A quantitative determination for the detection of immunoglobulin (IgG) on the surface of platelets

A sensitive method for the quantitation of IgG on platelets had not been demonstrated until 1975, when Dixon, Rosse, and Ebbert described a quantitative antiglobulin consumption test useful in detecting platelet associated IgG (N Engl J Med 292:230, 1975). A modification of that technique has rendered the assay reproducible and removed the need for daily repetition of a standard IgG titration curve for quantitation. This modification utilizes 1-ethyl-3-3(dimethylaminopropyl)carbodiimide HCl (ECDI) (Sigma, E-7750), in place of chromic chloride, as a coupling agent for attaching IgG (Miles 64-145) to sheep cells (SRC), used as indicator cells. The ECDI consistently couples IgG to SRC and does not subject the SRC to sporadic spontaneous lysis, as does chromic chloride. This modification permits the detection of IgG on platelets (Direct Test), or in sera (Indirect Test) by incubation of a washed platelet pool with sera in vitro, and testing as in the Direct Test. Normal values of 0.01-1.56 and 0.14-1.6 femtograms (F) per platelet have been obtained for the Direct and Indirect Tests, respectively. In six cases of suspected ITP, values ranged 12.0-221.0 F and 2.9-37.6 F for the Direct and Indirect Tests, respectively. In conclusion, in disease states or other abnormal situations, quantities of IgG can be detected that are not usually present on the platelets of normal subjects.     

The Mediterranean diet,fish oil supplements and Rheumatoid arthritis outcomes: evidence from clinical trials

The impact of dietary interventions such as specific types of diet or nutritional supplements in rheumatoid arthritis (RA) has been subject to increased attention in recent years. The recognition of the unmet need to better understand the effects of specific dietary interventions on disease outcomes in RA, along with the growing patient interest on lifestyle interventions beyond pharmacotherapy, have informed the undertaking of this narrative literature review. The benefits of the Mediterranean Diet (MD) have been shown in various studies, although only a limited number of trials focus specifically on RA. Based on the studies reviewed, the MD may provide benefits in reducing pain and swollen and tender joints in RA patients. There is more and better evidence that n-3 polyunsaturated fat (PUFA) supplementation has the potential to reduce inflammation and provide clinical benefit, possibly slowing progression to pharmacotherapy. Yet, many of these studies to date are limited in their methodology; this being partly a reflection of the complexity of the research questions being addressed. Consequently, the conclusions that can be robustly drawn from their results are restricted. With a focus on clinical trials on the MD and fish oil supplementation, this review critically appraises the evidence, discussing the findings of studies in the wider context of impact on RA outcomes, methodological challenges, and practical points to consider as part of the routine care of RA patients.     

High performance liquid chromatographic procedure for quantitative determination of urinary delta-aminolevulinic acid as indices of lead exposure

Summary A high performance liquid chromatographic method for the determination of delta-aminolevulinic acids (ALA) in urine, is described. 2-Methyl-3 carbmethoxy-4-(3-propionic acid) pyrrole was produced by the condensation of ALA with methylacetoacetate (MAA) while heating. The methylacetoacetate could be replaced by ethylacetoacetate. The ALA pyrrole thus obtained was injected into high performance liquid chromatography (HPLC). A stainless-steel column packed with octadecyl silanized silica gel was used. The mixed solution of acetonitrile/50mM KH₂PO₄ (adjusted to pH 2.5 with 0.001 volumes of 85 g/dl H₃PO₄)(20/80) was a favorable mobile phase for the separation of ALA. Amino acetone pyrrole was produced by the condensation of amino acetone with methyl acetoacetate. The amino acetone pyrrole appeared later than ALA pyrrole on HPLC. The method is simple and specific. It has a lower detection limit of 0.2 ng on column. The analysis and quantitative determination of one specimen can be performed within 20 min. Mean ALA concentration of normal urine by HPLC was 1.18mg/g creatinine.     

Synthesis of 5-aminolevulinic acid (ALA) and itst-butyl ester for the fluorescence detection of early cancer

5-Aminolevulinic acid and its derivatives, which are known to affect the early diagnosis and treatment of cancer, have been synthesized. Simple methods for the synthesis of 5-aminolevulinic acid (ALA), a precursor of porphyrins, have been developed in our laboratory for use in studies on the biosynthesis of porphyrins.     

Heme, iron, and the mitochondrial decay of ageing

Heme, the major functional form of iron, is synthesized in the mitochondria. Although disturbed heme metabolism causes mitochondrial decay, oxidative stress, and iron accumulation, all of which are hallmarks of ageing, heme has been little studied in nutritional deficiency, in ageing, or age-related disorders such as Alzheimer's disease (AD). Biosynthesis of heme requires Vitamin B(6), riboflavin, biotin, pantothenic acid, and lipoic acid and the minerals zinc, iron, and copper, micronutrients are essential for the production of succinyl-CoA, the precursor for porphyrins, by the TCA (Krebs) cycle. Only a small fraction of the porphyrins synthesized from succinyl-CoA are converted to heme, the rest are excreted out of the body together with the degradation products of heme (e.g. bilirubin). Therefore, the heme biosynthetic pathway causes a net loss of succinyl-CoA from the TCA cycle. The mitochondrial pool of succinyl-CoA may limit heme biosynthesis in deficiencies for micronutrients (e.g. iron or biotin deficiency). Ageing and AD are also associated with hypometabolism, increase in heme oxygenase-1, loss of complex IV, and iron accumulation. Heme is a common denominator for all these changes, suggesting that heme metabolism maybe altered in age-related disorders. Heme can also be a prooxidant: it converts less reactive oxidants to highly reactive free radicals. Free heme has high affinity for different cell structures (protein, membranes, and DNA), triggering site-directed oxidative damage. This review discusses heme metabolism as related to metabolic changes seen in ageing and age-related disorders and highlights the possible role in iron deficiency.     

Arterial wall strength after endovascular photodynamic therapy

BACKGROUND AND OBJECTIVES: Vascular photodynamic therapy (PDT) inhibits intimal hyperplasia (IH) induced by angioplasty in rat iliac arteries by eradicating the proliferating smooth muscle cells. This process may jeopardise the structure and strength of the arterial wall, reflected by a decreased bursting pressure. STUDY DESIGN/MATERIALS AND METHODS: Thirty male Wistar rats of 250-300 g were subdivided into 3 groups (n = 10). In all groups, IH was induced by balloon injury (BI). One experimental group received PDT at 50 J/cm diffuser length, the other group at 100 J/cm diffuser length. The third group served as control group and received no PDT. In half of each group the bursting pressure was analyzed after 2 hours (n = 5), in the other half after 1 year. RESULTS: Two hours after the procedure the bursting pressure was 3.37 +/- 0.58 (+/-SEM) bar in the BI + PDT 50 and 3.96 +/- 0.43 bar in the BI + PDT 100 group, compared to 2.20 +/- 0.27 bar in the BI group (P < 0.05). After 1 year these values were 3.18 +/- 0.87 bar in the BI + PDT 50 (P < 0.05) and 2.02 +/- 0.31 bar in the BI + PDT 100 group, compared to 2.10 +/- 0.30 bar in the BI group (NS). In the BI + PDT 100 group, 3 out of 5 rats appeared to have aneurysmal dilatation after 1 year. CONCLUSIONS: Endovascular PDT increases the arterial wall strength as measured by the bursting pressure at short-term. After 1 year, wall strength is not diminished as measured by bursting pressure, but aneurysmal dilatation nevertheless developed with 100 J/cm. dl. This may limit the use of high energy PDT.     

Increases in cytochrome P-450 in cultured hepatocytes mediated by 3- and 4-carbon alcohols

The amount of cytochrome P-450 was increased to different extents after treatment of cultured chick embryo hepatocytes with n-propanol, isopropanol, n-butanol, or isobutanol, These increases were associated with increases in benzphetamine demethylase activity, a cytochrome P-450-catalyzed oxidation, and glucuronidation of phenol red, catalyzed by UDP-glucuronyl transferase. The responses were similar to those obtained with ethanol or propylisopropylacetamide, which are phenobarbital-like inducers. Pretreatment of cells with cycloheximide prevented the increases in both cytochrome P-450 and glucuronidation of phenol red, indicating that protein synthesis was required for these responses.     

Neurotoxicity of δ-aminolevulinic acid and porphobilinogen

Rats were injected with δ-aminolevulinic acid (ALA) and with porphobilinogen (PBG) into the lateral ventricle of the brain. An ataxia- and catatonia-like state, followed by jumping seizures, occurred dose dependently and without significant differences between ALA and PBG. The relatively high amount required and the clinical observation that seizures are not typically seen in patients with a porphyric attack make these substances not likely causative agents for the porphyric symptomatology.