rabbits

We studied an animal model to test the ultrafiltration capability of three different peritoneal dialysis solutions: Brand A, containing lactate and manufactured in Canada, Brand B, containing acetate and manufactured in U.S.A. and Brand C also containing acetate and manufactured in France. Solutions with 1.5 g0/o and 4.25 g0/o glucose concentrations were tested. We found no significant difference in the amount of ultrafiltration produced with the three brands when glucose concentration was 1.5 g0/o. However with glucose concentration of 4.25 g 0/o ultrafiltration was significantly lower with the Brand C-French acetate solution comparing to Brand A-Iactate solution. Brand B (acetate U.S.A.) solution produced ultrafiltration volumes that were between the other two and were not statistically significantly different from either Brand A (acetate) nor from Brand C (acetate).

We concluded that the lower ultra-filtration produced by Brand C is not due to the presence of acetate buffer but to other factors operating alone or in combination with acetate.

Adequate peritoneal ultrafiltration for fluid balance is one of the main factors in the success of continuous ambulatory peritoneal dialysis (CAPD). Ultrafiltration failure associated with the use of acetate buffered dialysis solution has been described frequently in France (I, 2, 3), but only occasionally in North American centres (4,5,6).

It is still controversial whether acetate or some other element(s) is the factor responsible for the ultrafiltration failure observed in French patients. The first report of an international co-operative study revealed that ultrafiltration is significantly lower in patients using acetate, compared to those using lactate dialysis solutions (7). However, the second report of this study, which contained results from patients using a larger number of brands, showed that acetate may not be a responsible factor because there were patients using acetate-solutions manufactured outside France who had an ultrafiltration similar to that produced with lactate brands (8). Because of this, we chose to study in an animal model the ultrafiltration produced with solutions containing different buffers during acute experiments. This paper reports our findings.

Fibroblast Growth Factor 23 Predicts Mortality and End-Stage Renal Disease in a Canadian Asian Population with Chronic Kidney Disease

BACKGROUND

Chronic kidney disease (CKD) is a leading cause of morbidity and mortality. Biomarkers that predict end-stage renal disease (ESRD) and/or mortality could usher in new therapeutics to halt this onslaught. While fibroblast growth factor (FGF)23 can predict both ESRD and mortality, it has not been studied in North American CKD patients of Asian ethnicity.

METHOD

This is a prospective investigation about the role of FGF23 in 998 Canadian patients of Asian descent with CKD defined by an estimated glomerular filtration rate (eGFR) <60 mL/min/m2 and followed up for 3 years.

RESULTS

The mean age of patients was 68.9 years and 68.3% were males. The mean (range) eGFR, and median FGF23 were 40.2 (11.0-59.0) mL/min and 154.1 (7.0-7,823.0) RU/mL, respectively. Over the 3 years, higher values of FGF23 levels at baseline were associated with higher risk of ESRD (hazard ratio [HR] for log[Fgf23] = 2.16 [95% CI 1.20-3.89]). Despite the short follow-up, 42 patients died due to cardiovascular diseases (38.8%), cancer (14.9%), and infections (12.7%). Log-FGF23 levels were independently associated with death, HR 1.94, 95% CI 1.24-3.03. Mortality risk increased in FGF23 subgroups from <100 to >400 RU/mL. In a time-changing covariate analysis, serial log-FGF23 levels over the 3 years predicted mortality with a HR of 2.66 (95% CI 1. 79-3.95).

CONCLUSION

In a Canadian Asian population with CKD, FGF23 levels obtained at 6-monthly intervals for 3 years predicted ESRD and mortality suggesting that it is also a risk marker in Asians.

Identification and sequence analysis of a novel HLA-A*33 allele, HLA-A*33:88

HLA-A*33:88 differs from HLA-A*33:03:01 by one nucleotide exchange at position 475, G>A (codon 135 GCG>ACG).

Characterization and comparison of transgenic Artemisia annua GYR and wild-type NON-GYR plants in an environmental release trial

The anti-malarial drug, artemisinin, is quite expensive as a result of its slow content in Artemisia annua. Recent investigations have suggested that genetic engineering of A. annua is a promising approach to improve the yield of artemisinin. In this study, the transgenic A. annua strain GYR, which has high artemisinin content, was evaluated in an environmental release trial. First, GYR plants were compared with the wild-type variety NON-GYR, with regard to phenotypic characters (plant height, crown width, stem diameter, germination rate, leaf dry weight, 1000-seed weight, leave shape). Second, stress resistance in the two varieties (salt, drought, herbicide, and cold resistance) was evaluated under different experimental conditions. Finally, gene flow was estimated. The results indicated that there were significant differences in several agronomic traits (plant height, stem diameter, and leave dry weight) between the transgenic GYR and NON-GYR plants. Salt stress in transgenic and control plants was similar, except under high NaCl concentrations (1.6%, w/w). Leaf water, proline, and MDA content (increased significantly) were significantly different. Transgenic A. annua GYR plants did not grow better than NON-GYR plants with respect to drought and herbicide resistance. The two varieties maintained vitality through the winter. Third, gene flow was studied in an environmental risk trial for transgenic GYR. The maximum gene flow frequency was 2.5%, while the maximum gene flow distance was 24.4 m; gene flow was not detected at 29.2 m at any direction. Our findings may provide an opportunity for risk assessment in future commercialization of transgenic A. annua varieties.

Report on the 14th International Society of Blood Transfusion Platelet Immunology Workshop

BACKGROUND AND OBJECTIVES

The aims of the 14th ISBT Platelet Immunology Workshop were to evaluate in-house methods for detection of antibodies to human platelet antigens, to compare the sensitivity and specificity of antibody detection using a panel of monoclonal antibodies and to evaluate genotyping methods and establish procedures for drug-dependent antibody detection.

MATERIALS AND METHODS

Forty-two laboratories from 23 countries participated. Samples and reagents provided for the five different exercises.

RESULTS

The ability of participating laboratories to correctly identify the HPA antibody specificity in the nine samples ranged from 20% to 97%. The greatest difficulty was observed with samples that contained antibodies against HPA-3b and GPIV. The significant differences in optical density values by monoclonal antibody of immobilization of platelet antigens (MAIPA) assay were observed when testing the same platelet-specific antibodies. HPA genotyping of DNA with novel mutations did not significantly affect the results. The overall average discrepancy rate was 2·15% for genotyping of 10 DNA samples from well-characterized Epstein–Barr virus transformed cell lines. For detection of drug-dependent antibodies, excellent results for specificity and sensitivity were obtained by the laboratories using the MAIPA and flow cytometry.

CONCLUSIONS

Most laboratories were able to identify the majority of HPA antibodies; however, significant disparities were observed in proficiency testing. MAIPA assay sensitivity is influenced by the monoclonal antibody clone used. DNA with new mutations and EBV cell lines are valuable samples to ensure accurate genotyping. A sensitive and specific drug-dependent antibody assay performed well in the hands of participants.

Molecular genetic analysis for Ax phenotype of the ABO blood group system in Chinese

BACKGROUND AND OBJECTIVES

To elucidate the molecular genetic background of the Ax phenotype in the Chinese population.

MATERIALS AND METHODS

The ABO genes of eight Ax phenotype samples, four Ax and four AxB, were amplified by polymerase chain reaction (PCR) and were cloned, along with those of 10 random A(1) Chinese subjects. We analysed the ABO gene transcript structure and the sequences of two exons and one intron at the ABO locus.

RESULTS

Among the four Ax phenotype samples, we identified one Ax02, two Ax03 and one novel Ax allele with the 543G > T mutation in the A102 background. Two of five family members also carry the allele. Of the four AxB phenotypes, one was designated as cis-AB-1/B101; the other three were shown to carry one B allele and one O with the nt261G deletion. The B alleles of the latter three were identical to B101 except for single point mutation at nt700C > G, nt640A > G and nt641T > C, respectively. The novel B101-like alleles were first associated with A(weak)B phenotypes.

CONCLUSIONS

Two ABO*B(A) alleles and an Ax allele clearly differ from all previously reported ABO alleles, suggesting that the molecular genetic background of Ax is heterogeneous in the Chinese population.

Serum levels of prostate-specific antigen and vitamin D in peritoneal dialysis patients

Measuring the free:total ratio of prostate-specific antigen (f/t-PSA) can improve the specificity of single-serum PSA values, distinguishing between benign prostatic hyperplasia (BPH) and prostatic carcinoma (PCa) in men over the age of 50. Additionally, clinical trials have shown that dihydroxyvitamin D3 can slow the rate of PSA rise in PCa patients. However, little is known regarding the applicability of those findings in men undergoing chronic peritoneal dialysis (CPD). In the present study, we investigated the prevalence of increased serum PSA levels among CPD patients and correlated those values with serum levels of vitamin D [25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3]. We undertook a cross-sectional study of 71 male CPD patients without a known history of prostate cancer from 24 centers in Canada, Greece, and Turkey. All of the patients were more than 50 years of age. In these patients, we measured serum concentrations of PSA, free PSA (f-PSA), total PSA (t-PSA), prostate alkaline phosphatase (PAP), 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, and intact parathyroid hormone (iPTH). We recorded serum PSA levels < 4 ng/mL in 62 patients (87.3%, group A) and levels > 4 ng/mL in 9 patients (12.7%, group B). The f/t-PSA ratio was < 0.25 in 16 patients (22.5%). Group B patients were older than those in group A (median: 73 years vs. 65 years, p < 0.01) and had a lower body weight (median: 66.5 kg vs. 76.7 kg, p < 0.05). We observed no statistically significant difference between the two groups for serum 1,25-dihydroxyvitamin D3 (median: 9.8 ng/mL vs. 10.1 ng/mL) or 25-hydroxyvitamin D3 (8 ng/mL vs. 8.2 ng/mL) levels. Also, we observed no correlation between vitamin D levels and f/t-PSA, but iPTH levels were significantly higher in group A (200.5 pg/mL vs. 61.2 pg/mL, p < 0.04). Also, serum PAP levels correlated significantly with PSA (r = 0.49, p = 0.01) and with f-PSA (r = 0.56, p = 0.000). Our results showed no clear relationship between vitamin D and serum levels of PSA or-of f/t-PSA in PD patients. However, further studies are needed to better define the uses of these PSA markers in PD patients because, in such patients, other relevant factors might be implicated in their predictive value.

A novel enantioselective alkylation and its application to the synthesis of an anticancer agent

A novel enantioselective alkylation of double benzylic substrates with secondary electrophiles is reported. A simple norephedrine-based chiral ligand was synthesized that gives alkylation product in 95% yield and 95% ee. A unique water effect on the enantioselectivity was unveiled. Good to excellent ee values were obtained with a number of double benzylic substrates and secondary electrophiles. This novel reaction has been applied to the synthesis of a promising anticancer agent.

An anion-induced regio- and chemoselective acylation and its application to the synthesis of an anticancer agent

[reaction--see text] An efficient Grignard- and organolithium-induced regio- and chemoselective anionic acylation is reported. A number of tricyclic ketones are prepared in good to excellent yields via this method. This method is complementary to the Frieldel-Crafts acylation for electron-deficient substrates. A novel anisole-based Grignard reagent was developed to effect the cyclization of sterically hindered substrates. This novel reagent has been successfully applied to the synthesis of Sch 66336, a candidate for oncologic treatment.

Racial differences in survival of patients on dialysis

BACKGROUND

Recent studies have documented racial differences in the crude mortality rates of patients on dialysis. However, proper interpretation of these findings requires adjustment for potential confounders and comorbid risk factors between the racial groups.

METHODS

We examined the clinical data on 3752 Caucasian patients, 451 Southeast Asian patients, 322 South Asian patients, and 319 black patients who were treated with hemodialysis or peritoneal dialysis under a Universal Health Care system in Toronto and prospectively followed between 1981 and 1995. In all patients, a number of comorbid risk factors for survival was assessed at the start of dialysis and was reassessed with their outcome status (that is, continued dialysis, transplantation, death, or loss to follow-up) at least every six months. Cox proportional hazards analysis was used to fit multivariate models predicting patient survival. Pairwise comparisons of the relative hazards of death between the racial groups were performed after stratifying for cardiovascular disease, diabetes mellitus, and hypertension at the start of dialysis, and were adjusted for differences in other comorbid risk factors.

RESULTS

The risk of death in Caucasian patients was significantly increased when compared with Southeast Asian patients, South Asian patients, and black patients [multivariate relative hazards (95% CI): 1.63 (1.36 to 1.97), 1.36 (1.07 to 1.73), 1.34 (1.07 to 1.67), respectively]. Additionally, we detected an interaction between race and cigarette smoking (P < 0. 004), suggesting that in the dialysis patients who smoked, whites had a higher mortality risk compared with non-whites.

CONCLUSIONS

Differences in patient survival on dialysis exist between racial groups. However, the genetic and environmental determinants that underlie these differences are presently unknown.

Novel 2,2-Bipyridine Ligand for Palladium-Catalyzed Regioselective Carbonylation

[reaction: see text] A palladium-catalyzed highly regioselective one-step carbonylation of 2,5-dibromo-3-methylpyridine is reported. A range of alkyl esters and amides can be prepared in good yield with better than 95:5 regioselectivity via this method. Key to the high regioselectivity for the formation aromatic amides is the introduction of a novel nonphosphine-based 2,2-bipyridine ligand. This novel reaction was scaled up smoothly in the plant to a 130-kg batch size and facilitated the delivery of bulk material for the clinical trials of Sch 66336, a candidate for oncologic treatments.

Quinine-induced immune thrombocytopenia with hemolytic uremic syndrome: clinical and serological findings in nine patients and review of literature

Quinine-induced immune thrombocytopenia with hemolytic uremic syndrome (HUS) is a recently defined clinical entity. In this paper we have attempted to characterize the natural history and laboratory abnormalities typical of quinine-induced immune thrombocytopenia associated with hemolytic uremic syndrome in nine patients experiencing ten episodes of the disease. In addition, review of other reported cases of probable quinine-induced HUS is presented. The disease was characterized by the onset of chills, diapheresis, nausea and vomiting, abdominal pain, decreased urine output, and petechiae following quinine exposure. All patients experience significant anemia, severe thrombocytopenia, increased lactate dehydrogenase, elevated serum creatinine, and oliguria. Quinine-dependent platelet-reactive antibodies were identified in eight of nine using flow cytometry. Unexpectedly, drug-dependent antibodies reactive with red cells and granulocytes were identified in four and eight patients, respectively. All patients were treated with plasma exchange (range 1-12 procedures), and seven required hemodialysis. All survive without residual abnormality. Our experience with nine patients with quinine-induced HUS and the nine additional cases reported by others and reviewed in this paper establishes this condition as a distinct clinical entity. Adult patients presenting with HUS should routinely be asked about exposure to quinine in the form of medication or beverages. The mechanism by which quinine-dependent antibodies produce renal failure is uncertain, but preliminary studies (described elsewhere) suggest that drug-induced antibodies reactive with endothelial cells and possibly margination of granulocytes in renal glomeruli may be responsible for this complication. The prognosis in quinine-induced HUS is better than in other forms of adult HUS.

Antibodies in sulfonamide-induced immune thrombocytopenia recognize calcium-dependent epitopes on the glycoprotein IIb/IIIa complex

Drug-dependent IgG antibodies (DDAb) induced by sulfamethoxazole (SMX) and sulfisoxazole (SIX) were identified by flow cytometry in 15 patients who developed thrombocytopenia while taking one of these medications. Fourteen of the 15 DDAb were specific solely for the glycoprotein (GP)IIb/IIIa complex, and 13 of these reacted wholly or in part with epitopes present only on the intact GPIIb/IIIa heterodimer. None of 12 SMX-induced DDAb cross-reacted with SIX, but one of three SIX-induced antibodies reacted with SMX. Each of 10 SMX-induced DDAb tested reacted with the N1-acetyl metabolite of SMX, but only one reacted fully with the N4-acetyl derivative. Detection of the SMX- and SIX-dependent antibodies was facilitated by using bovine serum albumin (BSA) to achieve suspension of these weakly soluble drugs in an aqueous medium. Our findings indicate that DDAb induced by SMX and SIX, in contrast to those induced by quinidine and quinine, are mainly specific for GPIIb/IIIa and react preferentially with calcium-dependent epitopes present only on the intact GPIIb/IIIa heterodimer.