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D Lucas

Publications and source records attributed to D Lucas.

15 recordsLinked to original sources
PubMed1992

Sterility of refrigerated injectable collagen syringes after injection of patient.

BACKGROUND: Injectable collagen has been used for more than 15 years to correct soft tissue cosmetic defects. After injection, the collagen remaining in the syringe is often refrigerated for later use in the same patient, despite manufacturer and Food and Drug Administration recommendations to discard the unused collagen. OBJECTIVE: This study examined the incidence of bacterial contamination of stored collagen. METHODS: Syringe needle tips and collagen from 50 previously used syringes containing either Zyderm I, Zyderm II, or Zyplast were cultured separately under aerobic and anaerobic conditions. Bacterial isolates were identified. RESULTS: Propionibacterium acnes was cultured from 7 of 50 needle tips. One positive needle tip culture grew both P. acnes and Staphylococcus aureus. Bacteria were isolated from only one collagen sample that grew a nonhemolytic streptococcus that may have represented a laboratory contaminant. CONCLUSION: Syringes of collagen stored for repeated use rarely become contaminated with bacteria despite frequent contamination of their needle tips. Skin abscesses after collagen injection should be cultured under anaerobic, as well as aerobic, conditions so that infections caused by P. acnes will not be missed.

Collagen↗
PubMed1992

Preoperative embolization of the spleen in children with hypersplenism.

Splenomegaly associated with myelodysplastic disorders in children may be massive and can result in pancytopenia, abdominal discomfort, and respiratory distress. When these symptoms cannot be relieved by nonsurgical means, splenectomy may be indicated. Under such conditions, surgical splenectomy carries increased risks, as the thrombocytopenia is difficult to correct secondary to splenic sequestration. Additionally, the surgical anatomy is often distorted secondary to the massive spleen and dissection can be difficult. These factors can lead to uncontrollable hemorrhage. In an attempt to decrease intraoperative blood loss, the authors successfully performed preoperative splenic artery embolization in 11 of 12 children (age range, 1-11 years) with pancytopenia due to hypersplenism. Hypersplenism requiring surgical splenectomy was due to leukemia (n = 9), myelodysplastic syndrome (n = 1), immune thrombocytopenia (n = 1), and osteopetrosis (n = 1). Embolization was performed under general anesthesia, prior to surgery, with gelatin sponge particles alone, Gianturco coils alone, or a combination of polyvinyl alcohol sponge particles and Gianturco coils. Embolization allowed for safe surgical splenectomy.

Child↗
PubMed1992

Enzymatic production of acetaldehyde from ethanol in rat brain tissue.

The capacity for the brain to produce acetaldehyde (AcHO) from ethanol was determined in rat brain homogenates. Rat brains were perfused with saline-heparin solution and homogenized in a phosphate buffer. Varying amounts of tissue were incubated with ethanol (0-100 mM) for periods of up to 60 min. The reaction was stopped by the addition of desferrioxamine and ice-cold perchloric acid. Supernatants were treated with dinitrophenylhydrazine reagent, extracted with isooctane in the presence of an internal standard, and the derivatives were separated by HPLC. The addition of 4-methyl pyrazole (an alcohol dehydrogenase inhibitor) or metyrapone (a cytochrome P450 inhibitor) had no effect on the amount of recovered AcHO. On the other hand, treatment with the catalase inhibitors sodium azide, cyanamide, or 3-amino-1,2,4-triazole blocked the production of AcHO while the addition of exogenous peroxide or a peroxide-generating system enhanced the production of AcHO. Overall, these results suggest that AcHO may be produced in the brain during alcohol intoxication, through the action of the enzyme catalase.

Acetaldehyde↗
PubMed1992

Differences in hepatic microsomal cytochrome P-450 isoenzyme induction by pyrazole, chronic ethanol, 3-methylcholanthrene, and phenobarbital in high alcohol sensitivity (HAS) and low alcohol sensitivity (LAS) rats.

High and low alcohol sensitivity (HAS and LAS) rats have been selected for their differences in ethanol-induced sleep time. Liver monooxygenase activities were studied in HAS and LAS rats before and after treatments with known inducers such as chronic ethanol, pyrazole, 3-methylcholanthrene (3-MC) and phenobarbital (PB) to determine whether the selection procedure also selected for differences in the cytochrome P-450 (P-450) inducibility. This previously has been shown with long sleep (LS) and short sleep (SS) mice, which were selected using a similar criterion. 3-MC and PB, in conjunction with chronic ethanol treatment, were used in order to evaluate the interactions of ethanol with these inducers. Prior to treatment, total P-450 content was slightly lower in LAS than in HAS rats. However, both lines displayed the same microsomal monooxygenase activities related to different P-450 isozymes. This was demonstrated by ethoxyresorufin deethylation (EROD) for cytochrome P-450 1A1 (CYP1A1), acetanilide hydroxylation (ACET) for CYP1A2, pentoxyresorufin dealkylation (PROD) for CYP2B, 1-butanol oxidation (BUTAN) and N-nitrosodimethylamine demethylation (NDMA) for CYP2E1. After the different treatments, HAS rats did not differ from LAS rats in their CYP2E1 inducibility. However, pyrazole, PB and 3-MC treatment led to differences in CYP1A and CYP2B monooxygenase activities between the two lines. The enhancement of PROD by pyrazole treatment was less prominent in LAS (1.7-fold of the control value) than in HAS rats (3.8-fold).(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗
PubMed1991

Effects of [N-(L-(1-carboxy-2-phenyl)ethyl]-L-phenylalanyl-beta-alanine (SCH32615), a neutral endopeptidase (enkephalinase) inhibitor, on levels of enkephalin, encrypted enkephalins and substance P in cerebrospinal fluid and plasma of primates.

In halothane-anesthetized and -ventilated cynomologus macaque monkeys, the effects of administering vehicle (n = 3) or the neutral endopeptidase inhibitor N-[L-(1-carboxy-2-phenyl)ethyl]-L-phenylalanyl-beta-alanine (16 mg/kg, n = 5; or 100 mg/kg, n = 3, intravenously) was examined. Cisternal CSF aliquots were examined by radioimmunoassay: 1) for Met enkephalin; 2) after trypsin and carboxypeptidase B treatment for encrypted enkephalin (X-ENK); 3) for substance P; and 4) for unmetabolized drug. Similar measures were carried out in femoral artery and femoral venous plasma, except that substance P was not assayed. In CSF, prior to drug, low, but measurable levels of enkephalin (61 pg/ml), X-ENK (285 pg/ml) and substance P (16 pg/ml) were observed. Vehicle-injected animals showed no change from baseline levels over a 4-hr sampling period in either plasma or CSF levels. In contrast, following 16 mg/kg, in CSF, there was a significant 9-fold increase in MET and 11-fold increase in X-ENK at 30 min. CSF-substance P levels rose also by a factor of 2, with the peak effect observed at 60 min. All levels displayed a significant reduction by 4 hr. There was no statistical difference between the maximum effects observed with either the 16- or 100-mg/kg dose. Plasma peptide levels of enkephalin and X-ENK were not altered by drug. CSF displayed significant drug levels by 30 min, which were between 0.1 and 1% of levels observed concurrently in plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1979

Automated measurement of total cholesterol and triglycerides, in "tandem," on the discrete sample analyzer, Gilford System 3500.

We have developed an automated procedure on a discrete sample analyzer, Gilford System 3500, which alternately measures both total serum cholesterol and triglyceride concentrations as a "tandem" procedure. We used Dow Diagnostic's fully enzymatic, colorimetric reagents and aqueous standards to calculate unknowns ratiometrically. Cholesterol and then triglyceride reagent are dispensed into alternate cups; the produced color at 500 nm is measured after an ambient temperature incubation of 20 min. Reagent and sample carryover is less than 1.6%. Correlation coefficients of 0.997 for comparison for both automated tests with the manual methods at 30 degrees C and a typical CV of less than 2.0% show this "tandem" procedure to be reliable and accurate.

Autoanalysis↗
PubMed1977

The Salop Skate.

Explore the source record for details and available documents.

Adolescent↗
PubMed1977

Language differences and the family planning survey.

Language is an important but often neglected source of non-sampling error in family planning surveys. This paper examines the problems of language usage and of translation, in KAP surveys in particular, using examples from African and other research experience. The authors emphasize that language pervades all stages of family planning surveys, pointing out that interpretations of survey results should take into account the possibility of the influence of language differences. Various measures are suggested that can contribute to minimizing this source of response error.

Africa↗
PubMed1975

Rosette formation by canine peripheral blood lymphocytes.

The surface membrane characteristics of canine peripheral blood lymphocytes were investigated using erythrocyte (E) and erythrocyte antibody complement (EAC) rosette assays and immunofluorescent staining techniques. Canine thymus-derived lymphocytes formed nonimmune E rosettes with human and guinea pig erythrocytes at approximately the same percentages (mean percentage 36.3 and 32.4, respectively). Rosettes did not form with erythrocytes from seven other animal species. Cell surface immunoglobulins were demonstrable in a small percentage (4%) of the E rosette-forming lymphocyte population. Fragments of human erythrocytes inhibited E rosette formation by intact human red cells, but did not result in a significant decrease in rosette formation by intact guinea pig erythrocytes; likewise, guinea pig fragments had no inhibitory effect on rosette formation by human erythrocytes, demonstrating that separate receptors were required for the two red cell types. EAC rosette formation was not affected by addition of intact or fragmented human and guinea pig erythrocytes. Canine bone marrow-derived lymphocytes were characterized by immunoglobulin on the cell surface and EAC rosette formation. Serial tests of lymphocytes from one dog revealed a wide variation in percentage of cells forming E and EAC rosettes. A close correlation was observed between the immunoglobulin-bearing cells (mean percentage 46.6) and those forming EAC rosettes (mean percentage 49.3).

Animals↗
PubMedDate not supplied

Fertility and family planning in southern and central Africa.

Southern Africa comprises a zone where the total fertility rate is below 6 births per woman. To the north is a ring of countries with higher fertility and relatively low contraceptive prevalence rates. The experience of South Africa, Botswana, and Zimbabwe, which have successful family planning programs, is compared with that of neighboring countries.

Adult↗