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Etude du metabolisme des derives protidiques chez le drepanocytaire homozygote ssFA2 en phase stationnaire

Marie-Laure Hauhouot-Attoungbré*, Armande Yapi, Angéle N’guessan-Edjeme, Eric Yayo, Dagui Monnet
*UFR de sciences pharmaceutiques et biologiques, Département de Biochimie, Abidjan (Côte d’Ivoire) - Institut de Cardiologie, Laboratoire de biologie, Abidjan (Côte d’Ivoire)

Biochimica Clinica: 2005; 29(5-6): 457-460 [Article in franch]

ABSTRACT. It is about a transverse survey carrying on abnormal hemoglobin SSFA2 in stationary phase followed in the university hospital centers of Cocody and Yopougon. It concerned hundred (100) patients with for objective to establish the biochemical profile of urea,e creatine and electrophoresis of the protids. It comes out from this study the results following: - No sexual prevalence was observed among patients - The average age of the subjects is 17,33 years - Uraemia and the creatinemia are relatively weaker than those established at normal reference to people from Côte d’Ivoire, while the average protidemia is normal -Polyclonal gammopathy (77,78%) constitute the main part of the disturbances of the electrophoresis of proteins.

Homocysteine and related metabolites in essential hypertension and associated complications; possible role of cysteinylglycine

Mohamed A. Abdel Hafezo*, Nagwa Kamal Roshdy, Fatma Taha, Soliman Nasr
*Medical Biochemistry, Kasr Al-Aini Faculty of Medicine, Cairo University

Biochimica Clinica: 2005; 29(5-6): 461-467 [Article in english]

ABSTRACT. In the present work, the relation between plasma homocysteine (Hcy) and its metabolites (S-adenosyl homocysteine, SAH, and S-adenosyl methionine, SAM) was studied. Plasma folic acid and vitamin B12 were evaluated to clarify their role in Hcy-methionine interaconversion in pathogenesis of essential hypertension and related vascular disorders. The study was conducted on 65 patients suffering from essential hypertension either uncomplicated or with renal and non-renal (vascular) complications. Fifteen healthy age and sex matched subjects were included as controls. Plasma Hcy, SAH and SAM were determined by high performance liquid chromatography (HPLC). Plasma folate and vitamin B12 were determined by dual count radioimmunoassay. Significant elevation in plasma Hcy and SAH and decrease in SAM/SAH were observed in hypertensive patients versus controls. Significantly higher levels of Hcy and SAH were found in hypertensive patients with renal complications. Also, significantly higher levels of Hcy and SAH were found in hypertensive patients with CHD and CVS. There was significant decreases in plasma folate and vitamin B12 in hypertensive patients. Plasma cysteinylglycine was significantly higher in hypertensives. In conclusion, the risk of homocysteine-associated hypertensive complications may partly be due to low folate and vitamin B12 which decreased significantly with the severity of hypertension and coincided with the increased homocysteine level. Possible role of cysteinylglycine (Cysgly) particularly for end-stage renal disease was discussed.

Heme oxygenase gene expression in human azoospermic testicular tissue

Mohamed Talaat Abdel Aziz, Olfat Gamil Shaker*, Taymour Mostafa, Farid El-Asmar, Hazem Atta, Nagwa Kamal, Gamal Mohsen, Mostafa Abdel Reheem
*Department of Medical Biochemistry, Molecular Biology Unit, Kasr El-Aini Faculty of Medicine, Cairo University, 12311 Cairo, Egypt

Biochimica Clinica: 2005; 29(5-6): 468-474 [Article in english]

ABSTRACT. Heme Oxygenase (HO), a microsomal enzyme, catalyzes the rate-limiting step in heme catabolism. To assess the expression of HO-1 and HO-2 genes in human azoospermic testicular tissues, forty seven non-obstructive azoospermic (NOA) men were studied. They were divided according to the results of their testicular sperm extraction (TESE) into; successful positive TESE (n=19) and unsuccessful negative TESE (n=28) compared to 12 obstructive azoospermia cases with matched age. Serum FSH hormone was carried out by ELISA method. Testicular biopsies obtained from azoospermic men were subjected to histopathology, testicular sperm extraction (TESE) and detection of HO-1 and HO-2 gene expression by RT-PCR. The results showed that all azoospermic testicular tissue specimens expressed HO-2 mRNA cases. HO-1 mRNA expression was evident in all obstructive azoospermia and successful TESE positive NOA cases (n=19) as well as in 7/28 unsuccessful TESE negative NOA cases. HO-1 mRNA expression was negative in 21/28 negative TESE cases. It is concluded that HO-1 may play a role in the spermatogenic process.

Heme oxygenase: relationship to nitric oxide synthase/ nitric oxide system in murine schistosomiasis

M.T., Abdel Aziz, F., O. Shaker*, M.M., Abdel Fattah, R., Abdel Kader, H., Hosni, El-Asmer
Medical Biochemistry Departments, Faculty of Medicine, Cairo and Ain Shams

Biochimica Clinica: 2005; 29(5-6): 475-482 [Article in english]

ABSTRACT. The present work studied the possible relationship between the nitric oxide synthase (NOS)/nitric oxide (NO) production and heme oxygenase-1 (HO-1) expression and HO activity in the acute and chronic phases of murine schistosomiasis. Control and S. mansoni infested mice were sacrificed bi-weekly from the 6th to the 20th week postinfestation. The expression of HO-1, inducible (i)NOS and endothelial, (e)NOS were assessed in liver tissues by RT-PCR and gel documentation. In addition, HO activity, cGMP levels, malondialdehyde (MDA) and total nitrite and nitrate levels (Nox) were also estimated. The data showed that HO-1 expression and activity increased in both early and later stages of Schistosomiasis in comparison to normal controls. eNOS expression decreased at the 18th and 20th weeks versus the control. iNOS expression showed continuous induction starting from the 6th week till the 20th week, with a decline in the 18th and 20th weeks versus the 8th and 10th weeks. This was accompanied by an increase in MDA levels (at 16th, 18th and 20th weeks) and a decrease in cGMP in 20th week. A negative correlation was detected between MDA and both Nox and HO-activity. The present results also suggest that HO-1 may be mediated partially by iNOS/NO production, as indicated by the positive correlation between Nox and HO-activity. HO may be important in decreasing the toxic bursts of iNOS/NO production through degrading the hemoprotein iNOS at the protein level. However, in limiting hepatocyte injury, it may contribute to development of the reported portal hypertension, probably by also degrading eNOS which is responsible for maintenance of normal portal perfusion.

Determinazione di CA 27.29 nel carcinoma della mammella

Polidori Maria, Di Pietro Nino*, Savini Fabio, Ruffini Irma, Nubile Giuseppe
*Laboratorio Analisi, Presidio Ospedaliero G. Bernabeo Ortona, ASL Chieti

Biochimica Clinica: 2005; 29(5-6): 483-485 [Article in italian]

ABSTRACT. The measurement of the tumor marker CA 27.29 in serum is an useful tool for the early detection of mammary carcinoma. In our study, we analysed 1050 patients divided in three groups: 1) patients with mammary carcinoma; 2) patients with non-carcinogenic inflammatory or degenerative pathology; 3) healty subjects. Amoung the 308 patients of the first group, 236 (76,6%) had serum concentration of CA 27.29 >25 U/ml (cut off). Amoung the 392 patients of the second group, 330 (84,2%) had concentration <25U/ml. Amoung the 350 healty subjects, 339 (96,9%) had a concentration <25 U/mL. The overall sensitivity was 76,6%, the specificity 90,2% and the accuracy 86,2%. The positive predictive value was 76,4% while the negative predictive value was 90,3%. The odds ratio was 30,0.

Misura dell'attività catalitica della fosfatasi alcalina con N-metil-glucammina (MEG) e ammino-metil-propanolo (AMP) come tamponi: effetti sulla commutabilità dei materiali di controllo

Ferruccio Ceriotti*, Carlo Alberto Ferrero, Elena Guerra, Roberto Bonora, Mauro Panteghini per il Gruppo di Studio "Enzimi" della Società Italiana di Biochimica Clinica e Biologia Molecolare Clinica (SIBioC)
*Diagnostica e Ricerca San Raffaele S.p.A., Milano

Biochimica Clinica: 2005; 29(5-6): 486-494 [Article in italian]

ABSTRACT. Amino-methyl-propanol (AMP) and N-methyl-glucamine (MEG) buffers for alkaline phosphatase measurement: effects on commutability of control materials This study compares the effect of the modification of some analytical variables, i.e. pH, buffer concentration, NaCl concentration, and presence/absence of metal ion buffer, in two buffer systems previously recommended for alkaline phosphatase (ALP) determination, i.e. AMP and MEG, to test their robustness and different effects on a wide variety of control materials. Analyses were repeated on the same samples in two laboratories, using different automated analysers (Abbott Aeroset and Roche Hitachi 717) and experimental factors based on the molar absorption coefficient of the 4-nitrophenol to calculate results. Eight human serum pools (HSP) with different prevalence of ALP isoenzymes [normal (n=2), liver (n=2), bone (n=3), and placenta (n=1)] and 12 commercial control materials (CM) were tested. The effects of the variations of analytical conditions were evaluated by calculating the ratio of the results obtained in different conditions on HSP and CM. If CM ratio was within the ± 3SD interval of the HSP results (excluding the HSP obtained in pregnant women), the CM was considered commutable in that particular condition. All variables had an effect on HSP which was different from that on most CM, showing commutability problems in these materials. However, while pH and NaCl variations produced the same effects with both buffers, variations of buffer concentration and absence of ion buffer caused minor problems with MEG. The majority of the evaluated CM was not commutable since they consist of ALP isoenzymes different from the pattern which is usually detected in cases of liver or bone diseases. In particular, the use of placental or intestinal ALP to spike CM should be discontinued by the manufacturers. Conversely, it would be desirable to use recombinant tissue non-specific ALP to prepare CM.

The importance of analytical quality specifications for cardiac biomarker assays
Mauro Panteghini
Cattedra di Biochimica Clinica e Biologia Molecolare Clinica, Dipartimento di Scienze Cliniche "Luigi Sacco", Università degli Studi di Milano, Milano, Italy

Biochimica Clinica: 2005; 29(5-6): 495-500 [Article in english]

ABSTRACT. It is very important that cardiac biomarkers on which clinically relevant decisions will rest are measured with highly reliable assays. Adequate studies are needed before new methods can be implemented in the laboratory routine, and only well documented assays should be considered for clinical use. It is therefore critical that, as new biomarkers are proposed, quality specifications are developed. Only after appropriate analytical quality specifications are addressed, the issues pertaining to methodological differences that result in non-harmonized concentration values, and clinical interpretation of biomarker concentrations will be reconciled. Today, the technology to address many analytic problems is at hand, but commitment on the part of manufacturers and their customers in the laboratory and clinical communities is essential. The design control loop is not closed until the finished in vitro diagnostic system is adequately validated to meet the customer needs, including analytical quality specifications. It is essential to determine the attributes and performance characteristics of relevant competitive systems and their degree of acceptance by clinical laboratories in order to definitely demonstrate that user needs are met. The responsibility of defining and implementing these issues must be a shared responsibility among laboratorians, clinicians, industry, and regulatory agencies on an international front. To date, two sets of quality specifications have been published, one for cardiac troponin assays and one for B-type natriuretic peptide assays. Both address analytical factors, such as calibrator characterization, antibody specificity, assay sensitivity and imprecision, and interferents, as well as preanalytical factors, such as sample type and stability. It would be ideal if regulatory agencies, such as FDA in United States, accept these criteria for premarket approval clearance applications.

Aspetti pre-analitici ed analitici della determinazione automatizzata del lattato del plasma
Cristina Valente, Irene Moraschinelli, Mauro Panteghini*, Carlo Franzini
*Laboratorio Analisi Chimico Cliniche, Azienda Ospedaliera Luigi Sacco, Milano- Dipartimento di Scienze Cliniche "Luigi Sacco", Università degli Studi di Milano, Milano

Biochimica Clinica: 2005; 29(5-6): 501-506 [Article in italian]

ABSTRACT. Pre analytical and analytical aspects of automated measurement of plasma lactate Some aspects of the automated measurement of lactate in undeproteinized plasma, with a method based on lactate oxidation (lactate oxidase) coupled to colorimetric measurement of hydrogen peroxide, are evaluated. In particular, lactate stabilization by glycostatic agents (monoiodoacetate and fluoride), and their possibile interference on the enzymatic method, have been evaluated. Both agents performed satisfactorily, even if fluoride exhibited slightly better performance, and is therefore recommended. The whole analytical system (including the pre-analytical and the analytical phases) allows reliable plasma lactate measurements. Non parametric reference values for the system (including a mean overestimation of about 0.20 mmol/L due to glycolysis occurring during 1-3 hour storage at room temperature) are estimated to be in the interval from 0.62 to 2.35 mmol/L.

Calprotectina fecale: un nuovo indicatore di malattia infiammatoria intestinale

Claudia Merlotti, Alberto Dolci, Luisa Scapellato, Mauro Panteghini*
*Laboratorio Analisi Chimico-Cliniche, Azienda Ospedaliera "Luigi Sacco", Milano - Cattedra di Biochimica Clinica e Biologia Molecolare Clinica, Dipartimento di Scienze Cliniche "Luigi Sacco", Università degli Studi di Milano

Biochimica Clinica: 2005; 29(5-6): 507-514 [Article in italian]

ABSTRACT. Calprotectin is a S-100 family calcium- and zinc-binding protein. It derives predominantly from neutrophils and monocytes and it is detectable in body fluids and tissue samples. Fecal calprotectin is a marker of intestinal inflammation and it seems to be useful, in gastroenterological practice, for diagnosing and monitoring organic inflammatory bowel disorders (ulcerative colitis and Crohn’s disease) in adults and children. The aim of this review is to discuss biochemical, analytical and clinical findings of this promising marker of intestinal inflammation.

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