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Biomedical subjects

M Khattab

Publications and source records attributed to M Khattab.

At least 19 recordsLinked to original sources
PubMed2003

[Intracerebral granulocytic sarcoma. A case report].

Granulocytic sarcoma is a tumor composed of proliferating myeloblastic cells, generally found in the orbit. A brain localization is rare. We report the case of a 11-year-old boy treated in our unit for acute myeloblastic leukemia (AML 4 Eo. FAB). After 21 months of complete remission, he developed headache and facial palsy. The CT scan visualized the presence of two frontal and occipital masses. The spinal tap revealed blastic cells in the CSF. The study of the bone morrow showed medullar relapse. A new medullar and cerebro-meningeal remission was obtained with chemotherapy and radiotherapy. CSF and the bone marrow studies can help avoid stereotaxic biopsy can be avoided in this type of tumor

Bone Marrow↗
PubMed2002

Comparative study of the contractile activity evoked by ATP and diadenosine tetraphosphate in isolated rat urinary bladder.

The present study was designed to investigate the effect and possible mechanism(s) of action of ATP and diadenosine tetraphosphate (AP(4)A) on the isolated rat urinary bladder rings. ATP ( 0.1- 1 x 10(-3)M) or AP(4)A ( 0.01- 0.1 x 10(-3)M) produced contractions of the isolated bladder rings in a concentration-dependent manner. The contraction-induced by AP(4)A in the bladder rings was approximately ten times more potent than that produced by ATP. Addition of ATP prior to addition of AP(4)A or vice versa desensitized bladder tissue to the second agonist with great reduction in the contraction produced. Electrical field stimulation (EFS, 40 V, 0.5 ms, 2 Hz) produced contraction (79.8 +/-7.1 g tension x g(-1)tissue) in the bladder rings that can be greatly reduced by prior addition of ATP or AP(4)A. Theophylline, a P(1)-purinoceptor antagonist, significantly reduced the contraction-induced by AP(4)A and did altered that produced by ATP in bladder rings. Atropine, a non-selective muscarinic receptor antagonist, or indomethacin, a cyclo-oxygenase inhibitor, significantly suppressed the contractions of the bladder rings to ATP or AP(4)A. Similarly, nifedipine, an l -type Ca(2+)channel blocker, significantly attenuate the contractions induced by ATP and AP(4)A in the isolated rat urinary bladder rings. In conclusion, the results of the present study show that ATP, AP(4)A, and EFS evoked contractions in the rat urinary bladder rings and that the contractions induced by AP(4)A was more potent than that produced by ATP. Furthermore, the contractions evoked by ATP or AP(4)A were Ca(2+)-dependent and mediated at least in part through one of the cyclo-oxygenase products. Also, the present results suggested the involvement of the P(1)-purinoceptor in mediating the contractions evoked by AP(4)A but not ATP in the bladder rings.

Adenosine Triphosphate↗
PubMed2000

Modulation of nitric oxide synthesis in inflammation. Relationship to oxygen-derived free radicals and prostaglandin synthesis.

The role of nitric oxide (NO) derived from constitutive (cNOS) and inducible (iNOS) nitric oxide synthases and its relationship to oxygen-derived free radicals and prostaglandins was investigated in two models of inflammation, namely, carrageenan granuloma air pouch (acute model) and Freund's adjuvant-induced arthritis (chronic model) in rats. Inflammation was assessed by measurement of NO and prostaglandin E2 (PGE2) levels and the lysosomal leakage of the enzyme N-acetyl-B-D-glucosaminidase (NAG) into the exudate of the granuloma pouch 4 h after carrageenan injection. Evaluation of paw volume and determination of serum NO, lipid peroxide (LP), and PGE2 levels were used for the assessment of adjuvant-induced arthritis after either 4 days (early phase) or 16 days (late phase) of adjuvant injection. Results of the study showed that the administration of either NG-nitro-L-arginine methyl ester (L-NAME, non-selective cNOS/iNOS inhibitor) or aminoguanidine (AG, selective iNOS inhibitor), prior to carrageenan injection or during development of adjuvant arthritis, caused a significant reduction in NO and PGE2 levels and in the NAG activity of the granuloma inflammatory exudate, whereas decreases in paw volume and in serum NO level were noticed in the adjuvant model as related to untreated rats. Similar treatment with L-arginine failed to elaborate a significant change in the parameters measured. Other observations included: no noticeable differences between the results of early and late phases of adjuvant arthritis; no clear correlation between NO, LP and PGE2 levels in the adjuvant arthritis inflammation and inability of the NOS inhibitors to modify the levels of serum LP that is increased during adjuvant-induced arthritis. The data give further evidence that NO is implicated in the development of both acute and chronic inflammation and that NOS inhibitors have potential antiinflammatory activity. Further studies are required to unravel the mechanisms by which NO interacts with other mediators of inflammation.

Acetylglucosaminidase↗
PubMed1999

[Pleuro-pulmonary blastoma. Report of 4 cases].

Pleuropulmonary blastoma is an uncommon malignant lung tumor observed in children. Outcome is often unfavorable. Two boys and two girls, mean age 4.5 years, were admitted for nonspecific respiratory signs. Oriented by radiology findings, the diagnosis of pleuropulmonary blastoma was confirmed at pathology examination of a pneumonectomy specimen. Three of the children were given postoperative adjuvant chemotherapy. There were three deaths and one child was lost to follow-up. We discuss the clinical features of pleuropulmonary blastoma. No optimal treatment has been defined for this often fatal tumor.

Chemotherapy, Adjuvant↗
PubMed1998

Effects of diadenosine polyphosphates on systemic and regional hemodynamics in anesthetized rats.

Diadenosine polyphosphates (Ap4A, Ap5A, Ap6A) induce vasodilatation or vasoconstriction in various isolated vessels and influence central and peripheral hemodynamics. The influence of diadenosine polyphosphates on hemodynamics was studied in anesthetized rats in vivo. Mean arterial blood pressure (MABP) and heart rate (HR) measured in the carotid artery decreased with Ap4A, Ap5A, and Ap6A. Renal blood flow (RBF), femoral blood flow (FBF) and cardiac output (CO) were evaluated by an ultrasonic transit-time method. Renal superficial blood flow (RSBF) was measured by laser Doppler flowmetry. CO, RBF and RSBF were decreased initially by all three diadenosine polyphosphates. FBF was also slightly decreased. Total peripheral (TPR), renal (RVR) and femoral (FVR) vascular resistances were calculated. TPR was transiently increased by the dinucleotides following by a decrease. RVR and, to a lesser extent, FVR were also increased. These data show that diadenosine polyphosphates have effects on both the heart and the peripheral blood vessels. The effects on the heart and MABP were dominated by bradycardia and hypotension. In the kidney, diadenosine polyphosphates induced a predominant vascoconstriction. The effects on skeletal muscle blood flow were much smaller. Thus, the three diadenosine polyphosphates studied differ in the effects on heart and peripheral vessels.

Animals↗
PubMed1998

[Pseudotumorous focal xanthogranulomatous pyelonephritis in children. Apropos of a case].

Xanthogranulomatous pyelonephritis is a particular form of chronic pyelonephritis. It is observed less frequently in children and can sometimes present with a focal pseudoneoplastic appearance. An 11-year-old child was admitted with abdominal pain, alteration of the general state and weight loss without fever or palpable mass. Medical imaging was unable to distinguish between malignant renal tumour or tuberculosis. The diagnosis was confirmed by the inflammatory and purulent appearance of the mass and histopathological examination of the biopsy fragment. Percutaneous drainage of the abscess, combined with antibiotics provided marked improvement. Despite its rarity and its nonspecific clinical features, focal xanthogranulomatous pyelonephritis must be considered in order to propose conservative treatment.

Amoxicillin-Potassium Clavulanate Combination↗
PubMed1997

Differential effects of diadenosine phosphates on purinoceptors in the rat isolated perfused kidney.

1. The activation of various purinoceptors in rat renal vasculature by P1,P2-diadenosine pyrophosphate (Ap2A), P1,P3-diadenosine triphosphate (Ap3A), P1,P4-diadenosine tetraphosphate (Ap4A), P1,P5-diadenosine pentaphosphate (Ap5A), P1,P6-diadenosine hexaphosphate (Ap6A) was studied by measuring their effects of perfusion pressure of a rat isolated perfused kidney. 2. The vasoconstrictive response to Ap5A was completely due to P2x purinoceptor activation, that to Ap4A and Ap6 was P2x purinoceptor mediated to a large extent, as evidenced by the inhibitory effects of suramin and pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid tetrasodium (PPADS). 3. The vasoconstrictive effects of Ap2A and Ap3A were mostly due to stimulation of A1-receptors, as shown by the inhibitory effect of 8-cyclopentyl-1,3-dipropylxanthine (DPCPX). 4. The vasoconstrictive response to Ap6A was partially insensitive to A1 and P2x purinoceptor blockers. 5. In raised tone preparations Ap2A and Ap3A evoked vasodilatation, which was blocked by the A2 receptor blocker, 3,7-dimethyl-1-propargylxanthine (DMPX). 6. In raised tone preparations Ap4A evoked vasodilatation when the P2-purinoceptors were blocked by suramin. 7. The activation of different purinoceptor subtypes by diadenosine phosphates critically depends on the number of phosphate groups.

Adenosine↗
PubMed1994

The epidemiology of Schistosoma mansoni, hepatitis B and hepatitis C infection in Egypt.

There appears to be no epidemiological association between Schistosoma mansoni infection, the intensity of S. mansoni infection or S. mansoni infection complicated by schistosome hepatic fibrosis and the presence of antibody to hepatitis B virus core antigen (anti-HBc), hepatitis B surface antigen (HBsAg), antibody to hepatitis C virus (anti-HCV) or antibody to both agents. This was the main conclusion of a population-based study of an entire village in the northern Egyptian Nile Delta. All 1850 villagers were invited to participate and serological, parasitological and ultrasound examinations were completed on a high proportion of the total population (68% provided sera and higher percentages provided stool specimens and were subjected to ultrasound examinations). Testing with dual Kato slides indicated a high prevalence of S. mansoni infection in the village (49.1%), typical of the area. Hepatitis B virus (HBV) markers (presence of either anti-HBc and/or HBsAg) and anti-HCV were also found to be prevalent, present in 24% and 15.9% of the villagers, respectively. The age-adjusted odds ratios (OR) for infection with S. mansoni and HBV [1.13; 95% confidence interval (CI) = 0.87-1.48], HBsAg (1.11; CI = 0.47-2.58), or anti-HCV (1.02; CI = 0.7-1.37) were not significantly greater than unity. Similarly low and non-significant OR estimates were observed with those positive for both HBV and anti-HCV. No other outcome measures of S. mansoni infection (i.e. intensity of infection or ultrasonographically-determined schistosomal hepatic fibrosis) were found to be associated with HBV, HBsAg or anti-HCV.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Distribution of renal calcitonin binding sites in mammalian and nonmammalian vertebrates.

Calcitonin (CT), the hypocalcemic hypophosphatemic hormone, is present in many vertebrate species. The principal target organs for CT are, in mammals, kidney and bone, and in fish, bone and gill. We have investigated the presence of renal calcitonin binding sites in a fish (Salmo gairdneri), two amphibians (Bufo bufo and Rana esculenta), two reptiles (Pseudemys scripta and Gekko gecko), and two birds (Gallus domesticus and Cothurnix japonica). We compared their distribution to a mammal, the rat (Wistar strain), using quantitative autoradiography methods. Moreover, CT binding sites were also characterized in the chicken kidney by a membrane assay. No renal 125I-sCT binding sites were detected in the fish, the amphibians, and the reptiles studied. In the rat, binding sites were present in the outer medulla and in the cortex. In the chicken and in the quail, scattered binding sites were also observed in the medulla and in the cortex, whose pattern seemed to follow the distribution of the glomeruli and/or the collecting tubules. Chicken kidney membranes were also purified by sucrose gradient centrifugation. Scatchard analysis of the binding data revealed the presence of one type of 125I-sCT binding site with an apparent dissociation constant of 4.3 nM and a number of sites of 73 fmol/mg/protein. The present results suggest that calcitonin renal receptors appeared late in evolution and thus that a regulation of renal function by calcitonin was only effective in birds.

Animals↗
PubMed1989

Early calcitonin hypersecretion and C cell hyperplasia in rats with high incidence of C cell tumors (Wag/Rij).

Wag/Rij rats, a Wistar-derived strain, develop on aging a spontaneous medullary thyroid carcinoma which shows many morphological similarities to the human neoplasm. Using biochemical and histological methods, we studied calcitonin secretion and C cell distribution in young and adult Wag/Rij rats, to characterize possible modifications in calcitonin synthesis and secretion as compared to the original Wistar strain. During the period investigated, the mean basal circulating levels of calcitonin of both sexes were not significantly different between the two strains, although the Wag/Rij rats tended to have higher values. After a calcium challenge, the circulating calcitonin levels increased normally in the Wag/Rij strain as compared to Wistar rats of the same ages. Histological observations of their thyroids revealed a significant C cell hyperplasia, along with a weak immunostaining in some of the cells, due to a lack of secretory granules. Thus, in addition to the ability of developing C cell tumours on aging, the Wag/Rij strain is characterized by an early C cell hyperplasia leading to an increase of calcitonin secretion after a provocative secretion test.

Aging↗
PubMed1976

Alkaline phosphatase of human and calf small intestine. Purification and immunochemical characterization.

Alkaline phosphatase from human and calf small intestines has been prepared and purified until homogeneous, as judged by polyacrylamide gel electrophoresis, by means of the following techniques: n-butanol extraction, ammonium sulfate precipitation, acetone fractionation, ion exchange chromatography and isoelectric focusing in a sucrose density gradient. Three and two alkaline phosphatase froms from human and calf small intestines, respectively could be isolated by preparative isolectric focusing. The relative amounts of these components are not constant, but they have the same catalytic properties, suggesting that they may embody a common protein core with an identical active centre(s). Precipitating antisera for alkaline phosphatase from human and calf intestine have been prepard in rabbits by intramuscular, dermal, subcutaneous and intravenous administration of the pure major component of each enzyme species. Both antisera precipitate completely their homologous as well as their heterologous antigens (intestinal enzyme) and showed partial identity with placental alkaline phosphatase. There was no reaction with alkaline phosphatase from bone, liver heart, spleen, lung, stomach, pancreas, brain, bile-gall bladder and erythrocytes. Alkaline phosphatase preparation from human kidney contains a minor component of the intestinal type, beside many multiple forms which, on treatment with neuramindase, became identical in their electrophoretic and biochemical properties. At least eight multiple forms of the placental enzyme could be shown by isoelectric focusing in polyacrylamide gel. On treatment with neuraminidase these forms became less charged and only four forms remained. All forms were immunologically identical using either anti placental-enzyme or anti intestinal-AP serum. Monospecific antisera against human or calf intestinal alkaline phosphatase were obtained by absorption with purified placental enzyme. This monospecific anti intestinal-AP serum could be used for an immunological quantitative determination of the intestinal isoenzyme in sera or other liquids in the presence of other alkaline phosphatase isoenzymes.

Alkaline Phosphatase↗