High incidence of gram-negative bacillary infection and high mortality in adult patients with bacterial meningitis and nasopharyngeal carcinoma.
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Comorbidity↗
Biomedical subjects
C R Huang
Publications and source records attributed to C R Huang.
Community-acquired spontaneous Klebsiella pneumoniae meningitis in adult cirrhotic patients with and without diabetes.
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Aged↗
Identification of viridans streptococcal species causing bacterial meningitis in adults in Taiwan.
In order to determine the species responsible for viridans-group streptococcal meningitis in adults in Taiwan, seven cases of culture-proven meningitis due to these organisms were studied. The cases were all identified at the Chang Gung Memorial Hospital-Kaohsiung over a period of 3 years, and they accounted for 9% (7/78) of all cases of culture-proven bacterial meningitis occurring in adults during this period. Of the seven viridans streptococci isolates recovered, Streptococcus constellatus accounted for four, Streptococcus anginosus for two, and Streptococcus oralis for one. Thus, it appears that streptococci of the milleri group are the most common species causing bacterial meningitis in adults in Taiwan. The tendency for these organisms to cause invasive central nervous system infections in adults should not be overlooked when these species are recovered from cerebrospinal fluid specimens.
Adult↗
Community-acquired spontaneous bacterial meningitis in adult diabetic patients: an analysis of clinical characteristics and prognostic factors.
BACKGROUND: We analyzed the clinical characteristics and prognostic factors of community-acquired spontaneous bacterial meningitis (CASBM) in adult diabetic patients. PATIENTS AND METHODS: Over a period of 15 years, 47 adult diabetic patients with CASBM were identified. The clinical characteristics, laboratory data and therapeutic outcome of these 47 patients were statistically analyzed. RESULTS: The 47 patients were 31 men and 16 women, aged 22 to 79 years, and they accounted for 38.5% (47/122) of our adult patients with culture-proven CASBM. The most common causative pathogen was Klebsiella pneumoniae (n = 32), followed by pathogens of the streptococcal species (n = 6). Besides classic manifestations of bacterial meningitis, bacteremia and focal suppuration, especially liver abscess, were common features in this group of patients. Liver cirrhosis and/or alcoholism were the other frequent underlying conditions. 27 patients survived in the course of therapy. The prognostic factors with statistical significance were glucose ratio and cerebrospinal fluid (CSF) white blood cell (WBC) count. CONCLUSION: This study showed the high incidence of diabetes mellitus (DM) among the adult patients with CASBM in Taiwan. K. pneumoniae was the most frequent causative pathogen. Bacteremia and focal suppuration, especially liver abscess, were common findings. The values of glucose ratio and CSF WBC count had a statistically significant influence on the prognosis of our patients.
Adult↗
Protean infectious types and frequent association with neurosurgical procedures in adult Serratia marcescens CNS infections: report of two cases and review of the literature.
Serratia marcescens is a rare pathogen of adult central nervous system (CNS) infection. We report on the clinical features and therapeutic outcomes of two adult patients with such infections. The clinical characteristics of 13 other reported adult cases are also included for analysis. The 15 cases were nine males and six females, aged 19-83 years, in whom, underlying post-neurosurgical states and ear operation were noted in 93% (14/15). Fever and conscious disturbance were the most common clinical manifestations of these 15 cases, followed by hydrocephalus, seizures, and wound infections. The manifestation types were protean, including meningitis and focal suppurations such as brain abscess, cranial and spinal epidural abscess, cranial subdural abscess, and infected lumbar pseudomeningocele. One case of S. marcescens CNS infection was diagnosed postmortem; the other 14 were diagnosed by the positive culture from CSF or pus. Antibiotic therapy with or without neurosurgical intervention was the management strategy in 14/15 cases. The therapeutic results showed a high mortality rate.
Adult↗
Effects of surfactants on extraction of phenanthrene in spiked sand.
Problems associated with polynuclear aromatic hydrocarbon (PAH) contaminated site in environmental media have received increasing attention. To resolve such problems, innovative in situ methods are urgently required. This work investigated the feasibility of using surfactants to extract phenanthrene on spiked sand in a batch system. Phenanthrene was spiked into Ottawa sand to simulate contaminated soil. Six surfactants, Brij 30 (BR), Triton X-100 (TR), Tergitol NP-10 (TE), Igepal CA-720 (IG), sodium dodecyl sulfate (SDS) and hexadecyl trimethyl ammonium bromide (HTAB) were used. Adjusting the extraction time, mixing speed and surfactant concentration yielded the optimum extracting conditions. The concentration of phenanthrene was identified with HPLC. Under the experimental conditions, results indicated that those surfactants were highly promising on site remediation since the residual phenanthrene concentration was effectively reduced. The optimum operating conditions were obtained at 30 min, 125 rpm and surfactant concentrations in 4%.
Environmental Pollution↗
Screening solution-phase combinatorial libraries using pulsed ultrafiltration/electrospray mass spectrometry.
A method is described whereby a family of homologues is synthesized in a one-pot reaction, without isolation or purification, and the reaction mixture is screened using a competitive binding assay based on pulsed ultrafiltration/electrospray mass spectrometry (PUF/ESMS) to tentatively identify those derivatives having the highest affinity for a target receptor. As a model system to test this approach, a synthetic scheme designed to prepare a series of analogues of the adenosine deaminase inhibitor erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA), as diastereomeric mixtures, was carried out. Pulsed ultrafiltration screening of the crude reaction mixture against controls without protein detected protonated molecules corresponding to EHNA-type derivatives and three of its linear, alkyl homologues but did not show protonated molecules for an isobutyl or benzylic EHNA derivative, suggesting the latter was inactive. To verify this conclusion, we prepared E/THNA, the linear homologues, and the benzylic derivative (each as a diastereomeric mixture) and bioassayed them for them adenosine deaminase inhibition index ([I]/[S]0.5). The bioassay results for the individually synthesized analogues were in good agreement with that predicted by the observed relative ion enhancement in the PUF experiments. Thus, the PUF protocol might be used as a general method to quickly provide direction to the chemist in search of drug candidates.
Adenine↗
Pulsed ultrafiltration mass spectrometry: a new method for screening combinatorial libraries.
In response to the need for rapid screening of combinatorial libraries to identify new lead compounds during drug discovery, we have developed an on-line combination of ultrafiltration and electrospray mass spectrometry, called pulsed ultrafiltration mass spectrometry, which facilitates the identification of solution-phase ligands in library mixtures that bind to solution-phase receptors. After ligands contained in a library mixture were bound to a macromolecular receptor, e.g., human serum albumin or calf intestine adenosine deaminase, the ligand-receptor complexes were purified by ultrafiltration and then dissociated using methanol to elute the ligands into the electrospray mass spectrometer for detection. Ligands with dissociation constants in the micromolar to nanomolar range were successfully bound, released, and detected using this method, including warfarin, salicylate, furosemide, and thyroxine binding to human serum albumin, and erythro-9-(2-hydroxy-3-nonyl)adenine binding to calf intestine adenosine deaminase. Repetitive bind- and-release experiments demonstrated that the receptor could be reused. Thus, pulsed ultrafiltration mass spectrometry was shown to provide a simple and powerful new method for the screening of combinatorial libraries in support of new drug discovery.
Adenine↗
Neuroimages of Japanese encephalitis: report of three patients.
The cranial computed tomography (CT) and magnetic resonance image (MRI) studies of three Japanese encephalitis (JE) patients, 24 to 37 years of age, are reported. The initial findings of CT study were limited but initial MRI studies revealed multiple lesions involving the brainstem, basal ganglia and bilateral thalami. Follow-up MRI studies showed small residual lesions only. The result shows that MRI can delineate and detect brain lesions better than CT in patients in the acute stage of JE. The locations of lesions in MRI study are noteworthy and have a good correlation with pathologic anatomic distribution. Therefore, MRI study is helpful in early diagnosis of JE.
Adult↗
Hepatic resection of hepatocellular carcinoma in cirrhotic livers: is it unjustified in impaired liver function?
BACKGROUND: Resection for hepatocellular carcinoma in patients with cirrhosis and impaired liver function is usually unjustified because of higher surgical risks and poorer long-term prognosis. METHODS: A retrospective comparison of the background and resectional results of patients with cirrhosis and hepatocellular carcinoma was carried out between those with preoperative indocyanine green 15-minute retention rate of 20% or greater (group A, impaired function group, n = 36) and those with indocyanine green 15-minute retention rate of 10% or less (group B, normal function group, n = 34). RESULTS: The group A patients had significantly lower serum albumin level and higher serum bilirubin level, longer prothrombin time, higher incidence of associated esophageal varices, and poorer Child's classifications for cirrhosis. Although the tumor diameter in both groups was similar (A, 6.9 versus B, 7.1 cm; p = 0.94), the resected liver amount in group B was greater (227.4 versus 473.2 gm; p = 0.038) because of a greater extent of liver resection (p < 0.001) and a wider surgical margin (0.34 versus 1.85 cm; p < 0.0001). The amount of operative blood loss and blood transfusion, operative morbidity, and operative mortality were not different between the two groups. The pathologic characteristics and staging were also comparable. The 5-year disease-free and actuarial survival rates of groups A and B were 30.9% and 29.6% (p = 0.16) and 45.2% and 33.4% (p = 0.11), respectively. CONCLUSIONS: If the amount of resected nontumorous liver parenchyma could be reduced, resection of hepatocellular carcinoma in selected patients with cirrhosis and impaired liver function is still justified in spite of a narrow surgical margin.
Adult↗
Influence of Na+ on DNA reactions with aromatic epoxides and diol epoxides: evidence that DNA catalyzes the formation of benzo[a]pyrene and benz[a]anthracene adducts at intercalation sites.
Reactions of the benzo[a]pyrene (BP) and benz[a]anthracene (BA) metabolites, (+/-)-trans-7 8-dihydroxy-anti-9, 10-epoxy-7, 8, 9, 10-tetrahydro-BP (BPDE), (+/-)-trans-3, 4-dihydroxy-anti- 1,2-epoxy-1,2,3,4-tetrahydro-BA (BADE), (+/-)-BP-4,5-oxide (BPO), and (+/-)-BA-5, 6-oxide (BAO), were examined under pseudo-first-order conditions at varying Na+ (2.0-100 Mm) and native calf thymus DNA (ctDNA) concentrations. In 0.2 mM ctDNA and 2.0 mM Na+, at a pH of 7.3 most BPDE, BADE, BPO, and BAO (87-95%) undergo DNA catalyzed hydrolysis or rearrangement. For BPDE and BPO, overall, pseudo-first-order rate constants, k, in 2.0 mM Na+ and 0.2 mM ctDNA are 21-72 times larger than values obtained without DNA. For BADE and BAO, the rate constants are less strongly influenced by DNA; k values in 0.2 mM ctDNA are only 9-12 times larger than values obtained without DNA. Kinetic data for BPDE, BPO, BADE, and BAO and DNA intercalation association constants (KA) for BP and BA diols which are model compounds indicate that KA values for BPDE and BPO in 2.0 mM Na+ are 6.6-59 times larger than those of BADE and BAO. The greater DNA enhancement of rate constants for BPDE and BPO, versus BADE and BAO, correlates with the larger KA values of the BP metabolites. DNA adducts, which account for less than 10% of the yields, also form. For BPDE in 0.20 mM ctDNA, k decreases 5.1 times as the Na+ concentration increases from 2.0 to 100 mM. Nevertheless, the DNA adduct level remains constant over the range of Na+ concentrations examined. These results provide evidence that, for BPDE in 0.20 mM DNA and 2.0 mM Na+, ctDNA adduct formation follows a mechanism which is similar to that for DNA catalyzed hydrolysis. The pseudo-first-order rate constant for adduct formation, kAd, given approximately by kAd approximately equal to (kcat,AdKA[DNA])/(1 + KA[DNA]), where kcat,Ad is a catalytic rate constant. for BADE, BPO, and BAO, the influence of varying DNA and Na+ concentrations on k values is similar to that for BPDE, and provides evidence that the formation of adducts follows the same rate law.
Benz(a)Anthracenes↗
High-performance liquid chromatography-electrospray mass spectrometry of retinoids.
High-performance liquid chromatography (HPLC)-electrospray mass spectrometry (LC-MS) was used to analyze vitamin A-active retinoids including retinoic acid, retinol, retinal, and retinyl acetate. Unlike previous LC-MS methods such as negative ion electron capture chemical ionization, no derivatization of retinoic acid was required. HPLC separations were carried out on a C30 reversed phase column with gradient elution using mobile phases containing water, methanol, and methyl-tert-butyl ether. Ammonium acetate (5 mM) was added to the mobile phase to facilitate ion pair formation during reversed phase HPLC of retinoic acid, and acetic acid (0.5% v/v) was added to the mobile phase to enhance protonation during LC-MS analysis of nonacidic retinoids. During negative ion electrospray, retinoic acid formed abundant deprotonated molecules, [M-H]-, of m/z 299 without significant fragmentation. Although retinol, retinal, and retinyl acetate did not ionize during negative ion electrospray, the positive ion electrospray mass spectra of these retinoids showed an abundant protonated molecule of m/z 285 for retinal and base peaks of m/z 269 corresponding to elimination of water or acetic acid from the protonated molecules of retinol or retinyl acetate, respectively. No ions from retinoic acid were detected during positive ion electrospray. Limits of detection for retinoic acid, retinal, retinol, and retinyl acetate were 23 pg, 1.0 ng, 0.5 ng, and 10 ng, respectively.
Diterpenes↗
HPLC preparation of highly purified single-stranded M13 DNA.
Closed-circular, single-stranded viral DNAs are widely employed in DNA cloning and sequencing experiments. Because of their well-defined structure and sequence, closed-circular, single-stranded DNAs have also been used for ligand binding experiments and light scattering measurements. However, there is a high molecular weight impurity observed in light scattering experiments, which sometimes contaminates single-stranded DNA purified from phage that has been precipitated in polyethylene glycol, average molecular weight 8000, and purified by standard phenol-chloroform extraction. Three methods have been examined that remove this impurity from closed-circular, single-stranded M13mp19 DNA (SS M13 DNA). One employs a commercial peparation. This procedure yields pure but degraded SS M13 DNA, as shown by light scattering measurements and HPLC. Another employs a Whatman DE52 (diethylamino cellulose) column. This procedure yields intact DNA, but in poor yield (less than 20% of that obtained by phenol-chloroform extraction). The last was the most successful. This employs HPLC with a Waters AP-1 column with DEAE 8HR bedding. This procedure, which provides DNA in high yield (80%-90% column recovery) with an intact structure, is an efficient method for the isolation of high-purity, closed-circular, single-stranded viral DNA suitable for physical investigations and ligand binding measurements.
Artifacts↗
Nucleotide sequence of the coat protein coding region of the potyvirus tobacco vein-banding mosaic virus.
The sequence of the 3' 1184 nucleotides of tobacco vein-banding mosaic virus (TVBMV) genome has been determined. It contains a single open reading frame which encompasses the whole of the coat protein of TVBMV. The sequence of the first 20 amino acids at the N-terminal region of the coat protein has also been determined chemically to be GDDQTVDAGKNVQSNQKQRN. The sequence matches the translation product of the open reading frame starting with amino acid-271; a glycine residue. Thus the coat protein of TVBMV has a calculated M(r) of 30,210. The 3' non-coding region of TVBMV is 185 nucleotides in length. Sequence alignment of the coat proteins or the 3' non-coding regions from TVBMV and other reported potyviruses indicated that TVBMV is a separate species of the potyvirus genus.
Amino Acid Sequence↗
[Urogenital rhabdomyosarcoma in children: analysis of 39 cases].
From 1967 to 1992, 39 patients with urogenital rhabdomyosarcoma were admitted to our hospital. Of them 30 were male and 8 female and their age ranged from 4 months to 14 years (32 were less than 5 years). Primary tumor was located in bladder or/and prostate in 26, paratesticule 9, vagina 3, and penis 1. Among the 31 patients receiving treatment, 23 were followed up. There were 15 (65%) survivors, including 13 who were free from tumor for over 4 years. The eldest two patients were 20 and 21 years of age. Two patients with vaginal tumor and 4 with bladder tumor preserved their organs with normal function. Biopsy were done only in 8 patients. In recent years, conservative surgery combined with chemotherapy for urogenital rhabdomyosarcoma has been justified.
Adolescent↗
Room-temperature steady-state fluorescence properties of poly(dG-dC).poly(dG-dC).
We report the steady-state fluorescence properties of the alternating polynucleotide poly(dG-dC).poly(dG-dC) in low-salt solution at room temperature for excitation at the Hg lines 265, 280 and 297 nm. Its fluorescence spectrum peaks at about 325 nm and, within the experimental error, its shape does not change significantly with the excitation wavelength. The fluorescence anisotropy is found to decrease strongly for short-wavelength excitation, a behavior which is very similar to that exhibited by free guanine. In view of the fact that the anisotropy for free cytosine is virtually constant at the aforementioned three excitation wavelengths, the results suggest that in this polynucleotide the emission stems from guanine. The values of the fluorescence quantum yield for the three excitation wavelengths are found to be very low, 0.8 x 10(-5), 0.8 x 10(-5), and 2.8 x 10(-5), respectively; these are compatible with transfer of energy from the lower-energy electronic state of guanine, before vibronic relaxation is established, to cytosine. Upon denaturation, the fluorescence spectrum becomes very broad and the fluorescence quantum yield increases; these observations support the authenticity of the emission from the nondenatured polynucleotide.
Energy Transfer↗
Cloning and characterization of the latent membrane protein (LMP) of a specific Epstein-Barr virus variant derived from the nasopharyngeal carcinoma in the Taiwanese population.
A DNA fragment containing Epstein-Barr virus (EBV) terminal fragment sequence was obtained from a genomic library of nasopharyngeal carcinoma (NPC). One of the clones (clone 1510) contained the gene encoding latent membrane protein (LMP). Sequence analysis revealed that this gene had 95% homology with the LMP sequence of the B95-8 strain. Among the sequence variations, there was a change from G to T at nucleotide position 169,426, resulting in the loss of an XhoI site in exon 1 of the LMP gene. A pair of primers bracketing the XhoI site were designed to synthesize the EBV DNA fragment from nucleotides 169,081-169,577 by using the polymerase chain reaction (PCR) method. The PCR products were then subject to XhoI digestion and to DNA sequencing analysis. This restriction enzyme site polymorphism along with the sequence variations were also observed in 50 biopsy tissues as well as in the throat washings of 6 out of 20 healthy individuals that we examined, indicating that the EBV strain predominantly existing in these biopsy tissues was different from strains of B95-8, Jijoye or nude mouse passaged cells (C15) with an African origin, but closely resembled other nude mouse passaged CAO cells which were originally derived from China. Balb/c 3T3 cells carrying this NPC-LMP gene showed a transformed cell morphology and were tumorigenic in nude mice. The relationship between this unique type of EBV and NPC has yet to be established.
3T3 Cells↗
Singlet-singlet energy transfer along the helix of a double-stranded nucleic acid at room temperature.
An irreversible electronic energy trap has been formed in calf thymus DNA by methylating about 75% of its G bases at position N-7. This has allowed us to measure for the first time the efficiency of transfer of energy along the helix of a double-stranded nucleic acid at room temperature. It is found that about one out of every three photons absorbed by the other bases is trapped. We have also simulated the data with a stochastic model that uses the dipole-dipole interaction to calculate the efficiency of transfer. In order to approximate the experimental results, the model requires that: (i) the fluorescence quantum yield of T, C, and G in DNA be about 2 x 10(-3), which is about two orders of magnitude larger than the value of the fluorescence quantum yield reported for DNA; and (ii) the fluorescence quantum yield of A in DNA be negligibly small. Requirement (i) is consistent with energy transfer taking place before a very efficient fluorescence quenching process sets in, which could be formation of excited-state complexes (excimers) that do not fluoresce appreciably. Requirement (ii) implies a very short fluorescence lifetime for A, which is consistent with the reported absence of a significant number of photoproducts formed by A in DNA. The simulations find that, on the average, the excitation energy takes about 1.2 steps to reach the trap; that is to say, bases that are nearest and next nearest neighbors of the trap are, in effect, the only energy donors. Both intra- as well as interstrand energy transfer (the latter only for the C-trap base pair) make significant contributions. The value of the efficiency for pairwise base-base intrastrand transfer is about 60%, whereas those for base-trap intra- and interstand transfer are 90% and 80%, respectively. The corresponding values for the rate constant of transfer are 2 x 10(11), 1 x 10(12), and 4 x 10(11) s-1. Transfer is inefficient when A is the donor or the acceptor. In addition to the dipole-dipole term, the only other significant term in the expansion of the interaction potential is the dipole-quadrupole term which, however, makes only a small contribution to the overall transfer efficiency. The electron exchange interaction appears to be much less efficient than the coulombic interaction.
Animals↗