Biomedical subjects

D F Luo

Publications and source records attributed to D F Luo.

9 recordsLinked to original sources

PubMed1998

Halothane and isoflurane decrease alveolar epithelial fluid clearance in rats.

BACKGROUND: Active sodium transport is the primary mechanism that drives alveolar fluid clearance. In the current study, the effects of exposure to halothane and isoflurane on alveolar fluid clearance in rats were evaluated. METHODS: Rats were exposed to either halothane (0.4% for 6 h or 2% for 2 h) or isoflurane (0.6% for 6 h or 2.8% for 2 h). Reversibility of halothane effects was assessed after 2 h of exposure to 2% halothane. Alveolar and lung liquid clearance were measured by intratracheal instillation of a 5% albumin solution with 1.5 microCi of 125I-albumin, during mechanical ventilation with 100% FiO2 and the halogenated agent. The effect of terbutaline (10(-4) M) added to the albumin solution was tested after 2 h of exposure to 2% halothane. The increase in protein concentration in the airspaces over 1 h was used to evaluate alveolar liquid clearance. Lung liquid clearance was calculated gravimetrically. RESULTS: Alveolar liquid clearance rates were decreased by 24%, 30% and 40% compared with controls (P < 0.05) after 2 h of exposure to halothane, 6 h of exposure to halothane, and 6 h of exposure to isoflurane, respectively. After 2 h of exposure to isoflurane, alveolar liquid clearance did not change. In the 2-h halothane exposure group, alveolar liquid clearance returned to the control value 2 h after withdrawal of halothane. Terbutaline increased alveolar liquid clearance by 50% and 89% in the control and 2-h halothane exposure groups, respectively. In all experiments, the same results were obtained for alveolar and lung liquid clearance. CONCLUSIONS: Halothane and isoflurane caused a reversible decrease in alveolar epithelial fluid clearance. Two hours of exposure to halothane did not alter the stimulatory effect of terbutaline on alveolar liquid clearance.

Adrenergic beta-Agonists↗

PubMed1997

Insulin-dependent diabetes mellitus (IDDM) is associated with CTLA4 polymorphisms in multiple ethnic groups.

Linkage disequilibrium (association) analysis was used to evaluate a candidate region near the CTLA4/CD28 genes using a multi-ethnic collection of families with one or more children affected by IDDM. In the data set unique to this study (Spanish, French, Mexican-American, Chinese and Korean), the transmission/disequilibrium test (TDT) revealed a highly significant deviation for transmission of alleles at the (AT)n microsatellite marker in the 3' untranslated region (P = 0.002) and the A/G polymorphism in the first exon (P = 0.00002) of the CTLA4 gene. The overall evidence for transmission deviation of the CTLA4 A/G alleles is also highly significant (P = 0.00005) in the combined data set (669 multiplex and 357 simplex families) from this study and a previous report on families from USA, Italy, UK, Spain and Sardinia. Significant heterogeneity was observed in these data sets. The British, Sardinian and Chinese data sets did not show any deviation for the A/G polymorphism, while the Caucasian-American data set showed a weak transmission deviation. Strong deviation for transmission was seen in the three Mediterranean-European populations (Italian, Spanish and French) (P = 10(-5)), the Mexican-American population (P = 0.002) and the Korean population (P = 0.03). These results suggest that a true IDDM susceptibility locus (designated IDDM12) is located near CTLA4.

Abatacept↗

PubMed1997

Alveolar epithelial fluid clearance mechanisms are intact after moderate hyperoxic lung injury in rats.

The capacity of the alveolar epithelial barrier to remove excess alveolar fluid from the airspaces of the lung was studied in an experimental model of moderate hyperoxic lung injury. Rats were exposed to 100% oxygen for 40 h in an exposure chamber and compared with control animals exposed to room air. Extravascular lung water was calculated gravimetrically. Alveolar and lung liquid clearance were studied over 1 h by instillation of a 5% albumin solution with 1.5 microCi of 125I-labeled albumin (6 mL/kg into both lungs). The concentration of both the unlabeled and labeled albumin was used to calculate alveolar liquid clearance. Hyperoxic rats developed pulmonary edema, with a 33% increase in extravascular lung water to 5.3 +/- 0.1 g of water per gram of dry lung, compared with 4.0 +/- 0.2 g of water per gram of dry lung in control rats (p < 0.05). This degree of edema was associated with a significant increase in the alveolar-arterial oxygen difference (241 +/- 61 vs 124 +/- 14 mm Hg in control animals exposed to room air, p < 0.05). Despite this moderate degree of lung injury, alveolar fluid clearance was normal (30 +/- 3%) compared with control rats (33 +/- 6%). Furthermore, the hyperoxic injured rats responded normally to an exogenous beta-adrenergic agonist (terbutaline, 10(-4) mol/L) with a 67% increase in the rate of alveolar liquid clearance (50 +/- 5%). Thus, in the setting of moderate hyperoxic lung injury, the alveolar epithelial barrier is still capable of removing fluid at a normal rate and responding to beta-adrenergic agonist treatment. These experimental results have potential clinical implications for patients with acute lung injury.

Adrenergic beta-Agonists↗

PubMed1996

Paternally transmitted IDDM2 influences diabetes susceptibility despite biallelic expression of the insulin gene in human pancreas.

Whereas it is well known that the insulin gene (INS) region at 11p15.5 (IDDM2) confers susceptibility to insulin-dependent diabetes mellitus (IDDM), it is still controversial whether the parental origin of IDDM2 influences IDDM susceptibility. We have analysed the Pst I + 1127 polymorphism in 123 USA multiplex families and detected linkage only in male meioses using the affected sibpair analysis (P = 0.009). Application of the transmission/disequilibrium test (TDT) found significantly increased transmission of the IDDM-associated INS allele from fathers heterozygous for INS to their diabetic offspring (P = 0.00002), but the transmission from heterozygous mothers was not significantly different from random expectation. In non-diabetic families, the transmission from parents heterozygous for INS was not significantly different from random expectation in either paternal or maternal meioses. Maternal imprinting of the INS gene in pancreatic islets was originally considered the most favorable explanation for the observed gender-related difference. However, our study has demonstrated biallelic expression of INS in pancreatic tissues from the human fetuses and thus suggests that INS is probably not imprinted in the pancreatic islets.

Alleles↗

PubMed1996

Confirmation of three susceptibility genes to insulin-dependent diabetes mellitus: IDDM4, IDDM5 and IDDM8.

Previous genome-wide mapping studies have provided suggestive linkage evidence for several novel susceptibility loci responsible for insulin-dependent diabetes mellitus (IDDM); however, the evidence was not sufficient to confirm the existence of these genes. We analyzed 265 Caucasian families with IDDM and report the first evidence that meets the standard for confirmed linkage for three susceptibility loci. The maximum LOD scores (MLS) were 3.9, 4.5 and 3.6 in our data set, and 5.0, 4.6 and 5.0 for our data combined with non-overlapping data from the literature, for IDDM4 on chromosome 11q13, IDDM5 on 6q25, and IDDM8 on 6q27, respectively. However, we could not confirm linkage for IDDM3 on 15q26 and IDDM7 on 2q31-q33, or linkage disequilibrium between D2S152 and IDDM7.

Adult↗

PubMed1995

Intrafamilial and case-control association analysis of D2S152 in insulin-dependent diabetes.

We have performed intrafamilial and case-control association studies to examine the previously reported linkage disequilibrium between D2S152 and a type 1 diabetes susceptibility gene on chromosome 2q31-q33 (IDDM7). Significant linkage disequilibrium was observed in our subset of 47 Florida affected sibpair families (p < 0.02) but not in the other 57 USA families. We were not able to detect any significant associations between IDDM and D2S152 using case-control studies in a Caucasian data set of 270 unrelated diabetic patients and 370 normal controls ascertained from Florida, or in a Chinese data set of 90 patients and 169 normal controls. Our results suggest that linkage disequilibrium between IDDM7 and D2S152 must be very loose.

Alleles↗

PubMed1995

Affected-sib-pair mapping of a novel susceptibility gene to insulin-dependent diabetes mellitus (IDDM8) on chromosome 6q25-q27.

Affected-sib-pair analyses were performed using 104 Caucasian families to map genes that predispose to insulin-dependent diabetes mellitus (IDDM). We have obtained linkage evidence for D6S446 (maximum lod score [MLS] = 2.8) and for D6S264 (MLS = 2.0) on 6q25-q27. Together with a previously reported data set, linkage can be firmly established (MLS = 3.4 for D6S264), and the disease locus has been designated IDDM8. With analysis of independent families, we confirmed linkage evidence for the previously identified IDDM3 (15q) and DDM7 (2q). We also typed additional markers in the regions containing IDDM3, IDDM4, IDDM5, and IDDM8. Preliminary linkage evidence for a novel region on chromosome 4q (D4S1566) has been found in 47 Florida families (P < .03). We also found evidence of linkage for two regions previously identified as potential linkages in the Florida subset: D3S1303 on 3q (P < .04) and D7S486 on 7q (P < .03). We could not confirm linkage with eight other regions (D1S191, D1S412, D4S1604, D8S264, D8S556, D10S193, D13S158, and D18S64) previously identified as potential linkages.

Chromosome Mapping↗

PubMed1992

[Deafness, induced by sodium ethacrynate in guinea pigs, alleviated by microwave treatment].

Microwave is used to treat temporal hearing loss caused by intravenous injection of the ethacrynic acid in guinea pigs. The recovery of hearing is much faster in the treated groups than in the control group. The article proposes possible mechanism of the effects against the ethacrynic acid induced deafness and assume that the result of this research can provide an experimental basis for treatment of some perceptive deafness due to ischemia of stria vascularis of the cochlea.

Animals↗

PubMed1990

[Sulfur dioxide-induced bronchial constriction in asthmatics and its prophylaxis by salbutamol].

Patients with bronchial asthma often develop acute attack in kitchen while burning honeycomb briquet which is widely used for cooking in southern China. Burning of a honeycomb briquet produces 0.6-4.3 ppm sulphur dioxide (SO2) in the kitchen air. To assess whether the above concentration of SO2 can induce bronchial constriction, we performed SO2 bronchial provocation test on 21 asthmatics (male 11, female 10, average age 28.8 +/- 2.0 years), 10 patients with allergic rhinitis (male 3, female 7.28 +/- 1.6 years) and 20 healthy non-smokers (male 13, female 7, 28.1 +/- 1.5 years). FEV1 showed no significant change in both healthy and rhinitis group even a maximal amount of SO2 (10 ppm) was given. The calculated PC20 FEV1 and PC35 SGaW in asthmatics were 3.7 +/- 0.22 ppm and 2.5 +/- 0.18 ppm respectively, which fell into the SO2 range yielded by a burning honeycomb briquet. Orally administered slow release salbutamol created protective effect in 5 out of 8 patients. Salbutamol inhalation, however, completely blocked SO2 induced bronchial constriction. We suggest that patient with bronchial asthma should receive salbutamol aerosol inhalation before cooking with burning honeycomb briquet.

Administration, Inhalation↗