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Biomedical subjects

B Lee

Publications and source records attributed to B Lee.

At least 379 records · Page 21Linked to original sources
PubMed1988

Inhibition of duck hepatitis B virus replication by purine 2',3'-dideoxynucleosides.

Primary hepatocyte cultures from duck hepatitis B virus (DHBV) infected ducklings were used to evaluate the antiviral activity of purine and pyrimidine 2',3'-dideoxynucleosides. The purine 2',3'-dideoxynucleosides were very effective inhibitors of hepadnavirus replication, whereas the pyrimidine dideoxynucleosides were not. 2',3'-Dideoxyguanosine and 2,6-diaminopurine 2',3'-dideoxyriboside (ddDAPR) were the most effective antiviral agents studied. ddDAPR given intramuscularly twice daily at 10 mg/kg rapidly cleared DHBV-DNA from the sera of persistently infected ducklings but this effect was not permanent.

Animals↗
PubMed1988

Species-dependent antigenicity of the 34-kDa glycoprotein found on the membrane of various primate lymphocytes transformed by human T-cell leukemia virus type-I (HTLV-I) and simian T-cell leukemia virus (STLV-I).

Sixteen monoclonal antibodies (MAbs) against TA34 antigen found on the surface of human T-cell leukemia virus type-I (HTLV-I) infected cells were prepared. These MAbs and one previously prepared anti-TA34 MAb (TAG34) recognized 34-kDa peptide not only in HTLV-I-infected cells, but also in cells infected with simian T-cell leukemia virus (STLV-I), which is analogous in antigenicity and gene structure to HTLV-I. Radioimmuno-precipitation (RIP) tests with the MAbs showed that TA34 antigen had at least 3 overlapping epitope groups. The antigenicities of the TA34 antigens of HTLV-I-infected cells derived from various primates were investigated by immunofluorescence staining using 9 anti-TA34 MAbs. Cells from humans, apes and Old World monkeys reacted with all these antibodies, whereas cells from New World monkeys were stained by most of the antibodies, but little if at all by the remaining 2 (5A8 and TAG34). Similar results were obtained with various primate cells infected with STLV-I. All 17 MAbs used recognized a 22-kDa peptide in HTLV-I-infected cells cultured in the presence of tunicamycin. When incubated with 1% 2-mercaptoethanol at pH 7.2 at 37 degrees C, TA34 antigen lost its reactivity with TAG34, suggesting that the antigen has an intramolecular S-S bond. Twenty sera of adult T-cell leukemia (ATL) patients did not react with TA34 antigen in RIP tests.

Animals↗
PubMed1988

Predicting outcome among intensive care unit patients using computerised trend analysis of daily Apache II scores corrected for organ system failure.

Daily Apache II scores were determined prospectively on 310 consecutive adult Intensive Care Unit (ICU) patients to reflect the dynamic pathophysiological processes affecting ICU patients. Organ failure scores were derived from the Apache II scores by applying a coefficient which corresponded to the number and duration of organ failures to account for the increased mortality associated with established major organ-system failures. Computerised trend analysis of data from the first 100 patients was used to develop criteria for predicting hospital outcome of the ICU patients. The analysis took into account the absolute value of the daily scores and the rate of change relative to that of the previous day. Allowance was made for changes in scores as a result of surgery or major iatrogenic complications arising after admission to the ICU. The criteria were then tested prospectively on the next 210 consecutive ICU patients. Predictions by Apache II assessments were NOT used to influence clinical decisions during the study period. It was possible to predict with a specificity of 100% 37 out of the 72 deaths in the test group. The predictive power of daily organ failure scores was superior to those obtained from a single Apache II assessment or from daily Apache II scores by a factor of 5.3 and 1.4 respectively. The estimated long-term risk of a false prediction is 1.4% at the 95% confidence level.

Critical Care↗
PubMed1988

Audit of intensive care: a 30 month experience using the Apache II severity of disease classification system.

608 patients admitted to a general Intensive Care Unit (ICU) over a 30 month period were analyzed according to the Apache II Severity of Disease Classification System on day one of admission. Hospital outcome details were available on 583 patients in the series. The mean Apache II scores for survivors (396) and non-survivors (187) were 13 (SD 7) and 24 (SD 9), and their Risk of Death were 16 (SD 16) and 47 (SD 27) respectively (p less than 0.001 for both). The majority of deaths (75%: 141/187) in our series came from those with chronic ill health (55%: 103/187), of whom 37% (38/103) were in endstage disease, and those with "old" trauma (18%: 34/187) often with incipient sepsis transferred from other hospitals after a mean delay of 9 days. Our higher than predicted mortality (mortality ratio 1.2) in comparison with centres in the United States of America (US) may be partly explained by the high proportion of our population from these unfavourable groups, by our use of the best Glasgow Coma Scale in the first 24 h following admission, and the major differences between our patient population and that of the US upon which the Apache II was based. The presence of these large unfavourable groups indicates a change in our admission policy is warranted.

Adult↗
PubMed1988

Beta tubulin gene of the parasitic protozoan Leishmania mexicana.

A genomic DNA library was generated with Sau3A cut DNA derived from promastigotes of Leishmania mexicana amazonensis and the lambda vector EMBL3. The library was screened for beta tubulin clones using 32P-labeled heterologous probe of chicken beta tubulin cDNA. From the various genomic clones the one designated 23.1, which gave the simplest hybridization banding pattern, was further characterized. The leishmanial insert DNA was subcloned into plasmid vectors and the resulting clones were designated as T11, T28 and T50. Using these clones leishmanial beta tubulin coding region was sequenced by the dideoxy method. The result shows that the beta tubulin has 445 amino acids, a carboxyl terminal tyrosine, and no intron. Leishmanial beta tubulin has 93% amino acid sequence similarity with that of trypanosome and 82% with that of man: and there is a strong bias in codon usage for codons possessing guanine or cytosine in the third base.

Amino Acid Sequence↗
PubMed1988

Effects of proparacaine on actin cytoskeleton of corneal epithelium.

Chronic use of proparacaine, a topical ocular anesthetic, is associated with punctate keratopathy and delayed epithelial wound healing. Spreading corneal epithelial cells normally elaborate cytoplasmic arrays of actin-rich stress fibers which insert onto the inner surface of the cell membrane at discrete adhesion complexes. As actin is implicated in cell-to-substratum adhesion and cell motility, the effects of proparacaine on the actin cytoskeleton of corneal epithelial cells were studied in vitro. Spreading rat corneal epithelial cells in tissue culture were treated with proparacaine hydrochloride. At the lowest drug concentration used (0.01 mM), no effects were seen on the actin cytoskeleton. At 1.0 mM, some disruption of stress fibers was evident and actin was redistributed in a diffuse fashion. Many of the intact stress fibers had abnormal morphology, distribution, and orientation. Scanning electron microscopy showed a loss of cell extensions and cell-to-substratum adhesiveness at the leading epithelial edge. Above 1.0 mM, cell spreading was completely abolished and most cells detached from the substratum. After a washout period with drug-free media, these effects were reversible at concentrations of 1.0 mM or less. We postulate that one mechanism by which proparacaine inhibits corneal epithelial migration and adhesion is through alteration of the actin cytoskeleton.

Actins↗
PubMed1988

Predicting deaths among intensive care unit patients.

Daily APACHE II assessments to reflect the dynamic pathophysiologic processes affecting ICU patients were carried out prospectively on 212 adult ICU admissions for the purpose of predicting hospital outcome. Trend analysis of daily APACHE II scores was used to develop the first set of criteria for predicting deaths among the ICU patients. The analysis took into account the absolute value of APACHE II score of each day and the rate of change relative to that of the previous day. One hundred consecutive adult ICU admissions were used to determine the criteria that were tested on the following 112 consecutive adult ICU admissions. Daily APACHE II scores identified correctly 16 of the 34 patients who died. A second set of criteria was next derived by raising the values of the original limits in order to build-in greater margins of safety without too great a loss of sensitivity. The predictive power of daily APACHE II scores using the second set of criteria was superior to that of a single APACHE II score by a factor of 4. Predictions were not used to influence clinical decision-making during this study.

Aged↗
PubMed1988

Distribution of cytoplasmic microtubules in migrating corneal epithelial cells. An immunofluorescence study.

Microtubules constitute one of the three components of the cellular skeleton (cytoskeleton) and have been implicated in the control of cell polarity, shape, intracellular transport, directional cell motility, and mitosis. With specific antibodies against tubulin, the principal microtubular protein, the cytoplasmic distribution of microtubules was demonstrated in tissue-cultured rat corneal epithelium. This was compared with the distribution of actin, another component of the cytoskeleton. Microtubules are essential for the late phase of corneal epithelial wound healing, characterized mainly by cell mitosis. As yet, little is known about their function in the nonmitotic early phase of healing, but possibilities include the maintenance of cell shape and intracellular transport.

Actins↗
PubMed1987

Metabolic investigations with Femodene--an oral contraceptive containing gestodene and ethinyloestradiol.

The metabolic effects of a new oral contraceptive Femodene (SHD 356C) containing 75 micrograms gestodene (delta-15-levonorgestrel) and 30 micrograms ethinyloestradiol were studied in two groups of women. Group 1 consisted of women not currently using oral contraceptives; Group 2 consisted of women switching to Femodene from their current oral contraceptive. Changes in lipid metabolism were assessed by measuring serum levels of cholesterol, triglycerides, LDL-C, VLDL-C, HDL-C, HDL2-C and HDL3-C. Minimal changes occurred in lipid metabolism apart from increases in triglyceride concentrations. Women in Group 1 showed a 105% increase in SHBG levels and a 51% increase in caeruloplasmin levels compared to increases of 33% and 2% in women in Group 2. A comparison of the two groups of women suggested that the gestagen in Femodene exerted a less anti-oestrogenic effect than most of the gestagens currently used in oral contraceptives. No significant changes occurred in liver function (assessed by estimation of gamma-glutamyl transferase) or in the coagulation factors, Factor X and antithrombin III. Minor effects on glucose tolerance as assessed by blood glucose and plasma insulin levels were noted. These minimal effects on metabolism, combined with its high efficacy and acceptability shown in clinical trials, makes Femodene an ideal alternative to currently used oral contraceptives.

Adolescent↗
PubMed1987

Gastrointestinal dysfunction among intensive care unit patients.

This study used the Acute Physiological and Chronic Health Evaluation (APACHE II) system to select two groups of ICU patients with comparable risk of hospital death to evaluate the importance of GI dysfunction, defined as failure to tolerate enteral nutrition (EN), as a prognostic factor. In our ICU, patients who have not undergone recent bowel surgery are treated by EN. Those patients who cannot tolerate EN are treated by total parenteral nutrition (TPN). One hundred and eleven patients who tolerated EN (functioning gut) and 97 TPN patients who failed to tolerate EN (GI dysfunction) were studied. The mean APACHE II scores of the two groups were 17.7 +/- 6.5 (SD) and 17.7 +/- 5.1, respectively. The observed mortality of patients with GI dysfunction (51%) was significantly higher (p less than .0005) than that of patients with a functioning gut (25%). This was associated with significantly poorer APACHE II mean BP, oxygenation, and creatinine scores among the GI dysfunction patients. Our results suggest that shock, ischemia, and hypoxemia, in addition to causing impairment of renal function, may bring about changes in the GI tract, evident clinically only as a failure to tolerate EN, which have an adverse effect on the prognosis of ICU patients so affected.

Adult↗
PubMed1987

One year's experience with the APACHE II severity of disease classification system in a general intensive care unit.

The APACHE II sickness score was applied prospectively for one year in a general intensive care unit in Saudi Arabia. Two hundred and ten patients were studied, 66 of whom died in hospital. The mean APACHE II score of survivors was 11 (SD 7.1) and of non-survivors, 25.3 (SD 8.8). The mean Risk of Death was 13.3% (SD 13.1) for the survivors and 47.2% (SD 25.8) for non-survivors. The differences in APACHE score and Risk of Death between survivors and non-survivors are highly significant (p less than 0.0005 for both). No patient survived who had a Risk of Death greater than 60% and none died with a Risk of Death less than 7%. The sensitivity of the APACHE II system in predictions of death can be improved if the scores on the day of admission and on the 3rd day are taken into account.

Adult↗