Search PubMed⌕ Search

Biomedical subjects

B Lee

Publications and source records attributed to B Lee.

At least 397 records · Page 22Linked to original sources
PubMed1986

Use of APACHE II severity of disease classification to identify intensive-care-unit patients who would not benefit from total parenteral nutrition.

The APACHE II severity of disease classification system was tested for its ability to identify intensive-care-unit (ICU) patients who would not benefit from treatment with total parenteral nutrition (TPN). First, the classification was validated in our patient population by testing it on 210 consecutive ICU admissions. Then a retrospective study was done on 89 ICU patients who had received TPN, to define APACHE II selection criteria. When the APACHE II system was tested prospectively on 26 ICU patients treated with TPN, it predicted correctly, with a specificity of 100%, half of the patients who died.

Adult↗
PubMed1986

Antigens related to three core proteins of HTLV-I (p24, p19 and p15) and their intracellular localizations, as defined by monoclonal antibodies.

Three distinct monoclonal antibodies (MAbs) specific for human T-cell leukemia virus type-I (HTLV-I) core proteins with molecular weights of 24 kDa (p24), p19 or p15 were produced, characterized and compared. These antibodies were named NOR-1 (anti-p24, IgG2a), GIN-7 (anti-p19, IgG2b) and FR-45 (anti-p15, IgG2a). Immunofluorescence assay showed that they reacted specifically with methanol-fixed cells of virus-bearing cell lines, and that only GIN-7 bound, albeit weakly, to the surface of a small percentage of viable cells. Like natural antibodies to HTLV-I in human serum, GIN-7 stained the fixed cells brightly and diffusely, and gave more intense fluorescence than NOR-1 and FR-45, which stained restricted areas of the cells. NOR-1, GIN-7 and FR-45 specifically precipitated core proteins p24, p19 and p15, respectively, from a lysate of HTLV-IMT-2 labelled with 35S-cysteine. NOR-1 precipitated p53, p36, and p24, GIN-7 precipitated p53, p32, p28 and p19, and FR-45 precipitated p53, p36, and p15 from a lysate of 35S-cysteine-labelled MT-2 cells. GIN-7 also precipitated p32, p28 and p19 from a lysate of MT-2 cells, labelled by surface iodination, but NOR-1 and FR-45 did not detect any proteins in this lysate. GIN-7 also detected p28 in 3H-glucosamine-labelled MT-2 cells. Antibody binding competition assay showed that the sera of ATL patients significantly interfered with the binding of NOR-1 and GIN-7 but not with that of FR-45, to antigens of disrupted virus of MT-2 cells. This complete set of MAbs against the HTLV-I gag gene products is useful for biological and functional studies of the HTLV-I core proteins.

Animals↗
PubMed1986

Laser ablation of normal and diseased human ventricle.

The feasibility and safety of laser photoablation in patients with ventricular tachycardia (VT) and accessory pathways are currently being examined. We studied the qualitative and quantitative effects of argon laser radiation on normal and diseased human ventricle to determine the relationship between the size of tissue lesion and delivered energy. Twenty-nine human ventricle segments (normal ventricle = 10; diseased ventricle = 19) were excised from patients during mapping-guided subendocardial resection for VT (seven patients), mitral valve replacement (five patients), or immediately at autopsy (three patients). Lasing was performed with a 15 W argon laser coupled to a 300 micron optical fiber. Incremental laser discharges from 10 to 1000 J were delivered in air and saline with the optical fiber 5 mm from the endocardial surface. Gross and microscopic damage was quantified and correlated with laser discharges at low (10 to 100 J), intermediate (101 to 300 J), and high (greater than 300 J) energies. Histologic examination of laser-induced lesions in both normal and diseased human ventricle in either medium showed focal thermal injury with crater formation, vacuolization, and coagulation necrosis of endocardium and myocardium. In normal ventricle, mean lesion diameter and depth in air increased with increasing energies up to 300 J. Over 300 J, tissue perforation was frequently observed. In saline, the mean lesion depth was significantly reduced (p less than 0.02) at comparable energies. In diseased ventricle, mean lesion diameter and depth in air and saline also increased with increasing laser discharge energies up to 300 J. Higher energy laser discharges did not increase mean lesion dimensions or result in tissue perforation.(ABSTRACT TRUNCATED AT 250 WORDS)

Endocardium↗
PubMed1986

Isolation of a cDNA clone for the human lysosomal proteinase cathepsin B.

The cysteine proteinase cathepsin B is one member of the lysosomal acid hydrolases. Based on the peptide sequence of rat liver cathepsin B, an oligonucleotide mixture containing 128 different 17-mers was synthesized and used as a probe to screen adult and fetal human liver cDNA libraries. A recombinant clone with a 1540-nucleotide insert was identified from the fetal library, and DNA sequence analysis confirmed that this clone encodes human cathepsin B. The clone, designated pCB-1, has sequences for 81% of the coding region (for amino acid residues 50-252) together with approximately equal to 880 nucleotides of the 3' untranslated region of the mRNA. The DNA sequence also shows that the predicted carboxyl terminus of the coding sequence is longer than the mature protein by 6 amino acid residues. Southern blot analysis of restriction enzyme digests of human placental DNA revealed a simple pattern of hybridizing fragments using the cathepsin B coding sequence as probe. The result suggests that there is a single copy of cathepsin B gene per haploid genome.

Amino Acid Sequence↗
PubMed1986

Kaposi's sarcoma: a comparative analysis in 17 white and 19 black patients.

Kaposi's sarcoma is a multicentric, malignant, neoplastic process that manifests itself as multiple vascular tumors. We present a comparative, retrospective analysis of demographic and survival data involving patients with Kaposi's sarcoma seen at Charity Hospital, New Orleans, over a 35-year period. The proportion of blacks and women is significantly higher than previously reported. Both blacks and men suffered relatively greater morbidity. In addition, the incidence of second primary malignancies in this group of patients is lower than previously reported.

Aged↗
PubMed1985

Kinetic studies of human erythrocyte membrane resealing.

Following lysis in hypotonic media, human erythrocyte membranes will spontaneously reseal and regain their original low permeability for polar solutes. It is generally accepted that resealing will only occur when the membranes are heated above a critical temperature, and that the membrane lesions are stable under cold conditions. Contrary to these prevailing notions, a detailed investigation of the temperature dependence of resealing kinetics over the temperature range 0-22 degrees C revealed that resealing occurs at measurable rates at temperatures as low as 0 degree C, even in buffers of low ionic strength. At all temperatures studied, initial resealing rates were approximately first-order, and Arrhenius plots of these rates revealed a sharp, singular discontinuity at approx. 7 degrees C.

Erythrocyte Membrane↗
PubMed1985

The interaction between radiation and complexes of cis-Pt(II) and Rh(II): studies at the molecular and cellular level.

A range of Rh(II) carboxylates and cis-Pt(II) complexes have been examined for their ability to increase the radiation sensitivity of aerobic and hypoxic V79 cells in vitro. The transition metal complexes sensitize in both air and nitrogen, with the greater effect generally occurring in nitrogen. The cis-Pt(II) complexes only show small levels of sensitization with dose modification factors (DMFs) of no more than 1.2. In contrast, the Rh(II) complexes can give DMFs of 2.0. Radiation chemical experiments show the transition metal complexes to have substantially lower redox potentials than metronidazole and, in addition, neither type of complex undergoes electron transfer reaction or adduct formation on interaction with radicals derived from DNA bases. Thus, the inorganic complexes do not operate by mechanisms similar to those occurring with electron affinic or stable free radical sensitizers. The increase in radiation sensitivity for cells treated with the Rh(II) carboxylates, but not the cis-Pt(II) complexes, is attributed to the ability of the Rh compounds to deplete intracellular thiols. Further, the efficiency of sensitization by the Rh(II) complexes and their ability to interact with cellular thiols depends upon the nature of the carboxylate ligand and follows the order butyrate greater than propionate greater than acetate greater than methoxyacetate. The differences between the carboxylates may be due to differences in drug uptake. A combination of the Rh(II) complexes with misonidazole given to hypoxic cells irradiated in vitro gives an additive response. However, it was not possible to demonstrate a similar effect in tumours in mice given the combination of Rh(II) methoxyacetate and the misonidazole analogue RSU 1070.

Animals↗
PubMed1984

Treatment of diffuse poorly differentiated lymphocytic lymphoma. An analysis of prognostic variables.

Forty patients with diffuse poorly differentiated lymphocytic lymphoma (DPDL) Stages II-IV were treated with three different and successive combination chemotherapy protocols. Seventeen patients were treated with the cyclophosphamide (CTX) L2 protocol which included maintenance chemotherapy for 3 years. Only three patients were treated with the NHL-3 (non-Hodgkin's lymphoma) protocol, and 20 patients received the NHL-5 program. All protocols included radiotherapy (1500-4800 rad) to areas of initial bulky disease or persistent tumor, as well as central nervous system (CNS) prophylaxis with intrathecal methotrexate in patients with bone marrow involvement. Seventy-eight percent of local recurrences occurred in previously irradiated areas. Two-year survival rates were 55% and 70% for the CTX-L2 and NHL-5 protocols, respectively. Median disease-free survival for 24 complete response (CR) patients was 16.5 months. Of the 40 patients, 37 were evaluable for response to therapy. The CTX-L2 produced an 80% total response (TR) rate, a 60% CR, and a 20% partial response (PR). The patients on the NHL-5 achieved a TR rate of 95%, 74% CR, and 21% PR. Differences in TR and CR between the two protocols were not significant. Only 1 of 3 patients on the NHL-3 protocol achieved a CR. There was a trend for age greater than 50 years to lessen the chances of CR (P = 0.091); however, sex, symptoms, stage of disease, and LDH level were not significantly related to CR rate. Response to treatment (CR versus PR versus failure) was the most important factor influencing survival (P less than 0.001); age (greater than 50 years) was also significant (P = 0.008). Lactate dehydrogenase (LDH) was of borderline significance (P = 0.06). Cox regression model showed age (greater than 50 versus less than 50 years, P = 0.001), LDH (greater than 500 versus less than or equal to 500 U/L, P = 0.019) and symptoms (A or B) to be the best predictors of survival.

Adult↗
PubMed1984

The dynamics of the coronary venous system in the dog.

The coronary vascular system is characterised by a small blood-volume, high resistance arterial system, in which flow is primarily diastolic, a capillary-venule exchange system and a large blood volume, low resistance venous system with predominantly systolic flow. In order to understand the venous component we measured intramyocardial pressure (IMP), peripheral (PVP) and central (CVP) coronary venous pressure, as well as phasic coronary sinus outflow. Based on the experimental data, a model is proposed to describe the hemodynamics of the coronary venous system. This model consists of an intramyocardial vascular storage region into which the arterial blood flows during diastole. During systole, the pressure in the storage vessels increases, pushing the peripheral and epicardial venous system. Blocking the inflow tends to empty the 'storage' and the peripheral regions, reducing venous pressures. Occlusion of the outflow increases the blood volume in these regions, elevating venous pressures. The observations of peak (IMP-PVP) vs peak venous flow during vagal, right abd left stellate stimulation conform satisfactorily with the model.

Animals↗
PubMed1984

Radiosensitization of mammalian cells by transition metal complexes containing nitroimidazole ligands.

Various transition metal complexes containing nitroimidazoles as ligands have been shown to act as radiosensitizers of hypoxic cells in vitro. Sensitization by cis-Pt(II)Cl2 (nitroimidazole)2 complexes is no greater than that which can be demonstrated by the free nitroimidazole ligand alone. These results differ from those previously described for the compound FLAP where an ER of 2.4 was obtained at a concentration of 50 microM. We report that, even using the same treatment technique, the maximum ER that can be achieved is 1.2. Further, the sensitizing efficiency of FLAP cannot be improved when cells are kept in contact with the compound for 12 hours in air prior to deoxygenation and irradiation. In contrast, Rh(II) complexes show much greater sensitization than can be obtained with the free ligand and these compounds are in turn more efficient sensitizers than the comparable Pt(II) complexes.

Animals↗