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Biomedical subjects

K M Leung

Publications and source records attributed to K M Leung.

At least 19 recordsLinked to original sources
PubMed2006

Inhibitors of inducible nitric oxide (NO) synthase are more effective than an NO donor in reducing carbon-tetrachloride induced acute liver injury.

The exact functional role of nitric oxide (NO) in liver injury is currently a source of controversy. NO is enzymatically synthesized by nitric oxide synthase (NOS). In this study, we assessed the role of inducible NOS (iNOS) in carbon tetrachloride (CCl4)-induced acute liver injury using inhibitors of iNOS, and an NO donor. Adult ICR mice were injected with CCl4 with or without the iNOS inhibitors (5-methylisothiourea hemisulfate [SMT] and l-N6-(1-iminoethyl)-lysine [L-NIL]) and an NO donor (Sodium Nitroprusside [SNP]). Blood and liver tissues were collected for analysis. Immunohistochemistry (IHC), serum alanine aminotransferase (ALT), serum total 8-isoprostane analysis, RT-PCR, Western Blotting (WB) and EMSA were done. Our results showed increased levels of ALT, necrosis, total 8-isoprostane and nitrotyrosine after CCl4 administration. iNOS inhibitors and SNP abrogated these effects but the effect was more pronounced with SMT and L-NIL. RT-PCR, WB and IHC in CCl4-treated mice demonstrated upregulation of TNF-alpha, iNOS, and COX-2. The administration of iNOS inhibitors with CCl4 diminished the expression of these proinflammatory mediators. NF-kappaB was also upregulated in CCl4-treated mice and was reversed in mice pretreated with iNOS inhibitors. SNP pretreated mice also showed a lower expression of COX-2 when compared with CCl4 treated mice but TNF-alpha, iNOS and NF-kappaB activity were unaffected. We propose that a high level of nitric oxide is associated with CCl4-induced acute liver injury and the liver injury can be ameliorated by decreasing the NO level with iNOS inhibitors and an NO donor with the former more effective in reducing CCl4-induced liver injury.

Alanine Transaminase↗
PubMed2004

Expression of phosphacan and neurocan during early development of mouse retinofugal pathway.

We have investigated whether the two major brain chondroitin sulfate (CS) proteoglycans (PGs), phosphacan and neurocan, are expressed in patterns that correlate to the axon order changes in the mouse retinofugal pathway. Expression of these proteoglycans was examined by polyclonal antibodies against phosphacan and N- and C-terminal fragments of neurocan. In E13-E15 mouse embryos, when most optic axons grow in the chiasm and the optic tract, phosphacan and neurocan were observed in the inner regions of the retina. In the chiasm and the tract, phosphacan but not neurocan was expressed prominently at the midline and in the deep parts of the tract. Both proteoglycans were observed on the chiasmatic neurons, which have been shown to regulate axon divergence at the chiasmatic midline and the chronotopic fiber ordering in the tract, but phosphacan appeared to be the predominant form that persists to later developmental stages. Intense staining of both proteoglycans was also observed in a strip of glial-like elements in lateral regions of the chiasm, partitioning axons in the stalk from those in the tract. We conclude that phosphacan but not neurocan is likely the major carrier of the CS glycosaminoglycans that play crucial functions in axon divergence and age-related axon ordering in the mouse optic pathway. Furthermore, localization of these carrier proteins in the optic pathway raises a possibility that these two proteoglycans regulate axon growth and patterning not only through the sulfated sugars but also by interactions of the protein parts with guidance molecules on the optic axons.

Animals↗
PubMed2004

HAb18G/CD147-mediated calcium mobilization and hepatoma metastasis require both C-terminal and N-terminal domains.

HAb18G/CD147 is a heavily glycosylated protein containing two immunoglobulin superfamily domains. Our previous studies have indicated that overexpression of HAb18G/CD147 enhances metastatic potentials in human hepatoma cells by disrupting the regulation of store-operated Ca2+ entry by nitric oxide (NO)/cGMP. In the present study, we investigated the structure-function of HAb18G/CD147 by transfecting truncated HAb18G/CD147 fragments into human 7721 hepatoma cells. The inhibitory effect of HAb18G/CD147 on 8-bromo-cGMP-regulated thapsigargin-induced Ca2+ entry was reversed by the expression of either C or N terminus truncated HAb18G/CD147 in T7721deltaC and T7721deltaN cells, respectively. The potential effect of HAb18G/CD147 on metastatic potentials, both adhesion and invasion capacities, of hepatoma cells was abolished in T7721deltaC cells, but not affected in T7721deltaN cells. Release and activation of matrix metalloproteinases (MMPs), MMP-2 and MMP-9, were found to be enhanced by the expression of HAb18G/CD147, and this effect was abolished by both truncations. Thapsigargin significantly enhanced release and activation of MMPs (MMP-2 and MMP-9) in non-transfected 7721 cells, and this effect was negatively regulated by SNAP. However, no effects of thapsigargin or SNAP were observed in T7721 cells, and expression of HAb18G/CD147 enhanced secretion and activation of MMPs at a stable and high level. Taken together, these results suggest that both ectodomain and intracellular domains of HAb18G/CD147 are required to mediate the effect of HAb18G/CD147 on the secretion and activation of MMPs and metastasis-related processes in human hepatoma cells by disrupting the regulation of NO/cGMP-sensitive intracellular Ca2+ mobilization although each domain may play different roles.

Antigens, CD↗
PubMed2004

Overexpression of iNOS and down-regulation of BMPs-2, 4 and 7 in retinoic acid induced cleft palate formation.

The present work studied the induction of cleft palate formation in embryos developed from pregnant BALB/c mice treated orally with retinoic acid (RA). Previous studies on mature somatic cell types showed that RA exerted inhibitory effects on inducible nitric oxide synthase (iNOS) production. For the first time, our study has shown that RA actually stimulates significant expression of iNOS at specific zones of the affected embryonic palatal tissues at three consecutive stages, from gestation day 13 (GD13) to day 16 (GD16). Enzymatically, iNOS facilitates intracellular nitric oxide (NO) synthesis from L-arginine. When NO reacts with reactive superoxides it may result in irreparable cell injury. NO was also reported to induce apoptosis in some mammalian cell systems. Based on our findings, we propose that such an increase in NO production might be associated with apoptosis in the embryonic palatal tissues in the RA-treated mice. The detrimental effects of NO resulted in a reduction in proliferating palatal cells and therefore disturbed the normal plasticity of the palatal shelves. With iNOS overexpression, our findings also showed that there was significant concomitant down-regulation in the expressions of Bone Morphogenetic Proteins (BMPs) -2, 4, and 7 with regional variations particularly in the palatal mesenchymal cells for those embryos developing cleft palate. Since specific spatial and temporal expressions of BMPs -2, 4, and 7 are critical during normal palatal morphogenesis, any deficiency in the epithelial-mesenchymal interaction may result in retarding growth at the embryonic palatal shelves. Taken together, our study has demonstrated cleft palate formation in the BALB/c embryos involved overexpression of iNOS and down-regulation of BMPs-2, 4 and 7.

Animals↗
PubMed2003

Expression, immunolocalization, and functional activity of Na+/H+ exchanger isoforms in mouse endometrial epithelium.

The luminal fluid microenvironment of the uterus is important for sperm capacitation and embryo development. In an attempt to understand the possible role of Na(+)/H(+) exchangers (NHEs) in uterine function, the mRNAs of different NHE isoforms as well as their subcellular localization (apical versus basolateral) and functional activity were investigated in mouse endometrial epithelial cells using reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry, and intracellular pH (pH(i)) measurement techniques. The presence of NHE1, NHE2, and NHE4, but not NHE3 mRNAs were revealed by RT-PCR. Immunostaining showed that NHE1, NHE2, and NHE4 were present in both apical and basolateral membranes. The pH(i) recovery from intracellular acidification was Na(+)-dependent; however, the rate of pH(i) recovery depending on basolateral Na(+) was 12.4 times faster than that depending on apical Na(+). The Na(+)-dependent rate of pH(i) recovery was also inhibited by amiloride, indicating H(+) extrusion through NHEs; however, the amiloride sensitivity of the apical membrane was less than that of the basolateral membrane, suggesting the involvement of different types of NHEs in the two membranes. The results indicate that the basolaterally located NHE1, NHE2, and NHE4, in addition to participating in the homeostatic control of intracellular pH, may play a role in H(+) extrusion in order to achieve transepithelial HCO(3)(-) secretion. The apically located NHEs may be involved in mediating Na(+) absorption as alternatives of or complementary to epithelial Na(+) channels.

Animals↗
PubMed2002

Diffuse axonal injury: detection of changes in anisotropy of water diffusion by diffusion-weighted imaging.

Myelinated axons of white matter demonstrate prominent directional differences in water diffusion. We performed diffusion-weighted imaging on ten patients with head injury to explore the feasibility of using water diffusion anisotropy for quantitating diffuse axonal injury. We showed significant decrease in diffusion anisotropy indices in areas with or without signal abnormality on T2 and T2*-weighted images. We conclude that the water diffusion anisotropy index a potentially useful, sensitive and quantitative way of diagnosing and assessing patients with diffuse axonal injury.

Adult↗
PubMed2002

Organochlorine hydrocarbons in human breast milk collected in Hong Kong and Guangzhou.

In southern China, the awareness of persistent organic pollutant contamination has been increasing as a considerable number of past studies in Hong Kong had reported their trail in the coastal sediments, green-lipped mussels, muscle and viscera of pond fish, and foodstuffs. Hence there is an urgent need to assess their existence, contamination profiles, and potential impact on the public. In the present study, a survey was conducted to examine p,p'-DDT, p,p'-DDE, beta-HCH, and PCB concentrations in human breast milk, one of the most reliable bioaccumulation indicators. Milk samples (115 from Hong Kong and 54 from Guangzhou), in the lactation period from 3-5 weeks were analyzed. The results demonstrated that the mean levels of p,p'-DDT (Hong Kong: 0.39; Guangzhou: 0.70 microg/g of fat), p,p'-DDE (2.48; 2.85), and beta-HCH (0.95; 1.11) were 2-15-fold higher when compared with studies conducted elsewhere ( i.e., United Kingdom, Germany, Sweden, Spain, and Canada), and in contrast the concentration of PCBs (0.035; 0.031) was about 10 times lower. When compared to a similar study conducted 10 years ago in Hong Kong ( p,p'-DDT 2.17 microg/g of fat, p,p'-DDE 11.67, beta-HCH 15.96, and PCB 0.64), a considerable reduction in the levels of their contaminations was observed. The drastic reduction in body burdens in 10 years' time is presumably the result of effective regulatory actions. It is worth noting that body burden correlated positively with maternal age (total DDT, r = 0.93; beta-HCH, r = 0.91; PCBs, r = 0.77) and with historical record of seafood consumption (total DDT, r = 0.89; beta-HCH, r = 0.98; PCBs, r = 0.91) (p < 0.001) and potential uptake of the POPs by breastfed infants may pose adverse health hazards.

Adult↗
PubMed2002

Involvement of Na+-HCO3- cotransporter in mediating cyclic adenosine 3',5'-monophosphate-dependent HCO3- secretion by mouse endometrial epithelium.

The present study investigated the involvement of Na+-HCO3- cotransporter in mediating cAMP-stimulated HCO3- secretion across the cultured mouse endometrial epithelium using the short-circuit current (I(SC)) technique and intracellular pH measurement. Forskolin stimulated a rise in the I(SC), 55.6% and 52.1% of which could be reduced by the removal of extracellular Cl- or by eliminating the contribution of Cl- secretion by bumetanide, an inhibitor of Na+-K+-2Cl- cotransporter, respectively. More than 80% reduction in the forskolin-induced I(SC) was obtained when both Cl- and HCO3- in the bath were removed or in HCO3--free solution with bumetanide, indicating that the I(SC) depended on both Cl- and HCO3-. The presence of the Na+ channel-blocker amiloride in the apical solution did not reduce the forskolin-induced I(SC); however, the I(SC) could be abolished by removing Na+ from the bathing solution, suggesting that the Cl-- and HCO3--dependent I(SC) was also dependent on basolateral Na+. The forskolin-stimulated I(SC) could be reduced 43.6% by removal of HCO3- and 47.9% by a Na+-HCO3--cotransporter inhibitor, dihydrogen-4,4'-didsothiocyanostilbene-2,2'-disulfonic acid (H2DIDS). The inhibitory effect of H2DIDS was observed in Cl--free solution, but not when HCO3- was removed, thus confirming its effect on HCO3--dependent transport. Intracellular pH measurements demonstrated that the recovery from cellular acidification depended on the presence of both basolateral Na+ and HCO3-, further indicating the involvement of Na+-HCO3- cotransporter. Reverse transcription-polymerase chain reaction experiments confirmed the expression of Na+-HCO3- cotransporter in the mouse endometrium. The results suggest that basolaterally located Na+-HCO3- cotransporter is involved in mediating cAMP-stimulated HCO3- secretion across the mouse endometrial epithelium.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed2001

Heparan sulfate proteoglycan expression in the optic chiasm of mouse embryos.

Previous studies have demonstrated that heparan sulfate (HS) proteoglycans (PGs) regulate neurite outgrowth through binding to a variety of cell surface molecules, extracellular matrix proteins, and growth factors. The present study investigated the possible involvement of HS-PGs in retinal axon growth by examining its expression in the retinofugal pathway of mouse embryos by using a monoclonal antibody against the HS epitope. Immunoreactive HS was first detected in all regions of the retina at embryonic day (E) 11. The staining was gradually lost in the central regions and restricted to the retinal periphery at later developmental stages (E12--E16). Prominent staining for HS was consistently found in the retinal fiber layer and at the optic disk, indicating a possible supportive role of HS-PGs in axon growth in the retina. At the ventral diencephalon, immunostaining for HS was first detected at E12, before arrival of any retinal axons. The staining matched closely the neurons that are immunopositive for the stage-specific embryonic antigen 1 (SSEA-1). At E13 to E16, when axons are actively exploring their paths across the chiasm, immunoreactivity for HS was particularly intense at the midline. This characteristic expression pattern suggests a role for HS-PGs in defining the path of early axons in the chiasm and in regulating development of axon divergence at the midline. Furthermore, HS immunoreactivity is substantially reduced at regions flanking both sides of the midline, which coincides spatially to the position of actin-rich growth cones from subpial surface to the deep regions of the optic axon layer at the chiasm. Moreover, at the threshold of the optic tract, immunoreactive HS was localized to deep parts of the fiber layer. These findings indicate that changes in age-related fiber order in the optic chiasm and optic tract of mouse embryos are possibly regulated by a spatially restricted expression of HS-PGs.

Animals↗
PubMed2001

A possible role of p73 on the modulation of p53 level through MDM2.

MDM2, one of the transcriptional targets of p53, can target p53 for degradation in a negative feedback loop. The p53-related protein p73, however, can bind to MDM2 but is not consequently down-regulated. Here we demonstrate that p73 could transactivate the MDM2 promoter in p53-null cell lines. In p53-null cell lines, the level of MDM2 was increased by p73 due to increases in transcription and protein stability of MDM2. In transient transfection assays, inhibition of the transcriptional activity of p73 required a higher amount of MDM2 than that of p53. This is probably due to the fact that MDM2 can target p53, but not p73, for degradation. We demonstrated further that the level of p53 could be altered by a cooperation between MDM2 and p73, but not by transcriptional inactive mutants of p73. Expression of p73 resulted in a reduction of the ectopically expressed p53 in transient transfections or of the endogenous p53 induced by Adriamycin- or UV-mediated damage. These reductions of p53 were likely to be due to an increase in MDM2-mediated proteolysis. These results suggest the possibility that different levels of p73 in the cell may act as a mechanism to modulate p53 responses after DNA damage and other stresses and that an increase rather than a decrease in p73 may play a role in tumorigenesis.

DNA Damage↗
PubMed2001

International study of emergency department care for pediatric traumatic brain injury and the role of CT scanning.

OBJECTS: Our objective was to investigate the use of CT and its relationship to head injury severity and age. METHOD: The multi-center group International Study of Head Injury Project (ISHIP) serves as the administrative body for research design, data collection and analysis. This is a nonrandomized prospective study of longitudinal outcomes following examination and care in emergency department in five different countries. The subjects of our study were 4,690 children from birth to 15 years of age, all of whom were systematically evaluated. Each child was medically evaluated and categorized as to injury severity, mechanism of injury and findings on X-ray and CT scan. Follow-up interview and assessment was completed for comparison with the presenting clinical state. RESULTS: CT scans were performed for 674 (14.3%) of the children: 438 scans were normal and 236 were abnormal (P<0.001). Of the children with abnormal CT scans, 23.3% had mild head injuries, 42.7% had moderate injuries, and 33.8% had severe injuries, as determined by the GCS. By age, 10.5% of the positive CTs were in children aged 0-2 years, 56.3% in 3- to 9-year-olds, and 33% in 10- to 15-year-olds; only in 2% of cases were both CT and X-ray positive. CONCLUSIONS: The majority of children did not need significant medical intervention. Physicians ordered X-ray investigations more frequently than CT scanning. The use of X-ray to decide whether or not CT is necessary is not warranted. The implications of positive CTs in mild or moderate injuries were most noteworthy, as were age-related interactions with positive CT findings.

Adolescent↗
PubMed2001

Can saltwater toxicity be predicted from freshwater data?

The regulation of substances discharged to estuarine and coastal environments relies upon data derived from ecotoxicity tests. Most such data are generated for freshwater rather than saltwater species. If freshwater toxicity data are related to saltwater toxic effects in a systematic and predictable way, the former can be used to predict the latter. This would have economic advantages due to a reduction in toxicity testing of saltwater species. If toxicity data are plotted as species sensitivity distributions, four theoretical relationships between freshwater and saltwater can be envisaged. Examples show that each one of these relationships is supported by empirical data. These examples show that although there is considerable potential for freshwater to saltwater prediction, species parity and representativeness need to be examined for each chemical substance to avoid bias.

Animals↗
PubMed2001

Metallothionein induction and condition index of dogwhelks Nucella lapillus (L.) exposed to cadmium and hydrogen peroxide.

It has been suggested that metallothionein (MT) not only can regulate essential metals and detoxify toxic metals, but that MT can also play a significant role as an antioxidant and can be induced by oxidative stresses other than metals. This study is aimed at investigating the effect of hydrogen peroxide (H2O2), and the combined effect of H2O2 and cadmium (Cd) on MT induction and condition index (CI) in dogwhelks Nucella lapillus. Adult male dogwhelks (27 +/- 1 mm in shell length) were exposed for 20 days to (1) control (filtered natural seawater only); (2), 0.50 ppm Cd; (3) 2.0 ppm H2O2 + 0.50 ppm Cd; (4) 1.0 ppm H2O2 + 0.25 ppm Cd; (5) 2.0 ppm H2O2; (6) 1000 ppm H2O2 or (7) 1000 ppm H2O2 + 0.50 ppm Cd. The concentration of MT in the Leiblein gland of N. lapillus was quantified using the silver saturation method. MT or MT-like proteins in the animals were induced by Cd (0.5 ppm), H2O2 (2.0 ppm) or Cd + H2O2, indicating that MT in this gastropod species can be induced by either metal or oxidative stresses. Exposure to high H2O2 (1000 ppm) alone or combined with Cd, and exposure to Cd (0.50 ppm) or H2O2 (2.0 ppm), resulted in significant weight loss, indicated by a reduction of CI. However, CIs of groups (3) and (4) were similar to that of the control suggesting that Cd antagonistically reduces toxicity caused by H2O2 since Cd-induced MT may have a protective function against hydroxyl radicals.

Animals↗
PubMed2001

Survival, growth, metallothionein and glycogen levels of Nucella lapillus (L.) exposed to subchronic cadmium stress: the influence of nutritional state and prey type.

Dogwhelks Nucella lapillus feed mainly on mussels and barnacles, and may experience periods of starvation. We report effects of nutritional state and prey type on the survival, growth, cadmium (Cd) accumulation, metallothionein (MT) induction and glycogen stores in N. lapillus exposed to Cd in water. Adult dogwhelks, with similar shell length (30.0+/-1.5 mm), were either starved or fed to satiation with barnacles Semibalanus balanoides, mussels Mytilus edulis or Cd-dosed M. edulis, and kept in filtered natural seawater (< 0.01 microg Cd 1(-1)) or Cd-contaminated (400 microg Cd 1(-1)) seawater for 80 days. Mortality and individual growth rate were determined. Cd, MT and glycogen were measured in different tissues. Prolonged starvation and exposure to Cd significantly reduced the survivorship of N. lapillus, but feeding could help dogwhelks to combat Cd toxicity and minimise mortality. Extended starvation also caused tissue wastage, leading to higher concentrations of Cd and MT in tissues, whereas fed animals increased in weight and had lower Cd and MT concentrations because of the tissue dilution effect. Prey type significantly affected growth rate of dogwhelks and indirectly influenced Cd accumulation, MT induction and glycogen stores. Eating mussels promoted better growth and higher glycogen reserves than eating barnacles. Individual growth rate decreased with increasing Cd accumulation. Cd-exposed survivors grew faster and consumed more than control animals, implying that these survivors may have better fitness and greater tolerance to Cd toxicity. The use of growth, condition index, MT and glycogen as biomarkers of environmental pollution are discussed. These results indicate a need to incorporate biological data including growth (or at least condition index) and prey type into biomonitoring programmes to allow sound interpretation.

Animals↗
PubMed2001

Overexpression of BMP-2/4, -5 and BMPR-IA associated with malignancy of oral epithelium.

The aim of the present study was to determine the relationships between bone morphogenetic proteins (BMPs), BMP receptor type IA and carcinogenesis of oral epithelium. A retrospective study was performed on material obtained from oral mucosa, including nine cases of normal mucosa (NB), eight cases of nonspecific chronic inflammation (NCI), seven cases of hyperkeratosis (HK), five cases of squamous cell papilloma (SCP), 29 cases of squamous cell carcinoma (SCC) with various grades of differentiation and 10 cases of epithelium adjacent to carcinoma (EAC). Six cases of NB from hard palate (NHP) were chosen as a control group. The benign groups consisted of NCI, HK and SCP. The antibodies against BMP-2/4, -5, receptor BMPR-IA and purified bovine BMP (bBMP-McAb) were utilised using an immunocytochemical method. The results demonstrated that the immunostaining of BMP-2/4, BMP-5, BMPR-IA and bBMP-McAb was weak and not consistent in normal and benign groups. The immunoreactivity level was independent of the clinical and pathological grading of SCC. All cases of SCC showed positive staining for BMP-2/4, BMP-5, BMPR-IA and bBMP-McAb except for three cases and one case of SCC which negatively stained for BMP-2/4 and BMP-5, respectively. The staining intensity and proportion of the positively stained cells were markedly increased in SCC when compared with that of the normal and benign groups except for EAC. The metastatic carcinoma cells in lymph nodes were strongly and positively stained for BMP-2/4 and BMP-5 when compared with the primary lesions. Our results indicate that there was an overexpression of BMP-2/4, BMP-5, bBMP-McAb and BMPR-IA in the high-risk premalignant and malignant lesions of oral epithelium. Our findings suggest that BMP-2/4 and BMP-5 but not BMPR-IA might be involved in the metastasis of oral carcinoma cells.

Analysis of Variance↗
PubMed2000

Studies on thallium toxicity, its tissue distribution and histopathological effects in rats.

The distribution of thallium (Tl) in the body and its toxic effect on the histology and function of the liver and kidney of rats after Tl administration were investigated using biochemical and histopathological assays. Male albino rats exhibited a markedly dose-dependent increase in the serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) at 16 h after an intraperitoneal injection of 30, 60 or 120 mg/kg Tl. The serum level of creatinine in the rats injected with 30 mg/kg Tl, elevated significantly after 4 days of administration. The distribution of Tl in the tissues of intoxicated rats was uneven. The content of Tl was found to be highest in the kidney, followed by ileum, stomach and liver. Histological examination demonstrated frequent occurrence of hepatocyte necrosis and vacuolation in the liver and pathological changes of renal tubules in the treated rats.

Alanine Transaminase↗
PubMed2000

Outcomes of a population-based asthma management program: quality of life, absenteeism, and utilization.

BACKGROUND: Despite the availability of the National Asthma Education Program (NAEP) guidelines since 1991, asthma remains inadequately managed. To improve quality of life, functional status, and self-management behavior of asthma patients, a large health maintenance organization (HMO) in California implemented an asthma management program in 1996. OBJECTIVE: To evaluate the effectiveness of an asthma management program in an HMO setting. DESIGN AND SETTING: Prospective study. Survey data from members who participated in the intervention program and data from members who received usual care were analyzed using propensity score technique. RESULTS: A total of 1,043 asthma patients who responded both baseline and follow-up survey were included in the analysis. From baseline to followup, participants in the in-home intervention program reported significant improvement in functional status (improvements range from 0.2 to 7.2), daily use of steroid inhaler (+4.1%), daily peak flow meter use (+6.4%), self-reported knowledge of what to do for an asthma attack (+12.4%), and feeling that their asthma was under control (+10.8%). Absenteeism (-11.8%) and hospitalization due to asthma (-3.5%) were significantly reduced from baseline to follow-up. Participants did not report significant changes in overuse of beta2-agonists and emergency room visits due to asthma. In comparison with the asthmatic patients who received usual care (non-participants), participants had significantly greater improvement on daily use of steroid inhaler (+4.0% versus -6.0%), daily use of home peak flow meter (+6.4% versus 1.9%) and self-reported knowledge on what to do for an asthma attack (+12.4% versus +5.4%). CONCLUSION: These findings suggest that population-based programs can improve functional status, increase self-monitoring and knowledge about asthma, and decrease absenteeism and hospitalization for asthma by directly providing asthmatic patients with educational materials and self-monitoring tools. Such "direct-to-consumer" outreach programs may help bridge the gap between NAEPs 1991 practice guidelines and the reality of current asthma management.

Absenteeism↗