Biomedical subjects

M Lee

Publications and source records attributed to M Lee.

At least 163 records · Page 9Linked to original sources

PubMed2001

Forearm vasoreactivity in type 1diabetic subjects.

This study compared forearm vasoreactivity in 15 Type I diabetic subjects with 15 healthy controls. The groups were matched for age, exercise capacity, and the absence of other cardiovascular risk factors. Vasoreactivity was measured using strain gauge plethysmography, at rest, after arterial occlusion (OCC), and following OCC coupled with handgrip exercise (ROCC). Forearm blood flows were significantly elevated between conditions 2.58 +/- 0.37ml/100mltissue at rest to 26.80 +/- 6.56 after OCC and 32.80 +/- 8.26ml/100mltissue following ROCC in Type I diabetic subjects. There were no differences in forearm blood flow between groups for any of the conditions. These data indicate the degree of forearm blood flow is directly related to the intensity of the vasodilatory stimulus. However, our study did not reveal evidence of impaired vasodilatory capacity in Type I diabetic subjects compared to controls in the absence of other risk factors.

Adult↗

PubMed2001

Effects of clenbuterol on insulin resistance in conscious obese Zucker rats.

The present study was conducted to determine the effect of chronic administration of the long-acting beta(2)-adrenergic agonist clenbuterol on rats that are genetically prone to insulin resistance and impaired glucose tolerance. Obese Zucker rats (fa/fa) were given 1 mg/kg of clenbuterol by oral intubation daily for 5 wk. Controls received an equivalent volume of water according to the same schedule. At the end of the treatment, rats were catheterized for euglycemic-hyperinsulinemic (15 mU insulin. kg(-1). min(-1)) clamping. Clenbuterol did not change body weight compared with the control group but caused a redistribution of body weight: leg muscle weights increased, and abdominal fat weight decreased. The glucose infusion rate needed to maintain euglycemia and the rate of glucose disappearance were greater in the clenbuterol-treated rats. Furthermore, plasma insulin levels were decreased, and the rate of glucose uptake into hindlimb muscles and abdominal fat was increased in the clenbuterol-treated rats. This increased rate of glucose uptake was accompanied by a parallel increase in the rate of glycogen synthesis. The increase in muscle glucose uptake could not be ascribed to an increase in the glucose transport protein GLUT-4 in clenbuterol-treated rats. We conclude that chronic clenbuterol treatment reduces the insulin resistance of the obese Zucker rat by increasing insulin-stimulated muscle and adipose tissue glucose uptake. The improvements noted may be related to the repartitioning of body weight between tissues.

Adrenergic beta-Agonists↗

PubMed2001

7-Nitroindazole, but not aminoguanidine, attenuates the acute inflammatory responses and brain injury during the early phase of Escherichia coli meningitis in the newborn piglet.

We evaluated the anti-inflammatory and neuroprotective effects of the selective neuronal nitric oxide synthase inhibitor 7-nitroindazole and aminoguanidine, which predominantly inhibits inducible nitric oxide synthase, during the early phase of experimental bacterial meningitis in the newborn piglet. Meningitis was induced by intracisternal injection of 10(8) colony-forming units of Escherichia coli in 100 microl of saline. 7-Nitroindazole significantly attenuated the meningitis-induced acute inflammatory responses such as increased intracranial pressure, decreased cerebrospinal fluid (CSF) glucose concentration, and CSF leukocytosis at 2 h. However, meningitis-induced CSF leukocytosis at 4 h and increased CSF lactate and tumor necrosis factor alpha levels were not significantly attenuated. Reduced cerebral cortical cell membrane Na(+),K(+)-ATPase activity and increased lipid peroxidation products, indicative of meningitis-induced brain cell membrane dysfunction, were also significantly improved with 7-nitroindazole treatment. In contrast, although aminoguanidine significantly attenuated the increase in the CSF tumor necrosis factor alpha level, it failed to attenuate the acute inflammation and the ensuing brain injury in bacterial meningitis. In summary, 7-nitroindazole, but not aminoguanidine, significantly attenuated the acute inflammatory responses and brain injury during the early phase of neonatal bacterial meningitis.

Animals↗

PubMed2001

Effect of grapefruit juice on pharmacokinetics of microemulsion cyclosporine in African American subjects compared with Caucasian subjects: does ethnic difference matter?

This study aims to determine the effect of grapefruit juice (GJ) on microemulsion cyclosporine (CsA) in 11 African American subjects, and it was compared to those in 11 Caucasian subjects. Each subject received two oral doses of CsA with water (W) or GI as well as i.v. CsA. Regardless of race, GJ significantly increased the peak concentration (Cmax) and area under the time-curve (AUC) of CsA; however, the magnitude of GJ effects was different between African American subjects and Caucasian subjects (p = 0.0003). GJ increased peak concentration of CsA by 39% in African American subjects, while the difference in Caucasian subjects was only 8% (p > 0.05). GJ also increased AUC of CsA in African American subjects by 60%, while GJ increased that in Caucasian subjects by 44% (p = 0.0001). The absolute bioavailability of CsA was 21% lower in African American subjects compared with Caucasian subjects when it was given with water (p = 0.048), but these differences disappeared when it was given with GJ (p = 0.6). These findings suggest that concurrent administration of GJ increases the bioavailability of CsA in African American subjects in greater magnitude compared with Caucasian subjects.

Adolescent↗

PubMed2001

The fetal origins of disease hypothesis: public health implications for the Asia-Pacific region.

There has been rapid development in the Asia-Pacific region, leading to improvements in the food supply and nutrition. The high prevalence of low birth weight has been a problem in many countries and continues to be a problem in some parts of the region. In the past few years an epidemic of obesity and chronic disease has emerged. The fetal origins hypothesis links the high prevalence of low birth weight and recent increasing obesity to explain the emerging epidemic of chronic disease. One public health strategy to challenge this epidemic is the promotion of breastfeeding of all infants. Breastfeeding has been shown to protect against childhood obesity, and is "dose related", that is, the longer an infant is breastfed, the lower the risk of obesity.

Asia, Southeastern↗

PubMed2001

3-Aminobenzamide, a poly (ADP-ribose) synthetase inhibitor, attenuates the acute inflammatory responses and brain injury in experimental Escherichia coli meningitis in the newborn piglet.

The aim of the present study was to evaluate the anti-inflammatory and neuroprotective effects of a poly (ADP-ribose) synthetase inhibitor 3-aminobenzamide during the early phase of experimental bacterial meningitis in the newborn piglet. Meningitis was induced by intracisternal injection of 10(8) colony forming units of Escherichia coli in 100 microl of saline. 3-Aminobenzamide, given 30 mg kg(-1) as a bolus i.v. injection 30 min before induction of meningitis, significantly attenuated the meningitis-induced acute inflammatory responses such as increased cerebrospinal fluid (CSF) lactate concentration, CSF leukocytosis and increased CSF tumor necrosis factor-alpha level. However, meningitis-induced increase in intracranial pressure and decrease in CSF glucose level were not significantly improved. Increased cerebral cortical cell membrane lipid peroxidation products (conjugated dienes) and decreased brain ATP/phosphocreatine levels observed in the meningitis group were also significantly improved with 3-aminobenzamide treatment. However, the improvement of reduced Na+, K+-ATPase activity did not reach a statistical significance (p = 0.06). In summary, 3-aminobenzamide significantly attenuated the acute inflammatory responses and the ensuing brain injury during the early phase of neonatal bacterial meningitis. These findings suggest that poly (ADP-ribose) synthetase inhibitors such as 3-aminobenzamide might be a promising novel anti-inflammatory and neuroprotective adjuvant therapy in neonatal bacterial meningitis.

Acute Disease↗

PubMed2001

N(omega) -nitro-L-arginine methyl ester (L-NAME) attenuates the acute inflammatory responses and brain injury during the early phase of experimental Escherichia coli meningitis in the newborn piglet.

We evaluated the anti-inflammatory and neuroprotective effect of nonselective NOS inhibitor, N(omega)-nitro-L-arginine methyl ester (L-NAME), in experimental bacterial meningitis in the newborn piglet. Meningitis was induced by intracisternal injection of 10(8) colony forming units of Escherichia coli. L-NAME 10 mg kg(-1) was given intravenously 30 min before induction of meningitis. L-NAME significantly attenuated the increase in intracranial pressure and decrease in cerebrospinal fluid glucose concentration observed in the meningitis group. Systemic and cerebral perfusion pressure were even higher compared to the control and meningitis groups. However, the meningitis-induced increase in tumor necrosis factor-alpha level, leukocyte numbers and lactate level in the cerebrospinal fluid was not significantly attenuated with L-NAME administration. Reduced cerebral cortical cell membrane Na+, K+ -ATPase activity and increased lipid peroxidation products, indicative of meningitis-induced brain cell membrane dysfunction, were significantly improved with L-NAME treatment. Decreased brain glucose and ATP levels were also significantly improved with L-NAME treatment. These findings suggest that L-NAME was effective in attenuating the acute inflammatory responses and brain injury in neonatal bacterial meningitis.

Animals↗

PubMed2001

Dietary calcium consumption and astrocytic glioma: the San Francisco Bay Area Adult Glioma Study, 1991-1995.

Previous studies suggest an association between calcium consumption and glioma risk. In the present study, we compare consumption of calcium and other dairy components and foods (cholesterol, fat, protein, calories, milk, and cheese) of 337 astrocytic glioma case patients with 450 controls from the San Francisco Bay Area Adult Glioma Study, 1991-1995. We use unconditional logistic regression models to estimate odds ratios (ORs) by gender controlling for age, education, and income. A statistically significant inverse association [p (trend) = 0.05] was observed for dietary calcium intake for women only [OR = 0.49, 95% confidence interval (CI) = 0.24-1.03 for highest vs. lowest quartile of consumption]. In addition, we observed elevated ORs for highest vs. lowest quartiles of cholesterol intake among women and men (OR = 2.07, 95% CI = 1.00-4.28 and OR = 1.75, 95% CI = 0.92-3.31, respectively). Calcium may exert a protective effect through its known roles in apoptosis, DNA repair, and inhibition of parathyroid hormone production. Recent evidence suggests that parathyroid hormone may influence growth and dedifferentiation of astrocytoma cells. Finally, circulating estradiol might directly stimulate intestinal absorption of calcium and may therefore explain why the inverse association of calcium intake and glioma is confined to women.

Adult↗

PubMed2001

Variation in health and risk behavior among youth living with HIV.

Lifetime and current health practices and risk behaviors were examined among 350 youth living with HIV (YLH) aged 14-23 years from four AIDS epicenters (72.6% male; 26.2% African American, 36.9% Latino). YLH were relatively healthy (M CD4 cells = 499), had used substantial health care and were satisfied with the care. YLH's sexual and substance-use histories indicated substantial HIV related risk acts: the median number of lifetime partners was 25 with only 8% using condoms consistently; 14.9% had injected drugs, and 61.2% had used hard drugs. Compared with females, males had more lifetime and recent sexual partners and had used more drugs. Youth who were recently sexually active (81.3%) had multiple partners. Most of the sexually active YLH used condoms consistently (81.6%). YLH who were symptomatic or had an AIDS diagnosis were likely to have recently had more seropositive sexual partners than the asymptomatic youth. Youth disclosed their serostatus to about half of their sexual partners (53.9%). YLH with AIDS used fewer hard drugs than those without an AIDS diagnosis. Health and risk behaviors of the YLH varied significantly based on their disease stage, gender, and ethnicity, suggesting the need for tailoring interventions for subgroups of YLH.

Adolescent↗

PubMed2001

Challenges associated with increased survival among parents living with HIV.

OBJECTIVES: This study examined sociodemographic and psychosocial factors that predict survival among parents living with HIV. METHODS: Parents with HIV (n = 307) were recruited from 1993 to 1995 in New York City and repeatedly assessed. Survival was monitored among the sample (81% mothers; 45% Latino, 34% African American). RESULTS: Over a median period of 28 months (range = 0-53 months), 44% (n = 135) of the parents died. Having an AIDS diagnosis and being African American were associated with earlier death. Sex, age, and financial status were not related to survival. Parents who survived had initially higher levels of anxiety that decreased over time; in contrast, parents who died reported initially lower, but constant, levels of anxiety over time. After HIV diagnostic status was controlled for, it was found that parents who reported having more children, using a coping style of seeking social support, and being sexually active at baseline survived longer. CONCLUSIONS: The counterintuitive findings raise hypotheses regarding the role of change and responsibilities in the survival of parents with HIV.

Adaptation, Psychological↗

PubMed2001

Effect of hypothermia on brain cell membrane function and energy metabolism after transient global hypoxia-ischemia in the newborn piglet.

This study was done to determine the effects of hypothermia on brain cell membrane function and energy metabolism after transient hypoxia-ischemia (HI) in the newborn piglet. Cerebral HI was induced by temporarily complete occlusion of bilateral common carotid arteries with surgical clips and simultaneous breathing with 8% oxygen for 30 min, followed by release of carotid occlusion and normoxic ventilation for 4 hr. Rectal temperature was maintained between 38.0 and 39.0 degrees C in normothermic groups, and between 34.0 and 35.0 degrees C in hypothermic groups for 4 hr after HI. During HI, heart rate, glucose and lactate level in the blood and cerebrospinal fluid increased, and base excess, pH and blood pressure decreased significantly in both normothermic and hypothermic groups. After HI, these abnormalities returned to normal in normothermic group, but lactic acidosis persisted in hypothermic group. Decreased cerebral Na+,K+- ATPase activity and increased lipid peroxidation products, indicative of HI- induced brain injury, were more profound in hypothermic group than in normothermic group. Brain ATP and phosphocreatine levels were not different between normothermic and hypothermic groups. In summary, hypothermia applied immediately after HI for 4 hr did not improve the recovery of brain cell membrane function and energy metabolism in the newborn piglet.

Animals↗

PubMed2001

The impact of age on delivered dose intensity and hospitalizations for febrile neutropenia in patients with intermediate-grade non-Hodgkin's lymphoma receiving initial CHOP chemotherapy: a risk factor analysis.

The purpose of this historical case series study was to evaluate the association of age on delivered dose intensity of initial CHOP (cyclophosphamide/doxorubicin/ vincristine/prednisone) chemotherapy and the occurrence of hospitalizations for febrile neutropenia for patients with intermediate-grade non-Hodgkin's lymphoma (NHL). Findings are reported for 12 managed community and academic practices. Medical records of 930 NHL patients not enrolled on clinical trial protocols were reviewed. We reported on 577 of the study patients (62%) who received initial CHOP chemotherapy. Median age of the patients was 65.1 years. Older patients (age > or = 65 years) had more hospitalizations for febrile neutropenia (28% vs. 16%; P < 0.05) than younger patients (age, 18-64 years). In patients with advanced-stage NHL (stage III/IV), older patients received fewer cycles of CHOP (< 6 cycles, 35% vs. 22%; P < 0.05) than younger patients. Older patients were planned for lower average relative dose intensity (ARDI < or = 80%; P < 0.05) and had more heart disease and comorbid conditions (P < 0.05) than younger patients. Multiple logistic regression models showed that older patients were more likely to receive a lower dose intensity (ARDI < or = 80%; odds ratio = 2.46, 95% confidence interval [CI]: 1.62-3.72) during their first 3 cycles of therapy and to experience more hospitalizations for febrile neutropenia (odds ratio = 2.17, 95% CI: 1.43-3.30). We found the dose intensity of delivered CHOP chemotherapy for elderly patients to be less than standard CHOP therapy and the risk of hospitalizations for febrile neutropenia to be greater than in younger patients. Prospective clinical trials examining supportive care measures, such as colony-stimulating factor, for elderly NHL patients are recommended.

Adult↗

PubMed2001

Pyogenic liver abscesses due to Klebsiella pneumoniae in a diabetic patient.

Pyogenic liver abscess due to Klebsiella pneumoniae is a rare clinical entity. It has emerged as an important infection complication in diabetics and its incidence in diabetics without intraabdominal or biliary tract infections is increasing. We present herein a case of multiple pyogenic liver abscesses due to K. pneumoniae in a diabetic patient and discuss clinical course, treatment and possible reasons for association between K. pneumoniae liver abscess and diabetes.

Diabetic Ketoacidosis↗

PubMed2001

Identification of a transcription factor, an 80-kDa protein that interacts with the HLH recognition motif of the rat p53 promoter.

The p53 promoter has been shown to contain a number of potential regulatory motifs. It was previously reported that the upstream stimulating factor (USF) played a central role in regulating the p53 expression. The USF binding site, E-box, is located around 40 bp upstream of the major transcription start site. In this study, it was confirmed that the E-box binds to proteins by DNase I footprinting assay. In the electrophoretic mobility shift assay (EMSA), two retarded bands were detected. One band was abolished by the competition of USF consensus oligonucleotide, but the other band was not. This result indicated that a factor, other than USF, was bound to the E-box. The molecular masses of the binding proteins were determined by a Southwestern-blotting assay. As a result, 46- and 80-kDa proteins were detected. The 46-kDa protein was eliminated by the competition of USF consensus oligonucleotide. Also, the Southwestern-blotting assay with 32P-labeled USF consensus oligonucleotide showed only a 46-kDa protein. Therefore, the 46-kDa protein was USF. These results showed that USF and the 80-kDa protein were bound to the E-box. In addition, it was proved by in vitro transcription assay that this 80-kDa protein had a basal transcriptional activity.

Animals↗

PubMed2001

A restriction fragment length polymorphism based linkage map of a diploid Avena recombinant inbred line population.

A population of 100 F6-derived recombinant inbred lines was developed from the cross of two diploid (2n = 14) Avena accessions, CI3815 (A. strigosa) and C11994 (A. wiestii). Restriction fragment length polymorphism (RFLP) probes previously mapped in other grass species were used to develop a framework linkage map suitable for comparative genetics. Nine linkage groups were identified among the 181 loci mapped, with an average interlocus distance of 5 cM, and a total genetic map length of 880 cM. A cluster of five tightly linked crown rust resistance genes (Pca) was localized on the map, as were five loci identified by disease resistance gene analogs from maize, sorghum, and wheat. None of the five loci identified by the gene analogs were linked to the Pca locus. The linkage map was compared with previously published diploid and hexaploid linkage maps in an attempt to identify homologous or homoeologous chromosomes between populations. Locus orders and linkage relationships were poorly conserved between the A. strigosa x A. wiestii map and other Avena maps. In spite of mapping complications due to duplications within a basic genome a well as the allopolyploid constitution of many Avena species, such map comparisons within Avena provide further evi dence of substantial chromosomal rearrangement between species within Avena.

Avena↗

PubMed2001

A linkage map of hexaploid oat based on grass anchor DNA clones and its relationship to other oat maps.

A cultivated oat linkage map was developed using a recombinant inbred population of 136 F6:7 lines from the cross 'Ogle' x 'TAM O-301'. A total of 441 marker loci, including 355 restriction fragment length polymorphism (RFLP) markers, 40 amplified fragment length polymorphisms (AFLPs), 22 random amplified polymorphic DNAs (RAPDs), 7 sequence-tagged sites (STSs), 1 simple sequence repeat (SSR), 12 isozyme loci, and 4 discrete morphological traits, was mapped. Fifteen loci remained unlinked, and 426 loci produced 34 linkage groups (with 2-43 loci each) spanning 2049 cM of the oat genome (from 4.2 to 174.0 cM per group). Comparisons with other Avena maps revealed 35 genome regions syntenic between hexaploid maps and 16-34 regions conserved between diploid and hexaploid maps. Those portions of hexaploid oat maps that could be compared were completely conserved. Considerable conservation of diploid genome regions on the hexaploid map also was observed (89-95%); however, at the whole-chromosome level, colinearity was much lower. Comparisons among linkage groups, both within and among Avena mapping populations, revealed several putative homoeologous linkage group sets as well as some linkage groups composed of segments from different homoeologous groups. The relationships between many Avena linkage groups remain uncertain, however, due to incomplete coverage by comparative markers and to complications introduced by genomic duplications and rearrangements.

Avena↗

PubMed2001

Successful treatment of endobronchial amyloidosis using Nd:YAG laser therapy as an alternative to lobectomy.

Endobronchial amyloidosis may cause local obstruction associated with a variety of clinical presentations including recurrent respiratory infection. Although some patients may require surgical intervention, encouraging experience with endobronchial Neodymium (Nd):YAG laser therapy in the management of this condition is reported. Two patients with localized endobronchial amyloidosis were treated with endobronchial Nd:YAG laser therapy. One patient received two treatments for right upper lobe amyloid and another patient received three treatments for right lower lobe amyloid. Excellent clearance of amyloid was achieved in each patient. The first patient remains well, 16 months post-treatment with full patency of the apical and posterior segments. Ten months post-treatment, the second patient has full patency of the right lower lobe. No complications occurred in association with Nd:YAG laser therapy. Endobronchial Neodymium:YAG laser treatment should be considered for selected patients with localized endobronchial obstruction due to amyloidosis.

Airway Obstruction↗

PubMed2001

Iodine and thyroid cancer risk among women in a multiethnic population: the Bay Area Thyroid Cancer Study.

Research on the relationship between iodine exposure and thyroid cancer risk is limited, and the findings are inconclusive. In most studies, fish/shellfish consumption has been used as a proxy measure of iodine exposure. The present study extends this research by quantifying dietary iodine exposure as well as incorporating a biomarker of long-term (1 year) exposure, i.e., from toenail clippings. This study is conducted in a multiethnic population with a wide variation in thyroid cancer incidence rates and substantial diversity in exposure. Women, ages 20-74, residing in the San Francisco Bay Area and diagnosed with thyroid cancer between 1995 and 1998 (1992-1998 for Asian women) were compared with women selected from the general population via random digit dialing. Interviews were conducted in six languages with 608 cases and 558 controls. The established risk factors for thyroid cancer were found to increase risk in this population: radiation to the head/neck [odds ratio (OR), 2.3; 95% confidence interval (CI), 0.97-5.5]; history of goiter/nodules (OR, 3.7; 95% CI, 2.5-5.6); and a family history of proliferative thyroid disease (OR, 2.5; 95% CI, 1.6-3.8). Contrary to our hypothesis, increased dietary iodine, most likely related to the use of multivitamin pills, was associated with a reduced risk of papillary thyroid cancer. This risk reduction was observed in "low-risk" women (i.e., women without any of the three established risk factors noted above; OR, 0.53; 95% CI, 0.33-0.85) but not in "high-risk" women, among whom a slight elevation in risk was seen (OR, 1.4; 95% CI, 0.56-3.4). However, no association with risk was observed in either group when the biomarker of exposure was evaluated. In addition, no ethnic differences in risk were observed. The authors conclude that iodine exposure appears to have, at most, a weak effect on the risk of papillary thyroid cancer.

Adult↗