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M M Chang

Publications and source records attributed to M M Chang.

35 records · Page 2Linked to original sources
PubMed1992

Molecular characterization of a pea beta-1,3-glucanase induced by Fusarium solani and chitosan challenge.

beta-glucanases are prominent proteins in pea endocarp tissue responding to fungal infection. We have cloned and sequenced a partial pea cDNA clone, pPIG312, corresponding to a beta-1,3-glucanase in pea pods challenged with the incompatible pathogen Fusarium solani f. sp. phaseoli. The insert from the partial pea cDNA was used to probe a genomic library derived from pea leaves of the same cultivar. One of the genomic clones, pPIG4-3, contained the complete coding sequence for a mature beta-1,3-glucanase protein. The predicted amino acid sequence of the pea beta-1,3-glucanase has 78% identity to bean beta-1,3-glucanase, 62% and 60% to two tobacco beta-1,3-glucanases, 57% to soybean beta-1,3-glucanase, 51% to barley beta-1,3-glucanase, and 48% to barley beta-1,3-1,4-glucanase. Genomic Southern analysis indicates that the pea genome contains only one beta-1,3-glucanase gene corresponding to the probe used in this study. Accumulation of beta-1,3-glucanase mRNA homologous with the pPIG312 probe was detected in pea pods within 4 to 8 h after challenge with F. solani f. sp. phaseoli, f. sp. pisi, a compatible strain, or the elicitor, chitosan. In the incompatible reaction, mRNA accumulation remained high for 48h, whereas it rapidly decreased in the compatible reaction. After fungal inoculation of whole pea seedlings, the enhanced mRNA accumulation occurred mainly in the basal region (lower stem and root). This beta-1,3-glucanase mRNA was constitutively expressed in the roots of pea seedlings.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1990

Effect of combined substance use on laboratory markers of alcoholism.

This article examines the commonly used laboratory indicators of heavy alcohol use (elevated MCV, GGTP and AST values) in subgroups of drug-using and non-drug-using alcoholic men admitted to an inpatient alcoholism treatment program. A total of 380 consecutive admissions meeting DSM-III diagnostic criteria for alcohol use or dependence were studied. Of these subjects, 75% used both alcohol and drugs. The most frequently used drugs were marijuana, cocaine, amphetamines and tranquilizers. Overall, subjects who used drugs with alcohol had significantly lower MCV and GGTP values than subjects who used alcohol alone. More specifically, cocaine use was associated with lower MCV values, marijuana use with lower AST values and heroin use with higher AST and GGTP values. These differences between drug-using and non-drug-using alcoholics were significant even after controlling for variables that affect the laboratory values such as age, quantity, frequency and duration of alcohol consumption. These findings indicate that any study of laboratory markers of alcoholism needs to consider concomitant illicit drug use patterns.

Adult↗
PubMed1987

Clinician-entered computerized psychiatric triage records.

Computer systems have become more accessible to clinicians as a result of the introduction of user-friendly software and low-cost terminals and printers. At a Veterans Administration medical center in California, an automated psychiatric record system is being developed that permits direct data entry by clinicians. The process began on the triage service, where psychiatrists are using a computerized form to enter clinical data into the patient's record during the triage interview. The author describes the computerized form, the factors influencing user acceptance, and the problems and benefits of direct data entry by clinicians. He believes that linkage of the computerized clinical data bases being developed at various institutions offers rich research possibilities, but only if the data elements included in the records can be standardized.

California↗
PubMed1975

Comparison of the effects of biogenic amines on cyclic GMP and cycle AMP levels in mouse cerebellum in vitro.

Norepinephrine (NE) elevates levels of both 3',5'-guanosine monophosphate (cyclic GMP) and 3',5'-adenosine monophosphate (cyclic AMP) in incubated slices of mouse cerebellum. As little as 1 muM NE is capable of increasing the level of either cyclic nucleotide. Maximal elevations of cyclic AMP and cyclic GMP levels produced by NE are 15- to 40-fold and 2- to 4-fold, respectively. Dopamine, serotonin and histamine, other biogenic amines considered to be neurotransmitters in CNS, have no effect on mouse cerebellum cyclic nucleotide levels except at relatively high (1 mM) concentrations. NE-induced accumulation of cyclic GMP, but not cyclic AMP, is blocked by omission of Ca2+ from the incubation media. Theophylline does not alter the effect of this catecholamine on either cyclic nucleotide. In tissue slices incubated in buffered sucrose or in choline-Krebs buffer, NE is still capable of increasing both cyclic GMP and cyclic AMP levels; however, these elevations are less than those observed in brain slices incubated in Krebs-Ringer buffer. NE, in combination with glutamate, produces supra-additive elevations of both cyclic GMP and cyclic AMP levels. However, NE in combination with adenosine or high levels of K+ only has a synergistic effect on cyclic AMP and not on cyclic AMP and not on cyclic GMP combination. The elevation of cyclic AMP levels produced by NE appears to be mediated via both alpha- and beta-adrenergic receptor sites. In contrast, the receptor site(s) mediating cyclic AMP accumulation do not appear to be either typical alpha- or beta-adrenergic receptors.

Adenosine↗
PubMed1975

Effect of lactate dehydrogenase isoenzymes on the coupled enzymatic assay for alanine aminotransferase activity.

We show an example of the importance of specifying the form of isoenzyme and source of indicator enzymes to be used in coupled enzymatic assays. When we compared H-4 (pig heart) and M-4 (rabbit muscle) isoenzymes of lactate dehydrogenase for their suitability as indicator enzymes in the assay for alanine aminotransferase activity, we found that about fourfold as much M-4 as H-4 was required in terms of lactate dehydrogenase activity to reflect accurately equivalent amounts of alanine aminotransferase activity. Moreover, the substrate specificities of the two isoenzymes differed quantitatively.

Alanine Transaminase↗
PubMedDate not supplied

Fusarium solani DNase is a signal for increasing expression of nonhost disease resistance response genes, hypersensitivity, and pisatin production.

The inoculation of pea endocarp tissue with the bean pathogen Fusarium solani f. sp. phaseoli results in a non-host resistance response causing a complete cessation of fungal growth within 6 to 8 h. In addition to previously reported elicitation by chitosan, we now report that components of this response are also induced by a DNase released from this fungus. A single band of protein corresponding with DNase activity elicits phytoalexin production and the accumulation of RnA homologous with the pathogenesis-related (PR) genes DRR49, DRR206, and DRR230. Both the enzyme activity and the eliciting potential of the Fusarium DNase (Fsp DNase) are heat stable but susceptible to digestion by proteinase K. Fsp DNase mimics the intact fungus in inducing resistance against F. solani f. sp. pisi. Also, Fsp DNase causes similar cytologically detectable changes in pea tissue, such as increasing hypersensitive discoloration and diminishing fluorescence of Hoechst 33342-stained nuclei and fluorescein diacetate stained cells.

Benzopyrans↗
PubMedDate not supplied

Coats' disease: a study of 62 histologically confirmed cases.

We studied 62 eyes submitted to the Armed Forces Institute of Pathology (AFIP) from 1958 through 1980 that satisfied our criteria for the histologic diagnosis of Coats' disease. Our histopathologic definition of Coats' disease was the presence of a primary vascular lesion consisting of retinal telangiectasia with leakage of plasma to form intraretinal and subretinal exudates. In the cases we reviewed, Coats' disease occurred more frequently in boys, it usually affected only one eye, and was generally detected in the first decade of life. In 52 cases (79%) the clinical manifestations, strabismus and leukokoria, were thought to be caused by retinoblastoma. Angle closure glaucoma was present in 36 cases (58%). In all but one of the cases studied, the lesion was located peripheral to the equator. We further identified diffuse involvement of capillaries in the peripheral retina using trypsin-digest preparations. Associated histologic findings included: rubeosis iridis, cataract, vitreous neovascularization, and nodules resulting from fibrous metaplasia of the retinal pigment epithelium. These fibrous nodules typically occurred in the macular area and occasionally contained calcium or bone.

Child↗