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Biomedical subjects

Y M Yang

Publications and source records attributed to Y M Yang.

At least 73 records · Page 4Linked to original sources
PubMed1990

Pulmonary lipid nodules after intralipid infusion in a child with rhabdomyosarcoma and Staphylococcus epidermidis sepsis.

Pulmonary lipid accumulation associated with intralipid infusion has been observed in autopsies of premature babies and a few adults. We report a 6-year-old boy with radiographically identifiable bilateral pulmonary nodules while he had Staphylococcus epidermidis sepsis. At the time, the child was receiving intralipid as a part of total parenteral nutritional support and was undergoing chemotherapy and radiotherapy for abdominal rhabdomyosarcoma. Pathological studies of the biopsied nodules revealed lipid deposits and foreign body type granulomatous vasculitis. Possible mechanisms for intralipid nodules in the lungs are discussed. Pulmonary intralipid accumulation can occur antemortem and should be included in the differential diagnosis of pulmonary nodules in patients with malignant tumors who are receiving intralipid infusion.

Abdominal Neoplasms↗
PubMed1990

Factors affecting the follow-up rate of infants with a hemoglobinopathy trait in a newborn screening and follow-up program.

Multiple factors may contribute to a less than satisfactory follow-up rate of infants with a hemoglobinopathy trait in many newborn screening programs. We retrospectively reviewed the information in a follow-up service of a regional community program in southern Alabama for infants with trait (hemoglobin AS or AC). The follow-up service received the screening results of infants with trait and the mothers' addresses and telephone numbers by two routes: (A) the sickle cell center newborn screening coordinator, for infants born at the university hospital (group A), and (B) the state health department, for infants born in other hospitals in a nine-county region (group B). The follow-up service notified mothers by mail and offered counseling; when no response was received, telephone contact and outreach service followed. From January 1988 through December 1989, 505 infants with trait were referred to the counseling service. Of these infants, 211 were in group A and 294 in group B. The follow-up rate was 78% and 49% in groups A and B, respectively (P less than .001). The mean duration from birth to testing results received by the follow-up service was 27 days for group A and 131 days for group B (P less than .001). Of mothers in groups A and B, 92% and 47%, respectively, resided in the same county where the follow-up service was located (P less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Counseling↗
PubMed1989

Comparison of 252Cf plasma desorption mass spectrometry and fast atom bombardment mass spectrometry in identification of simple monoglucosyl conjugates.

The fast atom bombardment (glycerol) and 252Cf plasma desorption mass spectra of 16 simple monoglucosyl conjugates have been compared. Plasma desorption mass spectrometry, in general, has been found to be the superior technique for characterizing these low molecular weight conjugates because of the relative absence of interfering matrix peaks.

Glucosides↗
PubMed1989

Maternal-fetal transport of vitamin K1 and its effects on coagulation in premature infants.

We conducted a prospective study to determine (1) the maternal-fetal vitamin K1 transport in premature infants after vitamin K1 was given to the mothers antenatally and (2) the vitamin K1 effects on blood coagulation in the babies. Women in labor at less than or equal to 34 weeks of gestation were randomly selected to receive antenatal vitamin K1, 5 mg given intramuscularly (vitamin K1 group), or no vitamin K1 (control group). Eight infants, including one set of twins, were in the vitamin K1 group and six in the control group. Vitamin K1 concentrations were higher in the vitamin K1 group than in the control group (p = 0.06). Activated partial thromboplastin time was prolonged, and factor II coagulation activity and factor II antigen were proportionately decreased in cord plasma in both groups. The average ratio of factor II coagulation activity to antigen was not decreased in either group. Protein induced by vitamin K absence-II (PIVKA-II) was not detectable in any cord plasma sample in either group. These findings support previous reports that the decreased vitamin K-dependent coagulation activity in premature infants is the result of reduced synthesis of precursor proteins, rather than the result of vitamin K deficiency, and suggest that additional vitamin K1 is not likely to improve coagulation activity. Among those infants who underwent cranial ultrasonography, all four in the vitamin K1 group and one of five in the control group had mild intraventricular hemorrhage. Studies of a larger number of patients are necessary before it can be established that maternal antenatal administration of vitamin K1 results in improvement of coagulation and the prevention of intraventricular hemorrhage in premature infants.

Birth Weight↗
PubMed1989

[Study on leukemic-colony forming unit in 31 patients with acute non-lymphocytic leukemia].

Thirty-one patients with acute non-lymphocytic leukemia (ANLL) were studied with Dicke's soft agar marrow culture to identify leukemic colony forming units. Eighteen of them had leukemic colony formation, in those patients, the average survival period was shorter (65d), and none of them achieved remission after chemotherapy. The remaining thirteen patients had no colony formation and had a longer survival period of 119.8 d. In the latter group four out of six who had undergone more than two courses of chemotherapy went into complete remission. Our study showed that patients who had leukemic colony formation had a worse prognosis than those who had no leukemic colony formation.

Adolescent↗
PubMed1989

Combined in-beam electron impact-B/E-linked scan mass spectrometry of oxazoline derivatives for the structure determination of long-chain unsaturated fatty acids.

Long-chain unsaturated fatty acids (UFA) having up to six double bonds are derivatized to 2-substituted 4,4-dimethyloxazolines (DMOX) and then analyzed by combined in-beam electron impact (IBEI)-B/E-linked scan mass spectrometry. This technique provides highly characteristic mass spectra and may serve as an auxiliary means for direct structure determination of individual UFA in mixtures.

Fatty Acids, Unsaturated↗
PubMed1988

Magnetic resonance imaging of bone marrow in sickle cell patients.

Assessment of the bone marrow in sickle cell patients with or without pain crises can be accomplished using a variety of imaging techniques. Conventional radiography is the least sensitive of all imaging modalities in the early stages of the bone marrow infarct. Radionuclide imaging using 99mTc sulfur colloid shows sharply demarcated photon-deficient regions that are slow to resolve. Cumulative exposure to ionizing radiation would be of concern if repeated examinations with conventional x-rays and radionuclides were carried out. Magnetic resonance imaging (MRI) is a noninvasive technique that differentiates the bone marrow of sickle cell patients from that of normal controls. Furthermore, at least in some patients, acute tissue changes can be detected during early stages of pain crises using magnetic resonance. Further investigations are necessary to optimize the use of MRI in sickle cell patients with pain crises.

Anemia, Sickle Cell↗
PubMed1987

Detection of trehalose monomycolate in Mycobacterium leprae grown in armadillo tissues.

Trehalose-6-monomycolate (TMM) was isolated from the lipids of armadillo-derived Mycobacterium leprae. Only meagre amounts of this glycolipid were recovered, but its structure was unequivocally established. Only alpha-mycolates were detected in the TMM by 252Cf plasma desorption mass spectrometry. Electron impact mass spectrometry showed the alpha branch to be principally C20. Trehalose dimycolate (cord factor) was not detectable. Since we have also found TMM in M. lepraemurium and in every Mycobacterium species so far examined, we suggest that this glycolipid is truly ubiquitous amongst mycobacteria.

Animals↗
PubMed1986

Predominant osmotically active organic solutes in rat and rabbit renal medullas.

The mechanism that concentrates the urine to an osmolality several times that of systemic plasma results in high concentrations of solutes (particularly NaCl and urea) in extracellular fluid of renal medulla, but not in the labyrinth of the renal cortex. Intracellular and extracellular osmolality must be equal in animals, but the known intracellular levels of Na and K salts and urea in renal medullas are much too low to balance the high extracellular osmolality. The purpose of these studies was to identify the other intracellular osmolytes that must be present. Cortexes and medullas from rabbit and rat kidneys were analyzed by proton nuclear magnetic resonance, mass spectrometry, and chemical assays to determine the identity and amount of organic solutes. Large amounts of glycerophosphorylcholine, betaine, sorbitol, and inositol were found in both species localized almost exclusively to the inner medulla. In rabbits during antidiuresis glycerophosphorylcholine, betaine, and sorbitol were present in the inner medulla, at concentrations of 21.1, 34.8, and 20.8 mumol/g wet weight, respectively, but were not detected in the cortex. Inositol was present in rabbit inner medulla at 10.7 mumol/g wet weight and was also present in the cortex, but at lower concentration. None of the above metabolites was present in measurable amounts in urine or peripheral plasma. The accumulation in the cells of the inner medulla of relatively large amounts of betaine, sorbitol, glycerophosphorylcholine and inositol during antidiuresis suggests that they may play a significant role in the maintenance of intracellular osmotic balance.

Animals↗
PubMed1986

Separation of the components of commercial digitonin using high-performance liquid chromatography and centrifugal countercurrent chromatography. Identification of the products by californium-252 plasma desorption mass spectrometry.

Commercial digitonin has been separated into its components using high-performance liquid chromatography and centrifugal countercurrent chromatography. The individual glucosides have been identified by californium-252 plasma desorption mass spectrometry, occasionally supplemented by hydrolysis and analysis of the liberated sugars and aglycones. Mass spectra of commercial digitonin that have appeared in the literature are discussed in the light of their complex nature. A new glycoside of molecular weight 1035 is described and a structure proposed.

Californium↗
PubMed1986

Californium-252 plasma desorption mass spectrometry of skin lipids. Positive and negative ions formed by attachment processes.

Californium-252 plasma desorption mass spectra have been run on a series of typical lipids found in skin, including a fatty acid, a methyl and wax ester, a mono-, di- and triglyceride and an anhydride, in a effort to discover the nature of peaks caused by fingerprint contamination of the sample holders. The triglyceride was identified as the source, and peaks found by reattachment of abundant fragment ions to the original lipid were noted in several cases.

Californium↗