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Biomedical subjects

B Lee

Publications and source records attributed to B Lee.

At least 361 records · Page 20Linked to original sources
PubMed1990

[Effects of alminoprofen on the allergic reactions].

The effects of alminoprofen, a nonsteroidal anti-inflammatory agent, on the experimental animal models of allergic reactions were examined and compared with those of ibuprofen. Alminoprofen at 30 mg/kg given intraduodenally significantly suppressed passive anaphylactic bronchoconstrictions, while ibuprofen did not at the same doses. In vitro studies revealed that alminoprofen, in contrast to ibuprofen, exerted an inhibitory effect on arachidonate 5-lipoxygenase activity which initiates the bio-synthesis of leukotrienes. Alminoprofen inhibited arachidonic acid-induced ear edema in mice and homologous passive cutaneous anaphylaxis in rats at high doses, while ibuprofen did not at the high doses. From its characteristic feature of inhibitory effects on 5-lipoxygenase activity and the experimental model of type I allergic reaction, it is suggested that alminoprofen is a new type of nonsteroidal anti-inflammatory agent.

Animals↗
PubMed1989

Glycine to serine substitution in the triple helical domain of pro-alpha 1 (II) collagen results in a lethal perinatal form of short-limbed dwarfism.

Previous biochemical studies on cartilage tissue from a proband with Type II achondrogenesis-hypochondrogenesis (Godfrey, M., and Hollister, D. W. (1988) Am. J. Hum. Genet. 43, 904-913) indicated heterozygosity for a structural abnormality in the triple helical domain of pro-alpha 1 (II) collagen. Here we demonstrate that the mutation in the type II procollagen gene is a single base change that converts the codon for glycine (GGC) at amino acid 943 of the alpha 1 (II) chain to a codon for serine (AGC). The substitution disrupts the invariant Gly-X-Y structural motif necessary for perfect triple helix formation and leads to extensive overmodification, intracellular retention, and reduced secretion of type II collagen. These findings confirm the proposal that new dominant mutations in the type II procollagen gene may account for some cases of Type II achondrogenesis-hypochondrogenesis. Since recent studies (Lee, B., Vissing, H., Ramirez, F., Rogers, D., and Rimoin, D. (1989) Science 244, 978-980) have identified a dominantly inherited type II procollagen gene deletion in a non-lethal form of skeletal dysplasia, namely spondyloepiphyseal dysplasia, the data more generally demonstrate that different type II procollagen gene mutations eventuate in a wide and diverse spectrum of clinical phenotypes.

Amino Acid Sequence↗
PubMed1989

Identification of the molecular defect in a family with spondyloepiphyseal dysplasia.

Spondyloepiphyseal dysplasias (SED) are a heterogeneous group of inherited disorders characterized by disproportionate short stature and pleiotropic involvement of the skeletal and ocular systems. Evidence has suggested that SED may result from structural defects in type II collagen. To confirm the validity of this hypothesis, the structure of the "candidate" type II collagen gene (COL2A1) has been directly examined in a relatively large SED family. Coarse scanning of the gene by Southern blot hybridization identified an abnormal restriction pattern in one of the affected members of the kindred. Analysis of selected genomic fragments, amplified by the polymerase chain reaction, precisely localized the molecular defect and demonstrated that all affected family members carried the same heterozygous single-exon deletion. As a consequence of the mutation, nearly 90 percent of the assembled type II collagen homotrimers are expected to contain one or more procollagen subunits harboring an interstitial deletion of 36 amino acids in the triple helical domain.

Amino Acid Sequence↗
PubMed1989

Prediction of outcome in patients with acute variceal haemorrhage.

Prediction of outcome in 87 patients following acute bleeding oesophageal and gastric varices due to portal hypertension from chronic liver disease was studied at our hospital over a 30-month period. The overall mortality rate was 26 per cent (23/87), with the operative mortality rate (50 per cent) being more than triple the non-operative mortality rate (14 per cent). The initial prothrombin time ratio (PTR) alone was significantly different in survivors and non-survivors both in the operated and non-operated patients. The only survivor in the whole material with a PTR greater than or equal to 2.2 was a patient who was transferred and underwent successful liver transplantation elsewhere. Among operated intensive care unit (ICU) patients, the Glasgow predictor gave a mean probability of discharge of 0.81 (s.d. 0.15) in 13 survivors and of 0.35 (s.d. 0.35) in the 15 non-survivors (P less than 0.001). In the 11 non-operative ICU patients, who had failed sclerotherapy, the Glasgow predictor could not be validated. Fourteen ICU deaths were associated with significant hypotension defined as a systolic blood pressure less than 90 mmHg for greater than 1 h.

Acute Disease↗
PubMed1989

Transient gene expression in aleurone protoplasts isolated from developing caryopses of barley and wheat.

Methods have been developed for the isolation of aleurone protoplasts from developing caryopses of Hordeum vulgare and Triticum aestivum in order to study transient expression of introduced genes. Chimaeric gene constructs were introduced into aleurone protoplasts by polyethylene glycol (PEG). Transient expression directed by the 35S promoter from cauliflower mosaic virus (CaMV) of the reporter gene encoding chloramphenicol acetyl transferase (CAT) was detected in aleurone protoplasts from developing barley and wheat grains. Using a similar construct, CAT activity increased when the alcohol dehydrogenase intron 1 fragment from maize was ligated between the 35S promoter and the CAT coding region. The demonstration of transient expression in protoplasts from developing aleurone layers indicates that they may be useful for investigating tissue and developmental control of genes coding for cereal seed proteins.

Brassica↗
PubMed1989

An analysis of the utilisation of an intensive care unit.

We monitored the response to intensive care of 480 patients by calculating the difference in their organ failure score on the day of admission and that on the day of discharge, and related the response to hospital outcome. The patients were classified into: A) those who benefited (33%), B) those who might have benefited (28%), C) those who would never or would no longer have benefited (18%) and D) those who did not require intensive care management (21%). The criteria used were response to therapy, individually predicted outcome, hospital outcome and perceived need for intensive care. Group C patients used up 26.8% of the total intensive care unit bed days, while group D patients occupied 3.7%. We concluded that an acute terminal care unit to care for group C patients who have no hope of survival is more appropriate to the needs of our hospital than an intermediate care unit for overnight monitoring of uncomplicated postoperative and non-operative patients (group D).

Critical Care↗
PubMed1989

Anaerobic biosynthesis of unsaturated fatty acids in the cyanobacterium, Oscillatoria limnetica.

The mechanism for synthesis of monounsaturated fatty acids under aerobic and anaerobic conditions was studied in the facultative anaerobic cyanobacterium, Oscillatoria limnetica. The hexadecenoic acid (C16:1) of aerobically grown O. limnetica was shown to contain both the delta 7 (79%) and delta 9 (21%) isomers, while the octadecenoic (C18:1) acid was entirely the delta 9 acid. Incorporation of [2-14C] acetate into the fatty acids under aerobic conditions resulted in synthesis of the delta 7 and delta 9 C16:1 and the delta 9 C18:1. Synthesis of unsaturated fatty acids in the presence of DCMU required sulfide. Anaerobic incubations in the presence of DCMU and sulfide (less than 0.003% atmospheric oxygen) resulted in a two-fold increase in monounsaturated fatty acids of both delta 7 and delta 9 C16:1 and delta 9 and delta 11 C18:1. The synthesis of these is characteristic of a bacterial-type, anaerobic pathway.

Acetates↗
PubMed1989

The extracellular acid phosphatase of the mosquito-parasitizing fungus Lagenidium giganteum.

The mosquito-parasitizing fungus Lagenidium giganteum secreted a soluble acid phosphatase and beta-D-glucosidase into the growth medium. The acid phosphatase was isolated and purified to single component, and some of its physicochemical properties were determined. The enzyme exhibited a pH optimum of 5.6 in phthalate buffer with p-nitrophenyl phosphate and was temperature-inactivated at 55 degrees C. Enzyme activity seems to be limited to phenyl-phosphate substrates. A molecular weight of 42,800 was found and the amino acid content was also determined. A Km for p-nitrophenyl phosphate of 1.6 x 10(-7) M was found. The possible involvement of the enzyme in the infective process was discussed.

Acid Phosphatase↗
PubMed1989

Low catheter sepsis rate in a hospital-wide nutrition support service.

Four hundred and seventy-nine catheters were inserted into 471 patients over a 6 year period for the administration of total parenteral nutrition. Catheter insertion was carried out only by surgical members of the nutrition support service. Complications were recorded prospectively and stored, with all other details of treatment, on a microcomputer. The mechanical complication rate was 6.4% of catheters used and the incidence of catheter related sepsis (CRS) 2.9%. Catheters which grew organisms, but were not associated with CRS, occurred in 3.7% of catheters used. Catheter care was performed by nurses throughout the hospital under the supervision of the nutrition nurse. The results of our work indicate that restriction of catheter care to specialised nurses is unnecessary providing there is staff education and support. In addition, the value of routine catheter tip culture in patients, not suspected of having infection, is questionable.

Journal Article↗
PubMed1989

Accuracy of decisions to withdraw therapy in critically ill patients: clinical judgment versus a computer model.

Two clinicians and the nursing sisters working in the ICU evaluated the chance of survival of ICU patients every day. Patients were assessed either as "outcome unknown or will die." These predictions were compared with those made by computerized trend analysis of daily acute physiology and chronic health evaluation (APACHE II) scores corrected for the presence and duration of major organ system failure. The predictions were not acted upon during the study. Comparing the predictions with actual hospital outcome, the doctors and nurses had a false-positive diagnosis rate for dying of between 7.7% and 16.7%, while there were no false predictions by the computer model. The patients predicted to die by the doctors and nurses were not completely identical to those predicted by the computer. Predictions of doctors and nurses that were confirmed by the computer had a sensitivity of 20% and no false predictions of death.

Decision Making, Computer-Assisted↗
PubMed1989

Advances in catheter ablation use of unipolar electrograms.

Ventricular tachycardia in man can be eliminated by relatively small lesions in the reentrant circuit. This report includes a review of available energy sources, and methods for localizing arrhythmias. Methods to assure contact and prevent perforation using low frequency electrograms are presented including the new finding of reverse ST deflection with contact. Experience with laser energy in dogs showed discrete homogenous lesions. When compared with DC shock the animals showed far less arrhythmia and the lack of far field effect greatly reduced echo abnormalities in the post shock period. Studies with radiofrequency show ability to produce localized lesions similar to the laser but with a more flexible catheter. Localization requires a correlation of techniques including pacemapping, activation maps and pacing during tachycardia. Early activation (less than -60 ms) at times 180-320 ms, with comparable pace to QRS during tachycardia with no change in morphology best localized the slow zone of the reentrant circuit. The low frequency unipolar electrogram from the tip and immediately proximal electrode revealed contact with ST deviation. The distal deviation was always greater than the proximal RV free wall and posterior basal produced depression rather than elevation of the electrogram. While the mechanism of ST reversal with contact is not understood and may relate to the type of indifferent reference used (Wilson central terminal), the ST depression reveals the same information about contact that elevation does in most areas of the heart studied in our patients.

Animals↗
PubMed1989

In vitro and in vivo comparison of the abilities of purine and pyrimidine 2',3'-dideoxynucleosides to inhibit duck hepadnavirus.

Four purine and two pyrimidine 2',3'-dideoxynucleosides were studied for their ability to inhibit duck hepadnavirus replication. The purine 2',3'-dideoxynucleosides were more potent antiviral agents than the pyrimidine 2',3'-dideoxynucleosides. The concentration for 50% inhibition of viral replication (IC50) was determined for each of the effective agents. Two drugs with low IC50s, 2,6-diaminopurine 2',3'-dideoxyriboside and 2',3'-dideoxyadenosine, were chosen for in vivo studies. Animals received 10 mg/kg intramuscularly twice daily. Rapid clearance of hepadnavirus DNA from the sera of the animals was seen as a result of treatment with 2,6-diaminopurine 2',3'-dideoxyriboside; however, treatment with 2',3'-dideoxyadenosine did not clear the virus.

Animals↗
PubMed1989

Monoclonal antibody defining tax protein of human T-cell leukemia virus type-I.

We prepared a monoclonal antibody (MAb), Lt-4, which recognizes a tax protein expressed in HTLV-I-infected cells. Indirect immunofluorescence staining showed that the antigen recognized by Lt-4 MAb located mainly in the nuclei of HTLV-I-infected T cell lines such as HUT102, TCL-As2, MT-1 and MT-2, and also weakly in the cytoplasm of MT-2 cell line. Lt-4 MAb did not react with two HTLV-I-uninfected T cell lines tested and fresh and PHA-activated peripheral blood lymphocytes (PBL) of several normal donors. Furthermore, Lt-4 MAb stained the nuclei of HeLa cells infected with a recombinant vaccinia virus encoding the tax but not with a wild type vaccinia virus. In Western blot (WB) and radioimmunoprecipitation analyses, Lt-4 MAb detected a 40 kDa molecule (p40) in HUT102 and TCL-As2 cells, and p40 and p68 in MT-2 cells. These results show that Lt-4 MAb is highly specific for the tax protein.

Antibodies, Monoclonal↗