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Biomedical subjects

K Ahmed

Publications and source records attributed to K Ahmed.

At least 109 records · Page 6Linked to original sources
PubMed1993

[A case of Kartagener's syndrome with S. pneumoniae lung abscess].

A 38-year-old male with Kartagener's syndrome (KS) was admitted to our department for evaluation of recurrent pneumonia. Before admission the patient was diagnosed as having pneumonia in another hospital and received ofloxacin (300 mg/day). Fever and production of purulent sputum decreased initially but again increased in the middle of April. On admission the films of both X-ray and CT scan of the chest revealed several air-fluid levels and infiltrative shadows on the left lower lung field. The patient was diagnosed as lung abscess using bronchofiberscopy. Gram staining of the intrabronchial specimens revealed many Gram-positive cocci and neutrophils including phagocytosed bacteria. A new carbapenem (L-627, 600 mg/day), was started intravenously. After the therapy Streptococcus pneumoniae were eradicated soon from the sputum. At the same time the above symptoms including dyspnea on exertion subsided, and the findings of the chest X-ray and CT scan were also improved. Regarding KS the electron micrograph of the cilia showed the absence of the outer-dynein arms. While by both the saccharin test and the sputum cytology impaired mucociliary clearance was found. Lung abscess infrequently accompany KS. There are reports of respiratory infections in KS, but to our knowledge no report of lung abscess was found in KS. We present this case report describing lung abscess in KS.

Adult↗
PubMed1993

Thymulin modulates cytokine release by peripheral blood mononuclear cells: a comparison between healthy volunteers and patients with systemic lupus erythematosus.

Thymulin is a nonapeptide hormone isolated from the thymus gland. It has immunomodulatory effects which have not yet been well defined. Its major actions have been shown to be on T-cells and their immature precursors. In this study, thymulin was tested in vitro for its effect on the release of IL-1 alpha, IL-2, IL-6 and TNF alpha from peripheral blood mononuclear cells (PBMC) obtained from normal volunteers and patients with active systemic lupus erythematosus (SLE). In our experiments, PBMC (stimulated with LPS or PHA) were cultured for 24 h in the presence of 1,100 or 1,000 ng/ml of thymulin. Supernatants were subsequently assayed for cytokine activities using commercially available ELISA (IL-2, IL-6 and TNF alpha) and RIA (IL-1 alpha) kits. Thymulin (1 ng/ml) resulted in a significant (p < 0.01) increase in IL-1 alpha in the volunteers and a significant (p < 0.05) inhibition of this cytokine at all dose levels tested in SLE patients, whose basal levels of IL-1 alpha were significantly (p < 0.05) higher. Thymulin significantly (p < 0.05) inhibited IL-2 only in SLE patients at 1,000 ng/ml. At all dose levels tested, thymulin significantly (p < 0.01) inhibited IL-6 in volunteers, and, only at 1,000 ng/ml, it significantly (p < 0.05) inhibited it in patients with SLE. At the 1,000 ng/ml dose level, TNF alpha was significantly (p < 0.05) inhibited in both volunteers and SLE patients, whose basal levels of this cytokine were significantly (p < 0.05) higher.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Cloning of cDNAs encoding the alpha and beta subunits of rat casein kinase 2 (CK-2): investigation of molecular regulation of CK-2 by androgens in rat ventral prostate.

Casein kinase 2 (CK-2) is a ubiquitous messenger-independent protein serine/threonine kinase that has been implicated in the control of cell growth and proliferation. By employing androgen action in the prostate as a model of growth control, we have previously documented that androgens modulate prostatic CK-2 activity in a tissue specific manner. Here we have investigated the role of transcriptional control of prostatic CK-2 in androgenic regulation of its activity. We first cloned and sequenced full length cDNAs encoding the alpha and beta subunits of rat CK-2. The cDNA sequence encoding the alpha subunit corresponded with previously reported sequences for other species, as well as with the derived partial amino acid sequence reported for a rat cDNA. The cloned cDNA for rat CK-2-beta subunit, not reported previously, was also identical in amino acid sequence to that of other species. The cDNAs for alpha and beta subunits were employed as probes to examine the effects of altered androgenic status on transcription of mRNAs for the subunits of prostatic CK-2. Androgen deprivation caused a slow decline in transcription of the a subunit, so that no change was noted at 24 h postcastration; however, at later periods of androgen deprivation a progressive but relatively slow decline was apparent. Administration of a single dose of 5 alpha-dihydrotestosterone (5 alpha-DHT) to 6-d castrated animals did not elicit an early expression of new mRNAs for CK-2-alpha and beta subunits. However, a significant expression of mRNAs for the two subunits was apparent at 8 h (i.e., later stages of the prereplicative phase) reaching a peak in the proliferative phase of prostatic growth (i.e., at 24-48 h) following androgen administration. These data suggest that androgenic regulation of CK-2 gene transcription is not an early event related to androgen action, but is substantial in the prereplicative phase of prostatic cell proliferation mediated by androgen. Further, androgenic stimulation of the mRNA expression for the alpha and beta subunits of CK-2 appears to be differential.

Amino Acid Sequence↗
PubMed1993

Androgenic regulation of the expression and phosphorylation of prostatic nucleolar protein B23.

Protein B23 is a nucleolar and nuclear matrix phosphoprotein which has been implicated in ribosomal assembly and/or rRNA processing. Since androgen action in the prostate is accompanied by early changes in rRNA synthesis, we have investigated androgenic regulation of protein B23 expression and phosphorylation in rat ventral prostatic nuclei. The mRNA for prostatic protein B23 was relatively stable and decreased only after several days of androgen deprivation. However, androgen deprivation resulted in a rapid change in the amount and phosphorylation of protein B23 in prostatic nuclei, which was reversed on administration of androgens to orchiectomized animals. Phosphorylation of protein B23 appears to be catalyzed primarily by casein kinase 2 (CK-2). Early androgenic changes in phosphorylation of protein B23 appear to relate more to modulations in the protein kinase activity than in the amount of protein B23. The androgen mediated enhancement in the amount of protein B23 and its phosphorylation precedes the cellular proliferative phase following androgen administration to castrated rats, and appear to be temporally concordant with the rRNA synthesis in the tissue. The androgen mediated changes in the amount and phosphorylation of protein B23 are specific to the prostate and are not detected in the liver nuclei. Thus, androgenic regulation of the amount and phosphorylation of prostatic protein B23 may be related to the early changes associated with androgen mediated growth of the gland.

Animals↗
PubMed1992

Ultrastructural study on the adherence of Branhamella catarrhalis to oropharyngeal epithelial cell.

In the present study, it was observed that Branhamella catarrhalis adhere to the microplicae of the oropharyngeal epithelial cells. Both long and short microplicae patterns are present on the surface of oropharyngeal epithelial cells and the adherence ability of fimbriated Branhamella catarrhalis also varies according to the microplicae pattern. It was found that Branhamella catarrhalis attached more to one surface of the epithelial cell than to the other, suggesting that the presence of receptors are more on one surface than on the other. Branhamella catarrhalis did not attach to the mucus layer but directly to the epithelial cell surface. Ruthenium red staining specimen showed that Branhamella catarrhalis attached to a granular ruthenium red positive layer on the microplicae and also to a ruthenium red positive component, external to the unit membrane of the epithelial cell membrane.

Bacterial Adhesion↗
PubMed1992

Fimbriation, hemagglutination and adherence properties of fresh clinical isolates of Branhamella catarrhalis.

This study investigated the fimbriation on 24 fresh clinical isolates of Branhamella catarrhalis by electron microscopy. All the strains were isolated from patients with respiratory infections. The Branhamella catarrhalis strains were classified into three groups according to the grade of fimbriation. Among these 24 strains the incidence of densely fimbriated, moderately fimbriated and sparsely fimbriated isolates were 12 (50%), 7 (29%) and 5 (21%), respectively. After five-times serial subculture on Brain Heart Infusion agar, the average number of fimbriae per bacteria was decreased from 174 to 114 in the densely fimbriated strain and from 48 to 10 in the moderately fimbriated strain. Moreover, 20% of the population became non-fimbriated in moderately fimbriated strain after the serial subculture. In strains with higher hemagglutination titer the number of fimbriae was significantly (P < 0.04) more than in strains with lower hemagglutination titer.

Bacterial Adhesion↗
PubMed1992

Fimbriae of Branhamella catarrhalis as possible mediators of adherence to pharyngeal epithelial cells.

This study attempted to elucidate the role of fimbriae in the adherence of B. catarrhalis to human oropharyngeal epithelial cells. Antifimbrial immune serum was prepared by immunization of rabbit with whole fimbriated bacteria, and adsorption of the serum with a nonfimbriated B. catarrhalis strain. After pretreatment with the antifimbrial antiserum, the adherence of fimbriated B. catarrhalis to human epithelial cells was significantly decreased (p < 0.05). The adherence was also significantly (p < 0.001) decreased by trypsin treatment. Electron microscopy revealed destruction of fimbriae after trypsin treatment. These observations suggest that fimbriae are involved in the adherence of B. catarrhalis to epithelial cells.

Adult↗
PubMed1992

[Dynamic process of colonization by Haemophilus influenzae in children--is H. influenzae normal flora in the throat?].

Eighty-seven oropharyngeal isolates of Haemophilus influenzae were obtained by two time cultures six months apart from a total of 288 children who attend a kindergarten. We analyzed the strains by comparing their serotypes, biotypes, beta-lactamase activity and by performing electrophoresis of outer membrane proteins on polyacrylamide gels. Only nineteen strains were not identical, the rest of the 68 strains were classified into 23 types. During 6 months at least 15 types of strains lost from this group and 21 types of new strains were obtained. There were no children who had identical pairs of H. influenzae in their oropharynx during the 6 months. The classification of strains in oropharynx suggested that person-to-person transmission of nontypable H. influenzae can occur. We concluded that oropharyngeal colonization by nontypable H. influenzae is not a normal flora in children.

Bacterial Outer Membrane Proteins↗
PubMed1992

Role of radioiodine in management of thyroid cancer: experience with 70 cases.

Results of 70 cases of differentiated thyroid carcinoma managed with I131 and surgery have been reported. These results add to the body of knowledge that already exists in the field of treatment of thyroid cancer with radioactive iodine. These results also indicate that the success of radioiodine therapy depends on adequate surgical removal of the thyroid tissue.

Adenocarcinoma↗
PubMed1991

Modulation of cofactor requirement for the activation of protein kinase C by heparin. Possible effect at the regulatory domain.

Heparin was found to stimulate the phosphorylation of histone H1 but not protamine sulfate catalyzed by Ca2+/phospholipid-dependent protein kinase (protein kinase C or PKC). The effect of heparin on histone H1 phosphorylation appeared to be due to an increase in phosphatidylserine affinity for PKC activation in the presence of heparin. This effect of heparin was abolished when trypsinized, cofactor-independent, PKC was employed to phosphorylate histone H1. These studies suggest that heparin acts at the regulatory domain of PKC, and emphasize the importance of the negative charge in influencing the accessibility of the substrate to PKC action.

Animals↗
PubMed1991

Nature of the intrinsic protein kinases involved in phosphorylation of non-histone proteins in intact prostatic nuclei: further identification of androgen-sensitive protein kinase reactions.

Nuclei isolated from rat ventral prostate contain a number of messenger-dependent and -independent protein kinases. Studies were undertaken to determine the relative contribution of these protein kinases in phosphorylation of non-histone proteins (NHPs) in isolated nuclei. The data suggest that messenger-dependent protein kinases such as those dependent on cAMP or Ca2+/calmodulin or Ca2+/phospholipid may be present in very small amounts in intact isolated nuclei, and thus appear not to be significantly involved in phosphorylation of endogenous NHPs. Messenger-independent nuclear associated protein kinases PK-N1 and PK-N2 are known to catalyze the phosphorylation of NHPs in vitro (Goueli Sa, et al., Eur J Biochem 113: 45-51, 1980). Of these, the intrinsic heparin-sensitive PK-N2 as compared with heparin-insensitive PK-N1 appeared to be the predominant protein kinase engaged in phosphorylation of NHPs in intact nuclei. About 78-88% of NHP phosphorylation in intact nuclei was inhibited by heparin suggesting that the remaining 12-22% phosphorylation of NHPs was catalyzed via the heparin-insensitive protein kinase(s). Further, the data provide additional evidence that heparin-sensitive PK-N2 is the one that is most responsive to androgenic status in the animal.

Androgens↗
PubMed1991

Cyclosporine induces elevated procollagen alpha 1 (I) mRNA levels in the rat renal cortex.

Chronic cyclosporine nephrotoxicity is a poorly understood drug side-effect characterized by renal cortical interstitial scarring. To evaluate procollagen mRNA levels as an early factor in the development of this form of renal fibrosis, we measured renal procollagen alpha 1 (I), alpha 1 (III), alpha 1 (IV) and beta-actin mRNA levels in rats treated with cyclosporine (CsA) or the olive oil vehicle (OO) for one or four weeks. Renal morphology was similar without atrophy or fibrosis in one week CsA and OO and four week OO rats. Four week CsA rats had focal cortical interstitial fibrosis and tubular atrophy. Cortical procollagen alpha 1 (I) mRNA levels were increased in CsA versus OO rats at one week (P less than 0.02) and four weeks (P less than 0.02). One week medullary procollagen alpha 1 (I) and all other one week medullary, and one and four week cortical procollagen and beta-actin mRNA levels were no different in CsA versus OO rats. The early increase in renal cortical procollagen alpha 1 (I) mRNA levels precedes renal morphologic abnormalities, and may represent an important step in the pathogenesis of cyclosporine-induced renal cortical fibrosis.

Actins↗
PubMed1991

Possible presence of a capsule in Branhamella catarrhalis.

Clinical isolates of Branhamella catarrhalis from patients with respiratory infections were used in this study. Electron microscopic observation after treating Branhamella catarrhalis with immune serum and ruthenium red revealed the capsule. In the phagocytosis test, most organisms were not ingested by human polymorphonuclear neutrophils in the presence of normal rabbit serum (NRS), while organisms were primarily cell associated and apparently ingested in the presence of immunized rabbit serum (IRS). The capsule may be one of the virulence factors in this bacteria. This study demonstrates the possible presence of a capsule in Branhamella catarrhalis.

Microscopy, Immunoelectron↗
PubMed1991

Poisoning in children.

This study is a retrospective analysis of 670 cases of poisoning (including phenothiazine toxicity) admitted to this hospital in the past six years, accounting for 0.9% of all pediatric admissions. Nearly half (45%) of the cases were in the age group of 1-4 years. Medicines and chemicals were the commonest agents (53%), followed by pesticides (15%), kerosene (11.2%), plant poisons (9.4%), food poisoning (3.9%) and corrosives (1.9%). Accidental poisoning was the commonest (70%) followed by iatrogenic (29.6%) and suicidal (0.4%). Overall mortality was 1.8%. Stress is laid on judicious use of phenothiazines as antiemetics and replacing them with drugs of lesser toxicity.

Age Factors↗
PubMed1991

A procedure for rapid isolation of cloned cDNA inserts using the polymerase chain reaction technique.

A reproducible and rapid procedure for isolation of cloned cDNA insert from a lambda gt11 cDNA library is described. The procedure relies on the polymerase chain reaction method using forward and reverse primers for lambda gt11, followed by isolation of the cloned cDNA insert by a rapid technique. The procedure should also be applicable to isolation of cDNA inserts cloned in other vectors such as lambda gt10.

Animals↗
PubMed1991

Antigen-specific and non-specific depression of proliferative responses induced during contact sensitivity in mice.

Exposure of the flank of mice to either oxazolone or trinitrochlorobenzene (TNCB) 5 days prior to the application of oxazolone on the ear resulted in a reduced capacity of oxazolone-induced draining lymph node cells to express IL-2 receptors, produce IL-2, protein, RNA and DNA. However, histological examination of the draining lymph node suggest that antigen-specific and antigen-non-specific influences differ with respect to the frequency of pyroninophilic cells. Pre-exposure to oxazolone suppressed the number of oxazolone-induced pyroninophilic T cell blasts, whereas draining lymph nodes from TNCB-pretreated mice contained significantly more pyroninophilic cells than from oxazolone-pretreated mice. However, the majority of these cells were incorporating little or no thymidine. Thus exposure to certain contact sensitizers induces at least two systemic control mechanisms which serve to regulate subsequent lymphoproliferative responses. These mechanisms appear to exert their influences at different stages of in-vivo T cell activation.

Animals↗