Biomedical subjects

L S Hanna

Publications and source records attributed to L S Hanna.

At least 19 recordsLinked to original sources

PubMed1995

Schistosoma mansoni: egg granuloma reduction in challenged mice after vaccination with irradiated-attenuated cercariae.

Response of Swiss albino mice vaccinated with irradiated-attenuated cercariae or repeatedly infected with normal cercariae of Schistosoma mansoni were known to develop resistance to reinfection. The mean (+/- SD) of the hepatic granuloma numbers and diameters for vaccinated-challenged group (I) were 2 +/- 0.89/1mm2 and 116 +/- 11.5 microns, for repeatedly infected group (II) were 2 +/- 0.63/1mm2 and 2 +/- 0.89/1mm2 and 195 +/- 11.8 microns and for control group (III) were 4 +/- 1.36/1mm2 and 140 +/- 12.3 microns respectively. Mean of the diameter of the granulomas were significantly smaller in the group vaccinated with irradiated cercariae than the other two groups. Most of the granulomas in groups I and II were fibro-cellular while all granulomas in group III were cellular. Predominent cell types of the granulomas were lymphocytes in groups I and II and eosinophils in group III. The incidence of focal hydropic and fatty degenerations, necrosis and prominent kupffer cell hyperplasia were lower in group I. These results supported that granuloma size reduction in all vaccinated animals were apparently effective in sequestering egg toxins and reduced hepatocytes damage. The present study gives encouragement that a vaccine to enhance protection against disease in human schistosomiasis is possible.

Animals↗

PubMed1994

Schistosoma mansoni: IgG reactivity to soluble adult worm antigen preparation (SWAP) in sera of immunized mice with irradiated attenuated and virulent cercariae.

The aim of this work was to identify the antigens, that elicit a greater or unique immune response in the immunized host against Schistosoma mansoni (Egyptian strain) infection. Moreover the difference in immune response to this antigen between mice immunized with radiation-attenuated cercariae or immunized with virulent cercariae were investigated. Immunobloting technique was used to monitor the fine specificity of host IgG to SDS-PAGE separated SWAP in the sera of different test groups immunized with either radiation-attenuated cercariae or low doses of virulent cercariae compared to non-immunized group. Data from this study showed that groups immunized with virulent and irradiated-attenuated cercariae showed 74.7% and 68.3% reduction in worm burden respectively. Differences of humoral immune response of sera of different tested groups against SWAP proteins were definite. Sera of non-immunized mice precipitated non-immunogenic proteins of 87 and 83 KD. SWAP proteins of 106 and 97 KD were identified only by the sera of vaccinated animals with irradiated attenuated cercariae whether challenged or not. Resistant sera from animals immunized by either irradiated-attenuated cercariae or virulent cercariae recognized low molecular weight antigens that ranged from 34 to 52 KD in addition to 57 KD. This indicated that the 106 and 97KD may be the target antigens for protection by radiation-attenuated larvae, while the marker of resistance induced by attenuated or virulent larvae may be 34-52 and 75 KD antigens.

Animals↗

PubMed1989

Crystallization and preliminary X-ray studies of recombinant human granulocyte-macrophage colony stimulating factor.

Human granulocyte-macrophage colony stimulating factor (hGM-CSF) is an important regulator of growth and differentiation for mononuclear and polymorphonuclear phagocytes. Here we report the crystallization and preliminary X-ray studies of Escherichia coli-expressed hGM-CSF. The crystals are orthorhombic, with the space group P212121, and have unit cell dimensions a = 46.62 A, b = 58.73 A and c = 126.42 A. Recombinant hGM-CSF crystals diffract X-rays to 2.4 A resolution and are thus suitable for X-ray structural studies.

Colony-Stimulating Factors↗

PubMed1989

Transient cataracts in a young child with meningococcal meningitis.

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Cataract↗

PubMed1988

Ocular complications in meningitis: "fifteen years study".

The incidence of ocular complications in 4102 patients with meningitis was studied during a 15 year period. Cranial nerve involvement was detected in 23% of patients (sixth cranial nerve in 16.5%; third and seventh nerve in 3.0% each; and fourth and fifth nerve in 0.1% each). Pupillary changes were detected in 82% and fundus changes in 5.2% of patients.

Adolescent↗

PubMed1984

Comparison of structures of various human fibrinogens and a derivative thereof by a study of the kinetics of release of fibrinopeptides.

The kinetics of the thrombin-induced release of fibrinopeptides from several variants of human fibrinogen, and from the plasmin digestion fragment E thereof, have been studied by using an HPLC technique to separate the reaction products. The data were analyzed in terms of a Michaelis-Menten mechanism in which the A alpha and B beta chains compete for thrombin. Phosphorylation of Ser-3 of the A alpha chain appears to increase the rate of release of the corresponding phosphorylated peptide A from fibrinogen, due to enhanced binding of thrombin (lower value of the Michaelis-Menten constant KM). However, phosphorylation does not affect the rate of release of the unphosphorylated A or B peptides. Increase in the length of the gamma chain (at the C-terminus) does not affect the rate of release of any of the fibrinopeptides. The rate of release of the A peptide from fragment E (which is devoid of the B peptide) is similar to that for the complete fibrinogen molecule. These results are in agreement with an earlier conclusion [Martinelli, R. A., & Scheraga, H. A. (1980) Biochemistry 19, 2343] that the A alpha and B beta chains behave independently in their competition for thrombin; i.e., the hydrolyzable Arg-Gly bonds of the A alpha and B beta chains are both accessible to thrombin.

Fibrin Fibrinogen Degradation Products↗

PubMed1983

Kinetic analysis of nicotinate phosphoribosyltransferase from yeast using high pressure liquid chromatography.

A new procedure has been designed for the purification of nicotinate phosphoribosyltransferase and orotate phosphoribosyltransferase from the same baker's yeast extract. Using purified nicotinate phosphoribosyltransferase, the enzyme-catalyzed formation of nicotinate mononucleotide was analyzed using a new high pressure liquid chromatographic assay (Hanna, L., and Sloan, D. L. (1980) Anal. Biochem. 103, 230-234). Initial velocity measurements and product inhibition studies, with pyrophosphate, were performed. In addition, this assay procedure was used to demonstrate that purified nicotinate phosphoribosyltransferase possesses an ATPase activity in the presence of either product (pyrophosphate or nicotinate mononucleotide (NaMN] but in the absence of 5-phosphoribosyl alpha-1-pyrophosphate (P-Rib-PP). Moreover, exchanges of radioactivity between specific substrate/product pairs [( 14C]nicotinate/NaMN and [32P]PPi/P-Rib-PP) in the absence of other substrates were not observed when these pairs were incubated with nicotinate phosphoribosyltransferase, and binding of [14C] nicotinate to nicotinate phosphoribosyltransferase was not detected in the presence of ATP. In contrast, an exchange of label between ATP and [14C]ADP was characterized in the absence of other substrates and in the presence of either P-Rib-PP or PPi. These results indicate that nicotinate phosphoribosyltransferase proceeds through the use of an ordered Uni Uni Bi Ter Ping Pong kinetic mechanism during which ATP reacts with nicotinate phosphoribosyltransferase to form ADP and a previously described phosphorylated enzyme (Kosaka, A., Spivey, H. O., and Gholson, R. K. (1977) Arch. Biochem. Biophys. 179, 334-341). Thereafter, P-Rib-PP and nicotinate bind in order to the active site, to produce PPi and NaMN which are released in a random order followed by Pi. The Km values for ATP, P-Rib-PP, and nicotinate were calculated to be 70 +/- 10, 24 +/- 3, and 23 +/- 4 microM, respectively, whereas a value for Ki(PRPP) of 5 +/- 1 microM was determined.

Adenosine Triphosphatases↗

PubMed1983

The use of dexamethasone in preventing ocular complications in tuberculous meningitis.

Twenty-seven patients with tuberculous meningitis (TBM) were treated with ethambutol, isonicotinic acid hydrazide, streptomycin and dexamethasone and 28 were treated with triple anti-tuberculous drugs only. Only two of the patients to whom steroids were given developed ocular complications as compared to seven of those not receiving dexamethasone. High dose dexamethasone apparently prevents optic atrophy in TBM. Controlled double-blind studies with and without dexamethasone are needed to confirm this postulation.

Adolescent↗

PubMed1983

Effect of urinary bilharzial infection on male pubertal development and endocrine functions.

One hundred seventy-five males aged 9-20 years were selected. The subjects comprised two groups; controls and patients infected with urinary bilharziasis not associated with any other parasite. Pubertal development was assessed. Serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and progesterone were determined by radioimmunoassay procedure. Delay in pubertal development was evident in the normal control group as indicated by higher chronological age mean values at the various stages as compared to other world norms. Urinary bilharziasis exaggerated the delay in pubertal development as compared to that in the control group. In relation to the control group, the group with urinary bilharziasis had higher levels of serum FSH and LH, which were significant only at stages III and IV. No significant difference was noted between the two groups for serum testosterone and progesterone levels, except for the high progesterone mean value at stage V in the group with urinary bilharziasis.

Adolescent↗

PubMed1978