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Biomedical subjects

A Bali

Publications and source records attributed to A Bali.

At least 19 recordsLinked to original sources
PubMed2006

A distinct molecular profile associated with mucinous epithelial ovarian cancer.

Mucinous epithelial ovarian cancers (MOC) are clinically and morphologically distinct from the other histological subtypes of ovarian cancer. To determine the genetic basis of MOC and to identify potential tumour markers, gene expression profiling of 49 primary ovarian cancers of different histological subtypes was performed using a customised oligonucleotide microarray containing >59 000 probesets. The results show that MOC express a genetic profile that both differs and overlaps with other subtypes of epithelial ovarian cancer. Concordant with its histological phenotype, MOC express genes characteristic of mucinous carcinomas of varying epithelial origin, including intestinal carcinomas. Differences in gene expression between MOC and other histological subtypes of ovarian cancer were confirmed by RT-PCR and/or immunohistochemistry. In particular, galectin 4 (LGALS4) was highly and specifically expressed in MOC, but expressed at lower levels in benign mucinous cysts and borderline (atypical proliferative) tumours, supporting a malignant progression model of MOC. Hence LGALS4 may have application as an early and differential diagnostic marker of MOC.

Adenocarcinoma, Mucinous↗
PubMed2001

The effect of the preemptive use of the NMDA receptor antagonist dextromethorphan on postoperative analgesic requirements.

UNLABELLED: Both central sensitization after peripheral tissue injury and the development of opiate tolerance involve activation of N-methyl-D-aspartate receptors. In this double-blinded, randomized study, we investigated the preemptive versus postincisional effects of dextromethorphan, an N-methyl-D-aspartate receptor antagonist, on postoperative pain management. Sixty ASA I and II patients undergoing elective upper abdominal surgery were randomly allocated to three equally sized groups. The Preincisional group patients received dextromethorphan (120 mg) IM 30 min before skin incision and a placebo (isotonic saline) 30 min before the end of surgery. The Postincisional group received the same dose of dextromethorphan 30 min before the end of surgery and a placebo 30 min before skin incision, and the Control group received a placebo both 30 min before skin incision and 30 min before the end of surgery. A standard general anesthetic technique including fentanyl, propofol, isoflurane, and atracurium was used. Postoperative meperidine patient-controlled analgesia (PCA) was used. There were no significant group differences in the median pain scores except in the visual analog scale at 6 h both at rest and on movement; these were significantly lower in the Preincisional group than the other two groups (P < 0.05). The mean time to initiation of PCA was significantly longer in the Preincisional than in the Postincisional and Control groups (mean [SD]: 10.7 [2.2 h], 5.4 [2.1 h], and 3.7 [1.6 h], respectively; P < 0.001]. The 24-h PCA-meperidine consumption was significantly less in the Preincisional than in the Postincisional and Control groups (mean [SD]: 140 [60 mg], 390 [80 mg], and 570 [70 mg], respectively; P < 0.001]. The incidence of postoperative hypoxemia (SpO(2) < 90%) and nausea was significantly less in the Preincisional group (P < 0.05). In conclusion, preincisional IM 120 mg dextromethorphan compared with the same postincisional dose significantly reduced postoperative meperidine consumption. IMPLICATIONS: IM administration of preincisional dextromethorphan (120 mg), allowing the use of a larger dose sufficient to block the central sensitization caused by activation of the N-methyl-D-aspartate receptors, provides preemptive analgesia and has a supportive role in postoperative pain relief, as shown by a significant decrease in 24-h meperidine consumption.

Adult↗
PubMed1998

Blood meal identification by using Microdot ELISA in vector mosquitoes.

The blood meals of five mosquito species which are vectors for malaria, J.E. and Filaria were determined by using Microdot ELISA technique, which is a rapid and sensitive method. A total of 4354 freshly fed mosquitoes comprising of Anopheles culicifacies, An stephensi, Culex quinquefasciatus, Cx. vishnui gp. and Cx. tritaeniorhynchus were tested. Results of the study reveal that highest proportion of An. culicifacies between 76-100% fed on bovine host followed by 0.3 to 24.2% on human. Cx. vishnui showed 1.9% feeding on human, 49-87.7% on bovine and 7.4-12.3% on the pigs. It has been observed that malaria vectors namely An. culicifacies and An. stephensi are still zoophilic in nature. Similarly, the vector of J.E. namely Culex vishnui gp. and Cx. tritaeniorhynchus also fed on cattle but some samples have indicated feeding of blood meal from pigs.

Animals↗
PubMed1997

Molecular and immunological analysis of an ABC transporter complex required for cytochrome c biogenesis.

The helABC genes are predicted to encode an ATP-binding cassette (ABC) transporter necessary for heme export for ligation in bacterial cytochrome c biogenesis. The recent discoveries of homologs of the helB and helC genes in plant mitochondrial genomes suggest this is a highly conserved transporter in prokaryotes and some eukaryotes with the HelB and HelC proteins comprising the transmembrane components. Molecular genetic analysis in the Gram-negative bacterium Rhodobacter capsulatus was used to show that the helABC and helDX genes are part of an operon linked to the secDF genes. To facilitate analysis of this transporter, strains with non-polar deletions in each gene, epitope and reporter-tagged HelABCD proteins, and antisera specific to the HelA and HelX proteins were generated. We directly demonstrate that this transporter is present in the cytoplasmic membrane as an HelABCD complex. The HelB and HelC but not HelD proteins are necessary for the binding and stability of the HelA protein, the cytoplasmic subunit containing the ATP-binding region. In addition we show that the HelA protein co-immunoprecipitates with either the HelC or HelD proteins. Thus, the HelABCD heme export complex is distinguished by the presence of four membrane-associated subunits and represents a unique subfamily of ABC transporters.

ATP-Binding Cassette Transporters↗
PubMed1992

Excretion of ammonium by a nifL mutant of Azotobacter vinelandii fixing nitrogen.

A mutation in the gene upstream of nifA in Azotobacter vinelandii was introduced into the chromosome to replace the corresponding wild-type region. The resulting mutant, MV376, produced nitrogenase constitutively in the presence of 15 mM ammonium. When introduced into a nifH-lacZ fusion strain, the mutation permitted beta-galactosidase production in the presence of ammonium. The gene upstream of nifA is therefore designated nifL because of its similarity to the Klebsiella pneumoniae nifL gene in proximity to nifA, in mutant phenotype, and in amino acid sequence of the gene product. The A. vinelandii nifL mutant MV376 excreted significant quantities of ammonium (approximately 10 mM) during diazotrophic growth. In contrast, ammonium excretion during diazotrophy was much lower in a K. pneumoniae nifL deletion mutant (maximum, 0.15 mM) but significantly higher than in NifL+ K. pneumoniae. The expression of the A. vinelandii nifA gene, unlike that of K. pneumoniae, was not repressed by ammonium.

Ammonia↗
PubMed1991

The product of the nitrogen fixation regulatory gene nfrX of Azotobacter vinelandii is functionally and structurally homologous to the uridylyltransferase encoded by glnD in enteric bacteria.

We sequenced the nitrogen fixation regulatory gene nfrX from Azotobacter vinelandii, mutations in which cause a Nif- phenotype, and found that it encodes a 105-kDa protein (NfrX), the N terminus of which is highly homologous to that of the uridylyltransferase-uridylyl-removing enzyme encoded by glnD in Escherichia coli. In vivo complementation experiments demonstrate that the glnD and nfrX products are functionally interchangeable. A vinelandii nfrX thus appears to encode a uridylyltransferase-uridylyl-removing enzyme, and in this paper we report the first sequence of such a protein. The Nif- phenotype of nfrX mutants can be suppressed by a second mutation in a recently identified nifL-like gene immediately upstream of nifA in A. vinelandii. NifL mediates nif regulation in response to the N status in A. vinelandii, presumably by inhibiting NifA activator function as occurs in Klebsiella pneumoniae; thus, one role of NfrX is to modify, either directly or indirectly, the activity of the nifL product.

Adenine↗
PubMed1988

Iniencephaly.

Explore the source record for details and available documents.

Abnormalities, Multiple↗
PubMed1986

Effect of phospholipid structure on stability and survival times of liposomes in circulation.

The phosphatidylcholine (PC) component of liposomes was structurally modified by replacing its C-1, or both C-1 and C-2, ester linkage(s) with an ether and/or carbamyl bond(s) or by changing its steric configuration. Small unilamellar liposomes were formed from PC, traces of the corresponding 14C-labeled PC and cholesterol in the presence of 6-carboxyfluorescein (02.M) by sonication, and purified by centrifugation. These liposomes were administered intravenously to rats, and their stability in blood as well as the rate of their clearance from the circulation were determined. Stability and survival times of liposomes were markedly increased by modifying both the C-1 and the C-2 ester linkages in PC. A similar but quantitatively smaller effect was observed when only the C-1 ester linkage was modified. However, the stability remained unaffected by changing the steric configuration of PC, but this modification influenced the clearance rate of liposomes from the circulation. These results demonstrate that both stability in blood and the clearance rate from circulation can be modulated by structurally modifying the ester linkages in the phospholipid component of liposomes.

Animals↗
PubMed1986

Protection of mice against Plasmodium berghei infection by a tuftsin derivative.

In Plasmodium berghei infections, the mortality rate and parasitaemias were significantly reduced and the mean survival time was considerably enhanced by pretreating the animals with a tuftsin derivative, Thr-Lys-Pro-ARg-NH-(CH2)2-NHCOC15H31. This effect of the modified tuftsin was further increased upon its incorporation in the liposome bilayer. These results indicate that tuftsin and its derivatives may prove useful in enhancing nonspecific host resistance against protozoan infections.

Animals↗
PubMed1986

Influence of the phospholipid structure on the stability of liposomes in serum.

The effect of serum on the structural integrity of liposomes consisting of ether and/or carbamyl analogs of 1,2-diester phosphatidylcholine (PC) has been evaluated by measuring both the efflux of the entrapped 6-carboxyfluorescein and the lipid transfer to serum proteins, and the results have been compared with the egg PC liposomes. Replacement of the C-1 ester bond in PC by an ether linkage did not significantly enhance the liposome stability, but it was markedly increased upon introducing further structural changes in the C-2 ester region of the resulting 1-ether-2-ester PC. However, the stability was not influenced by altering the steric configuration of the latter phospholipid. These results strongly suggest that lysis of liposomes in serum can be prevented by structurally modifying the ester bond(s) in the phospholipid component of liposomes.

Animals↗
PubMed1986

Antibody-mediated targeting of liposomes to erythrocytes in whole blood.

F(ab')2 fragments derived from anti-rat erythrocyte antibody or normal rabbit serum IgG were covalently attached to the surface of liposomes consisting of equimolar amounts of egg phosphatidylcholine and cholesterol. These liposomes were interacted with rat, monkey or mouse blood, and their binding to both red and white blood cells was determined. Results of these studies show that coupling of liposomes to anti-rat erythrocyte F(ab')2 considerably enhances their binding to erythrocytes in rat blood. However, no such increase in the binding was observed with rat leukocytes or monkey and mouse erythrocytes. Besides, the interactions between the liposomes and target cells did not affect the permeability properties of the liposome bilayer. These observations indicate that liposomes coupled to cell-specific antibodies may serve as highly useful carriers for homing of drugs/enzymes to specific cells in biophase.

Animals↗
PubMed1985

Phase behavior of carbamyloxyphosphatidylcholine, a sphingolipid analogue.

The phase behavior of two series of phosphatidylcholines (PC) possessing carbamyloxy-linked fatty acids has been studied by differential scanning calorimetry. These non-natural phosphatidylcholines are of interest because they possess the capability of forming interlipid hydrogen bonds via the carbamyloxy function and as such can serve as a model for sphingolipids, the phase behavior of which is thought to be dominated by interlipid hydrogen bonding. Furthermore, carbamyloxyphosphatidylcholines form unusually stable liposomes, and thus have potential in drug delivery. Carbamyloxyphosphatidylcholines of the type di-(CnH2n+1NHCOO)-PC, where n = 13, 15, or 17, exhibit metastable polymorphism. Cooling from the liquid crystalline state results in formation of a metastable low-temperature polymorph I, which must transform into a stable low-temperature polymorph II before the liquid crystalline state can be reached again. Carbamyloxyphosphatidylcholines of the type 1-C16:0-2-(CnH2n+1NHCOO)-PC exhibit similar metastable polymorphism. This metastability is similar to that exhibited by certain cerebrosides and sphingomyelins and indicates that the sphingosine backbone is not a prerequisite for this type of metastability. Furthermore, the carbamyloxy group is reversed in orientation compared with the amide of sphingolipids (-NHCO- versus -CONH-), suggesting that the intermolecular hydrogen bonding potential, rather than some highly specific steric or conformational constraint, is responsible for the observed metastability of sphingolipids.

Calorimetry, Differential Scanning↗
PubMed1984

Specific interactions of liposomes with PMN leukocytes upon incorporating tuftsin in their bilayers.

Incorporation of tuftsin derivatives, Thr-Lys-Pro-Arg-NH-C18H37 or Thr-Lys-Pro-Arg-NH-(CH2)2-NH-COC15H31, into an egg phosphatidylcholine/cholesterol liposome bilayer led to significantly enhanced binding of the liposomes to PMN leukocytes at 37 degrees C but not at 0 degree C. Under identical conditions, no such enhanced binding of the liposomes was observed with erythrocytes and lymphocytes. These results demonstrate that grafting of tuftsin on the liposome bilayer enables the liposome to recognize specifically the PMN leukocytes and to deliver its contents to these cells.

Cholesterol↗
PubMed1983

Prolonged small-intestinal transit time in cystic fibrosis.

A lactulose hydrogen breath test was performed on 10 patients with cystic fibrosis and 15 control subjects matched for age and sex. All normal subjects had a fasting breath hydrogen concentration of less than 20 ppm. In contrast, seven of the patients with cystic fibrosis had high concentrations (25-170 ppm), which fell to 20 ppm or below on prolonged fasting (14-23 hours). Two patients showed no rise in breath hydrogen concentrations after lactulose, and in one patient the breath hydrogen concentration rose at 15 minutes, suggesting bacterial colonisation of the small bowel. Seven of the patients had prolonged small-bowel transit times (160-390 minutes) compared with those in the control group (50-150 minutes).

Adolescent↗