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Biomedical subjects

D T Lee

Publications and source records attributed to D T Lee.

At least 55 records · Page 3Linked to original sources
PubMed1996

Influence of water run training on the maintenance of aerobic performance.

The purpose of this study was to examine the effect of a 6-wk deep water running program on the maintenance of cardiorespiratory performance (VO2max, ventilatory threshold, running economy); metabolic measurements of blood glucose, blood lactate, and plasma norepinephrine; and body composition. Sixteen trained male runners (VO2max = 58.6 +/- 3.6 ml.kg-1.min-1) were assigned to one of two groups matched by VO2max, treadmill run (R) or water run (WR). Subjects participated in their respective training programs, which consisted of workouts of a) 30 min at 90-100% VO2max and b) 60 min at 70-75% VO2max alternated daily for 5 d.wk-1. Following 6 wk of workouts, no significant intra- or intergroup differences were observed for treadmill VO2max for R (pre = 58.4 +/- 2.3, post = 60.1 +/- 3.6 ml.kg-1.min) and WR (pre = 58.7 +/- 4.7, post = 59.6 +/- 5.4 ml.kg-1.min-1). Similarly, ventilatory threshold was unaltered in R (pre = 47.5 +/- 1.8, post = 48.2 +/- 3.3 ml.kg-1.min-1) and WR (pre = 46.5 +/- 6.4, post = 47.4 +/- 6.7 ml.kg-1.min-1), nor were there any changes in running economy in R (pre = 48.4 +/- 2.3, post = 48.9 +/- 2.0 ml.kg-1.min-1 at 255 m.min-1) and WR (pre = 51.8 +/- 2.0, post = 48.9 +/- 2.2 ml.kg-1.min-1 at 255 m.min-1). No significant differences were observed within or between groups for maximal blood glucose, blood lactate, and plasma norepinephrine concentration as well as for body composition indices. It was concluded that deep water running may serve as an effective training alternative to landbased running for the maintenance of aerobic performance for up to 6 wk in trained endurance athletes.

Analysis of Variance↗
PubMed1995

Exercise duration and thermoregulatory responses after whole body precooling.

Whole body precooling was hypothesized to reduce thermoregulatory and metabolic responses, thereby enhancing running time. Fourteen male runners completed two high-intensity running tests consisting of resting in 24 degrees C (normothermic condition; NC) or 5 degrees C (hypothermic condition; HC) for 30 min followed by 10-16 min of rest at 24 degrees C and then an exercise bout (24 degrees C) at 82% maximal aerobic capacity to exhaustion. Rectal temperature (Tre) before exercise was lower (by 0.37 degrees C; P < 0.005) and exercise duration was longer (by 121 +/- 24%; P < 0.05) in HC than in NC. Tre and mean skin (Tsk) and mean body (Tb) temperatures remained lower during HC (P < 0.01). Pre- and postexercise changes for Tsk, Tb, thermal gradient (Tre-Tsk), and heart rate (HR) were larger in HC than in NC (P < 0.05). Final Tre, Tre-Tsk, HR, and blood lactate were similar between HC and NC. During exercise, heat storage was greater (P < 0.01) in HC than in NC (173 +/- 46 and 143 +/- 38 W/m2, respectively) and subjects sweated more in NC than in HC (P < 0.01). O2 consumption was lower initially in HC than in NC (P < 0.05), but O2 pulse was not different. It was concluded that precooling results in greater exercise endurance with enhanced heat storage rate and less stress on metabolic and cardiovascular systems.

Adult↗
PubMed1993

Effects of calcium channel blockers on stimulation-induced changes in transmitter release at the frog neuromuscular junction.

We have examined the effects of various calcium channel blockers on stimulation-induced changes in end-plate potential (EPP) amplitude at the frog neuromuscular junction. We found that the addition of small concentrations (1-10 microM) of Cd2+ to the low calcium bathing Ringer reduced both the control EPP amplitude and the increase in EPP amplitude that normally occurs during repetitive stimulation under low quantal conditions. These effects of Cd2+, which developed rapidly following its addition to the bathing solution and were equally rapidly reversed, resulted from changes in the amount of transmitter released from the nerve terminal. The major effect of Cd2+ appeared to be on the facilitation and augmentation components of increased release. Cd2+ had little or no effect on potentiation of release. The other divalent cations tested, Zn2+, Co2+, and Ni2+, also decreased both control EPP amplitude and the stimulation-induced increase in EPP amplitude, but higher concentrations (> 100 microM) of these cations were required. The order of effectiveness in reducing stimulation-induced increases in EPP amplitude was: Cd2+ >>> Co2+,Zn2+ > Ni2+. The organic calcium channel blockers verapamil (20-100 microM) and nimodipine (20-50 microM) had little effect on stimulation-induced increases in EPP amplitude. The results of this study are consistent with previous suggestions that the different components of increased release represent different mechanisms. Furthermore, if Cd2+ is acting by reducing Ca2+ entry into the nerve terminal, then these results suggest that facilitation and augmentation are dependent in some way on Ca2+ entry.

Animals↗
PubMed1993

Systemic lupus erythematosus with pure red cell aplasia: a case report.

Pure red cell aplasia (PRCA) is an unusual early manifestation of systemic lupus erythematosus (SLE). Review of the 13 cases in literature revealed that the immune system played a significant role in disease pathogenesis. Immunosuppression has been thought to be the cause of the efficacy of corticosteroids in treatment. The case of a 28-year-old woman with SLE is described. She presented with PRCA, but has had good response to corticosteroid therapy.

Adrenal Cortex Hormones↗
PubMed1991

A unique human IgE-binding epitope on the Bermuda grass pollen recognized by mouse lambda-type monoclonal antibodies.

A group of six mouse monoclonal antibodies (MoAbs) with the unusual lambda-type light chain were generated by fusion of NS-1 cells with splenic cells derived from BALB/c mice immunized with crude extracts of Bermuda grass pollen (BGP). Four of them were IgG1, one was IgG2b, and one was IgG3. Binding inhibition assay showed that they recognized the same (or very similar) epitope. Using sera from BGP-allergic patients, it was found that the specific binding between the IgE antibodies and the MoAb 26-11-fixed antigen could be blocked by MoAb 26-11 itself and another MoAb 9-13 in a dose-dependent manner. It appears that the epitope recognized by the lambda-type MoAbs is a human IgE-binding antigenic determinant. Further physico-chemical analyses showed that this epitope was stable under heat but sensitive to treatments of sodium periodate and proteinase K. Results from these studies indicate that this unique epitope which leads to the generation of lambda-type MoAbs is part of a glycoprotein.

Animals↗
PubMed1991

Analysis of allergenic components of Bermuda grass pollen by monoclonal antibodies.

A panel of 16 monoclonal antibodies (MoAbs) directed against Bermuda grass (Cynodon dactylon) pollen (BGP) were generated for identification and purification of the major allergenic components of the eliciting antigen (Ag). Radioimmunoprecipitation (RIP) analysis revealed that there were at least eight antigenic components with molecular weights (MW) ranging from 12 kilodalton (12 kDa) to 200 kDa. Each of these components has distinct biochemical characteristics based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing (IEF). Among them, Cyn d Bd67K and Cyn d Bd58K were basic proteins, Cyn d Bd35K consisted of at least four isomeric components with isoelectric points ranging from 6.2 to 7.2. The other antigens (Cyn d Bd68K, 48K, 38K, Cyn d Bd200K, Cyn d Bd46K, Cyn d Bd25K and Cyn d Bd12K) were all acidic proteins. The IgE binding capacity of all these antigens was determined with sera from 11 BGP-allergics by using a modified radioallergosorbent test. All but one of the antigens (Cyn d Bd200K) were found to react with human IgE from sera of BGP-allergic patients. Among those human IgE-binding molecules, Cyn d Bd35K reacted with allergic sera most frequently (10 of 11), followed by Cyn d Bd58K (8 of 11) and Cyn d Bd46K (7 of 11) respectively. Our results suggest that Cyn d Bd35K, Cyn d Bd58K, and Cyn d Bd46K are major allergens of BGP, and the MoAbs we obtained should be valuable tools for further purification of these allergens.

Allergens↗
PubMed1988

Cockroach hypersensitivity: preliminary study of allergic cockroach asthma in Taiwan.

One hundred eight-two atopic patients were skin tested with cockroach antigen. Of these 182 patients, 54.9% gave positive immediate skin reaction by intracutaneous test. Among those atopic patients tested, 57.5% of patients with asthma and 50.7% of patients with allergic rhinitis were sensitive to cockroach extracts. The specific IgE antibody was determined by fluoroallergosorbent test. Of 79 cockroach-positive atopic patients, 39.2% were found to contain IgE antibodies against cockroach. No specific IgE was detected in cockroach-negative atopic and nonatopic subjects. Bronchial provocation test with cockroach antigen was performed on 15 subjects. Immediate asthmatic response was detected in six of nine cockroach-positive subjects with asthma. Two cockroach-negative subjects with asthma and four nonatopic subjects demonstrated no significant decrease in FEV1. The results indicate that cockroach induces antigen-specific IgE-mediated bronchial asthma, and cockroach is one of the major causes of allergic asthma.

Adolescent↗
PubMed1987

Bacterial interference by anaerobic species isolated from human feces.

Eighty-four anaerobic fecal isolates obtained from five healthy volunteers were tested for their ability to inhibit in vitro growth of eight species of Enterobacteriaceae, four species of faculative gram-positive cocci, and Pseudomonas aeruginosa. Forty-nine of the 84 anaerobic isolates (58%) inhibited the growth of at least one indicator bacterium. Isolates of Bacteroides and Bifidobacterium spp. were most consistently inhibitory. Anaerobic cocci and clostridia were infrequently inhibitory; eubacteria showed no inhibitory activity. Serratia marcescens was the indicator most often inhibited; 54% of all anaerobic isolates tested, all of nine Bifidobacterium isolates and 33 of 43 Bacteroides isolates inhibited this organism. No anaerobes inhibited the growth of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Citrobacter freundii, Citrobacter diversus or Streptococcus faecalis.

Adult↗
PubMed1986

Evaluation of the AnIdent system for the identification of anaerobic bacteria.

AnIdent is a new 4-hr system for the identification of anaerobic bacteria that depends upon detection of a unique set of preformed enzymes. A single AnIdent test speciated 76% of 333 anaerobes (89% agreement with a conventional system used at the Mayo Anaerobe Laboratory) without any repeat or supplemental testing (level 1). Additional testing increased the identification rate to 93% (level 2). We conclude that AnIdent is a reliable method for identifying clinically significant anaerobes which only occasionally requires the use of a small number of simple supplemental tests and avoids the necessity for performing gas-liquid chromatography.

Bacteria, Anaerobic↗
PubMed1986

Comparison of clindamycin, metronidazole, and penicillin for the treatment of experimental infections in mice caused by beta-lactamase-producing Bacteroides intermedius.

Turbid saline suspensions (0.35 ml, approximately 10(9) organisms) of a strain of beta-lactamase-producing Bacteroides intermedius were injected subcutaneously into the right groin of ICR male mice. Therapeutic intraperitoneal doses of clindamycin, metronidazole, or penicillin were administered 4 hr later, and thereafter at successive 8-hr intervals for a total of 12 doses. Necropsy with culture of the infection site was performed 4 hr after the final dose. None of 10 clindamycin-treated animals and none of 10 metronidazole-treated animals developed abscesses, and all cultures taken from the injection sites were sterile. Eight of 10 (80%) penicillin-treated animals developed subcutaneous abscesses; B. intermedius was recovered in pure cultures from all abscesses at necropsy. Nine of 10 (90%) untreated control animals inoculated with the same beta-lactamase-producing B. intermedius strain developed abscesses, all of which were culture-positive. The data indicate that treatment with clindamycin and metronidazole prevented the formation of subcutaneous abscesses in mice inoculated with a beta-lactamase-producing strain of B. intermedius. On the other hand, penicillin failed to prevent the formation of abscesses, 80% of which grew the inoculated organism.

Abscess↗
PubMed1983

A comparison of four methods for detecting beta-lactamase in anaerobic bacteria.

Four methods for detecting beta-lactamase activity in anaerobic bacteria were evaluated and compared to a nitrocefin saturated filter paper test. The methods studied were Cefinase, PADAC, Beta Lactam, and the slide iodometric technique. Fifty anaerobes were tested including species of Bacteroides, Fusobacterium, and Clostridium. The percentages of agreement with the nitrocefin test are: Cefinase 100%, PADAC 96%, slide iodometric 78%, and Beta Lactam 72%. Positive nitrocefin tests have been shown to correlate with a penicillin MIC greater than 0.78 micrograms/ml.

Bacteria, Anaerobic↗
PubMed1982

Recent experience with antimicrobial susceptibility of anaerobic bacteria: increasing resistance to penicillin.

Results of antimicrobial susceptibility testing of anaerobes were reviewed for the last 5 years and compared with two previous surveys from this institution. Allowing for differences in methodology, there appears to be a striking increase in penicillin resistance by the "non-fragilis" Bacteroides. Penicillin concentrations of 50 microgram/ml were required to inhibit 70% of 43 strains tested. The clinical implications of this observation are not known, but isolated reports of therapeutic failure when penicillin was used against the non-fragilis Bacteroides have appeared. Penicillin resistance among Clostridium other than C. perfringens was also noted in the current study. Several strains of clindamycin-resistant Bacteroides fragilis have been observed during the last 2 years, and whether this represents a true increase in resistance will require close scrutiny of clindamycin susceptibility in the future. Future surveillance of antimicrobial susceptibility of anaerobic bacteria will be useful in the detection of any major changes in susceptibility profiles. This knowledge will potentially affect the choice of antimicrobial agent in patients with serious infections caused by anaerobes.

Anti-Bacterial Agents↗
PubMed1979

Laboratory-based surveillance of influenza virus in the United States during the winter of 1977--1978. II. Isolation of a mixture of A/Victoria- and A/USSR-like viruses from a single person during an epidemic in Wyoming, USA, January 1978.

At a time when outbreaks and sporadic cases of influenza caused a A/Victoria/3/75-like and A/Texas/1/77-like H3N2 strain of influenza were occurring in the Rocky Mountain region of the USA, about 60% of the students of a high school in Cheyenne, Wyoming, were involved in an outbreak of influenza-like illness. Six influenza A(H1N1) virus isolates were obtained from throat swabs collected from 12 of these students. Virus isolated from a seventh student, however, contained a mixture of H1 and H3 (A/Victoria/3/75-like) hemagglutinins and N1 and N2 neuraminidases, as shown by the ability to clone from the mixture viruses with antigenic components H1N1, H3N1, and H3N2. An antigenic hybrid virus with H3N1 composition was re-isolated from the original throat swab. The results show that one student was shedding a mixture of A/Victoria/3/75(H3N2)-like and A/USSR/90/77(H1N1)-like viruses at the time his throat swab was taken.

Adolescent↗