Intra-cardiac Burkitt's lymphoma.
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Antineoplastic Agents↗
Biomedical subjects
S Ahmad
Publications and source records attributed to S Ahmad.
Detection of coins ingested by children using a handheld metal detector: a systematic review.
To determine if the use of a handheld metal detector (HHMD) can safely reduce the number of radiographs requested in cases of coins ingested by children, a search was performed to identify prospective studies of the ability of an HHMD to identify the presence or absence of ingested coin in children (17 years or younger). Outcome measures were presence or absence of coin on metal detector screening, and accuracy of coin localisation. Inclusion and exclusion criteria were defined. Mantel-Haenszel (fixed effect model) pooling with 95% confidence intervals (CI) was used to calculate overall sensitivities and specificities. In total, 11 studies met the inclusion criteria. The overall sensitivity of the HHMD at detecting the presence of coins was 99.4% (95% CI 98.0 to 99.9%) and accuracy at localisation was 99.8% (98.5 to 100.0%). The overall specificity of the HHMD was 100% (76.8 to 100%). Use of the HHMD is an accurate, radiation free, and cost effective method of identifying and localising coins ingested by children. An algorithm for investigating children with coin ingestion is proposed.
Adolescent↗
The psychosexual and psychosocial profile of male genitourinary medicine patients with a history of sexual abuse/assault or unwanted sexual experiences.
One hundred and forty-one male patients who attended a District General Hospital's department of genitourinary medicine completed a questionnaire including demographic indices, history of sexual abuse/assault, anxiety and depression, and sexual concerns and attitudes. Of these, 52 (36.9%) reported past unwanted sexual experiences (USE). A significantly higher proportion of the USE group consisted of homosexual men than the non-USE majority. The prevalence rate for USE involving other men was 15.6%, which is comparable to previous studies. Hospital Anxiety and Depression scores were significantly greater for patients with a history of USE (t = -2.82, P = 0.006, for anxiety and t = -3.01, P = 0.003 for depression). Patients with a history of USE also scored significantly higher on a measure of sexual concerns. However, there were no significant differences between the USE and non-USE groups on two brief measures of alcohol and drug consumption. Clinicians in sexual health settings need to be sensitive to the fact that a significant proportion of male patients may have an undisclosed history of USE.
Humans↗
Sunflower seed husk agar: a new medium for the differentiation of Candida dubliniensis from Candida albicans.
A sunflower (Helianthus annuus) seed husk agar medium has been developed and evaluated for differentiation of Candida dubliniensis from Candida albicans on the basis of colony morphology and chlamydospore production. All C. dubliniensis isolates (n=40) produced rough colonies with hyphal fringes and abundant chlamydospores whereas 101 of 105 (96.2%) C. albicans isolates produced smooth colonies with no evidence of chlamydospore production. Since this medium is free from oil droplets, chlamydospores can be examined with greater clarity by Dalmau plate technique. This medium provides a simple and cost-effective tool for the presumptive differentiation of C. dubliniensis from C. albicans and is particularly suited for clinical microbiology laboratories where biochemical or molecular methods for the differentiation of these two species are not available.
Agar↗
Rapid detection of ethambutol-resistant Mycobacterium tuberculosis strains by PCR-RFLP targeting embB codons 306 and 497 and iniA codon 501 mutations.
Mutations at embB gene codons 306 and 497 and iniA gene codon 501 occur frequently in ethambutol (EMB)-resistant Mycobacterium tuberculosis strains worldwide. The identification of these mutations in resistant strains has been achieved by labor-intensive DNA sequencing or by tedious amplification protocols followed by restriction endonuclease digestion. In this report, we describe PCR-restriction fragment length polymorphism (RFLP)-based methods for determining substitutions at embB codons 306 and 497 and iniA codon 501 directly in BACTEC cultures of M. tuberculosis isolates. The wild-type and mutant alleles are revealed by easily interpretable and different RFLP patterns. The methods optimized initially on reference strains were tested directly on BACTEC cultures of 25 randomly selected clinical M. tuberculosis isolates, seven of which were determined to contain EMB-resistant strains by phenotypic drug susceptibility testing. The PCR-RFLP methods identified mutations in four of seven EMB-resistant strains with three isolates containing mutated embB codon 306 and one isolate containing mutated embB codon 497. The results of PCR-RFLP were confirmed by DNA sequencing. The worldwide prevalence figures for mutations at embB codons 306 and 497 and iniA codon 501 suggest that nearly half of EMB-resistant M. tuberculosis strains could be identified within one working day even in developing countries equipped with simple PCR technology instead of weeks required for phenotypic drug susceptibility testing. Further, since EMB resistance is also associated with multiple-drug resistance from some geographical locations, detection of EMB resistance may also lead to rapid identification of multidrug-resistant strains of M. tuberculosis.
Codon↗
Group I metabotropic glutamate receptors in spiral ganglion neurons contribute to excitatory neurotransmissions in the cochlea.
Evidence has accumulated over the years supporting glutamate as the primary neurotransmitter used by hair cells in afferent cochlear neurotransmission. Besides acting on ionotropic glutamate receptors, glutamate also activates second messenger systems via G-protein-coupled metabotropic glutamate receptors (mGluRs) to modulate neuronal excitability. However, it is unclear whether mGluRs participate in cochlear neurotransmission. We present evidence directly supporting a functional role for group I metabotropic glutamate receptors (mGluRIs) in spiral ganglion (SG) neurons. The presence of mGluRI and downstream G-protein subunits was demonstrated by molecular biology and immunolabeling methods. Direct activation of mGluRIs in cultured SG neurons resulted in transient increases of intracellular Ca(++) concentration and transient inward currents that gave rise to firings of multiple action potentials. These responses showed mGluRI pharmacological specificity and quickly desensitized. We next examined changes in cochlear function after noise exposure as a result of pharmacologically manipulating cochlear glutamate neurotransmission. These in vivo tests showed that blocking non-N-methyl-D-aspartic acid glutamate receptors was sufficient to eliminate compound action potentials of the auditory nerve, and pharmacologically inhibiting mGluRIs in the cochlea did not significantly affect the hearing threshold. In contrast, blocking mGluRIs lowered the amplitude of compound action potentials at louder sound levels and reduced the noise-induced temporary threshold shift. Our results suggest that although mGluRIs did not initiate fast excitatory cochlear neurotransmission, their activation contributed to the growth of excitatory responses of the cochlea. As a result, the cochlea was more resistant to noise-induced temporary hearing losses without the activation of mGluRIs in SG neurons.
Action Potentials↗
Lipase-catalyzed esterification of palm-based 9,10-dihydroxystearic acid and 1-octanol in hexane--a kinetic study.
The esterification of palm-based 9,10-dihydroxystearic acid (DHSA) and 1-octanol in hexane as catalyzed by lipase from Rhizomucor meihei (Lipozyme IM) followed Michaelis-Menten kinetics. The esterification reaction follows a Ping-Pong, Bi-Bi mechanism. The maximum rate was estimated to be 1 micromol min(-1) mg(-1) catalyst in hexane at 50 degrees C, and the Michaelis-Menten constants for DHSA and 1-octanol were 1.3 M and 0.7 M, respectively.
Catalysis↗
Immunodominant B-cell epitope in the Mce1A mammalian cell entry protein of Mycobacterium tuberculosis cross-reacting with glutathione S-transferase.
The TB1-5 76C monoclonal antibody raised against a synthetic 60-mer peptide in the N-terminal part of the Mce1A mammalian cell entry protein of Mycobacterium tuberculosis has previously been shown to react with a linear epitope in the KRRITPKD region, residues 131-138 in Mce1A, and to cross-react with Mce1F. Six additional monoclonal antibodies raised against the same peptide were also shown to cross-react with Mce1F. Four of them reacted with a linear epitope in the same area, indicating that this area is immunodominant but showed distinct differrences in fine specificity. Two monoclonal antibodies did not react with synthetic peptides from this region on the solid phase in enzyme-linked immunosorbent assay, indicating greater influence of conformation on reactivity. None of the monoclonal antibodies reacted with 14-mer synthetic peptides from the corresponding area in Mce2A, Mce3A, Mce4A, M. avium, M. smegmatis or M. leprae. The reaction pattern of the monoclonal antibodies was analysed in relation to our model of the Mce1A molecule (AK Das et al. Biochem Biophys Res Commun 2003;302:442-7). The epitope is located on the surface of Mce1A, at the distal beta-strand-loop region in the beta-domain supporting its potential role in promoting uptake of M. tuberculosis in host cells. Monoclonal antibody TB1-5 19C cross-reacted with glutathione S-transferase of Schistosoma japonicum containing a PKE triplet. Monoclonal antibody TB1-5 76C gave a major band at about 44 kDa in Western blotting of M. tuberculosis sonicate, whereas polyclonal rabbit anti-Mce1A peptide antibodies reacting with the extended TTPKNPTKRRITPKDVI area of Mce1A showed a distinct band above the 160 kDa molecular mass standard.
Amino Acid Sequence↗
Mammalian cell-entry proteins encoded by the mce3 operon of Mycobacterium tuberculosis are expressed during natural infection in humans.
The mammalian cell-entry (mce)3 operon is one of four homologous mce operons on Mycobacterium tuberculosis genome that encodes six putative invasin/ adhesin-like proteins (Mce3A-F) possibly involved in the entry and survival of this bacterium inside macrophages. To study the in vivo expression of the mce3 operon-encoded proteins during natural human infection, the genes encoding Mce3A-F were cloned and expressed in Escherichia coli as fusion proteins with glutathione-S-transferase (GST) at the N-terminal and a x6 histidine (His) tag at the C-terminal end. The recombinant proteins appeared as major cellular proteins in SDS-PAGE gels and reacted with anti-GST and antipenta-His antibodies at the expected molecular mass of 70, 61, 68, 71, 66 and 72 [corrected] kDa for GST-Mce3A, GST-Mce3B, GST-Mce3C, GST-Mce3D, GST-Mce3E and GST-Mce3F, respectively. In Western immunoblots, all the six fusion proteins, particularly GST-Mce3A, GST-Mce3C, GST-Mce3D and GST-Mce3E, reacted with antibodies in combined human serum from 11 tuberculosis (TB) patients. Pure Mce3A, Mce3D and Mce3E could be isolated by specific proteolytic cleavage by thrombin protease of the respective purified fusion protein followed by preparative SDS-PAGE. The pure Mce3A, Mce3D and Mce3E reacted to various extents with antibodies in serum samples from TB patients. The Mce3E reacted with 51 of 55 (93%) and all the three proteins reacted with 34 of 55 (62%) serum samples. The Mce3A, Mce3D and Mce3E proteins also reacted, albeit at lower frequency, with one of 23 (4%) serum sample obtained from M. bovis bacillus Calmette-Guérin-vaccinated healthy subjects and four of 18 (22%) serum samples from long-term contacts of TB patients showing reactivity with all the three Mce3 proteins. The data show that Mce3A, Mce3D and Mce3E encoded by mce3 operon of M. tuberculosis are expressed and elicit antibody responses in humans during natural infection with this pathogen.
Antibodies, Bacterial↗
Simplified sunflower (Helianthus annuus) seed agar for differentiation of Candida dubliniensis from Candida albicans.
This study evaluated sunflower (Helianthus annuus) seed agar (SSA) for differentiation of Candida dubliniensis from Candida albicans on the basis of colony characteristics and chlamydospore production. Simplified SSA without creatinine and KH(2)PO(4) was also used. On both media, C. dubliniensis isolates (n = 25) developed rough colonies and formed abundant chlamydospores after incubation for 24-48 h at 28 degrees C, while C. albicans isolates (n = 53) showed smooth colonies with no evidence of chlamydospore formation. Cryptococcus neoformans isolates (n = 10) formed brown colonies on both media. Simplified SSA offers a simple and inexpensive tool for presumptive differentiation of C. dubliniensis from C. albicans in clinical microbiology laboratories.
Agar↗
Value of serum prolactin in the management of syncope.
OBJECTIVE: A meta-analysis of studies of the usefulness of raised serum prolactin in diagnosing generalised tonic-clonic seizures (GTCS) in patients presenting to the accident and emergency (A&E) department after a single episode of syncope. METHODS: A three part question was defined. Medline, EMBASE, PubMed, the Cochrane Library were searched to identify relevant studies. Studies were evaluated for eligibility and quality and data extracted to calculate sensitivity (SN), specificity (SP), and likelihood ratios (LR). RESULTS: Of 13 relevant studies only three met the criteria for evaluation. If a serum prolactin concentration is greater than three times the baseline when taken within one hour of syncope, then in the absence of test "modifiers": (1) the patient is nine times more likely to have suffered a GTCS as compared with a pseudoseizure positive LR = 8.92 (95% CI (1.31 to 60.91)), SN = 0.62 (95% CI (0.40 to 0.83)), SP = 0.89 (95% CI (0.60 to 0.98)) and (2) five times more likely to have suffered a GTCS as compared with non-convulsive syncope positive LR 4.60 (95% CI (1.25 to 16.90)), SN = 0.71 (95% CI (0.49 to 0.87)), SP = 0.85 (95% CI (0.55 to 0.98)). CONCLUSION: A positive test result is highly predictive of a GTCS, however a negative test result does not necessarily exclude a seizure. Serum prolactin should be measured in patients presenting to the A&E department within an hour of a syncopal episode, unless the cause is immediately obvious.
Cohort Studies↗
Pro-nociceptive effects of neuromedin U in rat.
The neuropeptide neuromedin U (NMU) has been shown to have significant effects on cardiovascular, gastrointestinal and CNS functions. The peptide was first isolated from the porcine spinal cord and later shown to be present in spinal cords of other species. Little is known about the distribution of neuromedin U receptors (NMURs) in the spinal cord and the spinal action of the peptide. Here we report on the expression of NMURs and a potential role in nociception in the rat spinal cord using a combination of behavioral and electrophysiological studies. Receptor autoradiography showed that NMU-23 binding was restricted to the superficial layers of spinal cord, a region known to be involved in the control of nociception. In situ hybridization analysis indicated the mRNA of NMUR2 was located in the same region (laminae I and IIo) as NMU-23 binding, while the mRNA for NMU receptor 1 was observed in a subpopulation of small diameter neurons of dorsal root ganglia. Intrathecal (i.t.) administration of neuromedin U-23 (0.4-4.0 nmol/10 microl) dose-dependently decreased both the mechanical threshold to von Frey hair stimulation and the withdrawal latency to a noxious thermal stimulus. Mechanical allodynia was observed between 10 and 120 min, peaking at 30 min and heat hyperalgesia was observed 10-30 min after i.t. administration of NMU-23. A similar mechanical allodynia was also observed following i.t. administration of NMU-8 (0.4-4 nmol/10 microl). A significant enhancement of the excitability of flexor reflex was induced by intrathecal administration of NMU-23 (4 nmol/10 microl). Evoked responses to touch and pinch stimuli were increased by 439+/-94% and 188+/-36% (P<0.01, n=6) respectively. The behavioral and electrophysiological data demonstrate, for the first time, a pro-nociceptive action of NMU. The restricted distribution of NMU receptors to a region of the spinal cord involved in nociception suggests that this peptide receptor system may play a role in nociception.
Animals↗
Epidemiology of Candida colonization in an intensive care unit of a teaching hospital in Kuwait.
The incidence of Candida infections in intensive care units (ICU) is increasing. Although most cases of candidemia are caused by commensal strains colonizing the patients' own body sites, recent studies have suggested that the source of Candida infection can also be exogenous. This study was carried out to prospectively investigate the frequency of Candida colonization among patients and health care personnel of an ICU of a teaching hospital in Kuwait. A total of 57 patients and 45 nurses were investigated. Candida isolates were identified to the species level by the Vitek identification system. The typing of selected isolates was performed by randomly amplified polymorphic DNA (RAPD) using three different arbitrary primers (CARAPD1, AP3, CT5). Of the 526 samples collected from 57 patients, 180 (34%) yielded Candida species. These included 112 (62%) C. albicans, 37 (21%) C. glabrata, 15 (8%) C. parapsilosis, 11 (6%) C. tropicalis, 3 (2%) C. krusei and 2 (1%) C. lusitaniae isolates. Thirty-seven patients (65%) were colonized by Candida at some point of stay in the ICU. Seven (12%) patients yielded more than one Candida species from the sites/specimens tested. The frequency of Candida isolation was highest from oropharynx, followed by rectum, groin, urine and trachea. Twenty-five (6%) of the 448 swabs from the nurses yielded Candida and included C. albicans (n = 16), C. parapsilosis (n = 4) and C. famata (n = 5). While all the three primers yielded varying patterns in RAPD analyses for each Candida species, the results obtained by AP3 were most discriminatory. The data showed that the colonizing Candida isolates recovered from various body sites of the patients, as well as the nursing staff, were different. However, when RAPD profiles of three blood culture isolates from candidemic patients were analyzed, the DNA fingerprint produced by one C. parapsilosis blood culture isolate was similar to C. parapsilosis recovered from the hands of two nurses, suggesting exogenous acquisition of infection.
Adolescent↗
Inexpensive vaccines and rapid diagnostic kits tailor-made for the global eradication of rinderpest, and technology transfer to Africa and Asia.
Rinderpest is an acute and highly contagious viral disease of ruminants, often resulting in greater than 90% mortality. We previously reported the development of first- and second-generation recombinant vaccinia virus vaccines which provide complete protection against rinderpest virus (RPV) and peste-des-petits ruminants virus (PPRV). These vaccines are safe even for immunodeficient mice and macaques with acquired immunodeficiency syndrome. We developed a third-generation recombinant vaccinia virus vaccine (v2RVFH) that expresses the fusion and haemagglutinin genes of RPV under strong synthetic vaccinia virus promoters. Cattle vaccinated intramuscularly with as little as 10(3) plaque-forming units (PFU) of v2RVFH were completely protected from rinderpest. Vaccinated animals did not develop pock lesions or transmit v2RVFH to contact animals. Cattle vaccinated with a standard dose of 10(8) PFU of v2RVFH developed long-term, sterilizing immunity against rinderpest. Thus, v2RVFH is safe, efficacious, heat stable, inexpensive, easily administered, and allows serological differentiation between vaccinated and infected animals. To aid in diagnosis and differentiation of vaccinated from infected animals, we developed indirect ELISAs (iELISAs) that use baculovirus-expressed RPV or PPRV nucleoprotein as coating antigens. A single larva contains enough viral antigen to test more than 10,000 serum samples, in duplicate. African scientists trained at the ILMB successfully transferred the iELISA kit technology to more than 30 countries in Africa, providing a model for technology transfer among developing countries. Vaccination with v2RVFH, in conjunction with the iELISA kits, greatly enhances the prospects for global eradication of rinderpest, as developing nations achieve independence in control efforts.
Africa↗
Antinociceptive and antidiarrhoeal activity of Zanthoxylum rhetsa.
The methanolic extract of the Zanthoxylum rhetsa Roxb. stem bark, given by oral route to mice at doses of 250 and 500 mg/kg, significantly reduced the abdominal contraction induced by acetic acid and the diarrhoeal episodes induced by castor oil in mice.
Acetic Acid↗
Metastatic infiltration of the dental pulp by medulloblastoma.
Medulloblastoma is an infratentorial primitive neuroectodermal tumour. It is the most commonly occurring brain tumour of childhood, accounting for 15-20% of all paediatric tumours. Extracranial metastasis is rare, but may involve the skeleton. Jaw lesions, however, have never been described. A case is reported of metastases of a medulloblastoma to the jaw including the dental pulp.
Bone Neoplasms↗
Cross-reaction between mammalian cell entry (Mce) proteins of Mycobacterium tuberculosis.
In addition to the previously cloned Mce1A and Mce1E genes of the Mce1 operon of Mycobacterium tuberculosis (Ahmad et al. Scand J Immunol 1999;50:510-8), Mce1B, Mce1D and Mce1F were cloned and expressed as glutathione-S-transferase (GST) fusion proteins in recombinant Escherichia coli. Polyclonal antibodies against a predicted B-cell epitope of each of the Mce1 proteins of M. tuberculosis were produced by immunizing rabbits with synthetic peptides coupled to keyhole limpet haemocyanin. These antibodies reacted specifically with the corresponding fusion protein, except for GST-Mce1F. A mouse monoclonal antibody, TB1-5 76C, raised against a synthetic 60-mer peptide corresponding to the residues 106-165 in the N-terminal part of Mce1A, reacted strongly with GST-Mce1A. The antibody cross-reacted with GST-Mce1F, but not with the other recombinant GST-Mce1 fusion proteins or free GST. Bioinformatic analysis revealed only slight homology between Mce1A and Mce1F, along the length of the polypeptide chains. Higher homology was found between the residues 106-165 of Mce1A and the residues 347-406, further into the mature Mce1F polypeptide chain. There was a striking, localized homology, indicating that the epitope reacting with the monoclonal antibody TB1-5 76C may be narrowed to the KRRITPKD region, the residues 131-138 in Mce1A corresponding to the residues 372-379 in Mce1F. This was confirmed in enzyme-linked immunosorbent assay, showing binding of TB1-5 76C to a 17-mer synthetic peptide containing the KRRITPKD sequence.
Amino Acid Sequence↗
Recovery from pH 6.38: lactic acidosis complicated by hypothermia.
Survival after extreme arterial acidosis is uncommon. A case of metformin induced lactic acidosis is described where the presenting pH was 6.38 exacerbated by hypothermia (29 degrees C). Increased anion gap acidosis, its varied aetiology, potential reversibility, and the role of hypothermia are discussed. Early liaison with a medical toxicology unit is recommended when this rare condition is suspected.
Acidosis, Lactic↗