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Biomedical subjects

M Hammad

Publications and source records attributed to M Hammad.

7 recordsLinked to original sources

Genomic characterisation and lytic potential of phage SF01 against multidrug-resistant Salmonella enterica subsp. enterica, a key agent of infection in poultry.

1. Salmonella enterica remains the key cause of salmonellosis in poultry, causing high morbidity and mortality. Due to the unprecedented resistance of S. enterica to antibiotics, bacteriophages have emerged as a powerful alternative to conventional antibiotics treatment for salmonellosis.2. In this study, a strain was isolated from infected broiler chickens and whole-genome sequencing (WGS) identified the strain SFD-01 as S. enterica subsp. enterica. Bioinformatics analyses revealed that the genome was 4.6 Mb in size with 4559 coding sequences (CDS), 77 tRNAs and 4 rRNAs. Additionally, 119 virulence genes, 125 antimicrobial resistance genes, 5 mobile genetic elements, 2 prophages and multiple copies of pathogenicity islands (SPI) were identified in the genome.3. To address this, bacteriophage SF01 was isolated from wastewater near a chicken slaughterhouse against host strain SFD-01. Transmission electron microscopy revealed that the phage had an 85-nm icosahedral head and a 130-nm long contractile tail. The Felixounavirus SF01 exhibited high stability across pH 3-9. Phage lytic activity at a multiplicity of infection of 0.01 restricted the bacterial growth.4. Whole genome analysis (WGS) identified phage SF01 as a Felixounavirus with 88-kb genome composed of 174 CDS, 20 tRNA genes and with no lysogenic markers, resistance genes or virulence factors. The strict lytic potential of phage SF01 makes it a highly viable option for use in the potential biocontrol of the novel strain S. enterica subsp. enterica serotype 42:z4,z23.

Felixounavirus↗

The efficacy of a school-based caries preventive program: a 4-year study.

This longitudinal study aimed at testing the efficacy of a school-based caries preventive program, by comparing dental caries status of two groups, a study group (436 children) and a control group (420 children) over a period of 4 years. The study group received a preventive program which consisted of intensive oral hygiene instructions sessions, and supervised daily tooth brushing using fluoridated tooth paste in schools. The control group received only oral hygiene instructions sessions. Annual dental examination to record dental caries status, using Decayed Missed Filled Teeth Index (DMFT) and deft, was conducted for both groups over a period of 4 years. At the end of the fourth year the efficacy of the program was tested by comparing the DMFT and deft indices for the two groups using Pearson chi-square test and Cochran-Mantel-Haenzele test. The level of significance was set at P < 0.05. The results after 4 years showed that the caries status of the children in the study group was better than that of the control group. The difference was statistically significant (P-value 0.001). The estimates of relative risk values also showed that children in the control group are 3.1 and 6.4 times at higher risk of having dental caries than those in the study group for age group 12 and 6 respectively. This study proves that supervised daily tooth brushing using fluoridated toothpaste is successful in controlling dental caries in children.

Cariostatic Agents↗

Synthesis of indole-N-propionitrile, N-propionic acid and N-propionamide derivatives of potential biological activity.

Cyanoethylation of a selected group from indole derivatives 1a-i using acrylonitrile in pyridine and potassium hydroxide afforded the corresponding indole-1-propionitrile 2a-h derivatives which readily hydrolysed in basic medium to the corresponding indole-1-propionic acid derivatives 4a-c. A several attempts to cyclize the above products-to the corresponding dihydropyrroloquinolin-4-one derivatives. The indole-1-propionamide derivatives reacted with diethyl carbonate and ethyl acetate under Claisen condensation also, with diazonium salts and nitric acid.

Amides↗

Significance of circulating plasma cells in multiple myeloma.

The number of circulating plasma cells (CPC) was determined on mononuclear cell preparations after Giemsa (morphology) and light chain staining (immunocytochemistry). Both methods gave reproducible and identical results when CPC were 1% or more. Using this limit, no CPC were observed in MGUS (0/11) and primary amyloidosis (0/2), whereas 45/98 (45.9%) multiple myeloma (MM) pts had > or = 1% CPC. 3/14 pts (21.4%) in stage I, 5/13 pts (38.5%) in stage II, 20/28 pts (71.4%) in stage III, 4/25 pts (16%) at plateau phase, and 13/18 pts (72.2%) at relapse had > or = 1% CPC (p < 0.001). Mean beta-2 microglobulin was 3.77 mg/l and 6.08 mg/l for pts without or with > or = 1% CPC, respectively p = 0.0001). Presence of CPC was also correlated with an higher percentage of bone marrow PC, but not with the number of Ki-67 positive BM-PC, and not with CRP or LDH levels. K/L and Gamma/Alpha CPC isotype ratio showed these cells as monotypic in nearly all pts. The prognostic value could not really be assessed in this study, as only the initial response to therapy was investigated, and the latter failed to give any difference between pts with and without CPC. So, presence of CPC is not an infrequent finding, but is highly related to tumor mass and active disease; in most if not all patients they are monotypic and certainly belong to the malignant clone. Their prognostic value is unclear but under current investigation; CPC are correlated with B-2M level.

Cell Count↗

Improved cytogenetic analysis of bone marrow plasma cells after cytokine stimulation in multiple myeloma: a report on 46 patients.

Cytogenetic analysis was successfully performed in 46 consecutive myeloma patients (40 newly diagnosed and six relapsed patients). Karyotype was performed on bone marrow cells after long-term cultures (6 d) stimulated by GM-CSF, GM-CSF+IL6 or GM-CSF+IL6+IL3. Nineteen patients (41%) had cytogenetic abnormalities including 17/40 patients at diagnosis (42.5%) and 2/6 patients at relapse. Hyperdiploidy was found in 12 patients and hypodiploidy in four patients. Of the 17 newly diagnosed patients with cytogenetic abnormalities, five died from myeloma after 1-14 months and three other patients had primary drug resistance. Our results suggest that cytogenetic analysis after stimulation of cultures by cytokines detects clonal abnormalities in 40-50% of newly diagnosed myeloma patients and that these patients often have a short survival and/or primary drug resistance.

Bone Marrow↗